924Board.org

[kris]

Since winter is approaching, I am now weighing the benefits of possibly going ahead & yanking the motor out & starting from scratch becasue I am finding new things I want to do all the time.

What I am curious of, is if I elect to go with a 937 style intercooler & want to add electronic fuel injection. Would it be logical to go ahead & do some chages to the basic block, pistons & rings? I am pulling everything back out anyways to detail the motor, so I am thinking of going as far as the block (clutch too)....

I know this is a pretty braod can of worms Im probably opening here. But I am curious what others have done? I would LOVE to pull 300 hp with this car if possible & gear it for the street. THEY JUST HANDLE SO DAMN GOOD!

Any thoughts would be nice to read, or directions to some prior posts about motor rebuilding....

[Rick MacLaren]

I suppose the only piece of advice I can give after doing mine, top to bottom, comes from what I didn't do, not from what I actually did.

If I had to do it over again I'd start with a reasonable horsepower figure and work backwards from that figure.

i.e., I want 225 HP. How can I get there?

I'd also do the math a little more. A really rough 5 minute sketch would go like this:

1. I'd find out what my richness/leanness curve looks like from my existing box across the RPM curve (measured at the tailpipe), I'd map out what air temperatures I have at the throttle right now, and what kind of fuel delivery numbers I'm getting.

2. Then I'd work to see what kind of boost I'd need to achieve my goal, and

3. Look at how I could achieve my goal by modulating or adjusting a few variables, or inputs, while ensuring that my car is being given the optimal amount of fuel and air.

It's just a sketch. But the idea is to work from your goal and then devise your methods to attain that goal. Most automotive catalogs are all about selling you add ons and 'isolated tactics' that are ok in isolation, but may not be appropriate for your car. That's how they make money.

The Porsche approach is to use tried and true methods. Like, some folks will throw on a front mount intercooler and up the boost. This gets them a safe 200 HP. Providing enough people have had success with that you're probably ok.

If you intend on 300 HP, get the guts of your head checked out, and maybe new valve guides. Do a compression test to make sure there is little variance across the cylinders. Get ready to go to EFI. I've been educated by the guys here on this matter - the system won't achieve 300 HP without it.

Good luck.