Racecar Project - Moment of truth...weight
04-24-2006, 08:02 AM
#17
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Thanks guys. While I have done almost all of the work myself, it can hardly be called single handedly built. Not having done this before as a complete project, I have definately had help and advice from many friends.
It is normal to for the corner weights to be off at this point. This was the first time the wheels have seen the ground and the spring perches are all over the place. Corner balance and alignment will be the last thing that gets done to the car. I was not sure that the GT3 Cup car tires would even fit under the chassis in the rear since they are 26.75" in diameter compared to about 25" stock. I'm still deciding about the final spring rates as well. I currently have 600/700lbs springs which may be too light, I don't know yet.
The mirrors are part of the door and not detachable. They are GT2 Evo doors and the outer skin contains the mirror. They weigh 10lbs with the lexan window.
The engine is a 3.8l engine and will have closer to 380-400hp on 93 octane street fuel if all goes as planned. The cams are my own camshafts built specifically for this engine to work with my intake and exhaust system bolted to the 9M heads. I will have some video of the car on the dyno to post in the comming month. It is my intention to take all of the photographs, some video from inside the car and outside and put together a 15-20 minute DVD type thing on the car. Since I'll have some spare time next winter
that will be my project.
I had originally planned to test the car May 17/18, but due to other projects, it is looking like the Zone 1 48 hours event on June 23/24/25 will be the first outing of the car. I feel confident that I have enough time to make that event.
Charlie, I was surprised at the weight myself. Don't forget, a 964 Cup is not much more than a stripped down C2. The only weight savings it has is - no interior, no undercoating, aluminum hood, smaller side mirrors (90/91), thinner glass, lightened wire harness, aluminum hubs, and of course no sunroof, A/C, etc. Wet, It looks like it will be only about 300lbs lighter than the published wet weight of a 964 cup at 2425lbs.
Tom, I went with the "less is more" approach and didn't go wide/wide body like your 993 conversion so I don't have the large wing or huge wheels and tires. I'm hoping the less aero and tire drag will help make up some. We'll see how well that strategy works when it comes to setting the car up for the track. To give you an idea of weight savings, on Saturday I just finished a complete MoTeC data acquisition wire harness for a BMW. It weighs 2.2lbs in total and runs from the front of the car to the rear. It isn't as complex as the one in my car, but mine shouldn't be more than double this one. Compare that to the factory wire harness which was 55lbs and didn't include all of the gauges the MoTeC replaces. I also cut every bracket I didn't need out of the car, undercoating is gone, and don't forget the car is dry, no oil (15qts) no gear oil (4-5qts with cooler), no brake fluid, no antifreze, no water in the washer bottle, heck no wipers and wiper motor, no HVAC system, nothing but the bare minimum. I have no parking brake assembly, and although my brakes are larger, they are lighter than stock C2 because they are 2 piece with aluminum hats.
It is normal to for the corner weights to be off at this point. This was the first time the wheels have seen the ground and the spring perches are all over the place. Corner balance and alignment will be the last thing that gets done to the car. I was not sure that the GT3 Cup car tires would even fit under the chassis in the rear since they are 26.75" in diameter compared to about 25" stock. I'm still deciding about the final spring rates as well. I currently have 600/700lbs springs which may be too light, I don't know yet.
The mirrors are part of the door and not detachable. They are GT2 Evo doors and the outer skin contains the mirror. They weigh 10lbs with the lexan window.
The engine is a 3.8l engine and will have closer to 380-400hp on 93 octane street fuel if all goes as planned. The cams are my own camshafts built specifically for this engine to work with my intake and exhaust system bolted to the 9M heads. I will have some video of the car on the dyno to post in the comming month. It is my intention to take all of the photographs, some video from inside the car and outside and put together a 15-20 minute DVD type thing on the car. Since I'll have some spare time next winter
that will be my project.I had originally planned to test the car May 17/18, but due to other projects, it is looking like the Zone 1 48 hours event on June 23/24/25 will be the first outing of the car. I feel confident that I have enough time to make that event.
Charlie, I was surprised at the weight myself. Don't forget, a 964 Cup is not much more than a stripped down C2. The only weight savings it has is - no interior, no undercoating, aluminum hood, smaller side mirrors (90/91), thinner glass, lightened wire harness, aluminum hubs, and of course no sunroof, A/C, etc. Wet, It looks like it will be only about 300lbs lighter than the published wet weight of a 964 cup at 2425lbs.
