Actually we've had great success with blower cars. The EPC is the ONLY way to go with forced induction cars. You simply cannot use the vacuum modulator mod in a blower/turbo 4L60E.

The customer we have that has ran 9.7's has the motor out of his car right now. He's building a new direct port nitrous combo, and pulling the blower off. Since the car is down, anyway, we had him bring the trans by for a check-up. We originally built it in May '05. After consistant low 10's all season, (before the nitrous shot) his 3-4 clutches were still reuseable! The 3-4's are the first place you'll see any signs of pressure problems in a '60E. The way we set these things up, and the modifications we do are just plain working.

As a side note, another shop had built this transmission previously with a vacuum modulator 5 TIMES! It only lasted a few hundred miles at the longest. When we built it, we removed the vacuum modulator junk and reinstalled an EPC. Needless to say, we have had much better success than the previous builder...LOL.

If anyone has any questions, please feel free to call me. 302-250-1202

Thanks,
Frank
CPT

 

why would the 3-4 go if you never use 4th gear at the strip ??? that wierd

 

Those clutches are on in 3rd and 4th gear BTW, we do have several customers making a 3-4 upshift in the quarter mile.

Frank
CPT

 

Vacuum mod has worked fine for me. I've almost got 50k miles on the tranny behind a TT without even a refresh. Granted, I'm not in the 10's, but I am in the high 11's in a very heavy Impala SS.

 

If that's true, you're one of the few and one of the lucky.

Frank
CPT

 

Hehehe,
I don't argue that at all! (knocking on wood) I have been expecting it to go south for some time, but it hasn't missed a beat. Heck, I have thought about pulling it for a refresh just to be on the safe side, but I'm afraid to touch it 'cause it's been working so well!

 

I think there's an old saying about that...."If it aint broke, don't fix it."...LOL

We hope you keep us in mind when/if you need one. We have several in Impalas. Our most notible is behind a N/A 383 Golen motor. He runs 11.6 @ 4200# with a 1.54 60 ft. time.

Frank
CPT

 

OK, so who programs the PCM to make the pressures come in when they should to keep the tranny alive? You're not using the stock tables for a blower car, are you?

 

What makes you think that the stock pressure tables shouldn't work?

Frank
CPT

 

What is an EPC?



Nick

 

electronic pressure control i think but i could be wrong

 

You're right on the money..EPC = Electronic Pressure Control.

Frank
CPT

 

My transmission builder was real worried about it, mostly because of the blower, although I think he might have been thinking more of roots type positive displacement blowers which make boost down low than centrifugal type, but he was worried about getting the pressure to come up sooner than it normally would for a car with half the power. He has a racing background and a department just for building torque converters that is larger than most tranny shops I've been in. After he tested it on the tranny dyno, I installed it and taped the pressure gauge to the windshield and watched my pressures as I tested the car. I also had to adjust the tables for the 58mm throttle body because a lot of it is based off of throttle opening, which means it will be off for a throttle that doesn't open as much for a given power level. My tranny is still alive after 6 years of street duty with about 2 or three trips to the track per year (about 15 passes per year) and a bunch of other testing.

 

You have a PM!

 

You have a response!

Thanks, Joe.

Frank
CPT