Whipple 2.9 power seems "inconsistent" and lackluster

Need some thoughts on this. Totally could be me... Maybe it's because this world of supercharged cars is new to me and I oversold my personal expectations ... but I do have a history with cars and building them and something seems "wrong", or at least "not right"...
I have a new Whipple 2.9 on a 2012 w/ big TB and BAP. (Stage 3 setup - for details see build thread)

How do you know if the bypass valve is not closing under boost or only closing partway (or fluttering)? I'm asking because of the size of the TB and intake, you can't see the bypass valve like the manual says to check that it's opening and closing...
Tonight I installed an Autometer boost/vac gauge spliced into the BAP line - to help troubleshoot this...
Sometimes when you get on it there's almost a "surging" that feels like boost / no boost...
Tonight with the gauge I did 4 hard hits to about 3/4 throttle on some country roads, here's what each one did:
* got the weird surge 1 time and the boost gauge was about 3-5psi
* had a really hard pull, SC really made that sweet whine sound, gauge showed 9psi. This was awesome...
* 2 others were "smooth" w/o surge but didn't feel as strong and the gauge was at 5psi
(It IS possible I hit it harder / faster the one time I got full boost, it's hard to look at RPMs, boost, same petal pressure and not hit something)

I feel like I'm going crazy... to me, this seems like the power difference and the whine / lack of whine suggests the bypass... but I have NEVER even heard of that as an issue...

The other question is - could a bad auto transmission part of the tune cause the surging (I know that wouldn't cause the boost psi differences tho)

Last data point - everyone talks about how with this blower I'm gonna need new wheels and the cheap Goodyears I have now should never hookup, even with traction control on... um, from a full stop, 100% drop the hammer WOT, with traction control on... the tires will break free, some... stock 18" and 3.15 gears. My built up expectation was w/ 93 octane - 1st would make rubber pudding for me... so... maybe people exaggerate, dunno.

FWIW - I have a dyno session set up for May 11 - but if it's something mechanical, that's a waste. I schedule the dyno to figure out if it's driver or vehicle!

Why are you testing it by only going 3/4 throttle? The reason your getting inconsistent boost readings is your probably giving it a different amount of throttle each time. Check it under WOT and see what it does then, when testing each test should be performed the same exact way such as same gear same amount of throttle etc....

I saw you have an x4, you should go out and do some datalogs. You have to remember your tune from Whipple is a one size fits all. With that said there is quite a bit of power left on the table from a custom tune.

I would data log the car and send the logs off to the tuner you were going to use. Everything you listed as a cause is a possibility but it's impossible to troubleshoot without data.

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Riddick said:

Why are you testing it by only going 3/4 throttle? The reason your getting inconsistent boost readings is your probably giving it a different amount of throttle each time. Check it under WOT and see what it does then, when testing each test should be performed the same exact way such as same gear same amount of throttle etc....

I saw you have an x4, you should go out and do some datalogs. You have to remember your tune from Whipple is a one size fits all. With that said there is quite a bit of power left on the table from a custom tune.

I would data log the car and send the logs off to the tuner you were going to use. Everything you listed as a cause is a possibility but it's impossible to troubleshoot without data.

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Yeah - I thought about datalogging - just don't know what to log.

And the reason why I did those 4 pulls tonight at about 3/4 is - when I hit WOT that surge seems "worse" so I was hoping to split the difference.

I was doing those 4 pulls on the same road, same speed, same everything - except for the human factor of 3/4...

Would the logs tho - since boost is mechanical - show is how / if it's fluxing? I suppose fuel use would show that?

Send me an email to [email protected]. I'll forward you the config file the tuner I use gave me. Only parameter you may need to add is boost

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Riddick said:

Send me an email to [email protected]. I'll forward you the config file the tuner I use gave me. Only parameter you may need to add is boost

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Sending an email now - but boost isn't datalogable...

Bad tank of gas? Just a thought.

Found this on another site regarding a problem with the bypass. "Went for a drive today and the actuator is not working correctly. If I stab the throttle it will close and make boost without a problem. If I roll onto it, it does not close. Once open, it is fine. Will make boost to 6k rpm's.

