I have a pullout 8.1 complete with wiring harness, computer, etc. going into a tube chassis 4x4. It will be bolted to a Turbo400 that has been built with rocks and my driving habits in mind (Meaning extra clutches, 900 stall, heavy right foot, etc). What I need to know is, what is the best bang for the buck for HP and TQ upgrades. (Headers, cam, etc.) I know that there isn't a big aftermarket following for this engine that's why I need your help. Also, does anyone here know where I can find a Marine version throttle body? They come setup for a throttle cable versus the stock drive by wire setup.

Thanks!

OMalley

 

I think headers would be a nice start... I think JBA actually makes a mid length for the 8.1L thats fairly reasonable on price. Then of corse the other usual stuff, cam, tune, etc.

 

I ran a Comp Cam gained 30rhp 50wtq. The guy I sold the cam to, dropped 2 sec off his 1/4 time with cam, tune, and exhaust. Use a standard throttle body for a small block, its the same as a marine 8.1l.

 

Let me make sure I understand you, A small block throttle body is the same size as a Big Block 8.1? Isn't that awfully undersized for the air requirements? Not trying to sound like a *****, but that doesn't make sense to me. Please enlighten me.

Thanks

 

yup, pretty sure they are same from the 4.8L - 8.1L

 

Thanks Linda! As for headers, does the JBA's come with o2 sensor ports? What about "the other guys"?

Thanks Again for the insight into something I know nothing about

OMAlley

 

Tie rod,
"I ran a Comp Cam gained 30rhp 50wtq. The guy I sold the cam to, dropped 2 sec off his 1/4 time with cam, tune, and exhaust. "
What other tuning do you do to a computer controlled engine? I have a Hypertech power programmer 3 for this particular engine. Will that address the comp cam? What particular cam did you run? Why did you get rid of that cam?

 

The main reason they share the same throttle body size, is the 8.1 does not turn the RPM the SB do. With the stock cam 4500rpm your done. Any big block header will work, you might have to weld in a o2 bung or might be able to order them with one. But all the header made pacifically for the 8.1 will have the prevision for the o2.
I ran Comps XR270HR, did a wonderful job. The reason I sold it, I had a nitrous backfire and blew a piston apart. I built a new engine and used Raylar heads, cam, intake, and crank. Sell the Hyperjoke on ebay, all it will do is add 4 deg of timing. Try Westers or Nelson mail order tune you will be much happier.
If you have anymore questions ask away.
Chris

 

I was told The Other Guys headers went out of buis?

 

Thats me.

Can you count a piece together exhaust from cats back?? granted was through stock mainfolds. And this was done with my own tuning with HPTuners. and ported TB, homemade ram air CAI

Also from what is sounds like, might want to go with hptuners or efilive for your tuning needs.