Racing tranny
 

Is there anyone who builds a road race tranny for the FB or FC ???

Steve
racerguy19

For $3-5K there are a few options, how much do you want to spend? Syncros? Dog ring? Rules?

Well it depends on if you want a stock tranny with diffrent internals or if you can make modificiations to adapt a diffrent tranny. Im running a Liberty Gears Tremec TKO600 transmission and im quite happy. Now i guess i have quite alot more HP then you will have and twice the displacment or more so i need a powerfull transmission.

But you do get quite alot of gearsets for the FD and FC transmissions. But they are quite expensive. And a Tremec transmission is not that expensive. And Liberty Gears do now make a bellhousing that will fit a 13b engine.

JT

I race at Mosport International Raceway in Ontario. It's bracket racing GTsprints, so the faster you go, the higher up the GT ladder you go with GT1 being the top. I am currently in GT4 with a B-port 12a and a car that weighs about 2000lbs.

I have gone through syncro's in 3 trannys in 2 seasons and want something beefier. I will spend what I need to get a good working tranny, but I am funded out of pocket like most weekend racers and $5k for a tranny is rich.

Steve
racerguy19

t5 with stright cut dog rings would be one hell of a trans, pretty cheap tooWanna say the trans used to be around $2000 or $2500 . Damian is running one in his FD You can use the following ratios
3.22 2.94 2.46
2.05 1.94 1.54
1.34 1.34 1.22
1.00 1.00 1.00
0.90 0.90 0.90

They have some other 5th gear ratios but they are available in syncronized only. They also have helical gear dog ring setups for the t5 as well which would be a bit quieter.

There's a bunch of options, both of newish manufacture and some vintage stuff. The old Mazda PBS competition dogbox works pretty well, I've seen a few people using the Saenz gearboxes (Prather used to at any rate) Taylor Race Engineering has a box based off Hewland Mk5 internals (probably somewhat marginal at your power outputs though) and I have another friend who is engineering his own similar thing... we're running an old Mandeville - Leeson crashbox ourselves.

None of these, however, are inexpensive options *at all* unless you get a good deal on a well used one.

I have a G-force T-5 dogbox straight cut trans and love it! the gearset is 1800 if u have the know how to install it urself. I built mine wasnt bad job. Talk to jason at G-force http://www.gforcetransmissions.com/
(717) 202-8367

They also have nice deal on old rebuilt nascar 4spds any ratio u want

Bill also runs one is his 240 time attack car http://www.youtube.com/watch?v=id2f4DO2hyc

I went with a GF 4A trans... it's a used NASCAR trans that has been rebuilt. It's a clutch assist trans, clutchless upshift and standing start. Just about any gear ratio you want is availible.

G force will figure out your needs and get you something, great guys over there.

Like Ryan said... talk to Jason.

"I have gone through syncro's in 3 trannys in 2 seasons and want something beefier"

Were you using fully rebuilt, every bearing replaced $900 pro built stock transmissions, or were you using something cheaper?

Transmissions take quite a bit of abuse racing. Not even the highest dollar race transmission will last forever - all road race transmissions need maintenance. I am using a high dollar race transmission, and it needs rebuilding occasionally to keep it in top form. One difference between the pure race transmission and stock transmissions is that the real race transmission has never failed to get me to the end of a race.

To add to speedturn's post; if you get into a dogring box thinking its something you put in and forget don't do it. Everybody that I know that has one has it apart all the time. Its either for swapping ratios or upkeep but its always something. If you skimp on upkeep it will end up costing you big. I have one friend that has put $3000 into a $5000 box just to make it right. It was an early Elite box and they weren't that developed. They are now made by another company, Taylor IIRC, and they have them pretty well straightened out.

Maybe you just need to lower the gear ratio? You could do that with a rear end swap. Are you redlining? (I'm not sure what kind of speeds you see). Anyway, that would reduce the stress on the tranny and maybe make you quicker all around... Just a thought.



.

I have the stock 4:10 LSD rear end and the car will do about 220kmh (about 135 mph) up the back straight.

I don't have a speedo in the car, I red line it at 8000 rpm

What car do you have?

U should try going with a 4.88 perhaps in the rear. I know alot of first gen racers use that.

This looks like the appropriate thread to tag onto ...

I, too, have gone through 3 trannies in 2 seasons.
Our Pro-7 rules do not allow anything other than stock boxes and it's much cheaper to buy a wrecking yard trannie than even have one rebuilt.
One box was replaced because of bad bearings, but two of them had synchro issues due to clutch balking and me forcing the issue.

The clutch is a 4 puck with no springs. The pilot has been replaced many times and runs free. The p/p is original to the car and appears to work ok.
The splines on all transmissions have been burr-free.
When it balks, the p/p spring force and hydraulic pressure feel fine.
However, I simply cannot get any gear to engage. After engaging/disengaging the clutch many times it will finally goes in, but it doesn't appear to have anything to do with the number of pumps.
I've variously tried straight 90 wt, 75/90 and synthetics.
It appears to do it more often during the first few laps of the race.
It has done it with every transmission, so that pretty well rules out the trannie.

The Mazda performance manual talks about placing a 1" block under the clutch pedal to keep the p/p form going over center at high rpms (I shift at about 8700). I haven't tried that yet. It appears the p/p is the next in line for replacement but the why it's doing this bugs me as p/p usually flat ass fail -- they don't usually "act up".

^Are you sure your hydraulics system is in check?
I leaky master or slave cylinder can keep a clutch from fully engaging, making it difficult
or impossible to go into gear. If you pumped the clutch, it would eventually build up
enough pressure to engage and let you into gear.
Just a thought.

Thats actually very true and the main reason why I grind. Should really get on my ass at fixing that before I kill a gear or two

I had that thought as well.
I'm not losing fluid and even during the heat of racing it doesn't feel any different. The pressure on the clutch feels the same. It's not like losing your brakes and having it go straight to the floor. Your eyes get real big when that happens, but the feel is also quite different. Not so with the clutch. Feels the same.
I wonder if during these episodes (which happen most frequently coming out of T3B at Pacific) if I'm not over-revving the engine causing the diaphragm clutch to over center and stay engaged.

In the book "how to hotrod and race your Datsun", it was mentioned that the racing teams used a 50/50 mix of gear lube/ATF. They claimed that the ATF provided plenty of lubrication, but also had lots of detergents that would clean up the synchros and keep them that way.

I've been doing this for 15 years now. I've never had an issue with it, and it has improved the shifting on every used car that I've tried it on. Might be a thought...



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I would go with the G-force T5 straight cut dog box as the most cost effective option . Im gonna go this route myself in the future. if you get luckey you can find a T5 in the JYD or mustang forums,break it down & send it to G -Force,get the ADPT plate& clutch . I would say you can pull it off for a lil under 2700 & if you use it properly you should have a gearbox that will last for maybe 3-4 seasons at , I would say 365 -450HP mark(Mar- NOV ) with regular fluid changes , & dont bang it toooo hard ,( with a cooler it may last a lil longer)& open it up midway just too look. Mechanical sequintial upshift FTW. Check out Damiens onboard you will be sold!!!! I like the idea of mixed fluids like the above poster said, I have doing a mix of a medium to heavy weight gear oil & a light engine oil, trannys are so clean inside & When draining particulate acyually comes out & It settles easier VS being suspended in 100% heavy gear oil & it flows through coolers better. HAPPY TUNING !!!!!