APKhaos

Not sure a DME chip is going to do enough to overcome the TurboS advantage of its larger turbo in the HP stakes.

competition

According to some, you can leave the rear brakes stock and change the fronts. See, www.vehiclecraft.com/Brakes/vciweb1.htm. I, too, think that if you make "all" the changes you could be competitive if you are at the min. weight. Well prepped and driven 964s are very fast. S2 R&P helps as does a good limited slip. As said earlier, you need to take advantage of "all" that is allowed according to the rules.

BBailey

Speaking from experience, you have to do absolutely everything in the rule book to the absolute limit the rule book allows for an early 951 to compete in E class. There wasn't any part of the rule book that my car hadn't exploited when I finally stripped the car and started racing with SCCA and NASA as well as PCA. I'd also start with a car that had ABS personally as it can be an advantage in certain situations.

If I was doing it over today, I'd find a nice turbo S and just build an E-class car. Much less expensive to go just as fast. And if you put the same level of prep and car into a Turbo S, you'd probably have a faster car.

Realize that there are very, very few guys in PCA club racing that go to the nth degree in prepping their cars. I for one don't know anyone that frequently rebuilds their brakes to lesson drag in an attempt to gain a couple horsepower at the ground. Nor do I know a lot of guys that do much parts bin blue-printing to find the best turbo for their car or the best intake or exhaust manifold, etc. All this stuff can create advantages, but the question then becomes, why? And is it worth it? Or is there an easier route?

PS - if you go this route, be prepared to come under a ton of scrutiny at the races, you can do some searching on the boards about my experience at the 2001 Road Atlanta Club Race if you'd like some entertaining reading. Like Mike said, my car was really fast way back when, I think with the improved prep levels today, it would still be competitive but not like it was back then. I would add however, that John Crosby and John Sullivan both had Turbo S's that were as fast if not faster than my '87 at the time.
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Brian Bailey
Autometrics Motorsports Porsche 996 - Grand-Am Cup #45
'87 Porsche 944 Turbo - PCA GT3s

BBailey

Here's a brief list of what I'd do.

Moton Club Sport coil-overs front and rear (or Triples if you really want to go all out)
Figure out how to deal with the rear torsion bars (do a search on the board)
Racer's Edge Bushings everywhere (Karl can help you a lot with set-up as well)
Vented Header Panel
Rebuilt engine & transaxle
S2 Ring & Pinion
Limited Slip
Custom exhaust
Custom Chip
Lexan Windshield
Lightweight wheels (some are using 18's but I think lighter 17's would be preferable)
Charlie A-Arms (or equivalent)
Adjustable sways
Strip the chassis of all sound deadening
Racing shells for driver and passenger
lightweight cage (cro-mo, think this is still legal, haven't looked in a while)
New Hoosiers every session (or at least new for qualifying and the race)
Data Acquisition is becoming more important day by day with more guys investing in it
Fiberglass rear bumper
Fiberglass front bumper (GT-Race Version)
I had the GT-Racing Lemans wing, though I think the 968 TRS wing is a better choice today
Front Splitter - size to balance the cars handling
Bolt any ballast as low and close to center as possible
Make sure air gets into and out of the engine as efficiently as possible
Make sure your Intercooler is doing the best job its capable of doing (cooling the intake charge)
Figure out a way to get cooler air to the air intake.
Figure out how to make the car run as cool as possible (heat is the enemy of turbo's)
Make sure you can get the car below minimum weight
Spend an absurd amount of time testing to find the right set-up
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Brian Bailey
Autometrics Motorsports Porsche 996 - Grand-Am Cup #45
'87 Porsche 944 Turbo - PCA GT3s

trackjunky

Brian:

Would this be to run in "E" as a prepared car?

I checked some old threads and see that you went the "D" route at one time. Did this work out?

Also, couldn't you just get a 26/7 (turbo S) turbo and turbo S ECU and run as a turbo S "E" car? Of course you would need to add S4 brakes, but otherwise they are the same car, right?

