I have a 2K Formula with 3.73 gears, and a beefed up factory 4L60E. After the tech did the build up and then test drove it, he told me the shifts were happening too soon, not allowing enough throttle pressure to build. I've noticed that in normal, around town driving, the trans has gone through all gears and is locking up at 31 - 35 mph. I don't think this is a good thing. I understand that with these gears, the PCM thinks the car is moving faster than it really is, thus resulting in early shifts.

The questions are: What is Throttle Pressure and how does this decreased pressure affect the transmission?

I used to have the problem with the lock-unlock-lock between the 3 - 4 shift, which was fixed by Ira's calibrator, but as far as I can tell, Hypertech still doesn't have a fix for shift points in 3.73 geared A4's, correct?

Some other parameters: Stock PCM programming, Vigi 3K stall, minor intake mods with stock screen-in MAF, stock size tires and custom exhaust system.

Your answers to these questions would be appreciated. <img src="graemlins/gr_hail.gif" border="0" alt="[hail]" />

Rich

[ February 10, 2002: Message edited by: Rich3fan ]</p>

 

Rich,
I don't know the specifics of how the throttle pressure affects the shift points and trans. For stuff like that, I'd recommend calling or e-mailing Chuck @ FLP. (630)820-9294 or transguy@sprynet.com I can tell you that I'm in 3rd before 30 MPH with normal driving, and converter lockup is at 30 MPH. Granted, this is with Ed Wright tuning.

 

[quote]Originally posted by Trevor D:
<strong>Rich,
I don't know the specifics of how the throttle pressure affects the shift points and trans. For stuff like that, I'd recommend calling or e-mailing Chuck @ FLP. (630)820-9294 or transguy@sprynet.com.</strong><hr></blockquote>

Huh? Call someone on the outside? After all the harrasment I endured when I joined this site? I don't think so!! This IS LS1Tech right? <img src="gr_images/icons/wink.gif" border="0">

Surely someone here... Bob #2, Patrick G, Joel, Colonel, John C. can tell me what throttle pressure is and how it works with the trans, can't ya? If it helps Bob, I'm originally from South Jersey. <img src="graemlins/gr_barf.gif" border="0" alt="[barf]" /> <img src="gr_images/icons/wink.gif" border="0">

[ February 11, 2002: Message edited by: Rich3fan ]</p>

 

It's all in the programming. So are you using the HPP3 or Ira's calibrator right now?

I've never heard of "Throttle Pressure." I would guess that he means that under part throttle shifts that the shifts are happening with the TPS at a lower value resulting in less line pressure in the transmission since the TPS is one of the things that effects line pressure.

[ February 12, 2002: Message edited by: Colonel ]</p>

 

Thanks for the reply Colonel.

I'm using Ira's calibrator for speedo correction and to eliminate the funky shift from 3 - 4, and stock programming. I don't recall HPP programming making any difference as far as the quick shifts are concerened, but I am going to load it in with the 3.73 gearing option after I get some info for AFTICA, regarding his line pressure issues. And it sounds like I'll be a candidate for LS1 Edit soon.