What is the best transmission for racing applications, and where would a person go about getting one for an 84?

I've been searching around looking for good info on dog boxes and whatnot trying to figure out if I want to run the standard transmission or go full race on it. But so far my searches haven't come up with much.

 

unless you're spending tons of cash on your vehicle program, stock is the way to go IMHO. Easier to get parts, cheaper, and less hassle.

 

The only problem with stock is rally + stock = scrap metal.

Or thats what I have found digging through a bunch of news articles and other forums. But this is the only forum so far that I have found with any knowledge conserning putting the 7 up to race standards.

 

http://www.rotorsportsracing.com/per....htm#dogengage

 

Rules for a given class typically make this decision for you.

 

This is a description of a tranny that was just sold over on the production forum:
" Saenz TC 840 Dog Ring Transmission
-This transmission has 1 season on it since new
It has custom gearing that I picked after extensive research that works perfectly at Mid-Ohio and any other track you want to run at.
I have had all of the gears REM treated which is a high polish treatment which reduces friction and gearbox temperature.
This transmission has the adapter plate and removable bell housing attached and is a direct replacement for a stock transmission. When I say direct I mean the input shaft, driveshaft output, and length are identical to the stock transmission. A slight modification to the top of the tunnel is all that is needed to make this transmission fit your first gen. car. It also uses the stock transmission mount.
The best dog ring transmission for the money. Over $5500 invested.

$4500.00 SOLD "

This was in a first gen. THe guy who sold it is Jesse Prather. I'm sure he could hook you up. pratherracing.com , great guy!

 

Try http://www.coloradoscca.org/prodcar/index.php

improvedtouring.com

Look for the GT forum, I don't know the address.

BTW - There was a guy selling a first gen tranny that said he had $8500 invested in it a while back. I would laugh but I might find myself in his shoes someday.

 

well, this isn't SCCA ground anymore.

SCCA dropped rally, its all NASA classifications now

http://www.nasarallysport.com/rules.html
And because I am (hopefully) upgrading my rear drum brakes to disk on the FB, that means I will be required to run in the Modified. And because the a/c and a couple other stock features didn't work when I picked the car up, that rules out the Super Stock classification.

And dear god, I hope that I never get to $8500 invested in a transmission.

maybe I should just pick up a couple dozen stock transmissions and run them until they crater for that kind of a price.

 

Kind of sucked that SCCA droped it. It's got the rest of us thinking that club racing might be next.
I've got a couple of spare tranies myself.

Are you going to turn your fb into a 4WD? I guess Rod Millen (not sure if that's right or not) used to run one back in the day.

 

Rod Millen ran an FB rally car, yeah. Don't think it was 4wd though. I have the specs of his car, it isn't that far off from stock, some drive line mods, reliability mods and not much else. I personally think it wouldn't be half as fun in 4wd car, especially an FB, and at this point I'm not prepaired or set up to do that kind of fab work.

Any spare transmisions you want to sell then?

 

Guru motorsports in Australia make Dog Boxes for RX7s which use a standard case with a dog engagement gear set which are worth about $6500 USD And these things are virtually un breakable!!!! i was testing one in my street car which runs 9.30@150mph down the 1/4 but they also have a rally version !!!

 

But rear disc was available on the FB's.

 

rwd cars plus rally = scrap metal.

unless you mean road race on tarmac instead of offroad.

 

J.W. Transmissions is making an adapter to mate a Jerico tranny to the rotary. Jericos are probably the strongest tranny out there, and can be purchased used for around $2500.

 

They were available on FB's, but not mine.

The rules state

"No updating, upgrading, or backdating of the car is allowed."

In otherwords, I can't legally change out the rear end to a GSL or -SE and still stay in the Super Stock classification. But, if I wanted to smudge the line a bit I'm sure that I could get it past the "scrutineering" since I don't expect any of them to know the difference between the FB models.

Only if you don't learn how to drive your car first.

4wd + rally = scrap metal
FWD + rally = scrap metal
rally = scrap metal.

It doesn't matter what configuration that you drive, a tree is a tree and if you hit it, the car is scrap. Even the pro's scrap out cars. All you have to do is look at the 2003 season to see that. Every one of the top runners rolled at least once, and the vast majority of them totalled one car. Its just the name of the game, and why I'm running FB's, they are cheap if they aren't in very good condition. Like the one I'm turning into the rally car right now, it had previously been run under a semi and had a junk hood but still ran perfect.

 

I'd consider that more of a lateral move than an upgrade. It doesn't really make sense otherwise. I'd definitely chat with a tech. inspector.

Rule interpretation is certainly part of the fun.

 

The biggest problem with any street transmission is that the ratios are too wide for racing. When you shift gears, you fall out of the fat part of the torque curve, and the car is a slug until the revs get back up to make serious torque.

I road race, and over the years went from street port to peripheral port. Even with a street port engine, I was amazed at how much acceleration I gained from having a close ratio racing transmisssion.

It is going to cost you at least $1500 to come up with a used close ratio racing transmission. I have about $6000 invested in my current G-Force GF-5R transmission.

With a good racing close ratio tranny, you will always have the right gear ratio to pull out of any corner and keep the engine well into the powerband. The more modified your porting becomes, then the closer the gear ratios you need to keep that engine singing.

 

He ran first and second gen RX7's in 4WD.

 

I competed in a first gen RX7 in rallying for 4 years. I ran a stock transmission with the Racing Beat heavy duty clutch, and never had a bit of problems (4 years of rallies, remember). I didn't find any problem with the ratios for rallying. I had a street ported engine that I ran to 9k rpms, and my power band came on at 4 and was still pulling hard at 9. A 5000 rpm powerband is more than enough to compensate for the "wide" ratios of a stock tranny. Remember, too, that on gravel, it's not as critical as in road racing to be in the powerband. On loose surfaces, you have far more possibility to spin the tires if you engage hard in the "sweet spot" of the band. So shifting coming out of a corner, and being at the bottom edge of the power band (and working your way up into it through acceleration) is not necessarily a bad thing, like it is in road racing.

Send me an email and I'll tell you everything I did with my car.