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Discussion Starter #1
help me figure out what to do.

i have a 95 mustang gt, with an untouched '95 5.0 cobra motor in it.
it is currently putting out 225 rwhp/275 rwtq,
currently with an aluminum drive-shaft, H pipe, no cats, stock exhaust manifolds, and AC delete.
it is currently legal, though underpowered, (for weight), for the Camaro-Mustang-Challenge spec NASA road-racing series.

i would like to see 265 rwhp, 315 rwtq, which would get me to a great point for running in the hotter CMC-2 division.

in CMC-1, essentially no engine mods area allowed,
in CMC-2, i could switch out to gt40p heads, and a ford racing e303 cam.

these would seemingly be good moves over a stock 5.0, but since this is already a "cobra" 5.0 motor, would these changes be a step forward or backwards?
 

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a cobra motor should already have gt40 heads, look into getting it dyno tuned that should pick up a few hp
 

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a cobra motor should already have gt40 heads, look into getting it dyno tuned that should pick up a few hp
The E cam will give you more horsepower, at the expense of low-end grunt.

IMHO, a better question to ask would be which group will I be more competitive in? If there are a ton of mature CMC racers and cars, and only a few CMC-2 cars and drivers, CMC-2 would be a better choice.
 

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Discussion Starter #4
The E cam will give you more horsepower, at the expense of low-end grunt.
this is what has me so stumped, as to how to get to max hp/tq for agiven weight; considering how little can be done

IMHO, a better question to ask would be which group will I be more competitive in? If there are a ton of mature CM racers and cars, and only a few CMC-2 cars and drivers, CMC-2 would be a better choice.
all advice and opinions welcome
I know the driver modification is MOST important, and I have been investing HEAVILY on that.
At the same time I know that if I am 40hp/40ft# shy, it will be hard for any amt of driver modification to make me competitive.

In that respect it seems easier to 'over-build' and then 'de-tune' an engine for A.I.'s power/weight ratio; and at least then I know I am leaving nothing on the table for a given vehicle weight.

Thoughts?
Doc
 

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Discussion Starter #5
Tune?

a cobra motor should already have gt40 heads, look into getting it dyno tuned that should pick up a few hp
In this spec racing series, we can't really change the tune per-se
timing adjustments and perhaps a little boost on fuel pressure are are tha are allowed. I believe.
 

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In that respect it seems easier to 'over-build' and then 'de-tune' an engine for A.I.'s power/weight ratio; and at least then I know I am leaving nothing on the table for a given vehicle weight.

Thoughts?
Doc

ur right about that, but u don't want to have to de-tune too much. pulling timing isn't bad, but if u have to start adding fuel to richen it up, u run the chance of washing out the cylinders, which isn't good for ur rings and severely reduces engine life.
 

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I don't run CMC and I never have, so double-check everything I say for legality.

The trick to a "spec" series (which CMC is very close to being,) is to optimize everything -- EVERYTHING, no matter how small. A 10th of a horsepower here, a ft-lb there -- it all adds up.

See how much you can mill off the heads to get the surface flat. You're not milling for more compression -- you're milling to repair a slightly warped head.

How thin can the head gaskets be?

Can you also deck the block slightly to guarantee a flat deck?

What pistons are allowed and what can be done to them? Can you find a high-mileage set with lots of carbon build-up?

What about casting flash? Can you clean up the ports on the intake and heads to remove casting flash?

Can the rocker arm preload be played with to increase lift?

What about the plumbing leading up to the throttle body? Can it be replaced with something smoother?

Obviously the car needs to be at the absolute minimum weight.

Run the lightest wheels and tires possible to get the rotational inertia down.

Run the best dampers the rules allow (I seem to remember AST developing a set just for CMC that BARELY is under CMC's cost limit.)

tweak-tweak-tweak.
 
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