It is really not the HP figure that your after it's TQ. You really need mid 500 - 600 foot pounds. Then your car is fun to drive. To get that torque you need lots of ci like 427 to 502 or a blower. I only have a 434 ci, but it is fun to drive with a 5 speed manual. I drive more than most people. I drove two days on the road and put 3000 some miles on my Vette. That is with no A/C in a 5 point harness and race seat.

I can drive to a track and do some low 11 second 1/4's or drive to the road racing track and whip up on most of c-5 and c-6, and Vipers then drive back home. Give them a wave while they are loading it up in a trailer.

I would not spend a dollar on a sub 427 ci small block unless it had a big blower.

 

Whatever HP amount is needed to push a car to the limit without killing its driver and roll apart is said to be 'enough'...

For example my 406's 575hp engine might not be 'enough' yet to push my '77 at the best of its possibilities, given the substantial upgrades of its braking, frame and suspension sistems...but it would be far more then enough if i kept everything stock but the upgraded engine...

 

i have 370 and really like it. i want more low end though, but that involves another cam or a big block. i would think that 400-450 is good for the street.

right now i have just begun saving for a 540 crate motor for once i'm out of college. there's a black '69 vette with white stripes and flares on here that has a 540...that is my ideal car!!

 

Build it as big as you can afford. You only live once. Use the power with caution and you will enjoy every minute. Do a 598 or a 632. Why not? It's just like a nice stereo, just cuz it goes to 10 does not mean you have to. Have you heard the sound of something near that size in a street car, it's unreal. I say Go for it

 

Once you get over 400 hp on a street driven car with street tires you start to get into alot of wheel spin depending on tires and rear axle ratio. You really need to be able to put the power to the pavement. Alot of people are driving cars that exceed their ability to handle them. Two of my cars are over 400 hp and are alot of fun to drive. Anything over 350 is satisfying to me.

 

If you want fun to drive go BBC and build for torque 500-600 ft lbs is about right. I have a 502 crate motor and 325/50 rear tires and I can get into it pretty hard with out to much fuss... To much skinny pedal will toast the tires in the lower gears even with a 3.08:1 rear gear. 3000 lbs wet (16 gal of fuel) 3250 lbs with me aboard.

When I AutoX I usually start the turn by chopping the throttle to break the rear end loose then twitch the wheel into the turn and steer out with the skinny petal. Kinda a flat track style.

If I use the brakes the car just goes straight... Hell its 2 miata's long and 2 miata's wide.

 

A 400hp LS2 is about 150 lbs lighter than a stock cast iron engine, can get over 20mpg with the right gearing, and will purr like a kitten around town and burn em up when you want. Throw a cam and heads on it and you can easily make 500 streetable HP. Better to have and not need.
They can also be picked up reasonable from most salvage yards. There are several GTO versions out there that with a little work would be the icing on the cake of that sweet ride you're building. But of course I am slightly prejudiced!

 

Just be carefull going from 200 HP to 500HP take a look at how many new Zo6's end up on their roofs on the way home from the dealership.
I believe you should work your way up. They don't let a bracket racer drive a Pro Mod car for a reason, he is not used to the power.

Like gkull says, it's all about torque on the street. The more torque the easier it is to drive on the street. M 550HP/510TQ 406ci is a pleasure to drive around town at 2000RPM and it will smoke the tires at 50mph too.

The big inch small blocks are fun, so much fun I am now building a 427ci small block with AFR227 heads, I am looking for 650+HP and 600TQ

 

I keep trying to find out........


JIM

 

 

For a streetable 3400 lb car, you really NEED about 260 at the rears. that's say about 320 at the fly wheel, net. that's for a streetable car, fun to drive, a good competitor, runs smooth, gets up and goes, and doesn't get 12 mpg. 500hp is in the supercar range, and may not be fun to drive, and may make you wish you didn't have it. 320 at the f/w plenty. C.

 

These cars act funny when you get them sideways compared to other things I have driven. When I did my motor and rear end going from a couple hundred at the crank and 3:08s to high 300's at the crank and 4:11s it was a huge leap and without drag radials to hold you down romping off the stop light will get your rear end sideways and convert your rears to dust.

