Quote: Originally posted by 83 Crossfire TA Do you have any more details on the car? There seem to be quite a few interesting things going on there. High on my list of things are the choice of the th400 over building up a TH200-4r or a TH350, or even a TH700. All of those would have had a packaging advantage in an f-body, and the 400 has the big disadvantage of being a power hungry pig and not really playing nice with anything else (what did you do with the TA…). I'd be happy to share any details about my car, but I'll stick to answering more specific questions scince I can write a book on everything I've done so far With regards to the tranny, I went with the TH400 mainly because I could build it and freshen it myself and scince I drive the car to races and events I wanted a trans that was pretty much gauranteed not to blow up and leave me stuck. I know I was giving up a good deal of rear wheel power with the 400 over a 200-4R but didnt want to spend thousands of dollars on a transmission that would probrobly still blow up eventually, especially considering that I launch at 4000rpm(@20psi)off a t-brake. Sometimes I wish I had gone with the 200-4R though as I'd probrobly be closer to if not at 130mph with the reduced power drain and lockup converter. One good thing about the TH400 is that the distance between the bellhousing and the trans mount is the same as a 200-4R so I fabricated a duplicate of the 2 pc TTA trans crossmember(thankfully I have access to a full metal shop/machine shop at work). Normally there is a provision to mount the torque arm to the crossmember but I left that out and went with a Jegster torque arm which bolts up in the driveshaft tunnel.I've attached a pic of the crossmember. For a driveshaft I had one custom made from the driveshaft shop out of 3" aluminum. After I split the aluminum one in two I had them make me up one out of 3" chrome moly with 1350 series joints and everything spicer which seems to be holding up well. I also run Mobilfluid424 high torque tractor hydroulic fluid rather than ATF which I feel really helps deal with the heat created from a transbrake. The last problem I had to tackle is getting the speed sensor to work, which I used Caspers Electronics dead end speed sensor and conversion box to operate the speedo and make the ECM happy. In the end I belive all the other tranny choices give up, to some extent, reliability where as the TH400 may cost you some power but it proven reliable and will get you home. Steve

ive seen his car in bellmore and on DPA and talked to him in person a few time over at bellmore, 83crossfireTA, steve knows what hes doing and his car moves....

Bah, Steve only THINKS he knows what he's doing

Damn, I need to keep quiet since he's rebuildling my TTA wiring harness lol

Steve, I thought you were still running that hydraulic fluid....how'd the trans look the last time you tore it down? I'm considering that stuff for the 7004r.

Thanks for the post…

Sounds about like what I was thinking. If you can snag a good, short tailhousing TH400 it's bulletproof pretty close to stock, and can be rebuilt by any monkey for a fraction of what something like a 700r4 or 200-4r. Parts of me wants to stay with the 700 that I have, but I'm not extraordinarily excited about having to treat a tranny as a wear item and the fact that they can't really be built to hold any real power in OD severely limits their usefulness in a somewhat well powered turbo car (since steep gears aren't really necessary to run fast with a turbo and decent displacement).

One the real debate there is can a TH350 be made to live under similar conditions? If it can it would be a better choice. I realize that it would require more aftermarket parts to get it to a reasonable point, but once you're there rebuilds shouldn't be any worse then the 400. The part I'm not sure about is if the 350 could ever be made nearly as happy to deal with serious abuse at the 400 without spending MUCH more money.

Is that the one you made in the pic? That looks a lot like the factory stamped piece… If you have the resources why didn't you just go tubular?

Do you have any pics of the jegster setup? Usually I'm somewhat anti most aftermarket TA designs, but obviously it's working at least OK with the 60's that you're running. When it comes down to it, if you can hook without skying the front hoops you'll go faster…

How different is the DS length with the 400 then it is stock? I was under the impression that a stock DS could be used…

How do you like the stuff? I've got a friend that swears buy it (or the valvoline equivalent) in a few of his more oddball cars. I may have some incomplete info on it, but I got the impression that it was fairly similar to atf but minus the detergents. Somewhat like running Type F. Should work well short term, but I'm not sure about long term, ford trannys running type F used to have all sorts of problems with gunk buildup.

