how much power do you really need?

[andrewb70]

I've never driven a car that I didn't feel needed just a little more power...LOL

Andrew

[mpozzi]

About half of what I've got ...

Mary Pozzi

[Randy67]

All these replies and no one quoted Donohue: "If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough horsepower."

Like a few said, once you get to 500 hp, you probably have enough. Get the rest of the car to handle that quite well, then you can go for more hp. Just my 2 cents worth.

[cornfedbill]

About half of what I've got ...

Mary Pozzi

Mary, I'll take what you don't need. I could use a bit more...

[Space Dynamics]

I sure wouldn't mind a little more than 170 myself. :-[

And even now I plan to do the suspension and brakes before I add power... Partially due to emmissions blehh!

[Cobra 498]

It is weight to HP and torque that matters I have a car that puts down 862 RWHP and it is very controllable but it is very heavy, my other car puts down about 725 RWHP and it is almost undrivable at more that 40% throttle opening. First car weight to hp= 4.25 with driver second car weight to hp = 3.50 with driver. Small number but huge difference in drivability

[sheck44]

Would be very interesting to hear about the specific details (vehicles, suspension etc.) between the two vehicles
Cheers
Steve

[CarlC]

Having too much power can make the car not much fun to drive. The throttle pedal becomes a tire spinning switch which just wastes everything.

The other drawback to making big horsepower is the expense. Sure, 1000hp sounds "easy", but to go from 500hp to 1000hp (2x) the right way will cost 4x as much (minimum) in time and money.

[Cobra 498]

First vehicle is a 2005 Ford GT with a 4 liter Whipple running 26 lb of boost, it has an Accufab throttle body, long tube headers, x-pipe, Magnaflow mufflers and 2 MSD fuel pump boosters it has about 59% rear weight which helps traction. front tire 265x18 rear tire 345x19 Michelin PS2. Suspension is independent front and rear with aluminum arms and uprights with modified geometry to improve handling. The car has skirts made from conveyer belt to keep air from entering from the side. It has a 7" extended carbon fiber splitter and a 72" wide GT1 wing at the rear, car was also lowered 2" from stock. The only electronic aid is ABS, It has a full belly pan with diffuser (stock) and very good aerodynamics overall. Car weight is 3470 less driver.

Second Vehicle is an original 1966 427 Cobra with modified independent suspension front and rear. Geometry is improved over original, weight bias 52% rear. Tires are 315x18 front and 335x18 rear. engine is a 498 CID Shelby aluminum block with moldex crank and Carrillio rods, 15 to 1 compression, blue thunder high rise heads with Ti intake and exhaust valves. Cam is comp with over 290 degrees on both intake and exhaust at .050" max rpm is 8000. engine has a 1650 cfm TB with 65 lb injectors run by a classic fast controller in alpha N. Max crank power 850@7600 max torque 632 @ 5700. Rear end ratio 3:31 with Jerico 4speed dog trans. First gear is 2.2 to help control wheel spin. Throttle is 6" of travel with the first 4" giving 25% opening to help modulation. Car weighs 2370 with all fluids less driver. The body is completely stock with no aero aids other than stock radiator vane.

[octane speed shop]

It all depends on how you are going to use the car, road course, autocross, pure street miles. one thing that can make some difference is how it's geared. did you mention what your trany is, or ring and pinion?

[NJSPEEDER]

More power is a nice thing but being able to use all the power you have all the time is ALWAYS better. Work on chassis and driver upgrades and worrying about adding power as your wallet allows.

[79-TA]

Would be very interesting to hear about the specific details (vehicles, suspension etc.) between the two vehicles
Cheers
Steve

Bruce was pretty modest to not mention that one car completely dominated the '09 OUSCI while the other was a top competitor in other years.

[lxmodguy]

I didn't see anyone mention this, but how you achieve the extra power plays s role. Ie electronics, turbos etc. Guys run 275 drag radial cars now well into the 4 ' s in the 1/8th with turbos and electronics. Street cars w proper sized turbos and proper tuning can make 700-1400 without a lot of hassle.

[Tomswheels]

It all depends on how you are going to use the car, road course, autocross, pure street miles. one thing that can make some difference is how it's geared. did you mention what your trany is, or ring and pinion?

This x2. In an Autocross my 250 RWHP 3000 lb car is very competitive. On a road course its not enough, but 475 RWHP would be plenty...

[David Pozzi]

600hp with 200 tread wear tires is a very nice combo for a PT car. You will be well hooked up from second gear & up with pretty good wheel spin control in first if you are careful. With 650 you have to be a lot more careful in first, & second can buzz the tires on the street. Bad Penny with 700 plus at the crank is tougher to hang on to depending on the surface, second gear traction is more like first gear traction in a 600 horse car, wheel spin with just quick throttle application. It requires skill & experience, & is a wild ride. On cleaner pavement like a road course, it gets better. A turbo or supercharged car will have more torque & spin the wheels even more.

[David Pozzi]

To be competitive, if you have the suspension already figured out, 600hp is about all you need.

-Dale

I like this answer, especially for a truck with less rear weight bias.

[Justin@EntropyRad]

350-400whp if you can make it stick...will certainly hurt lots of feelings, and land you in jail..so that's good for me

In my opinion, at least

[rockytopper]

I was always happy with my bone stock LS1 I think it's about 350 @ the crank. That was until we drove it up to Rocky Mountain national park and pikes peak it was a breathless dog trying to climb in altitude. I knew then why big power and torque is needed lol. I'm still happy with the 350ish @ sea level though.

[hotrodalex]

I was always happy with my bone stock LS1 I think it's about 350 @ the crank. That was until we drove it up to Rocky Mountain national park and pikes peak it was a breathless dog trying to climb in altitude. I knew then why big power and torque is needed lol. I'm still happy with the 350ish @ sea level though.

I wasn't a big fan of turbos until I started going back and forth between sea level and the mountains.

[no1udknow]

Thanks guys, lot's of great answers and info in here. I am a poor, cheap ******* so I won't likely be running big road course events. Probably the occasional autox. I also like to visit my family who live up in the mountains, as well as the occasional trip to Tahoe to our family cabin. I want a good road machine that I can throw into a corner with confidence, but when I show up at an autox I don't want to look feel a geo metro at the drag strip. I have done much deliberation and I think I have found the ballanced answer for power, cost, and meets my needs.

I have really wanted FI in my truck. I spent a lot of time as a motorcycle mechanic doing performance builds and dyno tuning and I think that I could do a lot with an FI system. Tht being said here in CA, I have a hard time finding an LS donor for less the $2-3k. Si I have been looking at the late 90s vortec trucks and Tahoes. I can pick up a complete running vehicle for under $1k which leaves me financial room for some mods and a manual trans setup. I will be looking for a 5.3l for my daily driver 2001 gmc though because the current engine has 289k miles on it and has developed a cold knock. :-( but I think staying in that 380-400HP range will be sufficient with some chassis modifications.