924Board.org

[924RACR]

Just an update for those following this. Latest (June) Fastrack has some updates on the Prod Comp Rules (PCS) for the 924. Looks like they have finally tried to make our stock M471 brakes legal!! No more crappy solid discs/drums!

Unfortunately, they mussed up the listing and wrote it down as vented fronts, solid rears. I sent in an email requesting that this be corrected, as well as the fact that they state years as 76-84!

Still, this was one of the big obstacles (IMO) to going over to Prod for racing, and looks like they may soon get it cleaned up.

Also, looks like we're listed in FP in at least Level 2 Prep... somewhat limited compression, I think it said 10:1, and valve lift at 0.500", but it's a whole lot better than EP where it used to be!

The other big hurdle is the requirement for a fuel cell, but this was just updated in the same Fastrack; now some cars are allowed to use stock tanks. However, it appears that the 924 is not yet on that list; I have also in my email requested that they consider the 924 for inclusion in the list of cars that are allowed to use the stock tank. Cost to convert over to a fuel cell is typically over $1000!

Of course, who knows if they will support that, but if the request gets in for review, I'll be sure to let everyone know!

I'm not yet sure I even want to run Prod, but this makes it a lot more appealing...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Rasta Monsta]

Interesting! I take it this may reshape your answer to the question I redcently posed to you. . .we need to chat!
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[924RACR]

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

[Scott Sanda]

Vaughan,

It's a losing proposition. Suspension and brake wise the car would be fine, and there is a generic rule for prod that allows all prod cars to go to disk rears. This may not apply to LP however.

The problem in the motor. You are limited to stock intake manifold, throttle body and TYPE of injection.

At the weight listed, you will need 190 to 200 HP just to play in the tops quarter, much less win against the big dogs, and you will never get anywhere near that out of what is allowed.

Believe me, I have plotted this out a million times.

The EP specs are actually very good, provided the allow the turbo head like the D prod cars had, but when I asked for that, I was shot down in flames. it would be worth asking again.

However, you need a full prep hand grenade race motor to play there, and I know from personal experience what that costs.

The LP 924 would probably be a lot of fun, but it won't win as classed.

Scott

[924RACR]

Thanks for the reply, Scott! BTW, I'm still getting GREAT use out of your old 933 struts...

Still, in that level of prep - what kind of output do you expect you could get out of the motor?
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Scott Sanda]

I have no idea.

Looking in my little spec book, you have the XH and XG motors at 100/110HP and 8.0:1 and 8.5:1 compression respectively. I can't find a valve lift spec.

Your stuck with the K jettronic, I don't know what that will support, HP wise.

If I had to guess? 140 to 150?

I may have some more old parts, bilstein shocks, etc, you can have for shipping costs. I need to look.

The 924 is still sitting, with a broken valve spring. I took it out at RA and second lap it went "ping".

I'm currently rebuilding a 924 GTR ex trans am car. Tube frame with some tub parts, built and ran by Heimrath in 82. It has a 968 motor ( the 2.0l turbo disappeared years ago...) They took a factory car, and cut it up to make the tube car after a careful read of the trans Am rules

It rocks, 350+ hp at 2100 pounds with me in it. Will run in GT2. I'll post pics if I can figure out how.

Needless to say, I sold the cup car. Realized it was boring and I wasn't grinning like I used to.

So now I have 2, one off unique 924's with no resale value at all except to another idiot.

Straight jacket? Anyone? Bueller? Anyone?

[Rasta Monsta]

[ideola]

[924RACR]

Looking at the cost of cell, fittings, surge tank needed for high-pressure fuel delivery with CIS/EFI, and fabrication... gets expensive real quick.

Also check certifications on the fuel cells - not all would be accepted for SCCA/NASA etc competition...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[924RACR]

Additional: FIA FT-3 or higher specs... at a minimum, foam-filled bladder encased in metal is required.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[ideola]

Got it, thanks!
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erstwhile owner of just about every 924 variant ever made

[gla924sem]

Been working with a race fab shop in Romulus on this.

Took him a removed fuel tank to work with for size & shape to go into the orignal location.

To meet the reqs of the vintage group (do not recall which SFI standard) I want to race with they figured around $2500. If more are interested the cost would go down.

If all goes well the old #27 will be out for shake down late October and in 2009 hopefully a fuel cell.

[ideola]

In my case, I'm much more interested in doing something like what JR Mock did in his 951. Not necessarily that particular form factor...but, I have another innovation in mind dealing with the rear axles where I need to do some fabrication beneath the hatch area, and open up some room. Having a stock-located tank is actually a detriment for my intended use.

I've been eyeballing a couple of the units from RCI that are 30" long with various heights and widths (12 gal, 15 gal, and 17 gal capacities are available). In my car, I'm running a snail shell, so something in that orientation should fit across the back of the car, although I have some measuring to do to confirm clearance with the trans & exhaust.

Anyway, I have a lot of noodling and measuring to do to see if I can sort something out, to say nothing of expanding the budget yet again
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erstwhile owner of just about every 924 variant ever made

[gla924sem]

Did some looking into that installation.

Even going that direction was well into $1500.

Just not ready to give up the stock look and a much smaller gas tank.

[ideola]

Actually, I did some measuring last night, and I don't think you'd have to give up much on capacity, although stock look is definitely out.

On my snailshell-equipped 931, I believe I can remove the fuel tank, leave a stock exhaust setup intact, and simply cut out the spare tire well, along with some of the under-curved sheet metal that is tucked in behind the rear bumper. In so doing, there will be a space there of the following dimensions:
• 26 inches wide (from the edge of the exhaust shield to the edge of the stock fuel tank on the right side of the car)
• 26 inches long (from the rear body frame forward to the back of the gearbox)
• 14 inches deep (quite simply the depth of the spare tire well)

Realistically, the second measurement above would have to be reduced just slightly (no more than an inch) in order to provide ample clearance between the fuel cell / cage assembly and the rear of the gearbox. The depth measurement is also quite conservative, as the bottom of the spare tire will is at least two inches or so higher than the bottom of the gearbox, so there is room to go even deeper if necessary.

In any event, what this leads me to believe is that a fuel cell could be easily mounted in that location without requiring all of the surgery performed in the JR Mock setup. 26x26x14 is plenty of space to accommodate a substantial cage, and fuel cells up to 22 gallons in capacity.

In any event, I did some add'l research, and from what I found last night, the only two brands of fuel cells that are listed as FIA compliant are ATL and Fuel Safe. The stuff on Summit Racing and JEGS might be compliant, but if it is, there's no mention of it on their sites. The lowest price I saw for a 15 gal cell was ~$500, but that doesn't include the surge tank, and may not include all of the fixtures and plumbing. So yeah, I could definitely see a minimal expense of $1500 (probably more) to do this properly and to FIA specs.
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erstwhile owner of just about every 924 variant ever made