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  1. #381
    Quote Originally Posted by UselessPickles View Post
    At part throttle, I can get my wastegate to open because it is reaching the target boost in the intake system before the throttle body (where my wastegate boost source is), even though my intake manifold may be a couple PSI below the target. The official Prodigy setup has the wastegate boost source as the intake manifold, so at part throttle, there may be situations where the wastegate stays closed trying to reach the target boost in the intake manifold, but the pressure on the other side of the half-way closed throttle could be above the target boost level, working the turbo harder than desired (hmmmm... I wonder if this could lead to compressor surge in these situations?).
    So are you saying that there may be something in the way pressure is equalized across the throttle body at part throttle? I understand that my system is sucking air through the TB and your system is pushing air through the TB. But I've often thought that my TB was not designed for FI. Too much "play" in the throttle plate.

  2. #382
    Senior Member Timmy's Avatar
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    Quote Originally Posted by gbaumann View Post
    Could not have written a better description of the "surge" us magnuson guys experience. Spot on right down to the RMPs! And I do have an auto trans. I know you're chasing turbo issues but I offer the observation in wondering if the aftermarket tuners could be missing the same thing regardless of the forced induction system.
    Hey guys. I read this and thought "oh, I've experienced this on my Audi." Any time I get exactly what Pickles describe, a smooth, linear hard acceleration, and then I get what feels like a small blip in power, I've learned, it's gas with too low of octane or is not good enough. I've driven with 93 octane gas and had my 93 octane tune loaded and it would do this. I drop down to the 91 octane tune and the issue would go away. When I lived back in the mid-west (and don't get me started on "mid-west," I have an issue with that word just like my "High Altitude" verbiage issue) I could almost always find 95 octane, so I just ran that with my 93 octane tune and my issue was gone.

    Now, you guys are must more technical about all this stuff than I ever am, BUT, if you haven't tried already, try to get some of the best gas you can find and see if it helps at all. If you're in the mid-west to north east, you might even get lucky and be able to find 95 octane! It's worth a tank of gas to see if that resolves the issue.

    [Urgh... couldn't help it... How can you have a "Mid-West" that is East of Central!!!! Stupid. If you ever here me refer to "Mid-East" that means the "Mid-West" area, not overseas.

    Worst possible sentence ever... "I drove from the Mid-West to the High Altitudes of the Rocky Mountains."
    Translation: I drove from the Rocky Mountains to the Rocky Mountains so my Jeep could fly above the ground.]
    2014 Jeep JKU Sahara, Manual - /OlllllllO\ - 4" Metal Cloak lift, 37" Toyo Open Country's on 20" XD Bully Rims, 4.56 Yukon gears, Mopar High Top Fenders, ARB Front Bull Bar Bumper, ARB Rear Bumper, Teraflex HD Tire Carrier, Teraflex Tire Carrier Accessory Mount, Twin Rotopax mount, Hi-Lift Jack mounted on front bumper, Reverse LED work lights, Warn 9.5ti winch, Synergy Drag Link, Trackbar Relocation Bracket, AMP Power Steps, JK1001 Radio, SpiderShade.

  3. #383
    Quote Originally Posted by gbaumann View Post
    So are you saying that there may be something in the way pressure is equalized across the throttle body at part throttle?
    No, it's just the very different ways that superchargers and turbos work, and that the purpose/function of a supercharger bypass valve is very different than a turbo wastegate. A wastegate will never cause a sudden change in power delivery like a supercharger bypass valve can.

    Quote Originally Posted by Timmy View Post
    Any time I get exactly what Pickles describe, a smooth, linear hard acceleration, and then I get what feels like a small blip in power, I've learned, it's gas with too low of octane or is not good enough
    Hard accelerations are actually smooth for me. It's the part throttle light/moderate acceleration where the problem happens. Also, the tune requires minimum 91 octane, and I'm running 93 octane (91 isn't very common around here).
    Last edited by UselessPickles; 02-28-2015 at 05:55 PM.

  4. #384
    I finally had my first encounter with another performance vehicle out on the road

    I'm at a red light, in the right of two lanes. The right lane ends about 1/4 mile after the intersection. There's a car beside me, and a modern Dodge Challenger behind me. Light turns green, and I accelerate normally, but faster than the car beside me, because I want to make sure I'm ahead enough to merge out of my lane before it ends without being a dick and cutting this other car off.

    I notice that the Challenger is staying very close to my rear bumper, probably waiting for enough gap between me and the car that was next to me so he can change lanes and pass me. I shift into 2nd at a fairly normal RPM because I'm not showing off at this point.

    Then I see the Challenger make his move. I see an aggressive lane change and hear the Hemi start to roar a bit. No time to downshift at this point, so I just step on the throttle in 2nd, but I'm not quite up to the RPM where full boost kicks in. The driver of the Challenger must have noticed I suddenly started accelerating more, because I then heard the Hemi transition to full roar, and the Challenger lunged forward.

