I'm putting a S5 TII in my vert over the next few weeks and was wondering if the na drivetrain is up to the task, or am I better off getting the TII tranny/driveshaft/and rearend?

 

I turbo'd my '91 about 2 years ago. I left the 6 port (yes, 9.7 to 1 CR) in the car, though. I took a T2 lower intake, and burned a couple of pounds of 4043 aluminum welding rod into it with the TIG welder, then machined the flange for the 6 port configuration. It actually turned out really nice after a little porting on the manifold. I did not install the 5/6 port slide valves. I removed the stock fuel injection and went with a programmable unit. The turbo and manifolds came from an 89 T2. Used a Starion front mount intercooler with my own 2 3/4" aluminum piping.



It ran really strong, although the turbo didn't flow enough to hold the boost much past 6000 rpms. It would peak at about 12psi at 5000, then by 7000 it was down to about 6 or 7 PSI. Still, it ran very strong!



Here is the damage list in order of occurence:

1. Was running a "sport" grade of clutch - when cold would slip really bad under boost. Once everything got warmed up it would hold ok.

2. Transmission suddenly started making a hammering noise while I was accelerating hard in 3rd gear. Babied it home, with it clacking all the way. Made it most of the way up my driveway before it completely stripped the gear. Basically ate all the teeth off input shaft and countershaft.

3. Accelerating hard in second - about 6000 rpms and 10psi boost there was a sound like a gunshot, then the engine went to rev limiter. Huge oil slick behind car. See picture below of what I did to my GTUs 4.3 diff!

4. Engine started using coolant and steaming on startup. Got disgusted and left it sit for last 8 months. Finally pulled engine and found signs of the rotor housing moving against the side housing - too much boost for my compression ratio!



After all that I am going to go back to non turbo. I decided to go with a little porting, and see how nice it is to be reliable again. I hope to be assembling an engine within the next week...

Jason

 

EEEP! I guess I'll go with the whole driveline then! I really like the reliabilty I've had with the 8 n/a Rx7's Ive owned, but the TII was so much more fun, to me personally. I only want an intake, dp/3"exhaust<nocats>, and a junkyard IC...volvo maybe.

 

Wow JLB! Yeah don't use an n/a drivetrain with boost. You seem like you have a lot of skill, portmatching the manifolds in all. Turboing an n/a motor is not the way to go, they can only reliably handle like 7 lbs of boost.

 

Yeah, I knew I was pushing it going in. But, I am not happy unless I am building something different or doing something people tell me not to try. I was really afraid of the high compression, and it did turn out to be the final weak link. But, on the other hand, it was an engine that I built out of a couple of freebie junkers (NA rotors and side housings with TII rotorhousings) and all I added was a new set of stock apex seals and a water seal kit. I got around 50k miles out of it starting out totally stock, progressing to my own version of a Paxton kit, and then finally going to the turbo with starion intercooler in front.



I actually am a very "gentle" driver, and hoped that the driveline would live if I didn't abuse it. I don't think I ever spun the tires from a standstill, no catching second, etc and yet it still didn't live.

 

did you also take out some of the vacuum nipples? I was wondering if I could cap those off and not worry about them.

 

Ok, one more pic of it in the car... This shows more of the weird stuff I was playing with. If you look at the Ignition you will see an early 80's distributor but it doesn't have all the plug wires connected. Then, if you look to the right you will see a normal second gen leading coil and a standard coil. I used the leading ignitor on the dist to fire the dual coilpack and plugs directly, while the trailing ignition worked through the standard coil and distributor. I was shocked to see that a distributor would squeeze in past the accessories!



The radiator is a stock '91 radiator. When the top tank cracked I pulled both tanks off. I was rather annoyed to see that the core was in GREAT condition. So, I made new tanks out of aluminum and welded them on... I don't think I'll have to worry about the plastic cracking again! Plus no more seal issue with the O-ring at the filler neck - that thing was a poor design!



Well, sorry to get off subject. I'll stop now!



Jason

 

a lot of custom work, nice!

 

Thanks!!! Yes, I did remove about all of the stock vaccuum ports. I used an aftermarket fuel injection so I stripped all the emissions stuff off. Not sure what you will need, though... I would think very little with the E6.

 

yea I'm just unsure and can't really get striagh answer of what all those vacuum ports do..... I am running premix too, I was under the assumption that some were for equal pressure across the vac lines. Hey do you still have the turbo---n/a manifold? I might be attemting something like this with a friends car in the future, and if you still got it, maybe I could buy it from you later on?