[Nicks67GTO]

So ive had this discussion with friends before and seen it elsewhere but im wondering what Pontiac owner opinion is here. First off lets keep it friendly and the more real world expierence we have here the better.

At what point does horsepower and torque become useless in a typical stock configuration street car? If you watch the NRE videos of their twin turbo 1500hp engines they are sticking in pro-touring cars youll notice several things. They are awesome engines and built great...then you will notice its all fun and games but 1000hp....1500hp...who gives a damn, its all just a giant expensive smoke show with a street car and tire.

Lets not define street car. Thats a whole different can of worms. Ill define the car below.

Lets call the car in question a typical crusier. A cageless 3800 lb A body with a full interior, AC, PS, PB and 4 wheel discs to get it hauled down. The car is running a tremec TKO 5 speed. It has a good stock style chassis configuration with brand new parts like some UMI rear control arms and typical street upgrades like poly bushings and a nice modern shock/spring package for the street. It can get the power down to the ground as well as any stock configuration rear ever has but there are no hardcore race parts. None. Just driver friendly upgrades that help with wheel hop. A rear 275 treadwidth STREET radial tire and 3.73 gears. All very typical parts.

What HP/TQ is just getting excessive when it comes to this kind of car. A lot of guys here run the good old 455/SD old faithful, KRE 290 package and thats supposed to be good for 550hp/600tq. Well under 6K RPM. I have to imagine that is getting close to the edge of being excessive for the car outlined above. It would seem with a flat Tq curve, short gear and street radials, this would blow the tires off on a wide open throttle hit in 3rd gear above 2500 RPM with that 5 speed.

So whats everyones opinion here? When is power just excesive and basically useless. You mash the gas and go up in smoke even with nice parts and tires? It could make for a fun discussion.

[Chris65LeMans]

I always chuckle whenever I read about roadrunners with "700 hp street hemis" and 4:10 (or higher) with a four speed running 10 second 1/4s with the "original" 14 inch bias-ply tires. I may not be a physicist, but I did read the book...

[71 Goatman]

I think it is easy to poo poo anything you can't afford. I have a 425hp/510ft lb 462......Don't you ever find yourself watching the Nelson Engine videos on You Tube with these 1,000 HP - 1800 HP cars saying how dumb is this? What could you ever do on the street with that much horsepower? It is useless on street tires? and on and on. To a point I agree, however if you could afford it who wouldn't want a 700 - 1500 HP pump gas engine? Let's face it, it is bragging rights.

Go to the chassis dyno at any event, people are not lining up to see the 280 HP @ the rear wheel Ventura or GTO, hell no they want to know when are they bringing out the big guns that make some real noise and put some big numbers on the board.

No, these cars in many cases will not beat a well set-up drag car at the strip with less than half the horsepower. However at an event on the chassis dyno, or with the nice graph posted in their window they will get some attention.

All in what you want, how you plan to use the car. If you watch the episode of Hot Rod's Road kill where they swapped out the blown big block in the crusher camaro for a Mast Motors 700 hp LS motor. Then proceeded to drive it 2400 miles and averaged 17mpg.

Well now, do I want my 425 HP motor that gets 14 - 15 mpg average on the Hot Rod Power Tour or would I swap it out for a 700 HP pump gas motor with an automatic w/overdrive that averages 17mpg? Hmmmmmmmmmm, That is a lot of smiles per gallon.

At the end of the day it is what you can justify in your own mind and more importantly afford. Some day when my kids are finished with college I will upgrade to something more towards the "excessive" or "ridiculous" end of the scale. I believe I could live with another 300 HP and several MPG and still fill up at the pump.

The main point is have some fun with it no matter the HP.

Just my .02

[taalltheway]

"the good old 455/SD old faithful, KRE 290 package ".....sounds just about right for me...especially with a manual tranny...i think what matters is not the powernumbers but the manners of the engine. For a real streetcar that you want to drive a lot you want an engine that you don´t have to fight with, nice idle, good vacuum, etc...anything more than the above mentioned package would push the combination intoi uncivilized territory. I would even suggest stepping down one size in camspecs...the increase in better idle, more torque down low will most likely offset the samll loss at the upper side of the powerband...in typical "streetrace"-situations more torque is going to give you a faster car than an engine that you have to wind out...

[Torquewar]

Good questions and comments.. Its all about the overall package and how its put together with parts that work together.The power needed to have fun is subjective but we all know it does have to be realistic.
Im in that 500+hp/ 600 torque range and its enough. I beat on it and u cant kick the smile off my face. Must add there is breakage when getting to those levels and upgrades are required$$$$
I will drive the car 100 miles to shows and cruise nights etc and dont give it a second thought.
The enjoyment is also to race on a friday night rip off some 11s and drive her home.
Bottom line is what are the individual goals .A long distance setup will require some carefull planning vs a shorter distance brute.

