zoltan944

ya, don't tune down the fuel, turn UP the boost
those really are great #s for an 81tho, seeing as tho there isn't much 'modifications' out there for them! Im anxious to see the 10psi results!

hacker-pschorr

It's going to be a while since July is a very busy month for me. No more car wrenching (knock on wood.....) just a lot of driving and trips to Road America.

10psi with proper air / fuel and SS manfolds should exceed 350rwhp.

With 2:73 rear end 5-speed - this damn thing is a tire shredder

PorKen

Git 'er dun!

WesM951

Wow, those are some nice numbers hacker. Next time i'm up that way i'll have to stop by for a ride.

AO

Sweet numbers. Have fun!

toofast928

Nice #s Hacker!
I the believe 4.5L is capable of 400 HP.

hacker-pschorr

Rear wheel hp? That's what I'm shooting for.

Imo000

impressive number!

Sounds like you running an FMU to controll fuel under boost. To bring the final pressure down you can switch out the spring and the diaphram for a smaller ration. This should bring down the fuel pressure under boost. Going with higher boost and having the FMU with the exisitng ration will make the problem even worst.

Bill Ball

Yep, that's why I got the supercharger - so I can run open road racing with the AC on.

hacker-pschorr

We know how to dial in better air / fuel - This is the Corky Bell unit which is easier to adjust than the standard Vortech units (no need to swap out any disks). If we turned town the unit for less fuel up top, it was too lean down below. There are a few different ways to adjust this unit - it was getting late so we "settled" for what I posted here.
We set it at the happiest setting for overall driving. Sure I could have cranked out an even more impressive top end number playing with the timing and top end fuel pressure (or the old dry ice on the intercooler trick). It wouldn't have been realistic.

Jim R.

Nice Numbers!

With the 2:73's that car must be a blast to drive.Might want to use a different ratio boost:fuel disc in the SFMU (if that is what you guys are using)-but you guys already know that.


Jim

hacker-pschorr

Talk about a grannie gear. I'm actually thinking about installing a 2:20 trans. 1st gear is almost useless now. Or I just need to learn how to drive.

We (Tim and I) started with the standard FMU from his kit. My car was not a happy camper. Under vacuum it was way lean. So I installed the Corky unit (TIm had one lying around, figured, what could it hurt) this allowed me to preload the fuel under vacuum - bingo - now safe to drive, them my clutch fell apart. Eventually finding out my massive air leak (still not willing to admit publicly what I did to cause this 100% my fault during my head reinstall) - so now looking back - the standard Vortech FMU should have worked fine, but this air leak was screwing up my stock system making the boosted numbers even worse.

So now that I know everything is 100% good to go, I can go back, rethink the setup, go from there. I might try putting the vortech unit back in.

So this is not a SFMU like Tim has on his 88 - it's the sliver space ship looking FMU made by Corky Bell. They pretty much do the same thing, I think.

anonymousagain

Nice numbers Hacker !!

Bet the manifolds alone will help significantly to let 'er breeeaaath.

Gotta imagine that thing is rediculous when you shift --> 321.7 rwtq @ 3,915rpm, with 2:73 rear... 2nd gears done, clutch to 3rd a-n-n-d neckbrace please !! That's a serious E-ticket ride !!!

BC

hacker - think clearly now - Rick can ship you steel MSDS 2V headers for 425-450 - he discounts them for me the last two times.

SMTCapeCod

I have a spare one of those "spaceship" FMUs..uninstalled, intended for boost referenced applications. Cartech/Begi. Email if interested, retailed around $250 I think.