    Right as the Challenger gets beside me, I transition to full boost. Couldn't have timed it more perfectly if I tried. Next thing I know, I'm several car lengths ahead of the Challenger, can still hear the Hemi roaring, but he's still falling back. I also notice at this point that I'm now going faster than I would prefer, and my lane is going to end soon, so I merged over and let off the gas to coast down to to more appropriate speed.

    The Challenger quickly catches up to me just as the right lane ends, and rides my rear bumper for a few seconds. Then he aggressively passes me at full throttle, flips me the bird, and speeds excessively up to the next red light. I had not cut him off, blocked him from changing lanes, or anything else rude. His rude gesture can only be the result of being a sore loser.

    I thought that was the end of it, but I was wrong. It turns out that "sore loser" is an understatement for this guy...

    He stops at the red light way ahead of me, but I can see he keeps inching forward, trying to get a jump on the green light. As I approach, he just takes off, running the red light before it was even close to changing (cross street still had a green light).

    There's another red light just about 1/8 mile ahead with two lanes now. This time he actually comes to a complete stop, but at a slight diagonal,partially occupying both lanes. I guess he really didn't want me to pull up beside him.

    I was actually going to be turning right at that intersection anyway, so I slowly/carefully squeezed past him, stopped, checked to make sure traffic was clear, and proceeded with my turn (right turn on red is legal here). The driver of the Challenger sat still, hands on the wheel, facing straight forward the whole time.

    I hope he's still trying to figure out wtf happened. I wonder if he could hear the turbo, or just watched me quietly pull away with my stock exhaust.


    Unfortunately, I forgot to check for badging to see if it was an R/T or SRT. I did some simple math based on dyno results I have found for Challengers and the difference in curb weight between them and my Jeep (Challenger is 400 lbs heavier than my Jeep!), along with Prodigy's recent 380 whp claim, to determine how the power:weight ratio compares.

    Newer 6.4 SRT: Nearly identical power:weight ratio (I have 3% advantage). This car was definitely not a 6.4 SRT, unless he never really went full throttle near the beginning, or else it would have initially blown past me, then I would have just barely maintained the gap between us as I transitioned to full boost.

    Older 6.1 SRT: Actually has nearly identical peak hp/tq numbers at the wheels, but due to weight difference, I have an 11% advantage in power:weight. This might be a possibility. He was definitely quickly gaining on me before my boost kicked in. An 11% advantage would definitely allow me to keep increasing the lead as long as I was in the upper RPM range, but I'm not sure if an 11% advantage is enough to let me increase the lead as quickly as I did. Really hard to tell.

    5.7 R/T: I have a 30% advantage in power:weight! That could make sense too. It seems like that big of an advantage would have put me further ahead more quickly, but I could be wrong.


    Wish I would have looked for the badge. Oh well. It was thoroughly entertaining and made me smile for the rest of the day.

  5. #385
    So to summarize, you smoked the muscle car!!!

  6. #386
    Basically. I was more surprised by his reaction. I expected either no reaction, or for him to try to catch my attention at the next light and ask me how the hell that just happened. Not pass me, flip me off, run a red light, then try to prevent me from pulling up next to him at the next light.

    I bet it was an R/T and he had already been wishing he could have gotten an SRT. I just rubbed salt in that wound and he couldn't handle it

  7. #387
    You knocked him out in a fair fight. I suppose you cant be too surprised he didn't get up and ask where you developed your awesome left hook. Most muscle heads will get up and sucker punch you while you're walking away. Yep, it was an R/T.

  8. #388
    It finally warmed up enough here to wash all the salt off my Jeep from this winter and add a subtle hint of what lurks under the hood. Have I endangered my sleeper status?




  9. #389
    ProCharger says: "comes standard with the industry’s largest and most effective air-to-air intercooler for the Jeep Wrangler JK. "





    Prodigy says: "that's cute"





    UPDATE: Procharger seems to have updated their website to no longer claim to have the largest intercooler
    Last edited by UselessPickles; 04-13-2015 at 11:17 PM.

  10. #390
    Senior Member Timmy's Avatar
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    Quote Originally Posted by UselessPickles View Post
    Have I endangered my sleeper status?
    Ba hahahaha... No Pickles, you are still far from endangering your sleeper your status.
    2014 Jeep JKU Sahara, Manual - /OlllllllO\ - 4" Metal Cloak lift, 37" Toyo Open Country's on 20" XD Bully Rims, 4.56 Yukon gears, Mopar High Top Fenders, ARB Front Bull Bar Bumper, ARB Rear Bumper, Teraflex HD Tire Carrier, Teraflex Tire Carrier Accessory Mount, Twin Rotopax mount, Hi-Lift Jack mounted on front bumper, Reverse LED work lights, Warn 9.5ti winch, Synergy Drag Link, Trackbar Relocation Bracket, AMP Power Steps, JK1001 Radio, SpiderShade.

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