Tom, I went with the "less is more" approach and didn't go wide/wide body like your 993 conversion so I don't have the large wing or huge wheels and tires. I'm hoping the less aero and tire drag will help make up some. We'll see how well that strategy works when it comes to setting the car up for the track. To give you an idea of weight savings, on Saturday I just finished a complete MoTeC data acquisition wire harness for a BMW. It weighs 2.2lbs in total and runs from the front of the car to the rear. It isn't as complex as the one in my car, but mine shouldn't be more than double this one. Compare that to the factory wire harness which was 55lbs and didn't include all of the gauges the MoTeC replaces. I also cut every bracket I didn't need out of the car, undercoating is gone, and don't forget the car is dry, no oil (15qts) no gear oil (4-5qts with cooler), no brake fluid, no antifreze, no water in the washer bottle, heck no wipers and wiper motor, no HVAC system, nothing but the bare minimum. I have no parking brake assembly, and although my brakes are larger, they are lighter than stock C2 because they are 2 piece with aluminum hats.
Last edited by Geoffrey; 04-24-2006 at 08:44 AM.
04-24-2006, 08:19 AM
#19
Apart from the car being amazing, the thing that impresses me the most is that you did it all in a regular ol' garage bay with a canoe hanging above. I mean sheesh....it gives regular joes like me hope!
04-24-2006, 01:24 PM
#23
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Geoffery: I look forward to hearing how it runs.
While I did increase the body size, the fiberglass panels did reduce the weight a bit from the stock panels. I think my wheels and tires are as light or lighter than the stock they replaced too. I see three significant differences: Doors (mine are still stock), roof (gutted but stock sans sunroof), and fluids. I'm about 2500 lbs with 1/2 tank or so of gas (have to check the latest corner weights). My winshield cracked after the last race so I've just switched to Lexan for the front (rear corners and rear window are still glass).
Maybe next years budget wil allow me to have a decent cage built, replace the roof, do a full Lexan conversion, and have the doors replaced. Building a new wiring harness will have to wait a couple years until I retire and have the time to play.
I suppose the bottom line is that while changing/removing many of the major systems gets you a few hundred pounds, it only really takes you to about cup car weight (sort of obvious when you think about it). To get below that, it's a fight for every pound and all the little things add up.
While I did increase the body size, the fiberglass panels did reduce the weight a bit from the stock panels. I think my wheels and tires are as light or lighter than the stock they replaced too. I see three significant differences: Doors (mine are still stock), roof (gutted but stock sans sunroof), and fluids. I'm about 2500 lbs with 1/2 tank or so of gas (have to check the latest corner weights). My winshield cracked after the last race so I've just switched to Lexan for the front (rear corners and rear window are still glass).
Maybe next years budget wil allow me to have a decent cage built, replace the roof, do a full Lexan conversion, and have the doors replaced. Building a new wiring harness will have to wait a couple years until I retire and have the time to play.
I suppose the bottom line is that while changing/removing many of the major systems gets you a few hundred pounds, it only really takes you to about cup car weight (sort of obvious when you think about it). To get below that, it's a fight for every pound and all the little things add up.
04-24-2006, 09:09 PM
#24
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Originally Posted by jeff522
2100 lbs and 400 hp I'm speachless.Awesome 
That's why I'll be working on a 450+bhp 4.0 litre for my comparatively lard-arsed 993RS CS in the coming months....
Geoffrey, you sure know how to set a precedent!
04-25-2006, 08:14 AM
#26
Nordschleife Master
Thread Starter
"Geoffrey, you sure know how to set a precedent!"
I don't think I'm the only one. I have lots of bad influence from friends...
"antifreeze??"
Well I don't have any...Just threw that in to see if anyone was awake.
I don't think I'm the only one. I have lots of bad influence from friends...
"antifreeze??"
Well I don't have any...Just threw that in to see if anyone was awake.
04-25-2006, 12:25 PM
#28
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Geoffrey, you make me jealous, 2100 is the number to beat
I had my first roll-out this year last weekend (on the "Ring")
Pauline lost only 5kg last winter (plastic rear window and other bits and pieces).
P.S.: I' using the 993RS linkage now. Shifting has improved. Thanks a lot for the hint.
I had my first roll-out this year last weekend (on the "Ring")
Pauline lost only 5kg last winter (plastic rear window and other bits and pieces).
P.S.: I' using the 993RS linkage now. Shifting has improved. Thanks a lot for the hint.