Gary Grigsby

The CMP weekend went reasonably well-lost compression in the #2 cylinder during my first "hot" lap in Sunday's Qualifying session. Went ahead and posted several laps, thinking that an exhaust header had cracked-loss of power/lowered exhaust pitch-so as to not have to start at the back of the grid for the Enduro. But it was not to be, as one of the 78,000 mile original exhaust valves had broken and the weekend was done. The rest of the motor is sound, so the #69 car will be back in action at Sebring.
Gary

Gary Grigsby

The 911 SC's are, almost without exception, the fastest cars in either "F" or "G", often outrunning "E" and the occaisional "D" cars. I try to keep close enough to get a passing opportunity under braking. Seems like the handling/braking of the SC is typically not as well developed as the powerplant-one notable exception is the '79 SC of Mark Hupfer, which not only accelerates like a bat out of hell, but also handles like it's on rails-at least at Putnam Park.
The 968's advantages are in it's excellent balance and braking capabilities over the older 911's.
I agree with Brian above, that, optimizing everything is the key to putting a competitive package together. Regular, frequent maintenance is also critical-with an eye towards your car's particular problem areas. You cannot win races with a car being worked on in the paddock!
The "CUP" car was a consideration, but I'm going to do at least 5 races in the Grand AM Cup in 2006-in a SYNERGY prepped 2006 997. We shall see...
Keep the Shiny side up!
Gary

Gary Grigsby

Sorry for the seperate replies-can't get a longer message to post.
Lost a steering rack seal during a race in 2003 on the #69 car. The only diffculty was heavier steering input during hard braking when the front tires were fully loaded. The lighter 944 should be easier to drive than the beefier 968-whose minimum weight for PCA is 3086 pounds.
Gary

BBailey

Yes, thats for a Prepared 951. Can't do a number of the items I listed and stay in Stock.

We toyed with the idea of going to D Class for a while, but locating the parts necessary to build a competitive D-Stock car was next to impossible (original Turbo Cup Parts to do a proper conversion). I'm not sure a Turbo S could compete in that class with more weight and less HP than the 944 Turbo Cup cars that race there. Though I think they could be made competitive with everything else in that class. Some of the Turbo Cups I've seen are just monsters.

The Turbo S also has some differences in the transmission and chassis bracing (off the top of my head) though most Scruts don't check this stuff and it would only come up if someone really complained about your car and got the scruts to really look at you hard.

Model Conversions can be done but they have to be complete conversions, not partial.

PS - forgot camber plates on the above list.

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Brian Bailey
Autometrics Motorsports Porsche 996 - Grand-Am Cup #45
'87 Porsche 944 Turbo - PCA GT3s

trackjunky

What about changing to a MAF and moving to D?

I'm not exactly sure how this could be accomplished while maintaining a stock KLR chip. As long as you keep the stock boost (1.75 bar max) why wouldn't this be allowed?

Also, what does "any aftermarket ignition" mean for a 944 turbo?

As far as cooling the charge, a vented nose panel would help, as would louvers cut into the hood over the header and turbo. You could do this and stay in either "E" or "D".

I have "maxed out" the options for F, but the driver is most likely holding the car back

BBailey

Stock boost is higher than that for the Non-S turbo's. Just in case you didn't know. It's listed as 1.75 Bar +/- 10%. Which means if you want to actually max out that car, you need to figure out a way to legally make closer to 1.90 bar of boost.

Though I would agree, in PCA racing the driver is a very large percentage of the equation.

__________________
Brian Bailey
Autometrics Motorsports Porsche 996 - Grand-Am Cup #45
'87 Porsche 944 Turbo - PCA GT3s

Oddjob

Brian,

Do you know what the PCA scrutineers check for on boost limits in the stock classes? I have never been tested, but have always been curious to know what they consider the max boost level for a stock class turbo.

The manual states the boost pressure in two ways, gage and absolute pressure. It says 1.75 bar +/- 10% (absolute) and 0.75 bar +/- 10% (gage).

10% of 1.75 is not the same as 10% of 0.75.

If they go by the absolute scale, you could run 1.925 bar absolute = 13.22 psig

If they go by the gage scale, you can only run 0.825 bar gage = 11.97 psig

That is quite a bit of difference, powerwise.

Also, if running stock chips in the stock class (F for 86-88 Turbos, E for TS cars), overboost protection in the chips will kick off the fuel if the boost gets too high. The chips certainly wont let the car run anywhere near 13 psi through the higher rpm range without killing the fuel. Of course, if progressing the car and using an aftermarket DME chip, the factory overboost protection is removed and it would be possible to raise the boost up to the upper limit of the factory specs.

Also, when you looked into running a D car, what turbo cup parts/components kept you from making the update? Mag intake and oil pan, anything else?

Chaos

The fastest F guys beat most of D and the fastest E guys beat some of C !