silver-mod-o

iTrader: (15)

How do you vac modulated guys tune your trans setups? Do you just zero all your trans pressure tables? leave them?

I'm shifting out of 1st WAY too early at part throttle and locking up in 3rd and OD very early as well... at WOT, everything seems fine. Shifting 1-2 @ 6800 and 2-3 @ 6400.... but around town, its annoying the **** out of me.

Its a Finish Line Level 5 4L65E trans with a Yank SS3600 converter, if that makes a difference.

Gilbert@Ace Racing

I know that Vince will be helpful here.... but I will tell you it is not related to the vacuum modulation. The vacuum modulator does not control shift timing, rather it eliminates the EPC solenoid... it controls line pressure.

You simply need to have the Transmission Tune adjusted for your combination... we found that the PCM's are sensitive to cam / converter / gear swaps some time ago.

The Transmission Tune is just a necessary evil when modding these computer controlled vehicles.

Good Luck

g

silver-mod-o

iTrader: (15)

my tuner is experimenting with the tow/haul feature on my truck so there's "track" and "street" trans setups... different shift points etc... I know the modulator only controls pressure and thats not my problem (as far as the early shifts go) but I was just curious how the other vac mod guys have their stuff set up.

so really, the only thing I can change in the PCM is shift timing, and points right??

Gilbert@Ace Racing

Ok that helps, thanks for the additinal info.

The vacuum mod. really has no bearing in tuning... the tuner can essentially ignore the pressure tables. I would bet he has probably recognized that already.

Yes, the shift timing is the essential component of the tune to focus on at this point. It can be very time consuming trying to get it right. I would not concern myself with a track or street tune for the tranny. I know the Vince uses a Trans Go HD-2 reprogramming kit and it will control the shift firmness at WOT. I would use the tow/haul feature for a different engine tune if it is needed. It's a cool bonus, maybe if you are using N2O.

Shift timing can be tedious to get right in some combinations... but usually those are the heavily modified combinations.

What is going to drive your tune parameters is the MAF, TPS, Converter and Gears... not the modulator.

Hope that helps. I'll be in and out all day... feel free to call me in order to discuss this in detail!

g

silver-mod-o

iTrader: (15)

Thanks for the help on the phone Gilbert!!! I appreciate you taking the time out to assist.

Gilbert@Ace Racing

You're welcome! Glad to be of assistance.

Just give me a heads up when you send those files and I'll carve out some time to look them over!

g

Tonner

MMM I wish I could have been a third party on that phone call, lol. tricky stuff tuning a tranny, so I now believe.