Ordering Intake

[Deliboy]

Loaded....runs much better now. No more hesitation or sputter at low speeds.


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[stoopid]

Het stoopid lol you datalog with the intake yet?

Submitted and now wait for a tune. Engine light was on, then off, and now back on again. Car seems to be running okay though (no major issues, even cold starts are mostly smooth now).

 

[Paradox]

Loaded....runs much better now. No more hesitation or sputter at low speeds.


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I'm waiting for my final tune, having a big problem with the low end torque and hesitation. Hoping the final tune will fix those issues.

 

[klb1.8]

Oh it will

 

[Deliboy]

Second that


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[Paradox]

So I got my final tune today, flashed it over, runs a lot better. My car vibrates like a madman for some reason at "warm idle" 700rpm always has since day one, so I asked Trifecta to bump up idle to 900rpm, smooth as silk now. I still have one problem though, just test drove the car, did some 0-60's, normal curising, etc. Did a few "normal" throttle up hill and there's still a lack power in 4th and 5th. I can push the accelerator from anywhere from 1/16 of a pedal estimated to past 1/3 and there's no acceleration what so ever... the only way it goes up a hill is by me pushing pedal past 1/3 and it downshifts or I go into 'M' mode and manually downshift...any suggestions? It just seems it's struggling, if I manage to get into 4th or 5th past 1500rpm there's no hesitation, has lots of power, but before 1500 rpm which it shifts into most of the time there's nothing, I actually start decelerating.

 

[stoopid]

I experience identical acceleration on an incline in higher gears. Seems that there's just not enough power under 1500 rpm to accelerate. I thnik the car is computing your needs incorrectly, assuming you want to maintain speed and not actually accelerate. It seems to assume acceleration won't happen until you 'punch it'. Maybe they can do something with the TCM.

In my last correspondance with BNR I mentioned this (before reading your post).

 

[Paradox]

I experience identical acceleration on an incline in higher gears. Seems that there's just not enough power under 1500 rpm to accelerate. I thnik the car is computing your needs incorrectly, assuming you want to maintain speed and not actually accelerate. It seems to assume acceleration won't happen until you 'punch it'. Maybe they can do something with the TCM.

In my last correspondance with BNR I mentioned this (before reading your post).

Hey Stoopid, I'm glad you mentioned it, I read on the cruzetalk forum Trifecta can actually tell the TCM at what RPM to shift. I was planning on forcing the TCM to shift into 4th and 5th gear around 1550 rpm. It would get rid of the issue, the only 'bad' part per se is that 3rd and 4th gear would rev higher than normal and fuel consumption would go down a bit, i presume. Guess i'll ask Trifecta to do it, and see what happens. I'll keep you updated.

 

[sx sonic]

The shifting problem sounds text book TCM. Its not really a problem so much as a nusance caused by the TCM having to factor so many variables and "assume" what you want it to do.

Shift points change based on 1. Road speed and 2. Throtle postion (driver intent). So going up a hill it can only muster so much power in that gear since the throttle will only open so much before a shift.

If you give it more gas it shifts into the next gear= higher hp RPM range, the throttle is also opened more= more HP generated.

If you could stay in the same gear but give it more throttl it wouldn't matter as you could still make more HP. That is why it works fine in each gear in "M" mode.

Careful TCM tuning can help and so can more HP. Its just a comrommise automatics have to face, tune them right for most driving and hills and strong headwinds can become problematic.

 

[sx sonic]

Tl;DR
Automatics can only generate so much power in each gear because the throttle is only allowed to open so far before a downshift is commanded.

This arrangement works fine for normal flat driving but can be a nusance with long inclines or strong inclines. You give it more gas to maintain speed and the TCM interprets it as a request to "go fast" and kicks it down a gear and allows more throttle.

Manual mode (M) and manual transmissions get around this by allowing full power to be achieved in each gear and each RPM range.

TCM tuneing and/or more power helps with hills. ( I took my automatic sierra in for tuning just to keep it from downshifting from 4th to 2nd on the interstate overpasses. Much better now)