Bare CSX's?

[Cobra #3170]

Originally Posted by ERA Chas

Nor did I. Thanks for weighing-in here Bruce, your car was discussed earlier.
So I can ask-why did you paint your car silver? (Besides the fact that it looks beautiful) I though that a 'take-no-prisoners' guy like you would save 50 pounds with bare skin.
I know, I know-800HP, what's 50 pounds?...

Good question,
When I first put in an aluminum engine I went all out on weight, I even had a magnesium water pump, 25 pound clutch and flywheel, a standard bell housing because my Lakewood was heavier, magnesium Jerrico trans, small battery, etc. etc. The car weighed 2180 with 10 gal of gas and 10 qts of oil. The handling was not good and the car was very unpredictable although fast in a straight line. I then decided to stiffen the frame with an insert using a round tube with a vertical blade rosette welded in the tube. The car then went to 2270 ponds but handled much better, after that I added the dry sump system, fuel injection and supporting electronics. Car weight is now 2350 but very drivable even in the wet, just illustrating that structure trumps weight but weight is still king if you can get it. A bare original Cobra is pretty ugly and needs lots of filler for acceptable paint. A polished Kirkham is a 1000 times nicer than any original and I am not sure you could ever get an original that nice even with a ton of body work so I stayed with paint to cover the many flaws of a hand hammered body. If I were to build another Cobra today I would start with a Kirkham and use my suspension, modify the frame and use carbon fiber brake rotors and a high horsepower Windsor based small block of about 650 HP that would rev to 10,000. I'll bet you could bring that in at about 1900 lbs, it would be killer fast and handle better than just about anything out there until aero took over, of course you could do a Daytona coupe in Carbon to solve the aero issues.

[ERA Chas]

More thanks for your car's resume and your great build progression. Very refreshing to see serious tech on here.
I think you and Morris have achieved the most success for road racing Cobras with the difference being yours is in more of a conventional configuration. You both agree on many points like starting with a KMP, stiffness, power required and lightness.
Just to pick your brain, an all aluminum, 9.5 deck small block (of 358 to 427 ") would weigh in around 470 pounds. Why such a modest power figure (650) when with Cup technology (na), you could achieve 730-800HP and a conservative 9000RPM top?
It's great reading your experiences and views.

[mreid]

Originally Posted by ERA Chas

Just to pick your brain, an all aluminum, 9.5 deck small block (of 358 to 427 ") would weigh in around 470 pounds. Why such a modest power figure (650) when with Cup technology (na), you could achieve 730-800HP and a conservative 9000RPM top?
It's great reading your experiences and views.

I would think the old cost/reliability formula comes into play here, but I also look forward to Bruce's answer.

Mark

[ERA Chas]

Originally Posted by mreid

I would think the old cost/reliability formula comes into play here, but I also look forward to Bruce's answer.

Mark

Bruce has obviously NEVER let cost stand in his way. Example: magnesium water pump!

[mreid]

Originally Posted by ERA Chas

Bruce has obviously NEVER let cost stand in his way. Example: magnesium water pump!

I don't know, Chas, I think he felt safe that as it is a water pump, at least that part of the car couldn't burst into flames!

[RodKnock]

Originally Posted by mreid

I don't know, Chas, I think he felt safe that as it is a water pump, at least that part of the car couldn't burst into flames!

I don't think water helps put out a magnesium fire.

[Cobra #3170]

Originally Posted by ERA Chas

More thanks for your car's resume and your great build progression. Very refreshing to see serious tech on here.
I think you and Morris have achieved the most success for road racing Cobras with the difference being yours is in more of a conventional configuration. You both agree on many points like starting with a KMP, stiffness, power required and lightness.
Just to pick your brain, an all aluminum, 9.5 deck small block (of 358 to 427 ") would weigh in around 470 pounds. Why such a modest power figure (650) when with Cup technology (na), you could achieve 730-800HP and a conservative 9000RPM top?
It's great reading your experiences and views.

I would use the short deck block and final weight would be around 380 pounds according to my engine guys. Engine acceleration rates would be unreal, think old trans-am cars with better heads Ti rods etc. HP could get close to 700 which would be way more than adequate at 1900 LBs. My car has so much torque now that we tried to kill some of it to help traction by going really big on the cam 292 @.050 N and 296@ .050 X
The small block would do that and still have a big top end and lots of flexibility with that rpm range. I stuck with the FE because it is an original car if it weren't, I would have gone the small block route. At one time I was looking at a DFX Cosworth Turbo engine but again the originality thing got to me so I did not do it, had a hell of a deal on one and it was under 400 lbs complete.

[ERA Chas]

I understand now. My experience was with alloy 9.5's at 427 and 460" with power between 625 and 710HP (solid rollers, Kuntz heads, Callies strokers-those were 470-480 pounds.
You're talking smaller, lighter block and tiny stroke cranks.
Cosworth Turbo eh? YIKES!
Please post your next mods on 3170 or your next project. I'd love to follow along.

[Cobra #3170]

Originally Posted by ERA Chas

I understand now. My experience was with alloy 9.5's at 427 and 460" with power between 625 and 710HP (solid rollers, Kuntz heads, Callies strokers-those were 470-480 pounds.
You're talking smaller, lighter block and tiny stroke cranks.
Cosworth Turbo eh? YIKES!
Please post your next mods on 3170 or your next project. I'd love to follow along.

Thanks for asking,
The Cobra is sitting under a car cover waiting for it's lazy owner to install a new flywheel and some larger front tires for this summers autox season.
I am currently working on my Ford GT trying to get into the 2011 Optima Challenge, I have upgraded because that blown LS chevy killed me on the straights last year. I have added a 6' wide carbon fiber rear wing mounted above roof line, a 7" deep carbon fiber front splitter, Penske shocks, 19x12 rear wheels and 19x9.5 front wheels, heavy springs, lowered it 2" from stock and added skirts to keep air from entering at the sides of the car. I also added a 4.0 L Whipple and long tube headers, and two MSD Boostapumps because we were running out of fuel on the chassis dyno. We are currently working on a new mass air flow and improved air cleaner to get rear wheel HP over 900. First Dyno runs were 862 RWHP and 790 lb/ft. The car melted the cats and plugged the exhaust the first time out at an Optima qualifier. I am working on a fix for that and will be running it at Willow Springs in May, hopefully all will go well this time. It is pretty quick now but weighs 3470 lbs so it is not nearly as agile as the Cobra.
It is lots more stable than the Cobra above 100 mph though and pulls like a train up there. Here is a link to a Youtube video where the cats are beginning to plug the exhaust. The speeds in gear are 1st 62, 2nd 102, 3rd 140 check out how quickly it pulls 1st, 2nd and part of 3rd it isn't the Cobra but it ain't bad.

http://www.youtube.com/watch?v=8vZcU6uSW1o[/url]

[ERA Chas]

Dude,
That thing corners flatter than my grammar school sweetheart. It pulls merely incredibly. You are working in a league apart from us.
Do you run JPL in Pasadena?