how much HP

[scootter]

Been there done that with the dyno!
Scott

[Cobra #42]

Nantucket you are so right on, we see so many people with "Huge HP" in the DFW area and 95% haven't a clue on how to drive. I really enjoy taking a car with 150 less HP on a road course and walking away from other cars in the twisties lap after lap while running street tires and the big HP boys are on racing slicks. I have to tell you, we have a lady in our DFW group that does come to the track ever chance she gets and my money is on her any day, because she practices. High performance driving needs to be practiced as often as possible. I guess it's one of the things I will never understand, owning a HP car and not being able to drive it to the limit. (except 50 feet at a time). Drivers find a local school in your area and go play, you don't have to go any faster than you are comfortable. Most track day events have instruction, get some. And then when you get into a situation on track or off, your talent gauge will not be OUT. db

[Excaliber]

Big horse power is nice, but STREERABILITY is nicer! You will be traction limited at some point. Keep the compression within the 'pump gas' range and the cam profile should match your expected cruising rpm, speed. Those are the two keys to maximize enjoyment on the street.

[speed220mph]

I have 575 hp from my FE 427 and, well, I would like more! See below:

[Red S/C]

One of the posts here suggests you'll lose between 35% and 45% flywheel to rear wheel horse power. Those figures are considerably higher than anything we've seen in the race cars we have built.

[BLUE427]

Maxum101.....

Get The Poly Mounts, I Just Put Them On For That Reason And Like Them Alot, Stops Alot Of Driveline Vibration Also.
Brakes Are Fine, Swaybars Might Be A Upgrade, I Havent Done That Yet, I Have A Roush 427, And Like It Very Much.

Blue427

[Cobra #3170]

Originally Posted by Red S/C

One of the posts here suggests you'll lose between 35% and 45% flywheel to rear wheel horse power. Those figures are considerably higher than anything we've seen in the race cars we have built.

Absolutely right, I have seen between 15 and 17% loss depending on the transmission make and drive line configuration. The major reason for low rear wheel numbers is that the engine never made the claimed HP at the flywheel.

[SP01715]

Originally Posted by Madmiles442

Idon't know Voss. I put the Olthoff sway bars and poly bushings and it makes a HUGE difference in handling!
Just my $.02

My car was set-up by Olthoff, but now that it is on the west coast Eric Voss has done some work on it for me. He is in SoCal and all he does is Cobra's, GT40's and Coupes. Great guy and does great work.

[Flyin_Freddie]

Horsepower's a little like sex...

...if a little is good....a lot's GOT to be better...!

[392cobra]

Originally Posted by Red S/C

One of the posts here suggests you'll lose between 35% and 45% flywheel to rear wheel horse power. Those figures are considerably higher than anything we've seen in the race cars we have built.

Stock/standard exhausts will drive the losses up that high.

You can't expect to get good rwhp numbers with low losses from the crank without a special effort put into the exhaust.

[jdean]

Powerful brakes are good too to go along with the HP and speed....dont forget about those.

[vettestr]

Originally Posted by Flyin_Freddie

Horsepower's a little like sex...

...if a little is good....a lot's GOT to be better...!

Horsepower is sex !
I would much rather die from too much than die from not enough.

[Cobra #3170]

Originally Posted by 392cobra

Stock/standard exhausts will drive the losses up that high.

You can't expect to get good rwhp numbers with low losses from the crank without a special effort put into the exhaust.

If you don't dyno with the equivalent or entire vehicle exhaust system you are not going to get accurate in-car results and a correct tune. I know that is difficult but not impossible especially with the outside systems used. I have dynoed all my engines this way and it translates well to rear wheel numbers IE 15 to 17% loss. The fuel air ratios, cam timing and ignition timing are also much closer to ideal. You could also do most of the tuning on a chassis dyno but changing cam timing can be a challenge in the chassis.

[aa4v]

I recently had my BDR Roush 402SR/TW/TK0600 on the Dyno at Performance Engineering. The dyno run that came with the engine from Roush showed 486 HP/487 TQ (at the flywheel). The PE dyno run showed 394 HP/383 TQ at the wheels.

[Got the Bug]

aa4v - I've got the same set-up in my SPF, so that gives me a pretty good idea of what my HP and TQ is at the rear wheels. Thanks for posting that.

[Red S/C]

aa4v - those numbers would be very close to the numbers we have seen. The engine (533 dual 750's) I currently have did 696 hp and when we do the chassis dyno we're looking for around 570 to 580. Sidepipes and headers are a big part of it. We used 2" pipes on the headers and 4" on the sidepipes with the spiral inserts which we had great success with in the past.

[FUNFER2]

Maxum 101 (and others)

I'm wanting more power also. Currently, with this engine, I have 400 @ the wheels. So, the numbers I have in mind is apx. 550 to the ground or 600 + at the flywheel. What I would like to bring to attention on this thread is, yes, high HP/TQ is just plain kick in the pants fun, and like I said, wanting more.

But, how much do we want to suffer in gas mileage vs the power we crave ?

I get apx. between 10-16 mpg city/hwy, depending on how much fun I have with the throttle.

With you guys having the 482 cu. or so, and having say,....500 + RWHP, how is your mileage ? (please be honest)

If it drops down to 8 mpg, I would have more serious thinking to do.

Maxum 101- have you thought about this issue too ?

[Nantucket427]

MPG what is that? The EPA sticker must have been lost in transit. I have never even tried to determine it. Will it stop me from going somewhere? No. I try to find away to take the car everwhere I need to go. My wife said I even make stuff up so I can take the car. I own a replicate because I want to drive it. I don't own an original to look at, I want the full experience. I am surly not worry about operating cost.

[Silverback51]

Originally Posted by Nantucket427

MPG what is that? The EPA sticker must have been lost in transit. I have never even tried to determine it. Will it stop me from going somewhere? No. I try to find away to take the car everwhere I need to go. My wife said I even make stuff up so I can take the car. I own a replicate because I want to drive it. I don't own an original to look at, I want the full experience. I am surly not worry about operating cost.

Well said.

[FUNFER2]

I do agree. Six other cars and I went to Kansas and back on the Hot Rod Power Tour. When we were planning on going, we all agreed to not worry about gas prices, and have a @hit load of fun, and we did. It was a blast and were going next year.

Come on guys, it has matter to at some point, especially with todays cost of gas.

What would you rather do, stay home and save up money for a while because your cobra gets 8 mpg and sit there wishing you could drive it or go anytime you want because you get say,...15 mpg.

If I still had my Pro-Street Camaro, I would not even think, about driving as much as I do the Cobra. It actually did get 8 mpg. That's one, reason I sold it to build the cobra.

(out of curiosity, what does your 462 get, honestly) ?

Like I said, at some point, you have to say,.....enuff z enuff.