I believe in physics :)
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I believe in physics :)
You have completely failed to comprehend nearly every explanation and formula I have provided. Your responses completely misrepresent what I have said, or state irrelevant information/facts/etc.
For example:
I have no idea what point you're trying to make here. Your statement does not at all back up your claim that my formula is wrong. Your statement is not in disagreement with my formula. I challenge you to prove that my formula for estimating volumetric flow rate of the engine is incorrect... with actual explanation of the physical processes and use of complete formulas as I have.
Again, a clear indication that you do not actually understand the relationship between pressure, volume, mass, and density of a gas. Two different devices both feeding air into the same engine at the same engine speed with the same amount of pressure in the same atmospheric conditions and same temperature cannot possibly be providing air at different densities (Lbs/ft3) it is absolutely physically impossible.
Density (Lbs/ft3) is directly proportional to pressure. All else equal (same engine, same rpm, same atmospheric conditions, same intake temp, etc). The only way one device could provide denser air is to provide air at a higher pressure. If both produce the same pressure, then they are both providing air with the same density and same flow rate.
You're making a HUGE assumption that I looked at (and misinterpreted) a turbo compressor map to determine the exhaust:boost pressure ratio. I never said anything about the compressor map. Where did you come up with this assumption?
If you must know, I used my knowledge of how the wastegate works combined with the rated boost level of the wastegate spring used in the kit (rated based on a 1:1 exhaust:boost pressure ratio), compared to the actual amount of boost that the spring allows in this turbo kit.
Anyway, it is very clear that you do not have a solid foundation of the physics involved to properly discuss this subject. Please stop. Seriously, this is going no where. Go take a physics class. Learn the Ideal Gas Law, and truly understand it. When you come back and re-read your posts, you will see how completely incorrect and/or irrelevant some of your arguments are. I truly do not intend this as an insult. I'm encouraging you to learn to understand things in a formal/logical/mathematical way that will allow you to more completely/formally express your ideas in terms of math.
I'm also not pulling a "I'm right, you're wrong, no matter what you say". I like to be proven wrong, because I like learning new things. You are, however, failing to provide any complete logical explanations to back up any of your claims. You have made several technically correct statements (by themselves), but have failed to bring them together with any consistency to prove/disprove any particular relationship. You say my formulas are wrong. Please, explain what's wrong with them. Show me the correct formulas. " take CFM x .076Lbs/ft3 and poof that is the magic number" does not count. Start with complete formulas (like the ideal gas law, formula for volumetric flow rate, formula for mass flow rate, etc) and combine/rearrange them to mathematically prove a relationship you are trying to communicate.
So then regarding the dyno results you're trying to reconcile it's looking like an erroneous claim or a different calibration. Question, does Prodigy use Diablosport to generate their calibration files or are they working independently with the CMR software? I wonder how different each mfg's calibration file can be. You'd think that Prodigy, Magnuson, RIPP have all gotten their hands on the others' calibration files and are looking at them.
Yes... my assertion is that either the claim is exaggerated, or RIPP just has a much better calibration at low rpms than Prodigy, or a mix of both. The difference in gains is too much to be explained by differences in efficiency of the RIPP vs Prodigy systems themselves.
Prodigy does their own tuning with the CMR software.
I do remember talking to either RIPP or Prodigy at one point, and they said they worked closely with Diablosport to develop some proprietary tuning capabilities in the CMR software so that they could properly account for boost in the calibrations. All the FI manufacturers work closely with Diablosport for CMR support. I don't know if there's some special calibration capabilities that are available to some manufacturers and not others, so it's tough to know whether it would even be meaningful to compare calibrations between different manufacturers.
I'm curious about whether the CMR software gives them control over the variable valve timing. I was just reading about how ideal cam timing is different at low rpm for a turbo, as compared to NA, to help the turbo spool more quickly.
Anyway, Prodigy is working on an improved tune. I know that low RPMs is an area they will put some effort into, because that have received feedback from multiple people about low RPMs feeling sluggish. It's possible that low RPM just was not a priority for Prodigy previously, so the hadn't yet put effort into optimizing it.
CMR had better include authority over cam phasing!!! If not, then what are we doing? Playing with AFR and spark timing?
And you've got four independently phased cams each with their own electronic actuator/sensor. According to Borg Warner the advanced VVT system is responsive to load in addition to RPM which sounds like torque management to me. Whatever it is it can most likely be optomized for a turbo. Most VVT systems phase intake and leave exhaust alone but not Pentastar. Huh. . . wonder if they included exhaust cam phasing in anticipation of someday bi-turboing the RAM 1500 or some other similar application. Ugh. . . It kills me that all of the raw materials are there but you have to have the software - ALL of the software - so you can make it work and the darn OEM won't release the code. And from my conversations with Magnuson, DiabloSport can be difficult at times. In fact, in one conversation a person at Mag who does not want to be on the record went on a five minute all-out rant regarding DiabloSport. In among the explitives were some salient facts such as the fact that DiabloSport actually generates the calibrations which goes beyond "support" to actual partnership. Also of interest was the fact that Mag pays thousands and thousands of dollars for the calibration engineers that DS provides. Of editorial color was the statement, "we are slaves to these guys. . . " I'll leave the rest out.