Talked to Whipple yesterday, they told me to see if the actuator arm closes when the engine is off. It does not. The actuator seems to be stuck in the open position. "

imeyers302 said:

Bad tank of gas? Just a thought.

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Fresh gas - from Sunoco - so I think it's ok...

What about belt slippage tho? I don't get a squeal - but anyone with "any" FI blower have thoughts on that?

As I thought about this last night - wouldn't a slippy / grabby belt give me this exact result set? Surge of boost / no boost feeling? Once in awhile it goes like a bat out of hell when it does grab... if i jam on the accelerator and it "slips'' some I'd get "less" boost than is if grabs the pulley completely and gives me full boost and the "Whipple whine"?

I'm gonna re-tension things today and try some "safe" WOT hits and see what happens... But this thought makes me feel kinda like I'm onto something

imeyers302 said:

Found this on another site regarding a problem with the bypass. "Went for a drive today and the actuator is not working correctly. If I stab the throttle it will close and make boost without a problem. If I roll onto it, it does not close. Once open, it is fine. Will make boost to 6k rpm's.

Talked to Whipple yesterday, they told me to see if the actuator arm closes when the engine is off. It does not. The actuator seems to be stuck in the open position. "

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Guess when I retension the belt - I'll pull the TB and look at the actuator too...

Normally if the belt is slipping you will hear it. One way to check is to look for belt dust in your engine bay around the idlers and supercharger pulley, a little is normal but if its excessive then its definitely slipping. On my previous car when we pullied down on the dyno it was slipping so bad it was smoking and squaling....... very distinct sound.

How does your tensioner look, I am not familiar with the Whipple tensioner but OEM tensioners have a tab you can reference to see how much tension is actually on the belt. Normally you want these right in the middle.

Riddick said:

Normally if the belt is slipping you will hear it. One way to check is to look for belt dust in your engine bay around the idlers and supercharger pulley, a little is normal but if its excessive then its definitely slipping. On my previous car when we pullied down on the dyno it was slipping so bad it was smoking and squaling....... very distinct sound.

How does your tensioner look, I am not familiar with the Whipple tensioner but OEM tensioners have a tab you can reference to see how much tension is actually on the belt. Normally you want these right in the middle.

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FWIW - I called the local place I'm gonna dyno the car on to get their thoughts to see if they thought I was bat$#1t or what... they said "they have seen this kit slip silently" - so I took them at face value and tightened the belt at lunch. The manual says to have it 70-80% of the tensioner - and yes - their tensioner looks like an OEM one - I'd say from when I first did the install to now things have loosened to maybe 60% of travel... so it was, perhaps a little loose, but not sloppy by any accounts. So now it's at 80%.

I was gonna datalog a trip at lunch too - but had "windows update" issues... and said screw it. I did drive the car. And I found some safe spots to do a few WOT hits.

I can't say as tightening the belt helped some or not.
I can say with 100% certainty there's "something" not optimal with the tune / or hardware...

From a 20mph roll, in 3rd (but in "D"), I hammered it WOT - and the car totally "surges"- almost "bucking", I know it's a Mustang but
Thing is - I repeated that in 3rd (in "S" mode) so it doesn't think about shifting - it just pulled strong, gauge looks like about 9psi, cool "Whipple" sound.

Now - that was the order - so tonight I'm gonna try the opposite - first WOT pull locked in 3rd, second WOT from 3rd in "D"... and hopefully have a log for those... if windows ever stops updating...

Given that lone datapoint - in my mind I am going back to the tune itself... the car is a 2012, the PCM is running 2014 software... which makes the transmission select-a-shift... I'm betting part of this is the tune itself is pure 2012 logic or something... dunno enough to know if that makes sense or not - but either way, even without a hard, weird, surgey pull, the shift points are retarded compared to the VMP 93 tune I used to have.

I probably will pull the TB to see if the actuator is open or closed at rest... just because... I'm stupid.

I am learning how different a boosted engine is vs NA in this process... I think some of my "less than full" boost numbers are obviously from a less than fully open TB... so - ok - learning.

fishpick said:

Fresh gas - from Sunoco - so I think it's ok...
W

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Regarding your use of Sunoco, when I first got my car I used nothing but Sunoco 93 and continued to do so after I installed my long tube headers which, after ~50 miles or so, caused the car to start throwing front O2 sensor codes.

