924Board.org

Lemming · Joined: 14 Apr 2004 Posts: 77 Location: Birmingham, AL

I had planned on stripping the interior of my 924S for weight savings. However, in looking over the PCA rules, it appears that other than seats, and possible the drivers side carpet, the interior must stay stock. Is this true for the other race series, such as the 944cup, SCCA, and others?
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Tim
'95 968 (White/Cashmere)
'88 924S? (sleeper

ryoji · Joined: 10 Oct 2003 Posts: 168 Location: NNJ

Here is the rule for 944Cup

http://www.44cup.com/buttons/inforules2.jpg

You can do limited but more than PCA in IT class of SCCA. A lot more in Production class. In GT?

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R.I.P.:a 924 ITA race car

924RACR · Posted: Fri Jun 25, 2004 10:32 pm Post subject:

No.

Being down that way, you ought to consider running with GTS Challenge, not 944Cup... we let you do so much more (to your car), and GTS Challenge will be really picking up speed in the SE starting now!

BTW, some pics from the weekend of some of the GTS cars:
http://red-line.us/nasa_road_atlanta_june_2004.htm
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lemming · Joined: 14 Apr 2004 Posts: 77 Location: Birmingham, AL

Ok, so it appears that the interior can be gutted for both GTS and 944cup, guess I'll get started this weekend.

I was at RA last weekend doing the HPDE (I got to solo two of three runs on Sunday). The two M3's show here (http://red-line.us/10chaseblur.jpg) had a fantastic race on Saturday, unfortunately, I didn't watch the races on Sunday afternoon.

I'm having Kirk Racing install a rollbar prior to the Barber DE in late July.
_________________
Tim
'95 968 (White/Cashmere)
'88 924S? (sleeper

924RACR · Posted: Fri Jun 25, 2004 11:02 pm Post subject:

In SCCA IT, you need to keep the stock dash (though not center console) and door panels (though you are allowed to discard the driver's door panel and glass and gut the door to put in NASCAR-style bars). GTS does not require this; not sure about 944Cup.

One note, be aware that most sanctioning bodies, PCA is the only exception, require a FULL roll cage to race. I know this is the case for both SCCA and GTS (I think actually for all of NASA).

Don't forget to remove the sound-deadening too!

When having the rollbar installed - make sure to have it attached to the rocker box sections, not the floor!!! The box sections are where all the strength is, not the floor. If they're using a cookie-cutter cage template that goes to the floor, don't get it, get a custom bar instead. Likewise, do not allow them to put rear main bar braces back to the wheel humps - there's no strength there. They need to go to the sides of the trunk floor, like near the filler neck, as that is where the main rails of the unibody are located. I can supply pics if needed.

I can provide other advice as well, if you wish it. Remember, it doesn't cost extra to do it right, but it does cost extra to go back and fix errors!!!
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lemming · Joined: 14 Apr 2004 Posts: 77 Location: Birmingham, AL

I am going with just the rollbar now and will add the rest of the cage later (since I still drive it on the road). It will be a custom job so all advice is welcome (Kirk racing is supposed to be really good). Photos of a good cage would be great.
_________________
Tim
'95 968 (White/Cashmere)
'88 924S? (sleeper

924RACR · Posted: Fri Jun 25, 2004 11:37 pm Post subject:

OK, cool... yeah, I've heard good things about Kirk.

#1 priority for you in designing it is to identify the key parts of the body structure and tie in to those. You might wish to tell them in advance that you intend to grow this thing into an IT-legal cage; that will cover the bases for racing, and make sure they do the basic layout right.

The main box sections inside the car (pass. compartment) can easily be seen once you peel back the carpet. The door sill is the main box section, so you want to tie into it (when you do a-pillar bars). Behind the doors, it widens out and provides a nice big flat surface to mount the main bar to - basically on either side of the A$$-buckets that form the rear seats, below the speakers.

