[flightlead404]

Originally Posted by sigchuck

Hi guys, I first want to thank everyone for documenting some extraordinary builds over the years. The information has been invaluable. I’ve read countless threads, the old BAE turbo manual, and Maximum Boost by Bell.

I have a stock (recently rebuilt to factory specs/9.3 CR) 1983 911SC. The horsepower bug is strong, and I’m considering adding a turbocharger, likely based in whole or large part on the BAE kit (thank you to Chappy for sending me a manual several months ago).

I would like to run without an intercooler/methanol injection, as I like the tail-less lid that I currently have. I know this will seriously limit the boost I can run, and I think makes it even more important to address timing and fuel enrichment issues that were not addressed all that well by BAE.

I would really appreciate any help with the following, very general questions that will hopefully help me decide whether it's feasible for me:

1. Will an adjustable (Lesak) or factory 930 WUR solve the enrichment under boost problem with the factory 911SC CIS?

2. Will fabspeed or rarlyl8 headers bolt up to my 911SC heads? Based off several threads, it appears the exhaust port sizes are the same on 78+ 930s and 911SCs, but a call to Fabspeed’s “tech” line indicated they won’t work. I use quotes around tech as they didn’t seem to know a lot outside of what the website told them.

3. Will engine longevity/reliability be seriously affected running .5 bar of boost without an intercooler? I love driving the car and it’s generally my daily if the weather is nice (targa top makes for a wet commute in the rain).

4. Does the MSD boost controller require manual input (i.e., knob turning) throughout the drive, or is it a “set it once and forget it” type device? If the former, is there a better way to permanently address ignition retard under boost?

5. Any thoughts as to turbo brand/specs for a low boost application like this?

Thanks so much for your help with this guys! A turbo is definitely an exciting prospect!

I had a similar set of considerations with my modified 930. Since I have CIS with lambda I elected to go with a FrankenCIS implementation, replaced the WUR with an eWUR, and running ignition and electronic boost control all from the MS. I'm not on the road yet but have good confidence it will work.

afaiak the leask style adjustable wur, coupled with rpm or vaccum based pierburg switches for mixture adjustment is an old rube goldberg setup that is unnecessary and suboptimal given the technology available today.