Oversized rotors cause power loss??!!!
 

OK guy this sounded totaly bogus to me. Last night i was watching this tuner show, i forget what it was called, it seemed kinda ****ty. Anyway the focus of the show was an RSX and boltons, on the dyno.

this is what they did:

Oversized rotors and calipers

Mungen catback exhaust with twinloop muffler

fullcoilover suspension

I think it already had an intake

Net gains: 12hp LOSS!!!!!!!



They were all confused so they called some people, and their conclusion was the rotors caused the 12hp loss which would equate to more with the addition of the exhaust at the same time, so basically what they were saying is the rotors caused a 15hp loss, if u include the 3 hp gain from the catback!!

OK this sounds way to ****ed up, i think they are dumbasses and messed up the dyno resaults (you cant mess up a cat back install) unless they forgot to take the bubble wrap off the muffler or something lol


They claimed its because the rotors surface area extenting out to the edges more, which takes more inertia to get rotateing or something... therefore causeing a powerloss at the wheels (which dynos measure)

I think they confused this information with wheel sizes:shrugs: I totaly understand how wheel sizes affect acceleration, and power at the wheels, but brake rotors and 15hp !!! now cummon


BTW THE ROTORS WERE LIGHTER THAN STOCK!!! lol


Does anyone else think this sounds bogus? if not please explain to me the sience of this, i find it interesting. :confused:

dude man quit watching TV :p most likely it wasn't the rotors but bad tuning dyno charts though are the important thing to look at ...

of course they could have a 12 hp loss at peak but the torque curve everywhere else could show lots of gains....

it's rotational mass, and as such of COURSE it causes a loss to the wheels. it's the same effect of having 40 lbs rims on the car... those fawkin rotors are heavy j00! If my "tuner" was surprised to see those reslults I'd kick him in the arse and send him back to mexico.

Well - I'd be interested to know what brake upgrade they used because most kits include aluminum pieces that will actually remove some weight from the whole braking assembly.

As BB said, if my "tuner" recomended parts that actually gave me no +'ve results...I'd be pissed.

And they also stated that their track times stayed identical, because of the 12 hp loss, but they made up for the power loss by brakeing later in the corners, and the coilover suspension, and all the other suspension mods they did...

SO the end resault was 0 gains in track time, and a loss in acceleration. Total cost probably 4 grand or more

NA<Turbo :thumbup:

YES THEY CLAIMED THE ROTORS WERE LIGHTER THAN STOCK!!!

they said it was the circumfrance of the rotor that caused the power loss, cuz it takes mor inertia to move them, but they are lighter!

I understand this with rims, but thats more surface area touching the pavement, rotors do not contact the pavement

NA setup just the bolt ons

Think leverage. the farther out the weight is from the wheel, the harder it is to turn. Ie. if you have a bar across your shoulders, and you hang 2 buckets of water on the outsides of the long bar... try to spin in a circle! then move the buckets right next to your shoulders closer in and spin in a circle. Easier, no!? But if the weight is lower the effect should be minimal unless it was like a 14 inch brake rotor :p

On the flip side of the coin, the farther out the braking surface is, the more leverage IT has to act on the axis of rotation, so the more clamping power it has! In this case, picture an electric drill.... it has a big ass polishing wheel on it. Grab the edge of the polishing wheel as it's spinning, and it'll stop. Now put a pencil in the same drill bit and try to stop the pencil from spinning - much harder.

turbo is also a bolt on :nods:

yup that makes total sence... 15hp loss tho (im adding the exhaust gains, cuz it was 12 hp loss from stock, and im sure the exhust gave it 3hp)

Now imagine losses like that on a civic lol, fak. stock brakes are even more appealing now:D but the willwood are so sexy :yummy:

Somone with a dyno should do a comparison for us!

bbarbulo your doing turbo and brakes right? so you will be on a dyno, do a before and after dyno run with your brakes, that would be very interesting:p :D

dyno runs cost money man, I'm not THAT interested in how much WHP I lose from the brakes :p I'll leave that up to magazines to do baseline runs and I'll just read about it. :D

Search the Sport Compact Car 5th gen hatchback project car, they have dyno runs w and w/o brakes I think...

I lose 15 hp, I'll just crank the boost up one more psi :wink:

bastard :p

maybe when they were installing the brakes they forgot to adjust them... so that the brakes were always applied a slight amount??

possibly punk....


like I said quit watching TV get out there and try stuff and figure it out on your own is the best way to learn .... and you will never forget it

haha i dont watch tv.... but my brakes had that problem... actually my rear still do but my car isn't gonna be winning any dyno awards so meh...

:dito:

the show was sports car revolution and it was their King Motorsports sponsored Mugen Project RSX

and a corection... they lost 12 hp with the brakes and the MTL gained 5 back, not lost 5 more, so they lost a total of 7 hp with the brakes in the end

its time for CF rotots :D

they do have titanium ones i think? :shrugs:

and i think they have carbon ones too