Then you have rear braces/downtubes, which need to go to the rear rails hidden under the trunk floor. Just tie in to the side edges of the trunk floor. You can see these rails if you get under the rear of the car with a light. The shocks also bolt to the inside of these rails. If you wish to run coil-overs in the rear later on, it would be a good idea to tie into these rails up at the front edge of the trunk, instead of further back (most cage designs tie in about mid-way back), since that's close to where the tops of the shocks are (and those mounting points will be carrying the load of added coilover springs).

Unfortunately, as I look through my website, I don't really see any good pics of just my cage.

Sorry.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lemming · Joined: 14 Apr 2004 Posts: 77 Location: Birmingham, AL

It sounds like I'm on the right track. The bar is being built so that the front of the cage can be added later, he also knows that it needs to be spec. We've also discussed tying into the rear shock area to make the car as tight as possible.

Back seats, carpet, and extraneous stuff come out this weekend.
_________________
Tim
'95 968 (White/Cashmere)
'88 924S? (sleeper

924RACR · Posted: Sat Jun 26, 2004 3:21 am Post subject:

Cool!
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

924RACR · Posted: Sat Jun 26, 2004 5:31 am Post subject:

There's a whole mess of pics, BTW, from Road Atlanta...
http://www.nasa-southeast.com/2004Jun19/event.shtml
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

ryoji · Joined: 10 Oct 2003 Posts: 168 Location: NNJ

so what is the minimum weight for stock na 924 for GTS-1?
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R.I.P.:a 924 ITA race car

924RACR · Posted: Sat Jun 26, 2004 10:36 pm Post subject:

There is none! It's based on rwhp/weight ratio; with a stock power output of 115hp, that equates to about 98 rear wheel hp (rwhp). Since the upper limit for GTS1 is 21 rwhp, that would mean you can run as low as 2058lbs (w/ driver). Good luck making that!

Of course, like I said, there's a lower limit on the ratio in-class, not a set weight, so if you had an earlier car with only 95hp at the crank, you could run even lighter.

But usually we find it a little easier and more economical to soup-up the engine, with exhaust, maybe a cam, higher compression, etc., to raise the output. I figure 2500lbs w/ driver shouldn't be too hard to achieve with reasonable expense in a 924, which would equate to a max of 120rwhp, or 141 hp at the crank.

I hope my IT car will be coming close to this threshold; I should be able to achieve 2500lbs in close to IT trim (plus fiberglass hood and lexan hatch), and I hope my engine will put out about 130-135hp at the crank - a ratio of about 22.7-21.7. If I can bump the weight down another 50lbs, that'll put me at a ratio of 22.3-21.3!

Hmmm, maybe I do need to get those fiberglass bumpers...

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

924RACR · Posted: Sat Jun 26, 2004 10:40 pm Post subject:

For future reference, here's the GTS rules:
http://www.gtschallenge.com/2004rules.htm

Classes are based primarily on the ratio of weight to horsepower. Only slicks and AWD will change the classification further. There are NO limits on modifications. To the extent that they impact your power to weight ratio, they could result in a reclass; otherwise it doesn't matter.

Want to run a big-brake upgrade, 17" rims, fiberglass bodywork, and a big wing? No problem. Just don't bust out of your bracket, or you'll be facing a lot faster cars!

Oh, yeah - engine swaps are legal too, as are turbos and blowers, etc etc. We expect to have a Benz 190 joining us shortly in the GTSU class... powered by a Ford 351 smallblock.

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

ryoji · Joined: 10 Oct 2003 Posts: 168 Location: NNJ

Thanks. I was not sure what hp to use in order to calculate its weight. It is clear that my car is not possible to GTS-2. That is good enough.

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R.I.P.:a 924 ITA race car

924RACR · Posted: Sun Jun 27, 2004 1:08 am Post subject:

Possible, yes, I think so... just needs power! How about a cam and a turbo?

j/k
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype