A big thanks to RPM Transmissions

JerryL · 08-19-2007, 12:58 PM

RPM just finished installing the TH400 in my car. This conversion is not a "bolt-in", it requires custom parts and opening up the tunnel. We're still running the IRS but the differential has been beefed up. The transmission and converter are custom units built by Coan Racing. I'm running a Precision Performance Products air shifter. The transmission has a pro-type trans-brake set up through a fully adjustable 2 step. It will likely be a couple of weeks before any track testing but I was able to make 3 data-logged launches in Rodney's driveway. Data shows no appreciable hesitation (my original problem) and the brake seems to release instantly.

So why the TH400? From my own track experience I don't believe it's possible to be competitive on a pro tree with a 4L60 type transmission. The transmission running through an IRS is slow (relatively speaking) to react. Most of the guys in the Corvette Challenge Pro 10 are deadly on the tree, you can't afford to give them .03 - .05 at the start. The TH400 can be built to be almost bullet proof. The downside is loss of streetability, among other things there's no overdrive on the 400.

For those running an automatic transmission I'd say a 4L60 type from RPM will satisfy most, even on the high horsepower applications. If you're racing on a full tree (versus the pro tree) there's no problem. I know there's a potential weakness in the overdrive unit, many of us were running the 4L60E without the overdrive. It will be interesting to see how the new 4L80s work out.

Anyway, if you need advice on any type of transmission issues you won't find a better place then RPM Transmissions.

Tsab · 08-19-2007, 02:06 PM

Jerry, an air shifter?

That must be super trick man

Sounds like the Pro 10 competiton just got tighter. I guess you won't be driving the car downtown for a cup of coffee anytime soon?

JerryL · 08-19-2007, 04:26 PM

Tom,
The air shifters are common in pure drag race cars. I have the same type in my super gas Cavalier shifting the Powerglide.

Tsab · 08-19-2007, 09:09 PM

I like it

I'll have to check out the set up next time at the track.

asmokegars · 08-19-2007, 10:37 PM

Congrats on joining the turbo400 club. You will love it I'm sure. What gear are you running in it. I have a 3.42 and have been toying with a 3.15.

Paul_Z06 · 08-20-2007, 12:04 AM

Well, you either race or you phuck around...... I quit phucking around after the first unsucessful "season"

JerryL · 08-20-2007, 07:59 AM

Quote:

Originally Posted by asmokegars

Congrats on joining the turbo400 club. You will love it I'm sure. What gear are you running in it. I have a 3.42 and have been toying with a 3.15.

Alan,
3:42 with a 2.75 first gear in the 400.

asmokegars · 08-20-2007, 10:37 AM

Quote:

Originally Posted by JerryL

Alan,
3:42 with a 2.75 first gear in the 400.

Very nice Jerry!

Look forward to seeing you run that combo. I think you will be an even more formidable competitor.

Emuffinman1 · 08-20-2007, 10:41 AM

RPM is the best! Jerry, good luck at the track. Paul

STEALTH 99 C5 · 08-20-2007, 04:20 PM

Good luck with it Jerry , an RPM built 400 should be indestructable . Are you going to Carlisle ?

NICK YOSKIN · 08-20-2007, 05:18 PM

todd and rodney are awesome!

JerryL · 08-20-2007, 09:50 PM

Quote:

Originally Posted by STEALTH 99 C5

Good luck with it Jerry , an RPM built 400 should be indestructable . Are you going to Carlisle ?

Thanks Mike. Weather permitting I'll be there on Friday.

tensecvet · 08-20-2007, 09:51 PM

Nice Job Jerry

RPM sounds like they did you right