Reply With Quote
***** MODERATED ****
Hey everyone, this was the point where this thread went off turbos into a discussion about tires, I moved all the tire talk to a new thread - "Pickles Tire Convo"
http://jeeplab.com/showthread.php?234-Pickles-Tire-Covo
I practiced some snow driving skills today. Listen to those turbo sounds
https://www.youtube.com/watch?v=_kfYyeRwRSI
***** MODERATED ****
Hey everyone, this was the point where this thread went off turbos into a discussion about tires, I moved all the tire talk to a new thread - "Pickles Tire Convo"
http://jeeplab.com/showthread.php?234-Pickles-Tire-Covo
How about some more geeky data...
So I was looking at a dyno chart of a RIPP supercharged Wrangler with a boost curve again, and I figured out that the boost curve just about perfectly matches a quadratic curve. That means I can now plot the RIPP boost curve on a chart with my turbo boost curve.
Here's the RIPP dyno chart again:
That must be the "high altitude" kit, since it is advertised to produce 9-11 psi at sea level. The standard kit is advertised as 8 psi, so i can plot that as well.
It's interesting that there's not a lot of difference between the standard RIPP and Prodigy at low rpms.
More interesting is that RIPP just claimed on another forum today that their kit produces 40% gains as low as 1800 rpm. How do they get 40% gains from less than 1 psi boost? And if RIPP can do that, why doesn't the turbo produce 40% gains as low as 2200 rpm, where it has similar boost as RIPP at 1800?
Well did you take into account the dimensions of the Ripp Vortex unit in comparison to the Prodigy Unit? Size is a big deal. What about the gear ratio that Ripp uses in the unit-- that matters. In your turbo, like the one on my diesel it is only run on exhaust gas pressure; so lower rpm means less pressure on the rear turbine so less Boost. Where as a supercharger usually has a gearbox so that at low rpm it creates a significant amount of boost.
I'm taking into account the actual recorded boost curve from a dyno run of a RIPP supercharger on a Wrangler. I don't need to know anything about the size, gear ratio or pulley size, etc. The RIPP is a centrifugal supercharger, so it doesn't produce much boost at low rpms, as evidenced by the dyno chart with the boost curve that I posted. Compare the boost curve from the dyno chart to the curve I plotted on my chart. Almost a perfect match.
Originally Posted by UselessPickles
Answer me if I'm wrong-- you want to know why your turbo and the Vortech V3 super that Ripp uses show differences at low rpm right?
I want to know how RIPP system could possibly produce 40% gains in torque/power at 1800 rpm (as claimed by RIPP), when there is less than 1 psi boost at 1800 rpm (that's less than 6.8% additional air above atmospheric pressure). And if somehow that actually is correct/possibly, then why can't the turbo produce 40% gains in torque/power as low as 2200-2300 rpm, where it is generating a similar amount of boost?
I'm trying to get a response from RIPP about this. I'm hoping it was just a typo, because the claim seems ridiculous.
Maybe at 1800 RPM the pentastar is making 100 hp. with the RIPP maybe it makes 140. I have no idea personally. But you are not talking about 40% of 285. The stock power made at 1800 is much less.
A 40% gain is a 40% gain regardless of RPM. The stock Pentastar has 90% of peak torque starting around 1900 rpm, so a 40% gain in torque down there would definitely be noticeable.
Manifold pressure doesn't always correspond with actual CFM. Roots Lobe type units for example have very low Manifold pressures but extremely high CFM ratings. And you can duplicate this effect with Centrifugal units if you gear them properly. That is the reason many aircraft superchargers during WWII were actually two speed units: they used a higher speed at high altitude for cruising giving them similar performance to the low altitude lower speed setting at higher engine rpms. Some where even two speed and had a second stage on the high speed unit to give them add pressures at high altitudes that was how the Junkers Jumo 207B a 16.6 L two stroke diesel engine developed nearly sea-level performance at 40,000+ feet..
To be honest it seems like a dubious claim given the type of unit they use in the system. But it could be true. You would really need to know exactly how they have spec'd out the V3 unit from Vortech and what sort of Garrett turbo you have in your system. The big difference is going to come down to how much air each of the system is capable of putting into the cylinder head at any given Boost Rating. That was what I clumsily attempting to get at last night. What is missing is in your analysis is enough information about each system to really compare them. You have only bits and pieces of the necessary data required to perform your analysis. The really critical data points your missing have to do with volume of air flow each unit is really producing at any given boost for specific rpm. The Vortech unit could have a 50% advantage in volume compared to your unit and that will make a big difference in power. So you can graph boost points and hp points all day long without knowing the specifics about volume into the cylinder head you really cannot say that Ripp is making a false claim.
For example Whipple makes an amazing Roots-Lobe unit that does just what I'm talking about produces 50% power at 5 PSI at Idle...
http://whipplesuperchargers.com/inde...product_id=149
Last edited by KaiserBill; 02-17-2015 at 05:24 PM.
Posting Permissions
Connect With Us