Quickin

Can this be done?

Put some huge Brembos up front, top-of-the-line and remove the rotors and calipers too from the rear.

How much RWHP would you pick up from the reduced rotating mass?

Damian

iTrader: (89)

LMAO!

Dude if you're doing this for dyno purposes you are one SICK individual..I think that would be a bad idea, even if your front brakes were 21 inches and platinum plated. You still need rear brakes....

Dom

iTrader: (2)

I'm driving with no drivers rear brake right now. Zero pressure. Too lazy to check what's wrong just yet. But it's not really noticable.

Black 98 T/A

iTrader: (3)

wait till you have to slam on the brakes

Quickin

My mind is always going. I was thinking about driving like that all the time, not just for a dyno pull.

Hell, isn't 70-80% of breaking from the front breaks anyway. I would think if you put some huge Brembos up front you would stop better than the stock 4-wheel set up.

Just a thought.

jRaskell

iTrader: (1)

Front brakes make up about 70% of your braking power, yes. You'd be crazy to give up that other 30% though.

Define huge Brembos. Most streetable setups are NOT going to provide an additional 30% more braking power to make up for loss of rear brakes, much less more than that. On top of that, why spend all that money to end up with, at best, stock braking power? Also, the benefits of the weight loss as a result of removing the rear rotors is negligible and far from making it worth the loss in braking power that comes with it. That weight loss will account for, at best, a 3-6hp increase. A 1-2% increase in horsepower at the expense of a 30% loss in braking? Not a good tradeoff in my book. Slap Brembos on front and rear and enjoy the significant increase in braking power ABOVE stock.

trackbird

iTrader: (4)

And...

The weight you lose from the rear rotors will be made up by the larger front rotors. On top of that, the larger diameter puts the weight even farther away from the bearings (increasing "moment of inertia") which will make a lighter, but larger diameter rotor absorb more hp to spin than 2 smaller ones of the same or even slightly more weight.

For the dangers involved for "dyno queen" numbers, I'd not bother.

absolut_speed

iTrader: (1)

Not usually going through the dictionary though, eh? I'll leave the brake theories to those who know the difference between brakes and breaks.

Quickin

Thats all I was wondering, how much RWHP would it be worth. I guess its not worth it.

Quickin

I spelled it right everywhere else, you know how it is when you're typing fast sometimes, brain fart.

gator's 99TA

iTrader: (2)

so you really are concerned about your dyno bragging so much that you want to ditch your rear brakes. and race brakes require tons of warm up and are worse on teh street than stock brakes under normal deceleration.

skip the idea. AGAIN if you want top speed and top rpm dynofag bragging power, switch to a manual tranny.

APeteSS

Don't do it, most of your braking feel comes from the rears.

Also, see what happens if you hit the brakes mid corner with only the fronts connected-- I think you'd go off.

Quickin

I never mentioned a dyno pull, I could care less about dyno numbers. You and a couple other people are obviously stuck on dyno numbers because you guys are the only ones bringing it up.

I was wondering how much RWHP you would pick up from the decreased rotating mass, THATS ALL. In a straight line run noone can tell me it wouldn't help their 1/4 mile time, you have to be one dumb son-of-a-bitch to think it wouldn't help some. 50 or so pounds less to spin WILL equal more power and a lower ET, PERIOD. And in straight line braking I don't think it would be dangerous at all.

Quickin

Thats true, not too safe in the twisties.

trax

iTrader: (2)

So you're concerned about RWHP, but not dyno numbers? Dyno numbers ARE your RWHP.


Are you sure it's 50 pounds off? More importantly, if this *was* safe, why don't you see this on professional drag cars? We're not trying to flame, we're trying to keep you from messing your car and / or body up.

Quickin

I'm meant I'm not interested in just putting the car on the dyno, pulling a number, and then re-installing the brakes, LIKE SOMEONE THOUGHT I MEANT.

I'm just wondering how much power it would be worth as a matter of just picking up power due to the decreased rotating mass.




When my Eradispeed rotors came in, they sure felt like 25 lbs a piece, not sure exactly what they weigh though.

Its probably not legal for NHRA rules, but it would sure make any car a little quicker.

BTW, I'm not a track person, this was really just a curious question.

trackbird

iTrader: (4)

Ok, I think I already stated that those "monster Brembos" you spoke of will add enough rotating weight to counter all or nearly all of the benefits of removing the rear rotors. The reason is what is called Moment of Inertia. That is, the farther weight is away from the point of rotation, the harder it is to spin. So, the extra weight of those big front brakes, though possibly lighter than the amout of weight you removed will probably take nearly the same amount of HP to spin due to being farther away from the center of the wheel. So, they will probably neutralize your gains, lighten your wallet by $2800 or so and make your car less stable when stopping.

This is the making of a good idea, you should let us know how it works.

Also, if GM could put the 13" Corvette brakes on the front (a bracket and rotor change) and remove the rear brakes, hydraulics, ABS sensors, etc. Don't you think, in an effort to save corporate dollars, they'd have done it by now? I do. But, since this is very likley to cause your car to swap ends in a panic stop, GM and very likley Federal regulations prevented it.

The rear rotors weigh about 18 lbs (20 max) each. But, since they are smaller in diameter than the new "Brembo" kit you spoke of, you will mostly be moving the weight around on the car. The dyno will show HP (not that you ever mentioned a dyno, but RWHP numbers have to come from somewhere), but the ET and MPH will probably not, and if they do, not much. But, when you are stopping at the end of a 105mph 1/4 mile pass, be sure to see how quickly you can stop. If you think it is not going to be too bad in a straight line, then prove it to us.

Have fun!

absolut_speed

iTrader: (1)

1) Please tow the car to the track if you want to try this for the sake of everyone else on the road
2) For the cost of larger brakes, there's got to be something more efficient to gain that .01 you're losing due to rear rotors
3) If you're so concerned about .01 seconds, why are you using such stiff springs that aren't exactly drag launch friendly?
4) Why the concern over weight in the rear? There's more to gain if you move the battery or remove the front bumper support material.

I understand it's rotating mass, but there are so many other things that are safer. If nothing else, buy some cross-drilled rotors and spend the cash on light-weight wheels.

Zeta

I *guess* it would be <5 hp.

To put it in perspective, what is the HP delta when going from 275/17 to 245/16 rears? It has been to long since I looked at the numbers but I think it is 7-10lbs per wheel difference. I would use those HP numbers to estimate the difference. What I know tells me the tire change is going to be the bigger number than deleting the rear brakes.

aram

iTrader: (7)

When I was deleting the ABS on my LT1 I couldn't get the correct fitting to connect the rear brakes for a while so I just put a plug in the master cyl when I needed to move the car about 50 miles and drove it that way (I got a custom hose made and have them working now ) I didn't really notice any difference in braking but I didn't try anything too crazy either.

Why not just get a set of drag racing brakes in the rear and not worry about it?