View Single Post
spuggy spuggy is offline
Registered User
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 2,835
Originally Posted by Alan L View Post
Thanks Goran - I had planned on reducing boost intially, at least until I got comfortable with the car. I may not need 0.8 boost anyway. My previous race car used to go past 3.0/3.2 911's without too much work. I spent some time on the performance Board considering building up a 3.2 motor to what I believe I need to go a bit quicker - about 260 hp. The consensus was this is easier done with a stock 930. In which case if I have power to burn, I would prefer to dial the engine back a bit. I don't like the idea of stretching it to the max.
From what you are saying, the spring sets the Minimum boost pressure, and an EBC simply allows more.
So, I had thought of starting with a 0.6 spring (do they make one) and work out what I need beyond that using EBC/AFR, and probably the 0.6 will be more than adequate and more controllable in the wet?
That looks like a repro Ruf valance? And Ruf Speedlines? Nice, love that look (just need the Speedlines).

You should post pics of the exhaust and motor. You may already have headers, maybe a K27 etc.

Trouble is, the stock 930 winds up like a big old doggy low-tuned 3.3L N/A and does nothing, nothing, nothing, nothing - and then it's a sledge-hammer blow to the chest as the front end goes light and the horizon does the Star Trek warp thing (least, it does with a 915 in a light car). You can get sideways from a straight line in the wet from the boost hitting if you just floor it..

Someone talking about AX'ing a 930 described it very well when they said that there's just nothing between 100 and 300 HP in the stock car, which pretty much sucks if you want 175 or 225...

Most common - and minor - modifications to help breathing like a modern turbo, better headers, intake, SC/964 cams, efficient intercooler - actually reduce lag and improve controllability - and make the car far more drivable. It actually "feels" slower to the butt-dyno, but it's making 1/3 or more power everywhere in the rev range. And while it may feel slower, looking out the window - it's not.. You could do those mods and run at reduced boost whilst getting the hang of the car, you'd still get the reduced lag and improved controllability.

See if you can get to drive a modified 930 - you might find that the car is a lot more predictable and thus better in low grip conditions.

Mine is now far easier to drive - and most especially in the wet, where it was quite evil before - than it was with a stock-ish motor - and it's making 395 HP/350 ft/lbs at the crank with a .8 bar spring. In fact, it makes .5 bar boost @ 2500 RPM under load, very different. (trouble is, I do kind of miss the sledge-hammer to the chest feeling. Ho hum).

You would also probably really like a differential lockup LSD like a GT or a Gripper - really helps keep the rear planted braking into corners, and transforms the way the car feels anytime you're not coasting or cruising - which is pretty much the whole time on the track, right? You can go for a really high decel lockup rate like 80% if you're not going to street the car at all, otherwise the 40/65 LSD seems to work well.
'77 S with '78 930 power and a few other things.
Old 09-13-2007, 04:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)