924Board.org

MikeJinCO · Posted: Wed Apr 08, 2020 12:12 am Post subject: The Track Car

https://imgur.com/a/O1zXavE

Started this in winter of 2015. The finished photos are from my first track day at Pueblo CO in July of 2019. Since then it has gotten numbers and a blackpinstripe.

I post a full set of specs.

The car is built to the Specs of the SCCA 1981 GCR

Hopefully the photos will show up
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

924RACR · Posted: Wed Apr 08, 2020 2:37 am Post subject:

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

Fifty50Plus · Posted: Wed Apr 08, 2020 5:34 am Post subject:

looks like a great build. What class, SCCA's F Prod? I see what you mean about the alternator cooling being an impediment.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

MikeJinCO · Posted: Wed Apr 08, 2020 7:05 am Post subject:

I belong to Rocky Mountain Vintage Racing. We class it small bore as cars are built to SCCA specs for 1959, 1972 and 1981. Mine is built to the 1981 Dp spec. We have many Spridgets, TR4, Spitfires, Lotus 7's, a few Minis, a 356, 914 and some 912's. Typical field is about 35 cars in small bore. There are basically no cars newer than 1981. The exception is our new last year "run what ya brung" class which have to meet some other organizations specs and have a log book. It includes a Chevy Super Late Model, a 1993 NASCAR truck, Things like Spec944's and Spec Miatas and the NASA stuff can run. Until the field fills out the production cars both big and small can run with them and double the track time. For beginner me it is real experience with a full race Mustang closing on you.
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

Fifty50Plus · Posted: Wed Apr 08, 2020 10:08 am Post subject:

Huh... The 924 ran in SCCA's DProd around 79-85. As a matter of fact, I raced a 2 liter 911 in that class against a few 924s back then. Doc Bundy, Tom Robertson and others won National Championships at Road Atlanta in that car. I thought they all had turbo heads and mechanical fuel injection, not to mention dry sump.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

MikeJinCO · Posted: Wed Apr 08, 2020 1:14 pm Post subject:

You are right, but the '81 specs are much more open than what those original 16 cars had. The 931 head was technically not legal,the 933 head was #933.099.100.22. I could use either the 931 gearbox(915?) or either of the earlier 4 speeds even the standard disc/drum brakes(heaven help us). I explained the head situation to the local Porsche race authority(914/6) and he approved using the 931 head after I contacted Don Meluzio and he said most people just used the 931 head when they needed a new one. If you look up RMVR.com, you can download the GCR for '72 and '81 it is amazing some of the stuff you find in there. The 931 gearbox had 5 sets of gears and at least 8 final drive ratios.
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

924RACR · Posted: Wed Apr 08, 2020 10:32 pm Post subject:

Wow, that makes me really not want to go Vintage with our ITB car any time soon!

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

Fifty50Plus · Posted: Thu Apr 09, 2020 6:53 am Post subject:

Yeah Vaughan. I'd looked at building an F Prod 924 back before the runoffs were at Daytona since our body is a long track slippery one. When I saw your video from Road Atlanta and what you did to the other IT-B cars on the back straight and under braking I decided to build one for IT-B. Wow, that was a bunch of years ago!
I talked with one of my old buds who built runoff winning engines about the Audi engine. I took him a bunch of parts and all the shop manuals and Limited Prep rule book. He did some analysis and said that the most he'd be able to get from the Audi NA head is 160-165 crank horsepower but the 931 head should be good for another 20 or so. Since F-Prod Miatas were getting 175 rear wheel HP and had much less frontal area, I abandoned my idea of the runoffs.

Mike, the carbs look good (actually looks great) but I found that a properly tweaked fuel injection produces more HP across the rev range than carbs. However, you would win a race for pulling the engine by multiple hours

_________________
1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

MikeJinCO · Posted: Thu Apr 09, 2020 9:20 am Post subject:

Our vintage racing is probably much different than the areas of the country where there are more people and cars. This is more like the ole boys club where everybody gets to go out and drive their cars as fast as they can. Nobody is looking to see if you did something illegal to the car, there are no class winners, you really don't want to touch another car as that can set you down for half the season and if you spin twice or go 4 off too many times your libel to get parked for the weekend due to over aggressive driving.

We are really pretty isolated out here with a few people coming up from New Mexico and a some times folks from Texas. We get very few spectators and admission is always free. I know a few of our folks like to go back to Elkhart Lake for their summer vintage weekend orout to Laguna Seca.

Years ago they used to have a street race at Steamboat Springs, they for a couple of years we had one at Snowmass near Aspen, but they got crazy with their money demands. Next year we are planning a street race weekend at Estes Park in July, the absolute middle of tourist season so that should be a great show.

My driving instructor said of his Spitfire that he could build a 125hp motor and go faster, but it would be a grenade, when he builds a 115hp one he can run it for years and have just as much fun. It 's a more laid back attitude. I've seen the whole Formula V crowd working on two cars to get them repaired for their next session after a mixup and some body damage.
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)