1968 Camaro "Badmotorfinger" v2.2

[Matt@BOS]

Originally Posted by Flash68

I considered lots of trannies... T56, TKO, M-22 Rockcrusher, Jerico.... but this fit budget and size and is bulletproof pretty much.

Dave, just a little warning given your penchant for going through transmissions - I've only ever driven one car with straight cut gears, but I was told to use the clutch as you normally would, because while the trans was designed to function without the clutch in the event of a mechanical failure, it was intended to be used with it. If I'm wrong though, and sound like an idiot, please correct me

Matt

[rwhite692]

Dave that T101 should serve you well, good choice!

[tones2SS]

Very nice Dave. Nice to see the updates for Badmotorfinger.

[coolwelder62]

NOW that's a real man's Trans.No girly tunner crap there. Frickin,awesome. Scott

[Flash68]

Originally Posted by 69MSA

Dave, just a little warning given your penchant for going through transmissions - I've only ever driven one car with straight cut gears, but I was told to use the clutch as you normally would, because while the trans was designed to function without the clutch in the event of a mechanical failure, it was intended to be used with it. If I'm wrong though, and sound like an idiot, please correct me

Matt

Hey Matt. I def have not authority to say you are wrong... or an idiot...
What I can say is I've spent the last couple months talking to all kinds of people on the subject of T101/Jerico dogbox trannies, and there were def mixed opinions on some subjects (using the clutch vs not, and clutch size/usage mainly). But most that I talked to who road raced -- and even 1 guy who built and maintained the T101A driveline for a Rusty Wallace Craftsman team for 8 years -- encouraged not using the clutch on the track.

Here is a video in a T101A thread on another forum I found, and what I will be trying to mimic on the track:






Oh, and since you mentioned I love to kill Muncies.... here is the current Muncie Graveyard at the shop.

[Flash68]

Originally Posted by rwhite692

Dave that T101 should serve you well, good choice!

Originally Posted by tones2SS

Very nice Dave. Nice to see the updates for Badmotorfinger.

Originally Posted by coolwelder62

NOW that's a real man's Trans.No girly tunner crap there. Frickin,awesome. Scott

Thanks fellers!

No girly crap here Scott! I love it! HAHA!

[senor_Camaro]

let me know if you would like to sell some of those muncies, I have some customers interested in 4 speed swaps.

[Matt@BOS]

That is quite the graveyard you've got over there. I'm just curious, but what is the logic behind the clutch/clutchless debate. I'd love to know a little more. I suppose the trans was designed around racing, seems like it was the right choice given what you do to the car, and probably won't be joining the Muncies any time soon, but I'm curious as to what maintenance is required. Do these last quite some time without a rebuild? I don't know much about the Jerico. I just know they're tried and true.

BTW, I think I know why you really went with this transmission. You don't have to heel-toe in your car anymore

Matt

[SBDave]

I could be wrong.... but I don't think this gearbox is straight cut gears, it's dog change. Dog change is a different style of engagement (most manual's are synchro). Dog change are more widely spaced engagement teeth on the gear and selector hubs to help with shifting at high rpm's. Done correctly you can shift faster because you are matching the rpm's of the gears and you are not relying on the synchros to match rpms which takes time.

You can still miss shift and beat the dogs up, but they are thicker than the synchro teeth and can take some abuse. The dog teeth are back cut so when you are on power they are locked together. When you don't match rpm's correctly you damage the leading edge of the back cut which if it gets bad enough (effectively ruining the back cut) allows the dogs to slip apart causing the trans to slip out of gear.

Sounds like a sweet setup! ....did you get it from racingjunk? I was looking for more info on the trans and found a wanted ad for one there.

-Dave

[Flash68]

Originally Posted by senor_Camaro

let me know if you would like to sell some of those muncies, I have some customers interested in 4 speed swaps.

That's a possibility. 2 of those are mine and 2 are Rich's. Actually only 1 has a broken gear. I'll talk it over with him.

Originally Posted by 69MSA

That is quite the graveyard you've got over there. I'm just curious, but what is the logic behind the clutch/clutchless debate. I'd love to know a little more. I suppose the trans was designed around racing, seems like it was the right choice given what you do to the car, and probably won't be joining the Muncies any time soon, but I'm curious as to what maintenance is required. Do these last quite some time without a rebuild? I don't know much about the Jerico. I just know they're tried and true.

BTW, I think I know why you really went with this transmission. You don't have to heel-toe in your car anymore

Matt

First thing I can think of is less of an rpm drop by shifting without the clutch and just lifting off the gas quickly. Beyond that I am not sure. I plan to street drive it before Buttonwillow and will try both ways.

Maintenance -- again, different opinions, but they are all pretty similar. The thing is... most everyone is using these trans in very heavy duty racing environments i.e. oval track, 200-300 mile races, or regular track days. I foresee 4-6 track days per year for me for the next year or so I can be a little less aggressive on schedule I would think. Every single person I talked to says to use Mobil 1 synthetic 75-90. Check/change fluid every 1-2 races and service/refresh every 1-2 years (or 1500 race miles. Uh, that's a lot).

And what do you mean I don't have to heel-toe anymore? I never did before!

Originally Posted by SBDave

I could be wrong.... but I don't think this gearbox is straight cut gears, it's dog change. Dog change is a different style of engagement (most manual's are synchro). Dog change are more widely spaced engagement teeth on the gear and selector hubs to help with shifting at high rpm's. Done correctly you can shift faster because you are matching the rpm's of the gears and you are not relying on the synchros to match rpms which takes time.

You can still miss shift and beat the dogs up, but they are thicker than the synchro teeth and can take some abuse. The dog teeth are back cut so when you are on power they are locked together. When you don't match rpm's correctly you damage the leading edge of the back cut which if it gets bad enough (effectively ruining the back cut) allows the dogs to slip apart causing the trans to slip out of gear.

Sounds like a sweet setup! ....did you get it from racingjunk? I was looking for more info on the trans and found a wanted ad for one there.

-Dave

Thanks Dave. I did get a few emails from racingjunk guys but they were either overpriced or not what I was looking for. Found this one on Memphis craigslist. I searched wide and deep!

Looks like you are partially correct on the dog ring vs straight cut deal. A dog ring trans can have either helical gears or straight cut gears, or a combination. Nice little write up here:

http://seacoastsubarus.com/forums/showthread.php?t=4916