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Micke · Post by **Micke** » Thu May 12, 2005 12:00 am

I didn't get our data logging files yet so I don't know how my 10'45 on the GP+NS compares to NS only. I guess it will be about 8'30 like I did with the VW Bora TDI (10'01 to the VLN Kehre). BTG times are for tourists

The Skyline is too slow to win. Dirk was driving it when a suspension arm broke. Lucky it was in a slow corner and nothing serious happened. It was the last race for the Skyline and next year they'll come up with a new car (Z350??)

The Skyline made 9'15 laps which should be about 7'30 NS. Fastest lap was the M3GTR with 8'47. This translates to 173 km/h average speed!! You need to do 300 on the straight to achieve this.

If winning overall is not the goal (toatally imaginary it would be), then situation isn't that bad. 5th overall was a GT3 cup with one minute slower lap times than winner. Keeping the car running is an essential thing at 24H. The same lap time was achieved by the winner of our class (<2000 cc) by a BMW 320 with 9'46. Made 11th overall. Must be possible with a reliable 3 liter. The Alfa 147 DIESEL made 13th place with a best time of 10'10.

Dirk would tune the suspension for me. (He would have done it on the TT as well if they ever got it running for Friday practise). I'm OK with springs but when it come to tuning shocks I don't have the needed experience.

Barry, Jim,

you don't think a 24V could do it? 350 reliable HP?

Jim K · Post by **Jim K** » Thu May 12, 2005 12:06 am

Mats, Maurizio, Ron's kit is available in 3 configurations: Fast road-track day (the one WE buy), ...almost race (single adjustable shocks) and full race ( double adjustment shocks), with obvious quality and price differences. Ithink its entirely usable in a 24h race in a PROPER chassis!
Jim K.

Barry, I'm with you on the 3-letter word for engines (you know, the one that starts with B and ends with W!)

Micke · Post by **Micke** » Thu May 12, 2005 12:17 am

For a 24h car I wouldn't even consider Ron's kit. I'm sure he would supply the things needed as well.

The reason is simple. 20 kg!

Dump the torsion bars, make longer lower A-arms (not from led like OE) and tune in some anti dive while getting the roll center right.

Post by **Zamani** » Thu May 12, 2005 1:18 am

BMW? What??? No way. What about a DC2 ITR with Mugen headers, JUN cams. Hehehe.

Jim K · Post by **Jim K** » Thu May 12, 2005 1:49 am

Micke, the 3liter 24v engine can put out your 350hp (which is 116hp/liter) with the standard valves, but it will have to go to 8600rpm to do it. If you want these revs, and want them for a 24 hour race, you must use Space Shuttle materials and assembly procedures. If you enlarge to 3,2liters for the same power, engine speed drops to 8000rpm, a welcome gain in reliability, with the same cost though. (See now why the M3 makes 340@7900 from 3,2liters? Sorry Mats, I said the M name again!). Sure its possible, it would be very interesting if the Mats/Maurizio/Zamani/Barry/you/me and others team could come up with a cost for such an engine, only for parts-not assembly.
Jim K.

Micke · Post by **Micke** » Thu May 12, 2005 2:06 am

Jim,

the piston speed isn't very high (rediculous compared to my Nord). What's the weak point.

I know the B, P and H engines are good but can't the AR engine be made reliable?

Mats · Post by **Mats** » Thu May 12, 2005 3:08 am

Do we need a timing belt change at around 12H? :/

Jim; I'll be back after a thorough study of the Rules. Six months should be enough.

Maurizio · Post by **Maurizio** » Thu May 12, 2005 3:37 am

http://www.mobile.de/cgi-bin/da.pl?bere ... d=24155645&

I know it is not a transaxle, but on this one we only need to work on the realiability for 24h

Jim K · Post by **Jim K** » Thu May 12, 2005 3:44 am

In order of importance, stock rods and pistons. A very good race-spec build should take care of the rest. I don't know about the mid-race belt change, there are new competition belts out (Kevlar based) but I don't have any info. Does anyone? Other than these items, the little (relatively speaking, compared to the huge Jag and Viper ocean liner and truck engines!) Alfa 3liter is a gem.
Carillo, Arrow,Saenz or what-have-you rods, ARP bolts, a good set of forged pistons and suitable cams AND headers and its real! The rest is race-practice assembly and believe me it takes time and know how. You can use ITB's if you expect up to 9000rpm (holy..) and any good EFI-there's plenty of them around.
The engine is the EASY part. What about the transaxle torque capacity for so long and the donuts? Personally I think that in a light 75 (under 1000kg) wheel bearings may survive. You'd be ok with 310-323 front discs fitting inside 16" wheels. I agree with the longer tubular A-arms (Team Competizione, Holland), but I'm biased in favor of Ron's race setup all-around. Rear outboard discs are good (although I'm not convinced by my limited experience, doing 40x2mile hard braking laps in dead summer here). A good cage, factory style to the front turrets is a must,to eliminate the torsion bars (weight).
Ok, thats it, if you agree, fine! I'm going back to the cheerleaders!