Speaking of cam phasing... I found a decent intro explanation of how cam phasing affects both NA and turbo engines: http://www.hamotorsports.com/cam-gear-tuning.html
With full control over the VVT system, it could be optimized throughout the RPM range. I'll try to get some details about how much control CMR has over the VVT.
Yeah, the exact nature of the relationships between the turbo/supercharger manufacturers and Diablosport is a bit of a mystery to me still. I know it's definitely more than a basic customer support relationship with regards to the CMR software. That's one reason I'm patiently waiting for Prodigy to improve their tune rather than running out to a local tuning shop. Prodigy is going to continue to work closely with Diablosport to improve their tune and to address issues reported by many customers around the world, and the resulting improved tune will be made available to all Prodigy owners. For free!
A local tuning shop will only work on my tune for the couple hours that I paid for. I'm sure they'll gladly allow me to pay for more tuning time if I come back and report some mild driveability issues, but they won't have the benefit of feedback/logs from many people around the world, and they sure don't have any motivation to continue tweaking, testing and improving the tune once I've handed them my money and drive away. And they won't have as strong of a partnership with Diablosport as Prodigy, RIPP, etc., to be a driving force to improve the CMR capabilities for the application.
Kinda off-topic, but not worth it's own thread...
I got bored and took pixel-perfect measurements at every 100 rpm increment from Magnuson's own dyno chart to add their boost curve to my collection:
http://www.uselesspickles.com/files/...uson_boost.png
I don't know why that chart stops at 6100 rpm. looks like the torque curve is leveling out, so it probably doesn't go up any more, if at all, as it approaches 6500 rpm.
I'd like to add Sprintex to the chart, but I can't fund any charts with a boost curve. Has anyone seen anything?
This chart really belongs in a thread about comparing all major power modifications in general. Seems like it would be good to have a continuously updated post that lists all the options, gives basic info about each, provides links to more info about each, etc.
Good explanation Pickles! I kept scratching my head with what was being written in the other posts regarding CFM... As an example... The idea that you could push 1000 CFM @ 1 PSI vs. 1500 CFM @ 1 PSI through the same pipe, what the!?! Did someone not play with a garden hose as a kid enough to know that to obtain an increase in CFM at the same pressure would require an increase in the diameter of the garden hose!!!
For those who didn't get to play with a garden hose as a kid, here's the real formula.
cfm = area of pipe * sqrt (2*Pressure/density)
The idea that one turbo could deliver higher CFM at the same pressure, on the same engine, at the same RPM versus another turbo is just silly. That goes against the laws of physics (as previously stated by said poster named Pickles.)
I just didn't feel like committing to fleshing out the beginnings of a complete FI comparison post at the time. Next time I'm looking to kill some time in the evening, I'll start a new thread with the intent to continue to update the first post as a basic comparison guide.
I took the boost data straight from Magnuson's own dyno chart (link in my post above was incorrect, but is now fixed). This is a chart that Ross posted on the wrangler forum, identifying it as a dyno chart from Magnuson:
http://www.wranglerforum.com/attachm...p;d=1390872766
If you know of any more recent data about that supersedes that chart, please point me to it so I can update my data.
BTW, this is from Magnuson's web site:
Quote:
In testing, this kit demonstrated between an 80 - 100 HP and 60-70 lb-ft increase at the wheels at just 6 psi.
Since water is incompressible (in practicality, at least), but air IS compressible, the garden hose is a bit oversimplified.
With water, there IS a direct relationship between volumetric flow rate (e.g., CFM) and mass flow rate (e.g., lbs/ft^3).
With air, the relationship between volumetric flow rate and mass flow rate depends on density, which depends on temperature, pressure and volume.
To make things more confusing, in the world of engine dynamics, they speak of the volumetric efficiency of the engine. It is often explained as the percentage of "volume" of the cylinder that gets filled with air. As I discussed before, the volume of the displacement of the cylinder never changes. So volumetric efficiency is a bit of a misnomer (but not entirely incorrect, either, as I'll explain later). It's really a ratio of the AMOUNT (mass) of air that gets into the cylinder compared to the AMOUNT of air that *would* fill the cylinder *if* it were allowed to reach full equilibrium with the intake manifold.
At 50% volumetric efficiency (number chosen arbitrarily to make my later example easier to comprehend), it doesn't mean that the cylinder is only filled 50% of the of the way with air. That's impossible, because whatever AMOUNT of air enters the cylinder will expand to fill the entire volume.
