Best Power Adder for Track/Autocross

[LowFast]

So I have my engine, 4.6 3v out of a 2006 Mustang with the 5spd maual. I have debated staying NA or going with a power adder, these engines respond so well to forced induction and it is more cost effective than NA. The question is what is the overall best pweradder for autocross and occasional track use, centrifical, positive displacement, turbo? I plan to stay fairly low boost while running on the stock internals and any of the three will easily get me 400hp+ at the wheels, but is one better suited for track (not drag strip) than the others?

[Murdermerc]

The centrifugal blowers power comes in a little late for autocross , I would go with a whipple since the power is instant.

[705.0Merc]

Turbo. Easy to adjust boost, and you can choose you spool time by the exhaust housing size.

[Bryce]

I have no issue with power out of my 289 in my light car. You should be fine.

[LowFast]

I have no issue with power out of my 289 in my light car. You should be fine.

Bryce,

Do you know what sort of numbers your 289 is putting to the wheels? I can realistically squeeze 400hp to the rear wheels without having to go into the block and raise compression.

[Bryce]

Maybe 375 on a good air day, at the crank.

FYI, I was hitting the rev limiter, 6400 rpm, in first gear at the GG autocross yesterday. That equals about 50 mph.

[SS PUNISHER]

Variable geometry turbo FTW!

[RSX302]

So I have my engine, 4.6 3v out of a 2006 Mustang with the 5spd maual. I have debated staying NA or going with a power adder, these engines respond so well to forced induction and it is more cost effective than NA. The question is what is the overall best pweradder for autocross and occasional track use, centrifical, positive displacement, turbo? I plan to stay fairly low boost while running on the stock internals and any of the three will easily get me 400hp+ at the wheels, but is one better suited for track (not drag strip) than the others?

For ease of install and quick power gains, superchargers are hard to beat. Turbos can respond well with no lag if sized properly. My tiny twins come in to full boost (10psig) by 2500rpm and drives nice. Positive displacement superchargers are immediate boost and can have some issues getting the tires to stick..lol. With the same boost levels, turbos will get you a minimum 40-50hp more over a belt driven blower.

I'm a turbo guy, but with the smaller 4.6 and lower power range, I would lean toward the positive displacement power adder for primary street/autocross use with occational larger track use. If you were using more for higher rpm/higher speed (larger tracks) then I would lean toward turbos.

[WS6]

How hard would it be to get an Eaton off a 03/04 Cobra? That's what I would do but I have no clue what the market is for take off parts on those cars. The water to air intercooler makes fitting it into your small car easier also. Certainly do not go with a centrifugal blower. ProCharger and Vortec make good products but they are not suited for autocross.

Speaking of the 03/04 Cobras, has anyone else noticed how those cars seem to have fallen off the face of the earth? They were huge a few years ago. Now I don't see them anywhere. What happened?

Oh, one more thing, there was a Saleen S281 that would solo2 in the Atlanta region. I believe he was mainly stock under the hood but he didn't have issues coming out of corners hard. I was impressed with how well he could put the power down given the blower.

[Vegas69]

A Miata may whip your ass in autocross. Power is the last thing you need to be concerned with. Road racing and the speed stop, drag race events are a completely different story.

[rustomatic]

I remember seeing a turbocharged Datsun 510 at an autocross years ago, and it was a complete mess. The thing ran fine, and handled fine, but the power, which was not astronomical (but high for the car), was not the hot setup for autocross; the car spun out every chance it got. Falcons do very well, in turns, with standard power levels. Even with a perfectly linear application of power, 400 will be a mess for most people in an autocross situation.

A couple years back, I found myself at an autocross in Arkansas, and there was a Viper group there. They were funny, to say the least; guys in 240SXs were kicking the crap out of them, as was a guy in a relatively stock Honda Civic...

[SLO_Z28]

The single most important thing in any autocross car is the driver. I would look into a school like Evolution Motorsports before doing anything to the car. Adding a supercharger will kick you into a modified class which is VERY fast VERY modified cars.

[WS6]

You can always run time only but you're not really competing for anything then.

[Ron.in.SoCal]

Good point Trey, but some of our cars do (at least mine does) not fit classic SCCA classes compared to ASCS. Come to think oif it, I don't even fit ASCS class...

[LowFast]

Not concerned with classes, just want to run for fun and against the clock. It seems to be the solution is either to stay naturally aspirated or go with a positive displacement/twinscrew set-up to help pull the car out of low speed corners. Also I think the PD unit would be the most fun for shenanigans on the street.

[Rod]

A Miata may whip your ass in autocross. Power is the last thing you need to be concerned with. Road racing and the speed stop, drag race events are a completely different story.

I agree with vegas on an autocross track power is needed but in limted amount, miatas are dang quick around an autocross track with there little 150HP motors, its all suspension and tires and

The single most important thing in any autocross car is the driver. I would look into a school like Evolution Motorsports before doing anything to the car. Adding a supercharger will kick you into a modified class which is VERY fast VERY modified cars.

as SLO says also the driver needs to be screwed in tight

You can always run time only but you're not really competing for anything then.

competing for fastest time, and fastest time is the winner, and the winner gets all the toys