[PONTIAC DUDE]

A 450 hp engine has plenty of street useable horsepower and you don't have to chase tune ups or drive ability. I build a lot of 400 and 455/400 to 450hp type combos and customers are happy. Pump gas friendly.
But then again there is no replacement for displacement with those numbers.

[David Jones]

Right off the TKO is max rated at 600/600, unless you have it "uprated", then max tq increases to 950.
Seems like to me that putting that kind of power down with a 275 series street tire isn't going to happen. And if you could a 45-50 year old chassis isn't going to be happy about it.
But, if somebody wants to spend the kind of bucks needed to achieve 1000hp/1000tq and stick it in a car that is not capable of dealing with it nor able to "use" it in a street car situation then spend away.
A true 450/500hp engine in a car as laid out above, driven on the street is perfect.....in my book.

[66bonne]

Originally Posted by PONTIAC DUDE

A 450 hp engine has plenty of street useable horsepower and you don't have to chase tune ups or drive ability. I build a lot of 400 and 455/400 to 450hp type combos and customers are happy. Pump gas friendly.
But then again there is no replacement for displacement with those numbers.

P-Dude built for me a 455, out-of-the-box KREs, and the "Butcher Special" cam for my 65 Catalina. Never dyno'd motor or car but it was probably around 450hp. Pump gas motor that behaved beautifully on the street and still turned high 11s at the track.

Jim

[marks73ta]

It's another "what's your opinion of...." question. My '73 TA, turbocharged 462 made 1065 on 15 psi boost, 950 TQ at 4000 and was just right. Before I turbo'd it, it ran 11.4 n/a and 10.2 on 150 shot but was very tractable on the street. Old leaf spring 10 bolt with the old style long slapper bars. Full manual TH400. It's all in how much you want or can handle. To some people, a little is a lot, and to some a lot is not enough (I'm the latter).
I really enjoyed the heavy cammed N/A-Nitrous engine but man, when that turbo comes on boost, you just have to experience it to understand. The same can be said for any high HP combination. Big power, big torque N/A, supercharged, Nitroused or turbo. Power corrupts totally.
I've had many fast cars, big blocks, small blocks, several turbocharged cars, etc etc,. But the most totally FUN car I've ever owned was a '91 Dodge, special run of the Spirit R/Ts. 2.3 liter turbocharged 4 valve 4, 5 speed, front drive, torque steer up the ying yang, tire frying, front end darting, steering wheel sawing, blow off valve wooshin', pure FUN machine 4 door sleeper. It was my daily driver for several years and I actually enjoyed the 18 mile 25 minute commute every day. It's all in how you perceive it.

Mark

[Skip Fix]

I can tell you my pump gas 455 in the 78 in any turn will blow the street tires(even DOT stickies) off and get sideways in a heart beat.

[geeteeohguy]

I would say 450-550 hp would be about perfect for a performance based street car that sees regular use. My '67 GTO is detuned with lower compression heads and a long legged 2.56 posi that I installed, but these 'downgrades' actually make the car more enjoyable to me....it's a high speed, high mpg (over 20mpg at 75+mph) touring car, now, able to gobble up huge distances at great speed while ticking along running cool. A lot of satisfaction in that on a 1000 mile weekend. It's all in the package and its intended end use, IMO.

[rohrt]

Originally Posted by PONTIAC DUDE

A 450 hp engine has plenty of street useable horsepower and you don't have to chase tune ups or drive ability. I build a lot of 400 and 455/400 to 450hp type combos and customers are happy. Pump gas friendly.
But then again there is no replacement for displacement with those numbers.

x2

My brother first dyno'd motor was 450hp and 500ft/lb of torq in his 68 GTO convertible (No cage). It was 468 Cubic inch, RPM intake, 825BG, Ram Air IV cam, 6x-4 milled Ported 250 street port, Dougs headers, 3" exhaust, 3:42 Gear, Th400 Continental 2500-2800 Around 12.80 1/4 time. I drove it once and it would lite of the tire in first gear like nothing. It just plain halled @ss, it was fun.

That motor went into his 66 GTO with M21 4 speed. Crazy long black marks in first and second. Motor still make that car fun.

The second motor he put in the 68 was very close to what Cliff runs. 470 Cubic Inch, RPM intake with 825BG, Old Faithfull cam, 3:42 Gears, Kauf 290 Heads, Th400 Continental 2500-2800, 11.82 at 115 w/o NOS. That one second difference is amazing. Car is loud as hell, worst drone ever, Launches like a rocket with the slicks and is just completely obnoxious. Is it fun on cruise nights? You better believe it. Does he like to cruise in the power tour with it. No! Why? Its like going to a rock concert, you just feel exhausted and deaf after 2 hours.