But if you think of it from the perspective of the intake manifold, the term "volumetric efficiency" actually makes sense: 50% efficiency means that 50% of the cylinder's volume worth of air in the manifold has filled the cylinder. For the Pentastar, a cylinder is 3.6L / 6 = 0.6L. Let's say the manifold pressure is 10 psi (easy number to work with). At 50% volumetric efficiency, that means 50% of 0.6L = 0.3L worth of the manifold's 10 psi air enters the cylinder. That AMOUNT of air will fill the entire 0.6L in the cylinder (when the piston is at the bottom of the stroke). Volume are inversely proportional. That means when that 0.3L of the 10 psi air expands by double to fill the 0.6L cylinder, the pressure will be cut in half to 5 psi* (see disclaimer below). The air in the cylinder now has 50% the pressure of the manifold, AND 50% the amount (mass) of air that would have filled the cylinder if it were allowed to completely "fill" with air from the manifold.
So because of the relationships between volume, pressure, density and mass of air, it can really be thought of as either volumetric efficiency (from the perspective of the manifold) OR mass filling efficiency. It all works out mathematically the same, and will produce the same result in the calculation to determine the amount of air in the cylinder.
*Disclaimer: I simplified a bit for the explanation. When that 0.3L of 10 psi air expands into the 0.6L cylinder, the pressure may not become exactly half, because I believe the temperature of the expanding gas will decrease as well. This gets into some complications that I don't understand. So some of my previous statements in earlier posts may be incorrect about the relationship of how much pressure gets into the cylinder, but the concepts would be correct if you worked in terms of mass rather than pressure.
No, genius air expands when it enters the cylinder head!!!! This why Roots Lobe Units are called Blowers-- because they develop very very low pressure all the time! So, since no engine runs at 100% volume metric efficiency throughout its entire rpm range-- you can squeeze in more air into the cylinders just by increasing the volume metric flow of the air reaching engine. Remember as the air expands to fill in the open space it will slightly cool. This is where Roots Lobe units really have problems because of the way they create pressure and volume they actually tend to heat the air up more at low rpm then they do at high rpm. But when it comes to volume metric efficiency across a broad RPM range the RL system is hard to beat. Now, with a more air friendly system like the Centrifugal unit Vortech uses the air at low pressures is relatively cold and dense-- the the more you add the greater air density in the cylinder head (up to a point). The point is this at .6 PSI there is a good bet that the Vortech unit can move enough air into the cylinder head to achieve a noticeable increase in the volume metric efficiency of the engine without requiring the engine to need extra manifold pressure to compress more air into the cylinder head. So basically, you might go form say 91% volume metric efficiency to 95% efficiency thus allowing you to burn more fuel creating a mere 30-40hp extra. Physics is just fine... All the fun laws of Boyle's, Charles', and the kinetic theory of heat are intact and happily loving each other.
What, I said was Manifold Pressure doesn't necessarily have a linear relationship between CFM and Boost Pressure! You can very well have two different turbos running at the same engine speed, on similar engines developing two radically different CFM outputs. Why do you think they make so many different units that fit essentially the same size displacement engines??? Is it because they just want to sell people two different turbos for no reason at all? No, it is because different sorts of performance goals require different types of units and peak CFM outputs for specific manifold pressures.
Then I proved to you people with a link to two Vortech V-2 mode Units that outwardly look identical with only minor differences in specifications that have 100CFM difference in peak output. And this translates to 50HP extra at peak performance all while maintaining a maximum boost of 17PSI. So, yeah, would like to try to stating again how wrong I am.
http://www.vortechsuperchargers.com/page.php?id=30157
http://www.vortechsuperchargers.com/page.php?id=30008
My entire point since day one is that if you look a boost graph and decide that some company is misrepresenting their claims on this data alone-- you will probably look foolish. There are just so many more factors that come into play with adding forced induction to an engine. If you don't know how the engines are setup and what goals each kit has-- then it is hard to say that one claim is preposterous because I've got Prodigy's turbo kit and it cannot do it. It might not be designed to do it. And that is just bummer for you. Personally, I think they put out boost graphs because they know most people buying kits aren't well enough versed in forced induction theory to really know what they are looking at.. So yeah you see 10PSI or 11PSI or 22PSI and think wow that is going to be so awesome in my car, truck, or jeep. And not knowing what exactly your engine is doing to start with gives you almost no way of knowing how effective that kit will be on your engine in the long run.
It is not a misnomer. What it is saying is that the distance between the molecules of air is now 50% greater. So let's say you have .6L of air in a 1.2L bottle that means the gas has twice the volume to fill-- now I can fill this same space with 50% more stuff before I start to need extra pressure to get air into the same space. That is all it means. It have this 1.2L bottle completely filled at 14.7PSI and I try to fill it up with 50% more air I will need roughly 50% more more pressure to do so. So, to get to 150% Volumetric efficiency I will need roughly 22.05PSI of pressure in the bottle which is the original 14.7 PSI to keep the air in and then addition 7.35PSI to compress it enough to get 50% extra volume in.
So, as I said before more air in the chamber means what??? More molecules which means greater density!
It's over. Stop. Please.
