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Discussion Starter · #1 ·
For some reason im stuck on having 400+ hp in my project when Im done. I plan on driving my car lots and lots when its finished then someday when Im old and life has passed me by having it made nice and pretty for Sunday afternoon drives with my wife and grand kids.

With the assumption that I plan on driving the car 3-4 days a week during nice weather, is 400 hp too much? Should I be shooting for mid 300's?

Thanks
 

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Depends on what you need to do to get the power. Getting that much from a 302 will create a car a little harsh "for Sunday afternoon drives with my wife and grand kids". In any case, doubt the ladies will appreciate the use of that much power with them or the kiddies in the car.

Have you ever driven a Mustang with, say, 320 hp? That's a LOT of fun, and can be done with a hydraulic cam that your wife could drive to church.
 
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Another way to ask it - how many cubic inches are you going to use or are you willing to go turbo/boosted? Also how much are you willing to put up with?

400 HP from a 351W stroked to 393 or 408" with good flowing heads you can use a real mild cam and cheap 87 octane fuel and have great torque and good street manners. 400 hp from a naturally aspirated 302 is going to require a cam that's on the edge of being 'daily driveable' (imho) and it's going to probably make power up higher in the RPM range and not be quite as 'fun' on the street since the torque from 1000-3000 RPM will probably be less than a more mildly built engine - you can make up for some of this by running a loose converter and low gears but then again streetability starts to suffer...

I've built small high revving high hp engine as well as larger CI 'small block' engines and almost always preferred the large CI engines on the street as most of my driving is done from 1500-2500 and when I put a little throttle into it the torque is 'right there' and makes it feel 'effortless' to accelerate the car - vs the high revving loose converter setups - you step on the gas and the revs shoot up and lots of noise and about the same acceleration - seems like you're trying harder than you really are - which might just be a preference thing.
 
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I agree with 22GT which does not happen that often :). Getting 400hp from a 302 may not give you the drive ability you are after. But 400 HP from a 347 or 351 can have great street manners.
 

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how much hp is too much for a driver? that depends on what you are willing to put up with as far as drivability goes. a 347-393 is going to be more drivable than a 289-331 making the same power. also remember that the more power you make, the more fuel you are going to use. can you put up with a drop in fuel economy?
 

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Have you ever driven a Mustang with, say, 320 hp? That's a LOT of fun, and can be done with a hydraulic cam that your wife could drive to church.
GREAT ADVICE! Don't get sucked into the magazine hp showdowns. Torque under the curve is where you should be paying attention for a street car. That said, you may want to drive/ride in a few cars that have the setup you are looking at before you commit. A modern (new 5.0) 400hp engine is very different than a stroked 351 with similar peak numbers.
First, make sure that you are comparing apples to apples in that you are talking RWHP or HP on a dyno stand, and even then are you making fair comparisons using the same dynos.

There are entire forums dedicated to this topic. But I think most people overestimate how much HP they really want for the street.
 

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Too Much Horsepower

This all depends on many variables: What cubic inches, what weight, what transmission, what rear end, etc? I really believe that in the older Mustangs, especially, where weight is in the 2700/2800 range, 300 horsepower would satisfy most any daily driver and even be fairly impressive as far as performance is concerned. Any more than this will begin requiring a lot of mods to the car that get very expensive.
 

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Never such a thing as too much HP! lol I would think that going over 1hp per cubic inch makes an engine fussy and harder to drive on the street. But everyone loves HP lol
 

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Boost can make up for radical cams, strokers, etc. My 700hp turbo Windsor had pretty good street manners...not saying it was a daily. I think a heads, mild cam, intake 302 in our light cars would be a blast to drive...especially if it's a manual. My opinion of course :)
 

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+1 on thinking about it compared to modern cars with all its variable this and computerized that. Any street car is a compromise and you should be more concerned with low/mid range torque for frequent driving fun. If you dont make max HP till youre over 6K rpm how often will you use that anyway. But if you have a nice flattish torque curve from ~2000-4500 youll be smiling with every gear change.
If you find you cant drive around a crowded parking lot smoothly then you have to much HP, but then its to late.
 

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GREAT ADVICE! Don't get sucked into the magazine hp showdowns. Torque under the curve is where you should be paying attention for a street car. That said, you may want to drive/ride in a few cars that have the setup you are looking at before you commit. A modern (new 5.0) 400hp engine is very different than a stroked 351 with similar peak numbers.
First, make sure that you are comparing apples to apples in that you are talking RWHP or HP on a dyno stand, and even then are you making fair comparisons using the same dynos.

There are entire forums dedicated to this topic. But I think most people overestimate how much HP they really want for the street.
I totally agree with this also! WHen you start optimizing cars for HP they start having narrow torque band and low torque. It is fine you are revving the poop outta your car but you usually don't do this on the street.
 

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+1 on thinking about it compared to modern cars with all its variable this and computerized that. Any street car is a compromise and you should be more concerned with low/mid range torque for frequent driving fun. If you dont make max HP till you're over 6K rpm how often will you use that anyway. But if you have a nice flattish torque curve from ~2000-4500 youll be smiling with every gear change.
If you find you cant drive around a crowded parking lot smoothly then you have to much HP, but then its to late.
You nailed it. :)
 

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Along similar lines to "you can never have enough HP" is this truism-
doesn't matter how much HP you have if you can't put it down.
 

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For a street car it's more of a question about TRACTION than HP.

A car with less power but great traction will be more fun to drive on the street than something that just overpowers the tires. It'll be faster too.

400hp in a mustang isn't easy to get traction on the street.


But really there isn't a magical number to hit or shoot for. Since you plan on keeping this car for a long time, just do 1 thing at a time. If you want more power.... do 1 thing more.

But if you want good street manners, don't go for something highly modified (i.e. a big cam).
 

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From your posts you're putting a 67 fastback together. You can do a 347 stroker and make 400 and it would be streetable. Or you can go 351 and stroked to 408 and have a very streetable engine with great torque. It boils down to several things. How much do you want to spend? Are you building the engine yourself or going with a crate engine? I have seen some awesome horsepower in street cars and the tires go up in smoke when they try to put the power to the ground.
 

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You can do it. It will work better with an overdrive stick and you will still need sufficiently low gears like 4.10's. Run a bit taller tire in the back. A roller cam will help broaden out the torque under the curve. Fuel mileage will suck it though, LOL. I would plan for cruise at around 3000 rpm in OD.
 
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