Gas Pedal Delay

DIGItonium

The first half of the video demonstrates quick and casual depress of the pedal to the floor. When I say "quick" or "slow," that is when I start pressing down on the pedal. You will hear 2 clicks from the pedal, one hitting the floor, and one when it is fully released.

The next half demonstrates a quick stab of the pedal to the floor in 1st and 2nd gear under normal conditions and after the extended period of driving (i.e., driving home from work).

Impressions
S-Mode or VDC does not appear to have any effect in holding revs. Regardless of the mode, the revs slowly climb, hang, and slowly return to idle when the engine is "hot." Also, the response is slower than usual as the engine does not easily rev past 2k RPM. Under "normal" conditions, the engine revs quicker easily beyond 3k RPM, the rise and fall is quicker, and it does not hang. After a cool down, it appears "normal" response returns, but it is no where near as good.

In normal conditions, I can literally peel out and go side ways for a moment from a roll in 1st. After an extended period of driving, I can barely get the car to budge in 1st. It feels like accelerating in 2nd from a standstill.

Now in 2nd gear, you can really see how slow the revs build up when the engine is "hot."

Unfortunately, I could not demonstrate the throttle delay. It was hard to hold the camera. If I demonstrate it with the tech, I will literally floor it while making a turn to prove the car will not burn rubber or go side ways.

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IcedZ

I'll get video later today. Mine is basically identical!

6spd

Im going out tonight to do some photography. with this video in mind, i'll try and replicate what you did and see what the result is. Ill post my opinion when I get back.

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-Jay- jonathanjamesphotographer.com

6spd

Update:

Just got home from the shoot and didn't experience anything like you said or like what was in the video. Even at 220 oil temp, no lag, no hesitation, nothing, just pure unadulterated POWA!

I had an enlightening thought as well during the ride. I used to have the FI exhaust, and when I installed it, I distinctly remember losing a ton of back pressure and low end "uumph". I sold that exhaust and just put the stock back on and the car feels so much better in the low/mid rpms, "uumph"-wise. Your problem may be back pressure related. It'd be a pain in the ***, but if you put the stock exhaust back on, you'd feel the difference.

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-Jay- jonathanjamesphotographer.com

christian370z

All of that lost low and midrange torque can be recovered and more with a tune (which Digi might have), back pressure wouldn't explain the notable difference in engine response whilst revving the engine without any load.

I have never had that kind of power or response decrease when warm, however I could feel the car get slightly weaker and less punchy as the oil temperatures went up. Now that I have my oil cooler, the car feels so much more punchy and powerful all the time thanks to temps between 180-190 at all times.

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-320whp / 259wftlbs-
SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob

6spd

Well hopefully his dealer can get to the bottom of it.

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-Jay- jonathanjamesphotographer.com

Boost_lee

Wow Digi, that last clip was horrible on the RPM climb. My car sometimes feels laggy, but I don't think its ever been that bad.

Hope you get to the bottom of this

DIGItonium

FYI: Tune is stock as I plan to go FI early next year.

It gets worse the longer I drive it, and it is easy to reproduce the problem in warm weather. My oil temps typically over around 220F and probably no more than 240F at the extreme. I'm not 100% sure about oil temp because I've had this issue occur even at 180F. VDC doesn't even matter either.

It really takes the fun out of driving because this car is capable of breaking my Hankook 285 tires loose on a rolling start. The stall under 2k and slow revving is pretty scary in situations where I make a turn in traffic as it feels like VDC is cutting power without indicators lit. I'll try to test with the sensor module disconnected and get back with you guys with my findings.

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6spd

See, the part about bogging pulling out into traffic Ive never experienced. Ive always thought of this car as the best feeling car doing that action I can remember, no bias though....!

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-Jay- jonathanjamesphotographer.com

IcedZ

Here's my car:



My car is still 100% stock (except for stereo, and it was off)

6spd

so are these pedal depressions all the way to the floor and up? When I did this last night it wasnt like that.

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-Jay- jonathanjamesphotographer.com

IcedZ

Yes, they are all the way down and up. My "quick" pushes are consistent, but the "slow" probably are less so. Even so, I think there is an obvious difference.

IcedZ

I did some more tinkering (not on vid), and proved that VDC and "S" mode have zero effect. I believe DIGI stated this earlier.

DIGItonium

^ Haha yup... isn't that weird? The question about the Z holding revs was asked before especially by 7AT owners. We all thought it was an S-Mode feature to hold revs, but at stand still? It makes sense to maintain RPM between shifts, but it's weird to see the difference in rise and fall time with hot or cold engine using oil temp as a reference. Plus, you can see how lazy the engine feels to rev past 3k.

Thanks for the sanity check, IcedZ!

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IcedZ

Lazy is a word I use to describe it sometimes. Also "mushy" or something. Hard to describe. I think I'm going to schedule an appointment with my dealership for early November. I don't think I can get in before =\ I think you have the right idea - have a drive with a tech. Also I might drive another one on the lot. Let me know what else I can do to help =)