I do need to correct myself on one detail, though. The reference for "volumetric efficiency" is atmosphere, rather than the intake manifold, as I incorrectly stated early. This does not invalidate any of the concepts or relationships I described, though. So volumetric efficiency is the percentage of a cylinder's volume worth of ambient atmosphere air (the amount of air, number of molecules, in that volume of atmosphere) that actually gets into the cylinder. Boost causes a volumetric efficiency of over 100%.
I don't know why you are shouting the obvious at me and think you need to give it to me as a clue. Your "clue" is not inconsistent with anything I have said. Please stop. Your lack of comprehension is hanging out and it's embarrassing.
I'm going to send this new understanding of volumetric efficiency to my buddies over at Caterpillar. They will love it.
P.S. A turbo doesn't have a 1:1 Ratio between exhaust pressure and boost. One impeller is compressing the air flow so it has a different geometry than the one that gases push against! These differences make a big difference in how much boost you get for specific volume of gas accelerating the unit. Also you will notice that the Intake housing is smaller than the exhaust housing[sometimes you need to measure it to see the difference]-- this is because the intake is trying maximize pressure by having a higher rotational speed than the turbine. Where as the exhaust is trying maximize the volume of gas pushing the against the turbine thus increasing the speed of the compressor. It is like having an overdrive where you get more rotations out of the smaller compressor wheel to keep up with the bigger slower rotating turbine.... So really you have more a 4-5 or even 10 to 1 ratio in favor of boost pressure over that of exhaust pressure. This is why the turbo becomes more efficient as the exhaust pressure increases and compress wheel's rpm goes up! You know it is the damn centripetal force formula.
OK, KaiserBill. You win. Kinda...
All of this completely tangential talk of volumetric efficiency got me thinking...
KaiserBill may be right, either by coincidence for the wrong reasons, or he could just be bad at putting together a coherent/consistent explanation. I really don't know.
The key to this could be a difference in volumetric efficiency at low rpm. The turbo system will have higher exhaust back pressure. KaiserBill did point this out (a few times I think), but never followed through with the connection that it could be reducing the engine's volumetric efficiency.
Ideally, during the intake/exhaust valve opening overlap, exhaust will completely flow out and be replaced with fresh air from the intake manifold before the exhaust valve closes. Then the intake stroke will continue pulling in more fresh air from the manifold. With more exhaust back pressure, it could resist that complete expulsion of exhaust, and leave some exhaust gasses trailing behind when the exhaust valve closes. That exhaust gas is now taking up space and reduces the amount of new fresh intake air that makes it into the cylinder. The total amount of gasses in the cylinder could end up being the same, but not all of it is new, combustible, fresh air from the intake manifold. This both means less fresh air for combustion (less power), AND less amount of air is consumed from the intake manifold. Less air consumed from the manifold means that air is flowing through the engine at a lower rate, which would be represented as a lower volumetric efficiency. And if the engine is consuming air from the manifold at a lower rate, then air would have to be flowing into the manifold (from the turbo) at a lower rate to maintain the same boost level as system with higher volumetric efficiency.
So there's an explanation of how a turbo and supercharger on the same engine could be operating at the same boost level, same engine speed, same temperature, etc., but the supercharger could be flowing air faster than the turbo and producing more power. I still maintain that it is not the flow capability (CFM rating) of the compressor that causes this difference, but the flow capability of the engine itself. I just previously failed to see that the engine's flow capability could be different between the supercharger and turbo.
I would be surprised to learn that exhaust back pressure from the turbo is enough to account for a 40% difference in power. I still suspect it has more to do with the tune.
Just be sure to send it to them properly revised with my own correction of myself that it's all relative to atmosphere rather than the intake manifold. I got it wrong initially, but my error was really irrelevant to the point I was trying to make.
My revised summary of my understanding/explanation of volumetric efficiency:
The ratio of the amount (number of molecules) of fresh intake air that enters into the cylinder compared to the amount (number of molecules) of air present in a cylinder-displacement volume of local ambient atmosphere, expressed as a percentage.
Like you've pointed out a couple times, it's the amount of air (molecules) that matters, which is why I said "volumetric efficiency" is a bit of a misnomer. Volume alone does not describe an amount of air.
I never claimed it did. I only mentioned TiAL's wastegate spring ratings that are based on an assumed 1:1 exhaust:boost pressure ratio. See the fine print in the lower-right of this image:
http://store.forcedperformance.net/m...MVSprings2.jpg
Now I could be completely misinterpreting this, so please correct me if I'm wrong. They only mention "back pressure", which I assume to be exhaust back pressure. And it's a ratio of "back pressure" to something. Since a wastegate involves a balance between exhaust pressure and boost pressure fighting against the spring pressure, I assumed they are referring to a ratio between exhaust back pressure and boost pressure.Quote:
Spring Pressures are calculated based on a 1:1 back pressure ratio. It is not uncommon to see a +/- 2psi differential.
