Autos and forced induction.
Ok I picked up a project car and its an Auto, anyway the plan is to make it a TT so prior to doing anything to the car I wanted to drive it around for awhile.

Driving it around I noticed that when the car wants to shift (IE I floor it to get some speed like passing) the tranny easy bumps the rpm's to redline depending on the speed meaning it happens fast. Now my concern lies with that, how fast it hits redline. Now say its forced induction and the tranny shifts like that IMHO I will end up with blown fragments of pistons everywhere.

So is there anyone that has Automatic FI that has ran into issues caused by the tranny downshifting.

I would think there is a way to contol the Tranny from downshifting at a certain speed but at the moment I dont know.

 

You pretty much have to use the tiptronic if you are going to get on it. I'd never trust the tranny to downshift itself if I were to gun it. Did you get a ride in my car when you were out here a couple of months ago?

Ty

 

No I didnt
I still would like to be able to adjust the shiftpoint somehow as I always let others drive my cars..

 

Honestly I don't even know where the computer that controls those shift points is located. Unless it's the ECU. Is it the ECU?

If you could just get it to downshift to one gear higher than it normally would you'd probably be ok.

 

I think its all part of the TCM which is separate from the ECU. Depending on the year, the TCM is built into the valve body.

As far as I have seen, nobody has cracked the TCM yet. Powertrain Control Solutions was working on a controller that was compatible with the RE5R05A, but it doesn't work on the integrated TCM controller like on the Z/G, only systems like the Titan which I believe uses the ECU for everything.

 

If I understand your question, you are concerned about blowing through redline on a downshift (5-4/5-3/5-2, etc)......I have never had a problem blowing throug redline in this instance....as a matter of fact, this is the best part of the F/I-forced induction match.......the tranny sorftware has no problem on these downshifts and will take you from 5 to 2, then back to 3, 4 and 5 faster than anyone I know.

 

No problems here . Since I got the VB done . Down shift are good and upshifts are very fast . I never hit the rev limiter unless the tires are spinning

 

+1 exactly my experience and as Booger pointed out an upgraded VB really helps with the rev limiter.

 

+1 exactly.I had this situation happen the other night.I was cruisin at 50mph in auto mode and the tranny was in 5th gear and a beemer rolled up next to me and then took off.I jumped on the gas and the tranny downshifted to 3rd and took off like a bat out of hell. Needless to say I caught the beemer in a split second and blew right by him.I do have a raised rev limiter but I,ve never bounced off the limiter in auto mode.I do have the SGP VB so the shifts are real fast.Hope this helps...........By the way the beemer was a 6series sedan with some troll driving and a beautiful blonde wishing she was in my Z