In the market for a new race car

[lateapex911]

Well, I've done all the peripherals and given theoretical 15% driveline losses, I should top out at 203hp at the wheels. I'm already at 195 or so horsepower... Does this mean that if I have the motor itself optimized for performance I'll only gain 8 more hp?

Maybe. Maybe less. Maybe more. Your car might be an overachiever. The Process is a big picture view, but each individual car has no guarantee of hitting exactly 25%..

There are a myriad of tricks and details that yield HP at the rear wheels. Some cars respond well to some of them. Some cars respond very well to a balance and blueprint, others, not so much. Sniff around and see what the experts on your engine have to say.

But, just off the top of my head, folks have done things like this to chase 'full build" power.

• Test multiple heads to find the stock examples that flow best.
• Test Multiple intakes to..." " " ".
• Buy buckets of stock pistons to find the lightest and balance to that.
• buy Buckets of XXX part, to find the lightest and ..." " " ".
• Build may headers looking for the best toque curve and Hp.
• Build extravagant cold air boxes to pull the most volume of the coldest air.
• Tweak engine oil pumps for proper pressures.
• Install crank scrapers.
• Spend days dyno tuning with the ECU to build the best fuel/timing curves.
• Tweak fuel pressures and control fuel temps.
• Reduce rotating masses wherever possible.
• Improve cooling and flow efficiency.
• Flow bench all porting mods.
• Reduce driveline rotating mass.
• Reduce internal engine drag.

And on and on....that's just off the top of my head...and a good engine builder has a far far better list. (But, he keeps his mouth shut, no doubt)

[gran racing]

25% is the total gain that IS expected from a TYPICAL full IT engine build,

Ohhh! Thanks for clarifying that. Yeah, not 25% from just the build - sorry about that. For my particular car, those extra bolt ons helped but it was the engine build portion that really brought it all together and is when I saw the gains. My engine saw about 12 hp gain, more in torque which to me is huge especially when talking at the wheels. Like Jake said, every engine will respond differently. Maybe your engine responds well to the simple improvements like a good header, exhaust, and intake?

[RedMisted]

Thanks Dave and Jake for the replies.
I've been all around the car but the engine is basically virgin territory for me. A problem with my car is that nobody else that anyone knows of is road racing a 3.8 liter V6 Mustang. Now, while there are drag race engine builders out there who may have constructed a few of these motors for the quarter-mile, I'd doubt that I'd use their help. I'd hate to be the guinea pig here for anybody else that is thinking of building a car like mine, but I guess that's the price of being an oddball...

[gran racing]

Time for you to do some research. Speak with people are familiar with your Mustang. American Sedan drivers? NASA? GrandAm? Call a few shops up to see what types of gains they'd estimate. You should be able to get a general feel for things.

[shwah]

My machine shop AMT Racing Engines does mostly drag stuff. They have done a decent job for me, Mathis and Albin over the years. In my case they did all the machine work and Chuck did the building.

Don't be so quick to discount those types of shops, just make sure they know what you are trying to accomplish and what the restrictions of the class are.