The spring in the Stage 2 turbo kit is rated at 7.25 psi, but it produces about 8.2 psi when used in this particular kit. Therefore, if that ratio TiAL refers to is correctly an exhaust:boost pressure ratio, then my exhaust:boost pressure ratio must be less than 1:1.
I have been unable to find anything that explains what "back pressure ratio" is in terms of a wastegate or turbo system. If anyone can point me to info about this, please do.
I previously claimed that due to this, boost pressure would be higher than exhaust back pressure in the 1800 rpm 0.3 psi situation being discussed. I now admit that I don't understand this exhaust:boost pressure ratio stuff enough to make that assumption. The more I think about it, the more I expect that exhaust:boost pressure ratio would not be constant, but would vary throughout different engine speeds and engine loads. In fact, I'm pretty sure a couple psi of exhaust back pressure is pretty normal even for a NA engine, which is clearly more than the amount of boost in that situation. The turbo would almost certainly create more back pressure than the stock exhaust system... then flow from this idea back to my previous post about how the extra back pressure would lead to lower volumetric efficiency...
Useless Pickles, as I've said I applaud what you are doing trying to figure out if Ripp's claims are legitimate claims. That is good for everyone. People who can and do test these claims are important. The problem is that most manufactures are really dodgy about the details of their systems on purpose. While they do put little disclaimers on their products like "*** Our Results We Obtained In A Controlled Lab-- Real World Road Experience Does And Will Differ..." That want to blind people with my 86PSI of manifold pressure at 15,000RPM claims. Which is all about marketing-- damn those Madison Avenue Bastards. It is a shame these guys just don't come out and give a full spec sheet of the units capabilities. It would make comparisons so much easier. Then again it would probably daze and confuse a lot of people with way too many numbers.
Back Pressure is a bad term. Let's call it resistance to flow. The impeller creates it in a turbo unit and the exhaust system itself creates it in a Normally Aspirated System. You cannot really get rid of it completely. And yes, you are correct, the Normally Aspirated Engines do indeed have back pressure that is lower than their Turbocharged counter parts. I'm sure that Prodigy has reduced this to a minimum by keeping the lengths of exhaust as short and straight as possible. Increasing the diameter of the exhaust will help a lot too from the turbocharger unit itself. If you are using stock exhaust from the turbo to the catalyic converter and muffler you getting more resistance on the back end of the exhaust then you would if you increase that size. This will make the turbo operate more efficiently at lower pressures. But you might not be able to change those diameters too much. They might have specified a system that uses pretty stock stuff. But I would call up Prodigy and ask what sort of benefit going up a .25 inch or even 1 inch in diameter would do for me. The lower the back pressure is at any rpm the better.
Well, if you are getting 8.2PSI on the manifold but are still using 7.25PSI rated waste gate spring-- then well there is your answer the stage two kit's Aftercooler is giving you 1.17... to 1 ratio of boost ratio. That's good actually. However, freeing up the exhaust system and getting the absolute least restrictive design can improve those numbers. Also letting the turbo operate at higher Boost Pressures can see an improvement on those too.
[From looking at Garrett's website that turbo class the 550HP can put out a lot of Boost depending on the specific size of the unit- they have a couple different ones in that class. But they all create killer power levels at 20-30psi. If you don't like your warranty much-- I would suggest getting a waste that can handle a 30PSI spring or greater. You know one that never actually lets the exhaust gas bypass the turbine... Add Water Methanol Injection and of course custom deep-dish pistons (increase the chamber volume a little and drop the compression ratio from 9.5 to 1 down to 4.5 to 1 or less ) and then stand back and see how much power your 3.6L engine creates! Of course this is only if you really don't like your warranty and your jeep is not your daily driver! It is not impossible to get a 180BHP per L with out much effort doing this. You know 648HP at 6500rpm has a way of intoxicating the owner/operator of the vehicle-- insurance companies are however never that impressed...]
The big problem with the Jeep's hood is that they didn't give you much room to play with in the engine compartment. That's a real bummer actually. Because the ideal setup on a V6 or V8 engine is a twin turbo kit. That will let you maximize the exhaust pressure from each bank of cylinders into its own turbo unit. However, that doesn't seem like it would fit under the hood given the space they have under their. But that would probably let you have a system with better low end performance but you might not be so hot at 6500rpm.
If you want to really want increase your analysis and ask Jeeplab if they can send you their raw data from dyno of the system. If you get the torque numbers you can actually calculate Volume Metric efficiency of the engine for any given boost level. Which means that you can really see if their claims are true or not. Of course I would call anything within 5% of the 40% percent claim too close to call. You will need to get the air-fuel ratio numbers too... you might have to use a range of those to get approximations-- but hey like I said if you get within 5% of that Ripp number then you know it is at least possible to do. And it should be possible to do that sort of performance with the Vortech unit.
