How much HP do you really need for Autocross?

[rohrt]

great info much appreciated.

[boneheadzz]

I'm running a 350 Chevy in my TA and do ok at the local SCCA events here. I roughly have 350 hp / 350 tq at the wheels. The group running our events has a short course event in a parking lot and I think they join another group to do a longer course down state at an airfield. I run in the CAM-T class here and usually there are only a few of guys in this class. Many of the smaller cars in their own classes are running quicker through the course than me so I'd say suspension and shocks are where I need improvements. That and my brakes don't react quick enough either. But most of all the driver needs to not steer with the throttle pedal.
Mike

[nokones]

That is called "throttle steering". In some cases throttle steering can be fast, usually with a Corvette or other fat cars. Corvettes like throttle steering. (No, I didn't leave out the " s" in fat. I meant fat as in obese.)

[Nicks67GTO]

That is exactly what I'm talking about. That is a HP number that is easy to achieve and he obviously has a very well setup car.

I have a HT 68 Firebird that I was mostly thinking on for this. It could very well be the last car I ever build. In thinking what I want to do with it, just has me going in circles, I want to be able to travel the country and yet do some fun events. For most any event you build a purpose driven car but the whole point of pro-touring is do everything well is it not? The HT FB car has no motor and is mostly in pieces but has a very solid shell from southern california. It was a parts car for the convertible. If I put all the left over pieces together now it would be red front clip, white shell and blue 400 hood. I kind of like the idea of a Joe Dirt/Road kill Red white and blue car.

Here is circular thinking at work:
I'm having the inner turmoil of stay Pontiac or go LS? Do I go automatic or manual? Do manuals slow you down in a autocross? Would I get sick of shifting all the time? I would love a LS3 crate motor but do you go with the 525HP motor or better to stay with the baseline motor since it would be a 85% road touring car. It would take years to save up for LS swap or do I lower my wants and go with a 5.3? But then I'm back to an iron block. But I'm a Pontiac guy. I have a bunch or parts to throw together a 428. Put the FITechh carb on top and maybe add a TKO to the back. Still would be as light as a LS nor would I get the same MPG. Look a squirl!




I might auto x the convertible if I get some SFC on it, and if another event comes around. The stock seats and belts give me a little concern. They don't hold me in at all.

Its all your fault Nick, talking about how much fun the Des Moines Good guy show was;).

Well...it was pretty fun. I would think a basic 400 Pontiac would scoot your Firebird around just fine. The first gens are pretty light. It seems like 450hp/450tq with a big flat tq curve would be easily achievable with basic components. Stick a good suspension under it and some C6 front/Fbody rear brakes and you're ready to go. Again my 455 is honestly a turd. It's all TQ with crappy top end power and it did ok. If you did a roadkill 1st gen you could probably source a complete used suspension from someone on here upgrading, find a used mill, TKO600, used 9" parts etc. The used car parts world is your oyster with those years. If you're going to do it let me know and ill keep my eyes peeled for parts. One of my ideas with my 70 Chevelle is to start a build thread stating i'm looking to build from used stuff, set a small budget, lay out exactly what i'm looking for and see how much used stuff I can source from here and within the thread.

[rohrt]

Well...it was pretty fun. I would think a basic 400 Pontiac would scoot your Firebird around just fine. The first gens are pretty light. It seems like 450hp/450tq with a big flat tq curve would be easily achievable with basic components. Stick a good suspension under it and some C6 front/Fbody rear brakes and you're ready to go. Again my 455 is honestly a turd. It's all TQ with crappy top end power and it did ok. If you did a roadkill 1st gen you could probably source a complete used suspension from someone on here upgrading, find a used mill, TKO600, used 9" parts etc. The used car parts world is your oyster with those years. If you're going to do it let me know and ill keep my eyes peeled for parts. One of my ideas with my 70 Chevelle is to start a build thread stating i'm looking to build from used stuff, set a small budget, lay out exactly what i'm looking for and see how much used stuff I can source from here and within the thread.

Nick,

I like your thinking.

Glad to see you resolved your clunk issue. Hope to see more pics of you racing your car soon.

[Rod]

I was taking notes on some of the top 1st Gen F body cars that compete in autocross racing and one happened to mention that there comes a point of diminished returns when it come to the HP you need to compete. Then I read were Kyle Tucker is competing with a simple 383 crate motor with a hot cam. I realize its a subjective question but wanted to hear what others feel that point is.

WOW kinda an open end question with lots of great answers here...

my question back is what arena do you want to compete in...

not all autocross is the same...Goodguys autocross usually takes less HP to be competitive...usually. and why i say usually is that most of the courses are short and tight...but once you win and you get the invite to Scottsdale AZ for the big GoodGuys show that track has dual straight-aways and big HP and RPM helps you there and thats how they drop off the entry level cars (I had to drive my ass off with my stock 350hp LQ4) and extra 100 Hp would have helped and if you run optima events I would use about a 500 to 600 hp unit just my opinions

[Boxjohn]

The gearing is big. I'm running a stockish smog era motor. 250hp on a good day. In a 4200+lb car. But I'm right in the power band on all my autocross courses so far, and honestly it's almost enough power. I can steer with the throttle and I can generally get going fast enough to need to brake for each turn. For someone learning, I don't know that more than 300-350 would be helpful if the gearing is right. If you're sort hanging out at the bottom of second gear though, then power may be wanting. And of course most things that build horsepower raise the rpm range, so if you're trying to get to stay in first or stay in second as opposed to upshifting, a high winding build may help.

[CanMove]

I have never even been to a pro touring event or a autocross. This is something i want and iam going to get involved in... Sucks being the FNG but this is not gonna stop me never has...!!!!
I've been dealing with Scot from www.gnsperformance.com and I have already upgraded all my brakes to Baer 13" drilled and slotted disk brakes at all 4 corners and 4 piston calipers.
My Grand National is in the shop as we speak getting a Ride tech Tru Turn Level II Coil Over set up installed.. Also some more suspension goodies from Detroit Speed.
Next is my engine work.. The car is a 26K original mile car... Pretty clean if i do say so myself!!!!

How much horsepower do i need?? That has been a question of mine and this thread has been very helpful...

Any other G Body guys here?? Just curious what your horsepower and torque ratings are... Just trying to learn here please so forgive me... Im new and excited...

Rich T

[Space Dynamics]

Well Hey I autocrossed my 79 Camaro with a stock 350, 170 HP, 145k miles on it and stock brakes, and it was great! Never felt like I was short on power (first time autocrossing it).
Really you just want to make sure you are on top of the maintenance so you know nothing will grenade when you go!

What really surprised me is how well the car actually handled compared to my E30 and E34 that I used to autocross.

[Ghiaguy]

I think the 'How Much HP do I need" question should be the last question you ask -- The first question should how am I going to stick what HP I have to the ground and get it to stop should be the first!!!!

You need TIRES, Brakes and the suspension to KEEP the tires and brakes planted





Look at the tires if you don't think that there is some down force at play there in the second picture

Second, Weight is your enemy -- enuff said there

I was at Fontana last weekend for the optima street car challenge -- REALLY nice cars there -- I would recommend attending a few events, see what other people have done, find out what works and what doesn't -- -- There was a all wheel drive GT-R there and it was beyond belief for acceleration and handling -- The new Vettes are great platforms stock --

That reminds me -- -- I need some sticker tires, some really sticky tires!!!!!!