What gives more HP?

[TBITB]

Originally Posted by navylife59

Lightweight pullies don't make power, they recover wasted energy. Think of it this way; a car, with only the driver, has a 0-60MPH time of 5 seconds. Now that same car loaded up with 5 more people has a 0-60MPH time of 6.2 seconds. Remove those 5 people and the car again does it in 5 seconds. The reason is that the motor had more of a load in the form of weight. The engine HP output did not change so it is a matter of work. Anything attachd to the motor (IE pullies, flywheels, rotating assembly, accessories) adds work to the motor. Lessen the weight, you lessen the load, hence more power to the wheels.

in another thread you wrote (paraphrasing a little) pulleys "recover" about 10 or so BHP and the wheels only get about a 2-3hp increase with a pulley. that doesnt sound like much to me. where else do you lose hp? clutch?

[bwood87]

Anything that moves because of the motor is taking away some HP. All the pulley driven things, clutch, transmission, diff., etc. 2 to 3 HP is not much but it could be that edge that you need to win. Any amount of HP to the wheels is a good thing.

[TBITB]

tru that bwood! i get it.

[navylife59]

Originally Posted by TBITB

in anoother thread you wrote (paraphrasing a little) pulleys "recover" about 10 or so BHP and the wheels only get about a 2-3hp increase with a pulley. that doesnt sound like much to me. where else do you lose hp? clutch?

BHP- Brake Horse Power (aka flywheel HP) as tested at the flywheel on an engine dyno.

WHP- Wheel Horse Power as tested at the driven wheels (FWD, RWD, AWD) on a chassis dyno (2/4wheel).

All vehicles experiance some sort of drivetrain loss. FWD apps on average have a 15% drivetrain loss (lots of plus and minus to this equation) "About 10BHP" has been the best that I have read on engine dyno testing. 2-3WHP has been the average gains that most power adders claiming 15-20HP increases. There has been very few posted chassis results on LW pulleys. As you may already know, chassis results can be very subjective making a definative result impossible. A slipping clutch can skew results negatively. The more power your motor makes, the more clamp load your clutch will need to prevent slip. Another thing to consider; if your motor has less of a static load on it, then your results will be less than a motor with more of a static load on it. Static load being defined by any parasitic load or centrifugal weight (torsional load) that remains a constant on an engine.

***Wikipedia Physics professors correct my science if it is flawed!

***Sorry to be so wordy. I am still trying for that A+ from my HS English Teacher!

[TBITB]

I got a c in physics in high school and got a c- in physics in college! so that last part about centrifugal weight gave me a headache! but i believe you!

[ac3 b00gi3]

lol
me two

[bwood87]

Guess I am the only one that paid attention in physics. Its not that Navy is wrong he just chooses the wrong words.

Torsion is the twisting of an object (just imagine ringing out a wet towel). Although torsion may play a role in the loss of power it would be an extremely small factor. A centrifugal force is one that acts away from a rotating axis. (centripetal force acts towards the rotational axis). For this one imagine being on a roller coaster, when you go on a loop and you are flipped upside down you are pushed into your seat, that force is centrifugal force (at the top you may start to come down, but that is because the force of gravity is getting stronger than the centrifugal force so for this example ignore that feeling).

There are several ways that the pulleys provide drag. To understand the drag that pulleys cause in respect to their weight and size we have to look at the moment of inertia. Just know that the bigger the pulley, the harder it is to spin and for two equal sized pulleys the heavier one will be harder to spin. Then there is the resistance from load devices. This one is pretty obvious, but just imagine pulling on a breaker bar trying to free a stuck bolt. Now imagine your friend is a jerk and pulling the bar the other way, now most of the force that was going to the bolt is now going to counteracting your friend.

So now that that is cleared up. Your pulleys are still not the main cause of loss. That would go to your transmission, and there is not much you can do about it. It has to do with the efficiency of gears and thats way too complicated to get into. Automatics tend to be a little less efficient because they have a torque converter.

I am a little bored today. Anyone stay awake through all that?

[navylife59]

That is what I said...... I think

Reading back I think that I meant to say the torsional forces required to spin the centrifugal loads. Thanks for the catch. You guys have to back me up and keep me honest. This ain't no Wikipedia Those Honda N/A B16's that twist up to 10K do that by removing as much weight as possible from the rotating assembly. Cutting and knife edging your crank counter-weights, running LW rods, low deck LW pistons, and removing the balancing shaft assembly has the added sided-effects of not withstanding the torsional loads imposed on them for very long, especially at 10KRPM.

FYI... Knife edging is done more to cut down on friction losses of the counterweight slinging thru the oil. This is another reason to run a dry sump oiling system or windage tray for high performance engines with the first being a race only app. The 2AZ-FE is a wet sump system, but the lower engine girdle houses the balancing shafts (short lobes) that acts as a windage tray. The balancing shafts are why the 2AZ-FE can run a LW crank pulley w/o torsional dampner and not cause damage to our blocks or rotating assemblies. Removing them to decrease rotational mass will, in effect, drastically lower the life expectancy our your motor. Leave that one to the professionals with a major sponsor and 3 extra motors in their back pocket

[TBITB]

Originally Posted by bwood87

I am a little bored today. Anyone stay awake through all that?

nope!

[omenbbt]

yo anyone know a good shop in philly tht will turbo my car

[gellar408]

This thread was so interesting & confusing. I want to know more about my car. & hopefully after graduation I'll start working on performances.

[TBITB]

Originally Posted by omenbbt

yo anyone know a good shop in philly tht will turbo my car

good question i'll look around im from Atlantic City and i dont know of any tuning shops in south jersey. most of them are in north jersey and new york.

[TBITB]

Originally Posted by gellar408

This thread was so interesting & confusing. I want to know more about my car. & hopefully after graduation I'll start working on performances.

read around the site and all the different threads. i've definitely learned a lot about the tC and cars in general since this site. do your research!

[navylife59]

Ask questions, ask questions, ask questions. Find knowledgable people and hang out with them. Always offer to help them work on their car or go on the hunt for parts (with the Net, does anyone do this anymore?). Attend any and all car shows. This is how I learned, osmosis.

BTW... Understand that the Dealership, salesperson and techs in general, don't really know all that much about the tC.

[TBITB]

Originally Posted by navylife59

Ask questions, ask questions, ask questions. Find knowledgable people and hang out with them. Always offer to help them work on their car or go on the hunt for parts (with the Net, does anyone do this anymore). Attend any and all car shows. This is how I learned, osmosis.

BTW... Understand that the Dealership, salesperson and techs in general, don't really know all that much about the tC.

ha ha, ditto on the techs and salespeople! i knew more about the 4.0 RS tC than my salesperson and the Scion Manager . they didnt even know it was coming out!

[gellar408]

Thanks dudes. What's the 4.0 RS Tc?

[TBITB]

the release series tC that comes out every year. this is the 4th year for the tC hence 4.0. they make minor changes to it each year to make it "special:" exclusive color, appearance mods, upgraded sound system, etc.

[ac3 b00gi3]

i still say it should be stock s/c
set a pure price for the RS different from the pure price for the regular models
but w/e .. i don't own an RS model