Originally posted by cjnico1
A free flowing exhaust seems directionally correct also, but I don't know how this engine responds to changes. My car currently has the factory exhaust...Original pellet converter, and factory stock mufflers. If I went with a monolith converter (or even a straight pipe) and 2 1/2" pipes before and after the mufflers, would that make a significant improvement in performance??
Going to a steeper gear with a 200R4 transmission to imporve torque multiplication seems good too. Are there any of you out there that have tried this?? What about converting to a manual transmission?? I have a T56 aftermarket transmission laying around that I bought for another project car, but never used. Is this a good alternative??
I know the "stock" engine will respond well to a less restrictive exhaust. When I first got my 81, I removed the catalytic converter. The engine was challenged to get a max of 3 psi with the cat. Without it, it was able to get to levels around 8. Granted, with that kind of change, it would seem that my cat was *far* below optimal. But, like most engines, it can benefit from a better exhaust system. I would imagine it would be very important to monitor knock after making exhaust changes. If there's less exhaust gas in the cylinder, the tendency to knock is going to go up.
I'm in the process of installing a throttle body injection system in place of the Q-jet. I generally like Q-jets. But, the electronic version has given me more problems than I care to admit. I'm using an ECM from the Syclone/Typhoon since it already comprehends boost. Since my 81 was already equipped with an ECM, most of the sensors and wiring are already present. With available parts, it's easy to mount the TBI where the Q-jet used to be.
I've also installed a 200-4R transmission with a 2200 stall converter. The swap is extremely easy. To make things simple, I bought a new crossmember from Bowtie Overdrives. With this crossmember, the transmission bolts right up. I've also purchased a new detent plate for the shifter to support the "extra" gear selection. If you're creative, I'm sure you could fab up the parts above instead of buying them.
Unfortunately, I haven't completed the project to give you any performance numbers. The engine will start and idle. But, the car is still on jackstands waiting to get the gas tank modified to support the fuel injection needs. (Return fuel line and some sort of sump.)
While I've been doing this, I've been thinking about the mounting of the turbo. I've seen what 3rd gen F-bodies are doing to mount turbochargers. And, I think it would be interesting to try this on a 2nd gen. If there's a way to relocate the AC (assuming you have AC and want to keep it), I'd like to try to mount the turbo in that area. The advantages I see are .... 1) a potentially more direct (i.e. fewer bends) route to the bottom of the car for the exhaust pipe, 2) the potential to go "blow through" instead of "draw through" and 3) the ability to use an intercooler. I haven't tried doing this. But, I think it will be the next project after I get the TA off of the stands.
Let me know if you have any questions.