The "tune" on the car was a Bama - 93 octane tune and for about a year or so, I replaced the O2 sensors, twice, and kept getting the codes (all while still using Sunoco 93). I was aware that Sunoco was not listed as a Top Tier licensed brand but I ignored it (http://www.toptiergas.com/licensedbrands/).

One day, I was running on fumes and unable to make it to Sunoco, I got Exxon 93. The check engine light was on for a front O2 sensor code and after 5-10 miles the check engine went off...code gone. Going on close to two years now and the only time the code came back was when I filled up with Sunoco (I had to test it!). I'm not saying Sunoco is causing your issue (or your perceived issue ) but I wanted to share my experience with Sunoco. My experience could be completely random and I'm sure there are people that love Sunoco but I'm sticking with Exxon.

FYI, Sunoco is now releasing a Top Tier approved gas (Ultratech https://www.sunoco.com/quality-fuels/ultratech/)

Your part throttle surging is prob from torque error due to TB data or Torque/inverse tables, not necessarily a mechanical failure. The heavier you mod the car, the more you need to dial in the Torque/Inverse tables. If you don't get them to zero torque error then you will get some throttle surge under part throttle, best way to not deal with it is to commit to WOT. There is almost no reason to ever be in the 60-75% throttle range. You have plenty of passing power even at 50% throttle, anything past that you should just go WOT

If you want to make it drive like stock then log torque error, it should be 0 almost all the time. You might get a random value here and there, but there should be nothing in the 100+ range

jn2 said:

Your part throttle surging is prob from torque error due to TB data or Torque/inverse tables, not necessarily a mechanical failure. The heavier you mod the car, the more you need to dial in the Torque/Inverse tables. If you don't get them to zero torque error then you will get some throttle surge under part throttle, best way to not deal with it is to commit to WOT. There is almost no reason to ever be in the 60-75% throttle range. You have plenty of passing power even at 50% throttle, anything past that you should just go WOT

If you want to make it drive like stock then log torque error, it should be 0 almost all the time. You might get a random value here and there, but there should be nothing in the 100+ range

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Good info. That's something I'll log with the new tune. There's so many parameters to log... glad I have the best dude out there on my car!

But I also know for SURE I have belt slip now. It's not even a question at this point.

Finally got rid of my exhaust that the blower made drone like a hive of 3500# bees and put on FRPP Tourings and am infinitely happier... AND that now let's me clearly hear a sound in the 3000-3500 range that's kinda like the whistle a steam valve letoff might make... when that sound happens I can watch my boost gauge drop to 5-ish... if I then feather off the accelerator and then back into it more gently the boost goes to 9-ish (if it does NOT make that sound) and the car pulls super strong. This sound is not the SC whine - it's not even close to it. And while this happens you can now also audibly hear the SC whine "be less" when the "whistle / squeal" happens...

The idlers are covered in a tan and black dust. And the cutouts in the Whipple pulley have dust in them after a short ride of making the car make that "whistle/squeal" 4-5 times.

Totally the belt. No doubt. Not saying the canned tune doesn't also have issues (I'm sure it does) but I gotta get the mechanical figured out before the software!

I have my tensioner at 80%. So my next steps were to remove the belt, turn it inside out, and look for glazing. None. I then cleansed all the ribbed pulleys with brake cleaner and pipe cleaners to get any and all possible lubricants off them (not that there were any, just ruling that out) and got a bit of black dust out of the grooves as well.

Today I'm going to flip the direction of belt travel and see if that changes things. And I have a 7/8" shorter belt arriving from Amazon today to try as well... (assuming the weather holds until after Mothers Day brunch)

Been talking with Whipple too - many of these suggestions were theirs.

Something's gotta work... (other than "get a 10 rib setup")




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fishpick said:

I have a 7/8" shorter belt arriving from Amazon today

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FIXED IT and... WOW -
fishpick's 2012 Coyote Vert Build Thread (Base GT Convertible) -> exact thread post
Link to thread post specifically for details...

Hmmm, wonder if they shipped you the wrong belt initially. Glad you got it sorted out. So, do you need new tires yet ?