Just replaced the anemic 256 blower with a 871 Littlefield and a whipple low pro intercooler. I am running an ecm tune from a similar setup and have an adjustable Fuel Pressure Regulator. Underdriven it should make 7 lbs of boost.

How much boost can I safely run (92 octane) with this setup?

If I flip the pulleys and ovedrive it, it should be around 10psi.

Jeb,
You'll need to run an air fuel meter to get this done correctly. I am running 10PSI without an intercooler (no room), so that shouldn't be a problem with one. I have aluminum heads so they do run cooler than the iron heads. Make sure you are using good head gaskets if you plan to run 10PSI.
Are you running my/Eric's program? If you are, my total advance is 30 degrees, and my static fuel pressure is 43PSI.
Regards,
Steve

Is the 871 taller than a 256. I don't have anymore room for height as I'm already running the whipple intercooler. Sounds like a better idea than running the smaller pulley like i'm already doing on the 256.


Called blower shop. Apparently quite a bit taller.

Yeah the 8-71 is quite a bit taller. Just put a 3.3 Whipple on it and call it good. You won't be sorry. It will outperform the 8-71 hands down and will fit under the hatch.
Eddie

Be careful with boost levels if you have steel heads and are running ethanol fuel. Ethanol fuel is not forgiving if you go lean.

You need to be around 12.0 to 1 AFR while in boost.

Call Mark at Precision and talk to him about what tune to run. He is the best. WWW.PMEFI.COM

Well I finally ran it this weekend and it turned out to be about 5.5 psi of boost...not as much as expected.

The fuel pressure was all over the place with the adjustable regulator. I originally adjusted it for 32psi at idle. The sender and guage were also new with the install. I am wondering if there is some air that rises into the sender and causes erratic readings?

Anyway, it started kicking a EST code 42...Electronic Spark Timing short. Never did get that figured out so the computer never took over to adjust the timing.

Jeb,
Save your self some time and money and get on I-65 south.
Set up an appointment with Eric. We've done this successfully several times.
Steve