chanothemekhanik

So I was looking and I found out what each thousands does to your compression but what's the lowest you can take it and have it somewhat safe and reliable?

951Dreams

This is off the top of my head, but I'm pretty sure I've seen .060, That's on a fresh new head that's never been worked before. Also, I've heard it's not linear. Taking off the first .010 will give you much more of a jump than the last .010, something to do with the design, and diminishing returns due to it.

For my money, on these, not having knock sensors (until much later) I'd personally not go over 11.0:1, really 10.8:1 if I wanted to run pump gas. To account for variations and bad gas. My 87 with 88 10.2:1 pistons I'll really need to run at least 89 maybe 91 to not ping.

Most guys I've read about go .020-.040, just to be safe. Higher has no room for error in your gas or your timing.

My head is with LR right now, I kicked around doing a .030 or something, but ditched it with my 88's. I don't want to be tied to 93 octane that I can't always find around here.

Sorry, that was more than you asked....

Disclaimer: I've just heard those #'s thrown around, I have no way of knowing for sure that either I'm remembering correctly, nor that the source was correct. On things like this, your on your own. Not responsible if it blows up your garage the first time you start it, nor for bent valves.

V2Rocket

It's a waste of time. Don't bother shaving the block.
Going from 9.5:1 to 10:1 or whatever the CR change is at max-shave is worth 1.5hp at best.
Compression really isn't worth much unless it is large differences (8:1 vs 11:1).


Get an offset camshaft key instead, and advance the cam.

chanothemekhanik

is that the one of 928 motorsports? And don't I loose too end with the timing advance or am I mistaken?

odonnell

I don't mean this in a rude way, but most of this info you are/have been asking about is easily found through google. Start your searches with "porsche 944" and you'll usually end up on here, on Pelican, etc. Lots of people (everyone who's owned a 944...or looked at buying a 944...) has asked about making more power at some point and there really isn't anything new under the sun.

V2Rocket

Yes, 928 motorsports.

Re: top end power, not with the stock 944 camshaft.
I made more power at the top end with an advanced camshaft, than with it straight up.
+4whp/+7wtq proven on the dyno.