Doing a build similar to the Dans TRC build. Would doing a built trans with upgraded 3rd/4th gears be enough or is a dogbox required? Definitely dont want to go sequential.

 

1000 horsepower most certainly needs a full dog box, you might get luck on stock Tranny for a little but it’s a ticking time bomb

 

A synchronized PAR gearset will hold the same power as any dogbox and keep the synchronizers.

 

Liberty Gears (Detroit, MI area) builds a strong face-platted trans for our cars. I've been running one for four years in my car. I have a fully built, aluminum rod 2.0L with a Precision 6870 that regularly makes 45-50lbs of boost on the street. Last time I put the car on a dyno it had a 6466 on it at 44-45lbs it made 850whp on a dynojet. I know its making more than that now.

I recommend the Liberty Face-platted trans for those who want to never get locked out of any gear as we do with a synchronized trans, but also don't want to have the constant gear whine that goes along with a straight-cut gear dog box transmission.

 

"Enough" is relative at 1000hp.

At that level, everything breaks eventually. With street use, a dog engagement trans will actually need more frequent service than a (properly shifted, no grinding gears because missed the clutch) synchro trans.

I typed this up then remembered the meme of a car you're trying to build...

 

1000whp on a 4 cylinder is going to need a large turbo and the fastest shifts possible. A dog box with strain gauge and wide open shifts with a cut is also a good idea IMO. The last thing you want is a slow shifting trans and lag.

Dan's car is incredible and he shifts the H pattern dog box like no other. The guys at AG have dialed that car in well. Some of us fight lockout or clutch issues on h pattern dogboxes at some point. Dan is using a Exedy triple and If you are going H pattern dogbox I would duplicate his setup or get with AG.


Now,
After driving a sequential evo with a strain gauge setup/gear cut I can tell you its magic. No clutch needed for WOT shifts and no gears to miss. Its loud and a race trans but for making big power there is always a tradeoff. It has a Alot runs on it and gets inspected periodically. Another nice thing about a tall geared sequential is less wheelspin/drama. Its amazing how much power you can put down on a 245 drag radial on these cars .

Either box and setup will need to be setup well and looked after carefully.

 

What do you do with your car any track days or just roll racing and drag/cruise? How much mileage have you had on the gears and have you had to deburr it yet?

 

I don't know the mileage on the transmission. But, I have about 5 seasons (Early April through October) on it with plenty of roll racing each summer and some drag racing. I am pulling it out this winter to have it gone through as a maintenance matter, but it has performed flawlessly for me.

 

Sorry for bringing this thread from the dead.
Ive been doing some research on what next for my trans. I dont necessarily want a dog box but something close. I came across PAR Engineering and they make a gear set which is straight cut gears 1-4 with synchros. Anyone on here running this or knows someone personally who runs this and talks about it?

Before people start talking about the noise of straight cut gears I really don't mind. I have a roughly 9-1kwhp evo with a hood exit so noise dont bother me. I do not daily drive it as well.

 

If you have a hood exit exhaust, then you're definitely not worried about noise. If it were me, I'd just put a dog box in it. Even if the gears are stronger with that PAR gear set, you're still going to struggle with lock-out issues at higher rpms, which is where I suspect you're spinning it since you're making close to 1k horsepower. Get a non-synchro transmission and don't look back. They shift amazingly well.

I've learned to drive mine like a fully synchronized trans around town with buttery shifts and hardly any noise. Double-clutching it while just puttering from stop light to stop light and it shifts perfectly fine with no noise.

 

Ya ive seen in some previous posts that you ran a liberty gears faceplated gear set. I mentioned it to a good friend and he said you might as well go dog box. You maybe right. BUT I also have the huy tran lock out shifter so there's that.

So you switched over to a dog box huh? I remember we had a very similar build. 2.0LR with 6870 spinning it to 50psi. so you like the dog box? Drivability isnt bad? You said you just double clutch when cruising the streets? How's the maintance on it?
thanks for responding