how much power do you really need?

[no1udknow]

So I have been doing a lot of contemplating duri g this winter down time and I keep bouncing back and forth between directions for my truck. The problem is every time I start looking at engine setups and trannys, my brain automatically screams "more power". I'm sure we all fall for this trap, especially when we see other people posting their 1000hp ls builds. But how much power do I really need to be competitive. I would assume that so much power would not be that usefull in pro touring as keeping that much power attached to the asphalt in a corner could prove tricky. So who is racing and doi g well, and what kind of power are you making, and how heavy is your car?

[vintageracer]

"How Much Power Do You Really Need?"


A LOT LESS than you would think!

I always considered the guys who boast about the big HP they in their vehicle to have "Big Dick Syndrome". Mine is bigger than yours! Big Deal. Well I guess it really could be a big deal!!!!!

RARELY can folks with 500+ HP "Put That HP To The Ground" on a road course to the point that all that extra HP really helps and even MORE RARE is a driver that has the skill and ability to drive their vehicle to it's capability with 500 HP much less a 1000 HP. Better Brakes, Better Suspension Setup and most importantly Better Driver Ability is going to trump 1000 HP every time in amateur road course/autocross Motorsports and particularly in the type of events PT enthusiasts like to attend.

Blasting down the straightaway with big HP and creeping though the corners due to lack of driver skill and car setup seems to be more and more the norm these days!

[Schwartz Performance]

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

-Dale

[Poorhousenext]

I'm old and Stupid, so my current project is to try and run in the 10's in 1/4 mile with under 400 RWP, and on Street tires, 200TW or more. The only way I can do that is to get weight of car down to get Horse Power to Weight ratio needed to pull it off. Car will ahve all the NHRA safety equipment required to run up to 10.00. Will have provision in place to make car legal to go 9.99 and under later on should I want to try that. The safty equipments added weight may be my downfall.

My current car can run in 11s even with 2.+ 60' times, with 360 RWP at 3559 Lbs with 4 gallons of fuel and me in it on 200 TW street tires and 3.55 rear gear. Can't even spin the rear wheels on preped track, in part because of little or no converter stall and 52% of weight being on rear tires.

I'm hopeing to get car finished by end of May so I can see if I can do it.

PS: I'm using a Mustang Dyno to tune on, along with LS2 style MAF to keep RWHP form going over 399. Dynojet Dyno numbers put engine RWHP numbers within 12% of crate Engine at the crank HP rating. Very unrealistic numbers for homemade headers and automatic trans I'm using.

[MonzaRacer]

I have plans for twin GT2871r turbos on my 283 in my Monza and at max boost it should turn over 600hp/600tq. all things considered I figure at 6 to 10 psi I can have a solid hard running car with reliability. My biggest issue is hooking it with a Monza,,,,,
I dont think running a big block in my 66 Caprice will be hard to hook, and I can always use same size turbos on my stock 454 and at 5psi it should be able to run upwards of 700hp if I push it.

[Interceptor5588]

My Formula is running about 300 rwhp and 370 rwtq and it's perfect for roadcourse work -- pulls pretty hard but very controlled, you can use the throttle like a switch most of the time. Don't have to worry about pedalling to control wheelspin, etc.

I guess it COULD use maybe another 100 hp or so though -- so 500hp/500tq at the crank in a 3000 lb car would be pretty good to shoot for. Of course I'm pretty old and conservative . . . well, maybe 200 more might be nice after all . . .

[no1udknow]

Well my current bored and but 350 (364) is supposedly making between 380-400hp at the crank but I haven't run it on the dyno yet..... hopefully this month my buddy will get the dyno set up in his new shop. Once I figure out whats happening undet the hood I will be deciding if I want to keep it or move to an ls

[GNon18s]

Running with the pro-touring crowd, you'll want 550-600. I've been getting by with @450 in a 3200lb car, but I've often wished I had 100 or so more.