He has a 76 T/A 428, Q-Jet, Iron intake, Kauff heads no porting, HO manifolds, Old faithful cam, Th350 intake. This too runs around 12.80 1/4 times

Then there is my car, 68 bird convertible, 455 stump puller on a 114 LSA, 455 + .060 #96heads (1971) 2.11 1.77 home Ported
Harland Sharp 1.5 Rollers, Forged TRW pistons/stock rods shot peened arp bolts, Stock 1969 4bb intake port matched to heads, 7028268 750 Q-jet By Cliff Ruggles
Longbranch manifold D ports with 2.5" outlets to 2.5" exhaust with X cross over.
Th400 Automatic TCI streetfight 2800RPM Stall, 8.2 Eaton posi 10bolt with 3:31.

My car was dead even racing my brothers 76.

So what does all this have to do with usable street HP? It really is in the eye of the beholder IMO. My car has a dead smooth idle, it feels like it lacks low end torq. I really should have gone with the smaller Conti converter with the higher stall. Once it gets above 3000 rpm it halls like a freight train. But my car is more comfortable to drive. It has a bad drone too.

The 66 GTO felt a lot faster then my car. Tons of torq down low and was a blast to drive hard not to want to lite up tires but if you recall all three cars were all around the same 1/4 mile time.

The 76 is chocked off with the stock intake and HO manifolds. It feels closer to my 68 with the way it drives. A loss of low end torq but halls like crazy once up in the rpms. Again it could use more stall converter. It being a 428 with a bigger cam, has a rougher idle as you would expect.

I also have a 64 Tempest convertible with a 326 and 2:56 gears. It can barely get out of its own way. Out of all of these cars guess which one I enjoy driving around the most? Oh yeah I'm getting old so take that into account. Right now its the tempest. I can just start it up and go and I'm getting about 20 mpg. My 68 gets about 13 at best, and I still haven't fixed the drone.

Each built different, each with there own feel. How fast do you need to be on the street? I think the question should be how fast does your ego tell you have to be on the street. I know I fall victim of comparison with others. In the end as long as you enjoy your ride and can have fun what does it matter. I admit though that I have a hard time not chasing the next HP. You guys are just enablers.


Sorry about the chevys photobombing the pic.

[Keith Seymore]

Originally Posted by Nicks67GTO

Useable street car HP/TQ. At what point is it excessive?

Never.



K

[J GLASGO]

Originally Posted by Chris65LeMans

I always chuckle whenever I read about roadrunners with "700 hp street hemis" and 4:10 (or higher) with a four speed running 10 second 1/4s with the "original" 14 inch bias-ply tires. I may not be a physicist, but I did read the book...

I dont get why its funny?

[Squidward]

Another factor to consider is how often you get a chance to open it up. Stoplight up to about 50 and the highway on-ramp are about the only times I get to thrash. Outside of that requires track time, which opens the boundaries of discussion.

My biggest constraint isn't under the hood, but at the hand that writes those really expensive tickets - I've had those tickets before and don't want more.

[Keith Seymore]

Originally Posted by Chris65LeMans

I always chuckle whenever I read about roadrunners with "700 hp street hemis" and 4:10 (or higher) with a four speed running 10 second 1/4s with the "original" 14 inch bias-ply tires. I may not be a physicist, but I did read the book...

Chris - if you are thinking of the Pure Stock/FAST racers they are in the 9's now...

http://www.fastraces.org/

K

[Hooter]

Ask me later this Spring. I'm building a 565 for my 65 Lemans street car. Should be around 800 hp. Turbo 400, 9" with 3.70 gears, all stock type suspension with TRZ components, full interior, 3700 lbs, etc. Hoping to make Norwalk and Drag Week with it.

[PontGuy]

1. Too much power for a street car is when the car just sits because it is a pain to drive.

2. Where that power level is depends on the intended use of the car.

The fastest street car I have ever driven was a Viper that was re-worked at the Shelby shop (Carroll even signed the dashboard). Fun- yes! But if it was mine it would rarely come out of the garage. It took way too much focus to keep all that torque and HP under control on the street, even with the massive tires.

[Chris65LeMans]

Originally Posted by Keith Seymore

Chris - if you are thinking of the Pure Stock/FAST racers they are in the 9's now...

http://www.fastraces.org/

K

Well, I'll be...

That's why I like watching the top fuel drag races: It just doesn't make any sense that they can go that fast.

As for the horsepower in a street car argument: I think there's no such thing as too much power for the car, although there certainly can be too much horsepower for the driver.

[dmac]

If it idles smoothly and you don't have to worry about it overheating while sitting in a traffic jam, it doesn't matter how much HP it has. It is a street car.

If you need to idle at 1100 rpm, and it exceeds the decibel limit in town, and the temps rise to over 220 degrees when moving in slow stop and go traffic even in mild weather, it isn't really a street car.