TheRealLefty

Looking for about 10-15 more hp for my 944 CSP autocrosser as attached. Decided to stick with the trusty NA for this year's autoX season and reserve my "new" 89 Turbo S for track days and nice weather highway use. Just too many issues that amount to decontenting a true super car to win a knife fight in phone booth.

That said, the black 7 handles like a kart, but I'm gonna swap out the OE transaxle for a 944 S box that should help keep it off the rev limiter and out of third gear for the longish, fast Cumberland Airport Autocross Series. But, I could use a little more grunt to push the short cogs.

In the combined experience of the Rennlist membership, is a ported throttle body worth the expense for an otherwise good breathing tight 2.5 NA engine?

WesM951

Interesting that you ask, because there is one on ebay.

Sorry can't help you, but i was wonder the same myself.

Eyal 951

you can have it ported for 100 bucks at max bore. That said, you're lucky to get 1.5 mm out of it. I'd say worthless for the NA, but I'm no expert. I'll eventually like to replace mine for a larger unit in an effort to free flow my entire intake trac. The head is done already.
~Eyal

tod84944

According to Jim Pasha, of Excellence mag. It is a waste of money. The throttle body is already 20% larger than what the engine requires in stock config.

DDP

Nice work with those side view mirrors....hehe.

Mark Lue

If you haven't already upgraded to a Wilk chip, you should. Althought it will not give you 10-15 ponies it will change the character of the NA engine. I recently upgraded to the Wilk chip and I can safely say it lives up to the hype. The engine response better at all rpm and makes the car easier to throttle steer and drive. I don't autoX but I would think that combination would yield some positive results.

IMHO, it is the best bang for the $$ for our NA cars.

Yabo

Great info, makes me anxious to put mine in

Sam Lin

I have one sitting on a shelf somewhere, it made the throttle response significantly crisper, but I don't think it made any more power.

Sam

Mark Lue

Sam, if it is a wilk PP2, is it for sale?

Damian in NJ

It did nothing for a 968 owner, in fact he felt he dropped a few hp.

TheRealLefty

Thanks for the input, guys. Side mirror deal is to reduce the temptation to "check my wake" for downed cones. If it's down, it's down, why screw up the rest of your run looking in the rear view mirror? The goal of 10-15 ponies is just an arbitrary number. It's a back and forth thing for low budget racers, I suppose.

Worked on the handling between my first two seasons and the car responded wonderfully. We stayed focused on the actual goal of improved autoxing and stayed mild and relatively soft. Yellow Koni's all around, 200# Weltmeisters with 1.5 inch drop, 19 mm rear M030 bar, lowest factory rear ride height. Then we played some tire magic, scored four 8 x 15 Fuchs and reduced the ride height further and lengthened effective rear ratio by using 225/45 Hoosiers all around. Very low unsprung weight with OE brakes, forged Fuchs and featherweight little R compounds.

With this set up, my NA will outrun my Turbo S with 968 M030 underpinnings by 3-4 seconds on most autox courses. Different story on track day, of course.

That said, I'm focused in now on squeezing another second or so out of the NA. Running the Welt throttle cam, custom one piece 2.25 exhaust from the down pipe to a Flowmaster, wrapped headers and adjustable FPR. I think the 944S tranny will help as I've been getting pinned between the riding the rev limiter in second and shifting to third for 150 feet at the end of chutes. New ratios will give me a little room there, but I'm a little concerned about loss of grunt with 10% shortening of first and second cogs...and thus am looking at improvements in breathing before I commit to anything in the head or short block.

Travis - sflraver

Ever thought about upgrading the front brakes? If it doesn't bump you out of class it may get you those 2 seconds your looking for.

TheRealLefty

Thanks for the thought, Travis...but that doesn't fit our autox set up theory. The car stops great, especially since we lowered it and added 75# of front spring (from OE 125 to 200). Those changes really reduced the amount of forward weight transfer. Our philosophy is that the limiting factor to braking power is the tire patch and the balance of the car on that patch, not the brakes, already Porsche strong point.

The other point is that autoX is a minute of action followed by 10-15 minutes of being parked, so some of the benefits of big brakes and their resistance to heat related fade that would be realized during track driving don't really apply in autox. At least not enough to justify the expense and the added weight of heftier hardware.

My Turbo S has the OE big blacks and, with the retrofitted 33/5 brake bias valve, it stops on dime, but can't go any deeper in an autox than the lighter, less stiff, less robustly fitted NA. Pads are important though and I have had great success with the Carbon Kevlar NA pads recommended by Jason at Paragon, an affordable alternative to Pagids, which are not easily found for NA applications.

TheRealLefty

PS: There's a good chance that a hefty portion of those missing two seconds are related to the shortcomings of the driver CSP is hotly contested in my neck of the woods and there are a few guys are just plain faster than I am. To match 'em, my car has to be significantly better than theirs

Geo

Actually, heavier springs and swaybars don't reduce load transfer. They speed it up.