[GNon18s]

Well my current bored and but 350 (364) is supposedly making between 380-400hp at the crank but I haven't run it on the dyno yet..... hopefully this month my buddy will get the dyno set up in his new shop. Once I figure out whats happening undet the hood I will be deciding if I want to keep it or move to an ls

If you already have a motor I would just run it. Worry about more power later.

[srh3trinity]

After having a mostly stock ls2 daily driver, I think my cammed ls3 stroker build will be plenty. I did the math on putting a zr1 blower on it but fortunately came to my senses. I do want a supercharged or turbo car at some point, but it would be overkill on my current build.

[Bonehead]

It all depends on your plans for the car. Once I have possession of my Chevelle here in my new home, I'm considering on reworking the car to participate in the Mojave Mile. Not quite sure I can get that brick to go 200 mph, but for now that's the goal. I'm going to guess its going to take around 1200 to the wheel to get that unaerodynamic pile moving that fast. Maybe even a bit more. Realistically, this might be a 5 year plan once I get started. We'll see. Maybe if you'd define "competitive", you'd get an answer you're looking for. :)

[72BBSwinger]

I think autox comp can be won with little power and good balance, good driver. Big road course comp, a big engine can shine.

[gscherer78ta]

A lot of it depends on the size of the course you want to run on. The larger and longer the course the more HP will be required to stay competitive. A shorter course will favor good balance and less hp. From what I see in my area, 400-500 at the crank and good balance on the car seems to do well in courses large and small.

[Gratefuldiver]

I have about 450-500 rear wheel hp and get beat up on by Miata's with less then 200 hp all day when I auto x lol

[cornfedbill]

I once watched a 1 liter Datsun powered Lotus Seven Series 2 that weighed 850 pounds empty run fasted time of the day at an autocross. He was consistently at the top of the pack. He was barely making 100 horsepower at the crank.

That said, I always say, "You can't have too much horsepower, just too little traction."

I'm running about 400 horsepower at the crank with lots of torque from my 377 small block. My goal is 3300 pounds for my Nova. I think I will be a bit shy on power, but able to have a lot of fun. I would love to have about 100 more horsepower. I think that would be as much or more than my tires could put to the ground.

[Mr.VENGEANCE]

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

-Dale

came to say this.. left satisfied.

[parsonsj]

My Z06 makes 540 at the tires. It's a handful coming out of turns. The only time I felt the need for more hp was at Daytona. A cool 200 additional hp would have been most welcome on those banks!

[HomeBuilt]

I once watched a 1 liter Datsun powered Lotus Seven Series 2 that weighed 850 pounds empty run fasted time of the day at an autocross. He was consistently at the top of the pack. He was barely making 100 horsepower at the crank.

That said, I always say, "You can't have too much horsepower, just too little traction."

I'm running about 400 horsepower at the crank with lots of torque from my 377 small block. My goal is 3300 pounds for my Nova. I think I will be a bit shy on power, but able to have a lot of fun. I would love to have about 100 more horsepower. I think that would be as much or more than my tires could put to the ground.

I think Bill here made an excellent point. I think what you're looking for is not a hp number to be competitive, but a lbs/hp. number so what you'll need will depend largely on what kind of weight you're throwing around and the type of racing you plan on doing. My motor made 507 hp and i'm shooting for 6lbs/hp so I'm focusing on taking out weight to run at Willow Springs. But I think anything in the 7-9lbs/hp range is pretty good.

[rchaskin]

I’ve found that most people that tell you “you don’t need that much horsepower” to be competitive, always have way more than me…….LOL........:hammer:

[SSLance]

My engine puts 283 hp\404 ft lbs to the rear tires and my suspension is very well sorted. On a tight technical type of autocross course it does very well and can beat the LS powered cars I typically race against. On a longer style, more wide open autocross course like you see at the SCCA Nationals, those same cars will nip me by just a tad on our best runs.

My car does okay on the road courses, is a ton of fun in the twistys...but on the straights it will get walked away from by the big powered cars. Nothing is more fun though than to get run away from on the straights only to run those same cars back down again by the time you come out of turn two. :D

[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.