Here are some more fun formulas for you:
http://www.turbobygarrett.com/turbob...choosing_turbo
Here's some fresh turbo porn from Prodigy:
http://www.uselesspickles.com/files/...gine_stand.jpg
They also mentioned on facebook that they got 382 hp and 380 ft-lbs out of their stage 2 test jeep now! Compared to the previous 359 hp and 373 ft-lbs, that means there's a small bump in peak torque, but more impressive is that the peak hp gain implies that torque falls off less after peak torque. This must have something to do with their recent efforts to improve the tune. I hope they finish it up soon and let us try it :)
"This is the Stage 2 Upgrade Kit for the PRO-2001 Prodigy Turbo Kit for the 2012-2014 Jeep Wrangler. This is a complete Jeep Turbo Kit upgrade that adds our legendary front mount intercooler and increases boost by and additional 2PSI. Everything you need to get the power your Jeep needs on or off-road. With 7 years of development, the finest turbocharging components, OEM level engine management calibrations and extraordinary dyno proven results this package will make your Jeep perform as good as it looks! More Powerful than ANY supercharger!"
From the Prodigy Website... That is funny- Legendary Front Mount Intercooler??? That is funny-- considering this sort arrangement has been around for decades-- one would be almost forgiven if they mistook Prodigy for being the inventors of front mounted intercoolers. And for all that legend what do you get 2 extra PSI!!!! I hope they decided to turn up the boost a little.
Yeah, "Legendary" seems a bit excessive, but that's marketing. The intercooler is very nice, though. Very solid and custom sized to just barely fit behind the grill on the Jeep.
You also get much lower intake temps, so the gains are better than just a small boost increase.
They have plans to turn up the boost, but this seems to be as much boost as they are comfortable selling as a reliable kit on the stock engine. All I know for sure is that they have shared pictures of some forged pistons. They're going to strengthen the engine before adding more boost.
BTW - I heard that one of their customers took it upon themselves to turn up the boost (to somewhere around 12-14 psi, I believe), and ended up requiring an engine rebuild due to the damage that was caused.
4 pages of catch-up reading and 4 Advils later and i must say that i enjoyed it.
I have to Applaud both UslessPickles and KaiserBill for their efforts and a great read, it tickled and teased my brain in more ways than one !! Lots of info.
Thnx guys
I'm not saying the intercooler is bad. I'm just marveling at wording of the ad. From the description you would expect that this Legendary Custom Intercooler would make you espresso coffee, turn your engine into a 500+hp engine, and keep the kids entertained. It looks like a nice package.
My one question about it would be proximity to the to the rest of the engine stuff in your engine compartment-- you have the turbo very close putting out amazing heat. You have the engine putting a decent amount heat, then you have the radiator which is also putting out extra heat and then you have the exhaust manifold. You've got all those heat producing elements in such close proximity to the intercooler tends to reduce efficiency.
Air to Air systems work great at high speeds due to the volume of air flow you get. They tend to really drop of the performance charts when you get off road with slow moving air-speeds. Couple this with the close proximity of the everything under the hood and you start to see performance from your intercooler drop off. It is just one drawback of attempting to put extra things under the hood the original engineers didn't account for or ever intend for you to put under their. I wouldn't scrap the intercooler-- I just wouldn't be surprised that if I spend 4 hours off road at 15mph to see the same sort of performance as I would at 70mph cruising down the highway.
This is specially true for the air intake being right by the engine I understand why they want the turbo to get a nice short straight shot of air. However, that is right in the nexus of heat if you will. It is high up where all the hot air is going to rise to and it is next to the engine. I would like my air intake outside the hood in the clear away from extra heat sources. But that is just me. You're on the trail all day and the air is 80F ambient, then you have the above sources of heat and almost no air flowing into the system other than what the fans for the radiator can draw. I would increase those myself.
Also, does Prodigy offer an oil-cooler kit? That would be a great addition to the system.
Do you think itll be worth selling my ripp kit in my 2013 for a prodigy turbo kit
This is why I painted my intercooler with radiator paint. It radiates heat more efficiently than bare metal. If I had been thinking clearly at the time, I would have left the back side unpainted, because the black color also ABSORBS heat radiation more efficiently! Oh well.
I did have some problems with excessive intake temps on a hot summer day driving hard on sand dunes, but that was with stage 1 (no intercooler) AND an install error that was producing excess boost. I also only had those problems when repeatedly racing up sand dunes at high RPM (5000+ rpm) with boost. I've never seen any signs of excessive heat problems while driving slowly or idling.
Keep in mind that this is an add-on turbo kit that is sized to provide its big gains in the mid and upper rpm range under significant engine load. When crawling around off road at low speed, especially in 4LO, there's just not enough engine load to really spool the turbo up. The engine along with proper gearing is plenty for most non-extreme off road driving. Since the turbo isn't working hard in these situations, it's not generating extra heat. It's essentially just part of the exhaust system. Yes, there is extra exhaust routed through the engine compartment, but that's at least partially balanced by the removal of the stock catalytic converters (which hang directly off the heads of the engine, one on each side). Ceramic coating or heat wrap on the exhaust could reduce heat if that's a concern.