Jim K.

Micke · Post by **Micke** » Thu May 12, 2005 3:47 am

I recall these have been for sale the last 4-5 years (as long as mobile.de exists?)

Now, this would be a REAL challenge for Jim & Co to detune it for 24h

Maurizio · Post by **Maurizio** » Thu May 12, 2005 4:04 am

Team Competizione, Holland

Link> Team Competizione is from Denmark

Micke · Post by **Micke** » Thu May 12, 2005 4:09 am

Hell, if it's about rods and pistons I can pinch them in. I didn't even expect to use stock there. (not valves either for that matter)

2.5 minimum weight is 1030 kg and 3.0 - 1100 kg. Respective rim widths 10"/11"

Headers are no problem. Cams I can get to the specs we want.

ITB's might be nice but probably not necessary (KISS)

An EFI I have hanging around in one of my moving boxes.

If we aim at >300 hp the tires need to be big to survive. Maybe 240/640R18 or 230/620R17. There's enough space for brakes where you don't need pad change.

Outboard disks would be good for the CV joints as well as heat related issues (flat underbody - remember). And NOBODY wants to crawl under the car with glowing disks to change pads. Copy the entire Evo axle while we're at it.

Donut problem must be solved and I guess the solution is to copy the one piece prop shaft from the homologation papers.

Actually, in 2000, I was watching the race and there was a 75 3.0 running. Almost cried as it was more or less the same speed as a VW T5 TDI bus

Mats · Post by **Mats** » Thu May 12, 2005 4:38 am

Is there really a donut issue? Everybody I've heard about that have had a breakdown have had very old donuts. I think the donuts are fine if we set up the drivtrain straight and use all new parts (duh).
rods/pistons/cams are naturally changed, valves and valvesprings I know nothing about but with a high lift cam maybe we need new springs at least. Solid tappet conversion?
electric water pump? oil squirters under pistons? ceramic coating of parts (pistons and headers)? redesigned cooling system?

Outboard brakes and an oilcooler for the transaxle is a must have, I have a meter for transaxle temp in my racecar and it's very high even with my silly engine.
We need some way of setting the angles on the rear wheel (camber/toe), building a new de-Dion from scratch would be the way, could probably lose about 5-10Kg on that WW2 anti-tank engineering beast we have now. Maybe some other way of keeping the axle sideways? Mumford link or similar? Something that can deal with the kind of wheel travel we can expect.

120l safety tank needs room.

Aerodynamics, wee need someone with knowledge, real knowledge that is. JimK aren't you a rocket scientist or something? Maybe you can lure someone in or is it all supersonic for you guys?

I think we could make a car under 900Kg with a hot 3.0 and then add weight until we reach the limit. That is the way for a fast car.

We also need some kind of environmental control for the driver, if you are comfortable you are faster. Also some kind of seat ing system that allows us to fit different sized drivers...

Edit: Almost forgot, naturally we need a proper brake MC setup with dual cyls and a bias bar, also an in-car-during-race-adjustable rear anti-roll bar is needed.
Radio + GSM equipment naturally and DAQ, telemetry would be nice but must be able to burst transmit due to the nature of the track.

Maurizio · Post by **Maurizio** » Thu May 12, 2005 5:31 am

OK now we are talking.

Oh man when I had a budget and would not need to work for my income, as in had enough spare time.
I would be doing someting like this at the moment.
Would love to put all my knowledge of stiff and light engineering in 75 shell.

Micke · Post by **Micke** » Thu May 12, 2005 5:40 am

I dunno about the donuts. They are OK with 190 hp and 8200 rpm so far. Double the power and we might end up braking them.

Forget electric water pump. We're not drag racing. Dry sump would be good but costs a bit.

I have 2 DeDions and we already done the modifications so this only costs some working time. Strengthening it is a must with wide slicks.

I have access to a wind tunnel but not full size. My friend who's in charge of it is a guru at this field.

Hmmm.... a sofa

I'd still prefer a bucket seat.

Adjustable AR bars are not allowed. Not necesarily needed either. Proper brakes I didn't think I have to mention.

Datalogging I have and using telemetry only takes focus off important things.