Cobra Build Update-Dyno Run - Page 2

gsharapa · #21 (**permalink**) 11-26-2010, 06:48 AM

One of my friends here in Dallas also has a KC 496 with hydralic roller in his SPF and his made 554 RWHP but it was dynoed when it was 50 degrees and no humidity. Humidity is a big kill factor on the dynos but a lot of guys that have dynoed their Cobra seem to loose 20 to 25% from the crank to the wheels. I had a SPF 6 years ago with a 427 small block made 638HP at the crank and 465 at the wheels which was 27% loss but we thought the single stage clutch was slipping a bit. I extremely pleased with the 530HP at the wheels with the conditions. The car is carbon fiber and with the aluminum engine is only going to be about 2,000 lbs so this much HP is way over kill anyway. At the end of the day it is what it is and I agree with others that different dynos will probably give you different results. I really put it on the chassis dyno to dial in the air fuel mixture through out the band as I'm much more concerned on having that correct vs the HP...........

ERA Chas · #22 (**permalink**) 11-26-2010, 07:14 AM

Quote:

Originally Posted by gsharapa

....a lot of guys that have dynoed their Cobra seem to loose 20 to 25% from the crank to the wheels.

OK I see our difference. All the IRS Cobras I have seen and read about, including my own, have been between 15 and 19%. And yes clutch slip will change the percentage of loss.

SSSammy · #23 (**permalink**) 11-26-2010, 09:10 AM

Fwiw ... my KC482, mild hyd roller cam, Stage II heads, 750 cfm Holley 4150, was originally built by Keith in 2007 and then tuned by Rob in Plano. It ran 571 HP on Keith's engine dyno and 422 HP on Rob's chassis dyno in 2007. Then in 2008, it was rebuilt by Keith after a rocker shaft failure at Run N Gun, and it dynoed 566 HP at Keith's and 418 HP at Rob's.

So it could be some combination of parasitic losses, plus some variation in how the dynos are calibrated. The car has ERA headers and side pipes, McLeod Al Flywheel, 12" McLeod PP and disc, Tremec 600, and Jag style IRS.

Sam

gsharapa · #24 (**permalink**) 11-26-2010, 10:11 AM

Thanks Sammy. Good example of a ERA with a 482 and the loss is in that 22 to 26% range...as the engines and cars were dynoed on the same ones.

wedgerton · #25 (**permalink**) 12-01-2010, 04:34 AM

Your car looks and sounds great.

Where did you have the Dyno test done? I'm almost ready to be there and would like to maybe do the same.

Wayne Edgerton

gsharapa · #26 (**permalink**) 12-05-2010, 10:59 AM

C & S Performance in Plano, TX (north suburb of Dallas). Rob Camp is the owner and tuner...

Mike_I · #27 (**permalink**) 12-05-2010, 12:52 PM

Where would one buy an Exact Cobra? Pricing?

gsharapa · #28 (**permalink**) 12-05-2010, 06:41 PM

Austin, Texas. Roger Bolick built 11 cars and finishing new demo right now. He is focusing on stock piling all the new parts he has developed and then plans to build another 10 cars in the future so he doesn't have any right now unless he would sell his new demo. After I saw a couple cars and read up on Double Ugly's build I really wanted one as the engineering and quality is really something not to mention it is carbon fiber.

Keithc8 · #29 (**permalink**) 12-05-2010, 07:02 PM

Gary the car turned out real nice. I really like the color of the car. Sounds like it is a real light weight car. The Kirkham I have comes in at about 2100lbs.
On all of the dyno questions I would need to ask Rob if they have a way to calibrate or check the chassi dyno. On the SuperFlow engine dyno we hang actual wieght on the dyno strain gauge to check the torque and calibrate it. It almost sounds like the chassi dyno is reading less than when Rob first got it.
In the end they are tools that we use the test the engines and tune them. I know that my NHRA drag race customers run pretty much dead on to what my dyno says they will. Look forward to seeing you at the Texas meet in March.

Thanks, Keith

gsharapa · #30 (**permalink**) 12-05-2010, 07:06 PM

Thanks Keith. Roger told me this car's weight was 2,000 with the iron block 427 center oiler so probably just a bit lighter with the all aluminum engine you built me. I agree on the dyno comments and really I just wanted to get the air/fuel close. We only leaned the air bleeds out a bit from your dyno tuning of just the engine going from 31s to 36s.

James Baldwin · #31 (**permalink**) 12-08-2010, 03:12 PM

gorgeous Gary. Congrats ! cant wait to see it in person

gsharapa · #32 (**permalink**) 01-09-2011, 10:36 AM

Well finally finished the Cobra yesterday with installing the truck and door weather stripping and saftey wired the wheels. Need to paint the Goodyear tire letters sometime (maybe I can get my wife to do it like Gary Morris had Susan do) but it's pretty much ready for some test runs. Hopefully this snow will dissappear as fast as it's coming down today and I can get the car registered in the next couple weeks and start heading out.

Feels great to be back in a Cobra!!!!!!

rodneym · #33 (**permalink**) 01-09-2011, 11:23 AM

Simply beautiful!
Keep those updates coming.
And maybe a little video of that maiden voyage.

Buzz · #34 (**permalink**) 01-09-2011, 11:32 AM

Congrats Gary! These Exact carbon fiber cars are among the most beautiful and correctly proportioned Cobras out there. An absolutely stunning looking car.

gsharapa · #35 (**permalink**) 01-09-2011, 12:24 PM

They are so accurate. I'm really impressed with it and all the Shelby and Kirkham stuff fits perfect. He really needs to build more cars as many are asking where they can by one...