I would like to eventually build some kind of heat shield around the air filter to see if that has any significant effect on intake temps. It should be pretty easy to test with some back-to-back data logging with and without a heat shield. I expect it will have no significant impact at street driving speeds where there's good air flow, and it will probably only slow down the heat soak a bit at low speeds, rather than permanently reduce inlet temps.
Haven't heard of any plans for this. The Pentastar already has an oil-coolant heat exchanger, so I'd guess that oil temps would not be an issue unless maybe you're really beating on it, like continuous high load, high boost operation, desert racing type stuff.
I have not driven a RIPP, so can't really comment on how different the performance is, and therefore whether it would be worth switching. Jessee and Ross might be able to provide some insight, but I also think the upcoming update to Prodigy's tune needs to be taken into account before making a comparison.
Has anyone had a problem with the wast gate?
Will it show in the log?
What are the common signs?
I had a problem with the wastegate causing about 1.2 psi excess boost when I had stage 1. I had a damaged o-ring on the hose fitting for the boost sensing line to the wastegate, and I also had an exhaust leak where the wastegate mounts to the up-pipe. I'm not sure which issue caused the excess boost.
Any problem with the wastegate would show up as either too much or too little boost, which would show up in data logs. The shape of the boost curve over the entire RPM range could reveal if a wastegate is hooked up improperly too.
Do you suspect you have a problem? What are the symptoms. If you record a data log of full throttle acceleration in 2nd gear, from about 2000 rpm to redline, I can take a look at it and see if there's anything obviously wrong.
Have you given any thought to changing your t-stat to the Mishimoto or RIPP 180deg.? I've read a bit about it and it seems you need some custom tuning to adjust fan operation but for forced induction motors lower coolant temp could be a small part of the power recipe. In reading about the t-stat I came across information about the pentastar oil pump system that has a step-up solenoid that gets actuated by the PCM based on temp., RPM, engine load, etc. Again, small items and I AM NOT MAKING AN ACCUSATION but if RIPP's test jeep/motor has a lower temp t-stat and a custom tune which is generating lower engine compartment temps and keeping oil pressure at optimum without taking unnecessary power for the pump then we might start to see a difference in dyno charts. Also, I believe (not 100% sure) that the coolant passages in the heads include the cast-in exhaust runners. I know that GM's 3.6L bi-turbo Cadillac motor works that way. The exhaust helps get the engine up to operating temp faster at low load. At high load the coolant helps prevent damage to the catalytic converters. But, maybe it would be beneficial for the turbo guys to lower exhaust temps across the board and lower heat under the hood.
I'm not going to mess with thermostats unless Prodigy tunes for it. Modern engines are designed to run at higher temps for efficiency and emissions, and I don't want to risk throwing things out of balance.
Yes, the pentastar does have coolant passages in the built-in header. If exhaust temps are not causing excess under-hood heat, then any attempt to reduce exhaust temps would actually hurt performance. Turbos are driven by the heat expansion of exhaust leaving the engine, and the pressure differential across the turbine.
Speaking of which... minimizing post-turbo exhaust pressure is probably a good thing to look at. Zero exhaust pressure post-turbo would be ideal. A first step would be to actually measure exhaust pressure in the stock exhaust system with a turbo to see if it is a major restriction to begin with. Reducing pressure hear would also improve volumetric efficiency, and reduce post-turbo exhaust temps, which would all work toward reducing under hood temps a bit.
I do realize the limitations add-on kits have when it comes to space and so on and so forth. Prodigy has made a very neat package. That cannot be disputed. However, I question why they didn't wrap the entire exhaust system with insulation and add some insulation to the intake as well. I've been thinking about doing it for some time on my 7.8L Diesel Engine. I doubt I will see more than .5% increase in performance but what the hell right? Worked for Jack Burton???? However, I say put the shield around the intake and then add some cool tape to the intake side of the turbo some heat tape to the exhaust and see what you get performance wise. And if that doesn't suite you go for the gusto and put the MW-50 on it!!! Nothing says lovin' like a turbo with a drinking habit! Some times you just need a turbo that drinks like a sailor!
Where I would be concerned the most with a turbo's inter cooler that is air to air is on the low speed side of things. That is always where air to air units really show performance issues. However, you could put in larger fans and change the thermostats settings so they run at lower temperatures say 20-30F lower than normal that way you make up for the inter-cooler's added heat and disruption of air flow to the radiator. This would really help at low speeds.
As for the oil-cooler. I didn't actually know the Pentastar had a dedicated oil cooler that is a nice feature. Now, the only question is can it handle the added heat? Also how much did you increase your oil capacity to account for the turbo unit? That is the big issue, if you cooler cannot handle the extra heat it doesn't help to much. However, I'm betting it is just enough to get the job done at normal driving speeds. You might want to see if you can get a bigger unit for times when you are running the engine hard in an environment where cooling is minimal.