Strange question… what would you like to change about the car if you were starting over?

huh, just had another question about it... what stall converter are you running?

I've been told the Th350 can be made to withstand the power but I dont know what kind of modifications that requires. All of my experiences with TH350's in performance applications have been bad. I have been told however that the TH350 will not stand up as well to really hard transbrake launches as the TH400 does, and scince I planned on launching as hard as I could off the brake that ment alot to me. And when it comes right down to it even the case is stronger. I'm going on my third season with this tranny that I have not freshened or did anything to except change the fluid before the season starts. I have taken it apart during the off season just to see how it's holding up and every time everything looks like new. If your thinking about doing your own tranny I reccomend the book "How to Work with and Modify the Turbo Hydra-matic 400 Transmission" by Ron Sessions.

Yes that is the crossmember I made in the pic, belive me there is alot of welding and grinding done there to get it to be pretty much an exact copy of the factory part. Making a tubular one would definatly look more like a race part and probrobly would have been easier to make, but I have an unusual quirk with this car in that I like to keep the car looking like the factory would have, or could have built it. Not to mention I went through great lengths making this car as much like a TTA as I could, doing things like swapping 1LE front brakes(from a parted TTA), getting all of the original TTA harnesses for the engine and dash to make the motor and the original TTA instrument cluster work.

I dont have any pics of the torque arm at the moment but I'll snap some pics in a day or two(I have to get some measurments on my intercooler too while I'm under there). I agree with you in that I dont like most aftermarket torque arms(the spohn one's in particular)but have to say I think this one does a nice job of keeping the tires planted and keeping the car from squatting hard(and wasting energy). Rather my car seems to lift up all around and launch forward, I think it's one of the reasons I get low 60fts but keep the front wheels on the ground. Plus not having to mess with the torque arm when pulling the trans is a nice perk.

How different is the DS length with the 400 then it is stock? I was under the impression that a stock DS could be used…

I dont know the length of my shaft compared to the stocker but belive it would have to be about 3/4 shorter than a TTA driveshaft, because the TH400 is 3/4 longer than the 200-4R.

I dont know about the Valvoline or anyone else's equivelent to the Mobilfluid 424 but I swear by the stuff too. It is supposed to have all of the properties of ATF but have a higher flash point and can withstand higher temperatures without burning/breaking down. Plus I'm told it has better viscosity throughout the temperature range and has a better ability to cling to hard parts like the planetaries helping keep the lubed and cool. As for it's effect on transmission life, I havent had a problem yet and all I do is change the fluid every year before the season starts. And while some people call my car a race car it definatly sees more street duty than some street cars. Tony can attest to this, I drive my car alot, and I drive it pretty hard(I never really take the ET Streets off unless I'm going over 100 miles away, and even then I might leave em on). So far it's been spotless inside.

I have a PI vigilante 9.5" converter, it stalls around 2600-2800 with no boost but scince turbo motors are basicly variable power motors the higher I bring the boost up against the brake, the more it stalls. I usually launch against the converter around 4000-4200rpm with 20psi boost.


Thats actually an excellent question, I think the biggest thing I would do different is I would have selected lighter parts, like maybe tubular subframe connectors instead of SSM connectors and chrome moly cage rather than DOM mild steel. Keeping the weight off would make life so much easier on the drivetrain.

Partswise I'm happy with the power the motor is making, though I shoulda gone with the bigger injectors right from the start and I would probrobly go with a slightly larger turbo from the get go(maybe a PT70 GTQ). I definatly want to go with a lockup converter and may do that eventually if I can find the extra money. With these low rpm/high torque motors I really belive in the concept of a lockup converter to help eliminate converter slippage, keep the rpm's down, and put more of the power to the wheels. And I shoulda went with the 3.42 gears from the start also.

Steve