 

I think 160 million will be just enough like the Saturn V rocket. Got them to the moon and back!

 

This idea has been touched on some here… build your way up! What I mean there is build your engine to be Easley upgraded later. Use only high quality parts in the bottom end and get some heads that are on the almost to big / good for your present combo. That way you are not paying big money on good parts now only to yank them off and put on better ones later. You may wish to think about a something like a powerdyne supercharger or if you want to go crazy think about a twin turbo. Having said that DON’T put that on now just build the engine to accept it later. Naturally aspirated you will be in the 350+hp range. This will make a good street car and you may find it is just what you want. If you later decide you need a little more put on the forced induction. If you did the short block correct you will have about 9.5 compression so no engine mods should be necessary. Start the forced induction with a small amount of boost and if you see you still want more just adjust the amount of boost.
Little history on me… I worked my way up over the years to a 700+ hp street car with NOS. I could drive it just fine because I worked my way up from about 200hp over the years. I sold the beast when I got married, I later had children, I got a good job but need to commute so I got a TDI Jetta 90hp and drove that for several years. Long story after about 12 years without any real power I got back into cars and built what I thought was a small 500+ naturally aspirated Vette. The first time I got on it the car went every direction but straight! I forgot how to “DRIVE”. I got lucky and was able to save it. It had nothing to do with my skill because I had none after all those years. I found out that although my plans were to go bigger and get more I am not going to change a thing. I also learned that proper regulation of the right foot will keep those around me alive and I will also be able to see my kids grow up! Wide open is for the track.

In short start smaller and work your way up. Have fun and be around to enjoy it.

 

I'll throw this out. When I was planning my rebuild, I was going to build a 350 and was looking for a good 400/400 engine set up that was street freindly yet had the umph when needed. After much reading and a lot of help from folks here I am ending up with a 383 stroker that isnt making much more power but with a milder build, more TQ and HP but better street manners.

 

I have a stock 190 horse 81 and it has enough power and speed to exceed my driving skills.
If I had the money for a new Z06 I would surely enroll myself in a driving school.
Just my 2 Cents worth.
Ken

 

When you get into the bigger motors the potential is insane. I figure if the tires are spinning...you have enough....so I like to skew the TQ curve higher to allow it to hang on and keep revving when I want to play serious. The first version of my 540 made peak TQ around 4600 when un capped and 4300 when capped up. Peak HP was at 6200. It was a lot of fun to light the tires up literally at a 70 mph roll... but it was a handful. Big motors will rev a lot faster than folks might think and if you stomp it at 3000 rpm...you go through 4500 and on to 6000 rpm in about a nano-second if you don't have traction.....not much slower than that if you do have good tires.

I purposely changed the curve of the motor with cam/head/intake changes to give up 100ft lbs at 4000 rpm.....yet make 231HP more at 7000 rpm. It only make about 100 more peak HP....but it never dropped off at higher rpm like it did before. The car is MUCH more fun to drive because it is somewhat manageable. It still has plenty at low speed to do any smoke show you want....but it's a freight train up at higher RPM.

So I would agree that TQ is good stuff....but TQ at higher RPM (to a point) is what you really want with a serious motor. Anything under 4000 rpm ought to be pulling into a parking place! Once you go full throttle you're past 4000 so fast it doesn't matter much what it makes below that unless you have really high gearing. I've driven the ZZ502 crate motors and they are a perfect example of how to build a TQ monster that acts like a good tow truck motor. It's diving off a cliff at 5200- 5500 rpm. Simple Cam change gets you out to the 6000-6500 range and HP goes up like crazy and the car is much faster and fun to drive.


JIM

 

Tough to answer.. to me more is better..

 

It's also not a bad idea to consider how much stopping power your car is going to have when you consider the power you are going to load into the engine bay. A brake upgrade might be a necessity when you start climbing into the higher HP ranges. 500HP plus may be completely awesome when you turn it loose on the pavement, but it kind of looses the fun part if you can't stop it in a quick fashion.

 

I would say 350-450 is a very fun to drive and streetable range and anything over 500 is for a more aggressive driving type of person not the daily driver type of car either.