2276 turbo, how much transaxle for the road?

[juki48]

engine's running, now I need a gear box. the engine is a 2276 turbo built for lower rpm's and high torque. cam runs out by 6k rpm. based on similar engine's dynos and my 0-60 time I guess around 180hp and 190lb/ft torque at 6psi. I plan to turn up to 10 psi, closer to 200hp. This is a semi daily driver, couple days a week to work and evening/weekend cruises. i currently have the stock 74 ghia transaxle and like the gearing. this is a single side trans, probably the only reason it's still together. my question is, what do I need to get so I can feel confident when I get on the throttle. Don't want to drag race, just want to have the freedom to tromp on it, break the tires loose a little and not worry about my gear box blowing up.

[MinamiKotaro]

Four-spider diff, race axles, and coarse-tooth 3rd and 4th should take care of it. I went a little further with a Rhino case and 100% Weddle internals.

[juki48]

is a chinese 4 spider diff really better than the german one in there? I get the whole 4 gears instead of two thing but unless the tolerances are really tight I don't see how all 4 could bear the load at once.

type 1 race axles or do i need type 2 or 4? and how do 930 compare? Do thing axles fit? sorry for all the questions, I've never had to dive into the drivetrain before.

[MinamiKotaro]

is a chinese 4 spider diff really better than the german one in there? I get the whole 4 gears instead of two thing but unless the tolerances are really tight I don't see how all 4 could bear the load at once.

type 1 race axles or do i need type 2 or 4? and how do 930 compare? Do thing axles fit? sorry for all the questions, I've never had to dive into the drivetrain before.

Oh, right, you are IRS. I'm swingaxle. Somebody else will have to chime in on whether you need bigger axles or not.

[juki48]

anybody have advice for axles?

[sideshow]

Stock IRS axles are tough, if you are at stock ride height I would assume it is rare to use anything other. The breakage tends to come from CVs and lots of angles (off road), that require better CVs.

[Chip Birks]

If you can get Thing stubs and drive flanges, you can use t2 CVs which is money well spent. Type 1 axles will probably be fine. Although, if you can just use the whole thing axle setup, you will probably be a little bit ahead. As far as the gearbox is concerned minami's advice is pretty much spot on. Unless you are planning on actually launching the car, a mildly built setup with super diff will do you just fine. Can't go wrong going with a 3.88 r&p. If you have the cash, and someday intend to actually beat on it, put some real gears in there. I built a pretty nasty box for mine, but also planned track time. Weddle 1-4, 3.88 R&P, spool, SAW axles, all in an Aluminum Rhino case. $$$$ but I haven't hurt it yet, even launching the car off the 6.5k limiter on slicks, making 278whp.

[juki48]

have any of you had the fine tooth 3rd and 4th fail? I've got my trans at the shop, trying to figure out what to put in it.

[Pablo2]

is a chinese 4 spider diff really better than the german one in there? I get the whole 4 gears instead of two thing but unless the tolerances are really tight I don't see how all 4 could bear the load at once.

You are correct, juki .. only 3 of the spiders are sharing the load in any of the cast iron 4-spider diffs that I have checked. But at least the IRS diffs don't self-destruct from lack of oiling like the swingaxle ones do (at least I don't think so).

You are also correct to be wary of the fine-toothed Type I gears. While the later 091/094 fine-toothed are pretty stout, I wouldn't trust the Type I fine-tooth gears.

[56speedster]

have any of you had the fine tooth 3rd and 4th fail? I've got my trans at the shop, trying to figure out what to put in it.

I have. I think I still have them in the garage if you'd like to see a picture. There are only a few teeth left after spinning. I went with the welded coarse tooth gears and abuse them every time I drive it.

[juki48]

of course I want to see pics! what trans was it? did they spin or did the gear teeth strip? I'm told the AT trans has welded hubs but the fine teeth are weaker.

[56speedster]

Stripped gear teeth from AT code trans.

gears.jpg

[juki48]

ouch. that's not pretty. did you use weddle gears or bus gears when you fixed it? also, is a .82 4th with a 3.88 r/p a bad idea? I know i've got the power down low to pull it but I worry about cooling. that would put me at 2645 rpm at 60mph, which is where I do most of my driving.

[56speedster]

Welded coarse 3rd and 4th. I have the 3.88 with the .89 fourth and thought about the .82 fourth and am glad I decided on the .89. I do most of my commute to work at highway speeds and have no complaints. I would suggest the .89 and definitely have the power with the turbocharged 2276 to pull the .82 as well but really wouldn't want a larger jump from third to fourth than what the .89 provides. It's easy enough to pull past the 120mph mark as it is so there's really no reason (in my opinion) to need much more top end.

The Speedster is pretty light at 1600lbs and cooling is perfect! Not sure how heavy your car is and am only suggesting the .89 as it works well for my setup and I believe it would work well for yours as well. If you went with the .82 and had cooling issues or concerns, you could always switch to the Porsche alternator pulley to speed the fan up a bit.

[Pablo2]

Juki .. for your other issue, reference these following discussions (passing this along to you here so as to avoid a total meltdown elsewhere) ..

http://www.thesamba.com/vw/forum/viewtopic.php?t=557933
http://www.thesamba.com/vw/forum/viewtopic.php?t=568339
http://www.thesamba.com/vw/forum/viewtopic.php?t=530289
http://www.thesamba.com/vw/forum/viewtopic.php?t=546488
http://www.thesamba.com/vw/forum/viewtopic.php?t=539881
http://www.thesamba.com/vw/forum/viewtopic.php?t=549819