[no1udknow]

Oh... and one other thing, I'm currently running a 364ci, th350, with 3.73s

[Zspoiler]

Depends on how much power you and your pocketbook are comfortable with. I have seen people build high horsepower cars and used to stock car . And it scares them to death to drive it .So they end up selling the car.

[Camicus]

This is a great thread. I have been going back and forth about how much HP I want also. After reading this I have decided to take a more conservative approach since I don't plan on racing my car :)

[cornfedbill]

I put a relatively mild cam in my 377 and really like the broad usable torque curve. I have used hotter cams in the past and have always been frustrated with throttle response and low end power.

I would do the same again. Cam limited motors can be so easy and fun to drive.

[High Plains Mopars]

But how much power do I really need to be competitive. I would assume that so much power would not be that usefull in pro touring as keeping that much power attached to the asphalt in a corner could prove tricky. So who is racing and doi g well, and what kind of power are you making, and how heavy is your car?

Competitive in what? Define the type of racing you are pursuing. Wheel to wheel or timed events? Short or long course? Are there any rule limitations to be aware of?

[groho]

By no means am I an expert, only using my experience on past shade tree builds, my goal with my 66 coupe is have just enough hp/torque to achieve absolute edge of traction at WOT and pull as hard as physically possible without breaking the tires loose. Any more, and all you do is smoke the tires, any less and its a slug. I came closest to achieving that with roughly 330hp, 3:90 gears at 3200 lbs. My goal this time is 350hp, with 3:73 to 3:90 gears and <3100lb mustang. Fingers crossed.

[kiwigt]

^ This. I had 350rwhp and 3.50 gears in my 66 Mustang. It was the perfect combination in my opinion of pulling like a freight train under acceleration (in any gear) while not lighting up the rear tires too much. I've had more HP in other cars; but this was the sweet spot for me with that car.

[LS1NOVA]

First off, I just want to say I race for the fun of it. Do I need all the power? Of course not but man it is fun.

Im making around 1100whp out of a twin turbo 5.3 in my 71 Nova. I have always had drag racing roots but like to try out other events also. The car does pretty well at autox and smaller road courses with boost turned waaay down. I havent had it on anything longer than a mile track and don't really plan too as the temps would get pretty out of control. It can be done but with about 300lbs worth of coolers and hose. It runs high 8's on 275. Hook the swaybar back up, switch tires, adjust shocks and away you go.

One thing is for sure, everytime I drive the thing, it is a huge stress relieving, adrenaline pumping, riot,and I want MORE!!

Here is the best vid I can find at the strip. Fast forward to :30.
https://www.youtube.com/watch?v=Cy67mBFycgQ

and at Holley LS Fest against Danny Popp. Fastforward to 2:20 if you want.
https://www.youtube.com/watch?v=cs67KeElTZs

[Nicks67GTO]

Nathan, do you get down to CF raceway often? It's about 10 minutes from my house

[LS1NOVA]

Nathan, do you get down to CF raceway often? It's about 10 minutes from my house

Yes, I raced their four times last year. I'd consider it my home track even though it is 3hrs away. I don't really plan when I will go but this year I will be there Aug 29th for a grudge racing event and also on Friday night Sept 25th for a "drag week" style event I organized.

[TheJDMan]

I watched the Autocross event at Crusin the Smokies last weekend and one thing that struck me was that the ultra high power cars could not use all the power they have on tap. Once they got into their power band the tires would simply go up in smoke. It doesn't take a rocket scientist to know that when the drive tires are spinning the car is not accelerating as quickly as it could be. The guys in NASCAR call this forward bite and they go to great lengths to minimize it. It occurred to me while watching these cars spin their tires under acceleration that maybe some form of traction control might be worth looking into. A device which would reduce power when wheel spin is detected might actually make a car faster.

[LS1NOVA]

Holley Dominator EFI with the add on Davis Technologies traction box!!

[TheJDMan]

Holley Dominator EFI with the add on Davis Technologies traction box!!

Clearly these guys are not running such a system since they just spin tires.