Have you put an Exhaust Gas Temperature Gauge in yet? That is a nice option to have. That way you can tell what is happening in the exhaust part of your system. I need to put on in my truck. But I'm lazy about cutting into the exhaust system.
You sure do suggest a lot of expensive and complicated improvements for problems for which there is no evidence that they need a solution :)
Things like exhaust wrap or ceramic coating aren't included in the kit because it's not necessary for daily driving and having some fun on the street. Including it in the kit would drive up the price with diminishing returns for most customers. Prodigy provides a solid, fully functional and complete kit with room for custom improvements if necessary, or if you're the type that thinks the extra money is well spent on such improvements.
I haven't seen any evidence of any heat issues at low speeds off road. Most low speed off road driving does not involve continuous periods of high engine load that would create a lot of boost and heat. Mudding is probably the most obvious exception to this. I do not like to play in deep mud, so I'm not concerned. Even when I was on the sand dunes repeatedly attempting to climb a dune with the turbo screaming at 5000+ rpm on a sunny 85*F summer day, moving slowly up the dune, getting stuck, backing down, trying again, about 6-10 times in a row, the coolant temp gauge would only move to about half way between the middle and 3/4 marks. After coming to a stop and idling, the temp gauge would move back to center after several minutes.
The oil system already has a larger than typical capacity: 6 quarts. I would be interested in data logging the oil temperature, but that doesn't seem to be available for logging on the Diablosport InTune.
I don't have an exhaust temp gauge. I'm not tweaking the turbo system to run any differently than designed, so I'm trusting that Prodigy designed it well enough and putting my money and effort into more useful things than double checking their work. I'm no expert on tuning, so I would really even know what to watch for with exhaust temps.
The tapes and wraps aren't really outrageously priced items. It is just a matter of wanting to put them on that can be annoying. It is easier then the system is being installed to wrap the stuff then put it on the engine.
Jegs Super High Temp Exhaust Header Wrap is about $63.99 plus Shipping/Tax for 25Feet you might need two rolls. So about $160.00 total
Jegs Heat Shield Tape (aka Cool Wrap by some manufacturers) rated for 1100F ranges in price from $19.99 to $29.99 depending roll size and some have free shipping so you could get out with perhaps 29.99 + tax
If you want higher heat protection they have a product rated at 2000F for $51.99 +shipping and tax
Now ceramics are great but pricey. This stuff will set you back maybe $350.00 when all said and done. And you can see improvements in performance under the right conditions. When you driving on a sand dune I bet you would notice a difference if you had the right gauges. Most of the time the driver will not be able to tell the difference in performance but it is there.
EGT-- is good to know because you don't have to tune the vehicle to get into a problem area. Certain types of usage can cause dangerous temperatures. Driving at high speeds for prolonged period on asphalt on a 120f day from LA to Vegas can cause issues EGTs. Ideally speaking when you see those numbers climb to some point that is dangerous that is when you would hit the WM-50 system and "BAM!" watch them drop and performance increase.
If I were going to do anything with the exhaust, it would be ceramic coating. I don't really like the idea of having a cloth-like wrap on my exhaust that will be getting dunked in muddy water.
For the cold side, there's not really much to be wrapped. Most of it is elbow-shaped silicone couplers going through very tight places. There's only about 1 foot of actual pipe. Similarly, if anything, I might get that pipe ceramic coated along with the exhaust, but I wouldn't expect any noticeable gain from it at all.
If I were to go with water/meth injection, I would set it up like my brother's system on his STi. It automatically starts at a certain boost level, and ramps up to full flow at a higher boost level (the controller for the system has adjustable end points for this ramp up). His stock intercooler water spray is also integrated into this system to automatically start spraying at some boost level (before meth injection starts), rather than requiring a manual press of the button as it does in stock form.
I think an automated intercooler sprayer with a manual override button (to force a spray) might be a nice way to get some noticeable improvements without getting too intrusive or requiring any custom tuning to fully take advantage of it.
Pickles,
im not sure what the problem is but I'v looked at the obvious as much as I can and now I'm thinking it might be something deeper.
I used to love the way the turbo sounded when you put your foot down and you get that distinctive whine followed by the whoosh when you release, but recently when I accelerate the whine is now mixed with some whoosh ( excuse the funny talk but I have no other way of explaining it) also while accelerating the car tends to hesitate, feels like it's beeing held back at times, and at cruising speed the boost comes in and out, you can hear the turbo spool up and release even though I'm holding a constant speed on a level road and no wind.
Also something weird happened to me on the highway, cruising at 80mph 2800RPM 5th gear the temperature starts to increase at a steady rate, had to slowdown because it didn't look like it was going to stop increasing, this is what I don't understand, same speed at on 4th gear RPM 3500 and the temperature starts to backdown and sits dead center on the gage, tried it again on 5th same speed temp up select 4th higher rpm same speed temp comes down.
My lack of knowledge in terms of reading or maybe interpreting the logs dose not help in getting my point across.
I will try and get a log to you by tomorrow and tell me what you think.