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-   -   Whp? (https://www.subaru-svx.net/forum/showthread.php?t=34825)

black beast 08-20-2006 09:44 PM

Whp?
 
What does one have to do to get hp to the wheels?
I have the 5spd, so, what?
what would a sport clutch and flywheel do? I was thinking ACT with the prolite flywheel, (the streetlite one is 12lbs, and they say the prois even lighter) Is that going to get power to the wheels? I really don't understand this so any non-joking replies would be nice.

black beast 08-20-2006 09:45 PM

Oh, the clutch and flywheel would not be until next summer, as I have no money.
Thanks

gest24 08-20-2006 10:17 PM

The lighter clutch will cut down on drivetrain loss/rotational mass. Inturn your engine would have to work less to spin the fltwheel. It can end up in a power increase and you might see a difference at the wheel. Its the same reason we do the crankpulley swap and run synthetic oils. It all cuts down on parasitic drag. Hope that helps a little and I'm sure someone with more know how can add to this.

Trevor 08-21-2006 01:15 AM

Quote:

Originally Posted by gest24
The lighter clutch will cut down on drivetrain loss/rotational mass. Inturn your engine would have to work less to spin the fltwheel. It can end up in a power increase and you might see a difference at the wheel. Its the same reason we do the crankpulley swap and run synthetic oils. It all cuts down on parasitic drag. Hope that helps a little and I'm sure someone with more know how can add to this.

The fact that any reciprocating component is lightened, or reduced in mass, can in no way increase actual power. However there will be an increase in acceleration to the point of maximum power.

I contend that any possible reduction in crank pulley weight will have virtually no effect because of the small diameter involved. Fly wheel weight is another story as is reducing pulley diameter and therefore parasitic load.

ItsPeteReally 08-21-2006 03:09 AM

Quote:

Originally Posted by black beast
What does one have to do to get hp to the wheels?
I have the 5spd, so, what?
what would a sport clutch and flywheel do? I was thinking ACT with the prolite flywheel, (the streetlite one is 12lbs, and they say the prois even lighter) Is that going to get power to the wheels? I really don't understand this so any non-joking replies would be nice.

By going to the 5 spd gearbox you have already removed the most significant power losing component in the transmission system.

A lightweight flywheel reduces the rotational inertia of the engine, so that the engine revs will more closely match the blipping of the throttle when the clutch is disengaged. This should enable faster gearchanges to be made and thereby reduce the amount of time that the engine is not accelerating the car because you've got the clutch pedal depressed.

The sport clutch should grip harder and faster than the standard one, with the result that even less time is spent with the clutch disengaged when changing gear.

None of this gains you a single additional horsepower, how could it?

All it does is enable you to spend a greater proportion of time with the clutch engaged and the engine driving the car.

The downside of this arrangement is that is now much easier to stall the car when pulling away from rest and that it becomes very much more difficult to drive the car smoothly.

Reducing the rotational inertia of the engine is not going to help much when the clutch is engaged, the major factor slowing the car's acceleration will now be the enormous weight of the car itself.

A lightweight pulley is going to be even less effective than a lightweight flywheel, there is very little rotational inertia in the pulley.

An underdrive pulley might liberate a couple of extra horsepower by reducing the parasitic load of the alternator etc. simply because you are now driving them slower, but it isn't going to to make a significant difference in everyday driving, and you run the potential risk of gradually developing a flat battery if you don't rev the car enough.

black beast 08-21-2006 08:49 AM

Ok then, how does one get power to the wheels? The car mags mae it seem like the loss is through the drive train and therefore by getting a stge higher in train you get more power to the wheels. How do you then?

Speedklix 08-21-2006 09:59 AM

Well, the lightened flywheel isn't going to help do anything but allow the engine to change it's rev faster. The clutch is another story.

I assume you are using the wrx flywheel and clutch which should be just fine for normal driving. It will slip and lose any power you throw at it as soon as you go showing off though. To make use of more horsepower you will need 1 of two things or both.... 1 is a better gripping surface on your clutch wheel, the other is a tighter gripping pressure plate. I have both. I run a sprung (has spings in it for less shock) 6 puck copper ceramic wheel and my housing is rated at I think it was 1700lbs. could have been more, it may well have even been 2100 I can't remember now, but I do remember the builder told me it would be good for about 320 hp, he said I could get about 450 out of it with another pressure plate (housing) So that is always an upgrade option to switch just that and save some money. I use a different clutch than you, so it wouldn't be exactly the same, but there it is. You should take a year to learn how to drive your 5 spd svx before trying this anyway. An pay no attention to "stage 1"...2...3... junk anyway. All that is most the time is to sucker you in to buying what you don't need... or less than what you need :eek:!! Look for real numbers, not "32% increase" and crap like that. That is just for people who don't know any better. Maybe I'll post a bit more later, but for now... I hope this answers a little.

poweredx2 08-25-2006 12:36 PM

If a company made weber carbs for this engine I 'm sure that would be at least 30whp alone.Thats about what the company got from a bone stock rsx type s.

Trevor 08-25-2006 10:47 PM

Quote:

Originally Posted by poweredx2
If a company made weber carbs for this engine I 'm sure that would be at least 30whp alone.Thats about what the company got from a bone stock rsx type s.

Think again, but if you would like to try, I have a couple for sale.

mbtoloczko 08-28-2006 10:51 PM

Converting to a manual tranny makes the biggest difference. A lighter flywheel and lighter tires/wheels will improve acceleration which will be perceived as more HP. A lighter flywheel will make the car a bit more difficult to get moving from a stop.


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