Interesting Horsepower

[F23]

Hello everyone,
I've been thinking recently about what a good street engine would be like (for myself), and figured that about 550-600hp would be real nice. This is for a 351w by the way. So I started looking into supercharges, and realized that there was no 'perfect solution'. Either a roots lacks top end or a centrifugal losses bottom end. Same thing with high flow engine components: high flow (200+) heads give great high power but very little bottom end, while smaller openings die off at higher rpms. Which got me thinking... Could you combine massive cylinder heads (220+) with a roots style supercharger and get a power curve that was flat and decently high throughout the curve? The extra air flow from the supercharger at low rpms would boost power, and when the roots started to drop off like they do at high engine speeds, the high flow heads would already be pulling in enough air to keep velocity up. Am I missing something? You could run a meth injection to keep the compression decently high, even with the blower. I figure I've got to be missing something because if this worked then a lot of people would do it.



Thanks,
F23

[DreamRyder1963]

The parts have to work together to make good power. That's why you have to figure out what speed your engine needs to make power. If you have a heavy street car then you want to make low end power. If you have a light race car then you want to have maximum power higher up.

[F23]

Understood, but not directly answering the question. Is there anything stopping an engine from making the type of power curve described. I understand that it wouldn't make as much power as an engine specifically designed for high or low end, but I believe the average hp would be higher.

F23

[1BADBET]

550-600 N/A hp is possible no need for a supercharger. Save the money for a good set of heads and as many cubic inches as you can get. To get a wide power curve you need good parts that are properly matched, but if your looking for an engine for YOUR car there are many other factors any real engine builder would need to know like max rpm, idle quality, car weight, max rear gear ratio (overdrive?), stick or automatic, usage (street, strip, track or what combination and what compromise your willing to make) engine platform, and most important.... Budget, gotta pay to play lol.

[cactuss4]

I don't see mention of turbo's and for the request that is being made, it escapes me why they would not be considered. Can give you the torque bump you want while increasing the HP, can be tuned for more or less, can be designed for more or less.

don't even need displacement, but depending on the size of the turbo it obviously helps keep a power band in the rpm
s that you want, vs like one of my cars 618hp but I don't have full boost until 5K, that's extreme but not as bad as many.. Higher displacement would move that down quite a bit and obviously picking the right turbo. Superchargers run out of breath, but are nice for instant power, but I don't know of many people when talking about speed are shifting anywhere near 500 and 2500rpm, soooo..

<shrug>

[WallaceMFG]

My question is how high of RPM are you wanting to run? Just for an example, the LS9 is supercharged and makes peak power at 6,500 rpm. That seems plenty high to me for a street car motor. If you wanna run higher, then I can see why you'd have problems. As it was stated above, my choice would be turbos. If they were the correct size there would be no turbo lag and they would make good power at higher RPM.

[1BADBET]

dont mean to hijack but..... in a typical heavy street car with street tires traction is going to be an issue. So you want to give up some bottom end power in order to get the tires hooked up and make the same power at a higher rpm. If your turning more rpm you can put more gear in the car and thus you get more torque multiplication... you win twice! Now you do want to make the most power over your usable rpm curve ( max rpm to rpm drop on shift) Turning more rpm also make the car easier to drive, you can roll into the throttle faster coming off turns because power comes on at higher rpm and the higher (numerically) gear makes the car accelerate faster as apposed to having an overly sensitive throttle making lots of bottom end, losing traction and having a low (numerically) gear. Your not going to be able to hook up 550hp on street tires no matter what, making that power at 5,500 rather than 7,500 is going to make it harder to do, and not as fast.... sorry rant over

[angrybird]

I've got a combo like this:
427 windsor 10.5:1CR, trickflow highport 240cc, custom grind 264/272@050 712lift, ported super victor with FAST XFI fuel management.
That made 507WHP @6600rpm on a mustang dyno (Thats the same hp as the corvette zr1 make on the mustang dyno, on the same RPM)
Completely driveable if you can handle 1000rpm idle :-)

[72BBSwinger]

I plan, hope, expect my stroked Gen III Hemi makes AT LEAST 600hp at the flywheel. The heads have stupid flow, .600 lift cam, 11.1 and 421CID. Other people with very similar combos are in the 660-720hp depending on dyno.

[F23]

Badbet,
That makes a lot of sense. To answer other questions, it would be used on an approx 3100lbs car used mainly for road course and street, and for the planning stage, budget doesn't really matter to me. For those who recommended turbos, I did look at them very seriously, but decided I wanted more immediate response over absolute horsepower.

Thanks,
F23

[1BADBET]

F23,
You CAN have immediate response AND absolute power with a turbo, you just have to find the right engine builder. I might be able to do something for you, pm me if your interested.

Thanks