358chevycamaro

iTrader: (10)

For a drag only setup you have the option of running a bias ply front runner as opposed to your cheap typical 165 metric radial tire on your skinnies up front. My question is what kind of gains you could expect in losing 10 lbs a piece in your front tire by switching to a tire such as the Moroso Drag Special Tire? (25x5.5-15 weighing 10lbs)

***This is not a discussion about streetable tires or radial vs. bias ply tires, just a discussion about the gains of losing rotational/unsprung weight in a drag setup.***

Demonicbird00

iTrader: (17)

theoretically its said that 1lb of rotating mass is equal to 10lbs of dead weight

-brandon

358chevycamaro

iTrader: (10)

So with that theory being said it would equate to an estimated 200 lbs of dead weight. I know there would probably be a noticable difference (or atleast I would assume even at 20 lbs in the front tires) but I am not sure if it would pick my car up roughly 2 tenths and 2 mph.

What I do know is that with eliminating 10 lbs in a single tire as opposed to removing the same ammount of weight in the rim, the weight is further from the center of the rotational mass (center of the wheel) so it should be more effective removing the weight from the tire. Or atleast this is what was explained to me by a physics major graduate, which makes sense to me.

If no one has any results from doing this, I will have to swap front tires one day at the track. (A gas station/garage is located less than a 1/4 mile from where I race every weekend.) I think swapping them the same day at the track, other factors such as track conditions and weather conditions would be less of a factor in altering the actual results in trying to compare the possible gains...

95z28camaro

iTrader: (15)

Well i just bought some m/t et fronts 26x4.50x15 and ill be changing from the 165/80/15 kuhmos so i may have some numbers here soon. That is if they make it in by this friday. But im thinking around a consistant 5-7 hundreths, not only because they are lighter(like 8lbs for me) but because they are suppose to have a lot less rolling resistance.

358chevycamaro

iTrader: (10)

Sweet, keep us updated!

If I saw .05-.10 of a second drop in my times just from a tire swap I think that would be pretty simple and bad ***!

BadBandit69

iTrader: (13)

I thought it was 1 pound of rotational was equal to 4 pounds static weight.

358chevycamaro

iTrader: (10)

That sounds much more feasable than 10 lbs of static weight.

Reboot

iTrader: (5)

So doiing drag brakes should be one of the best bang for the buck mods available...Correct?

cbra-klla

iTrader: (52)

might just have to order me some new tires

Demonicbird00

iTrader: (17)

yes that would be right.... you take off 80 lbs from going to drag brakes. im not sure what the actual weight is of the rotors tho.

w/ the 1:10 is about right...w/ kart racing its said to be 1:6 and they are by farther smaller then a car....

people say just throw more power at it, i do everything i can to get a better hp:lb ratio

between doing brakes, gun drilled axles,spool,and weight reduction thats a good amount of weight taken that will make the car faster w/out adding power

-brandon

Villain281H

iTrader: (5)

Let keep this on topic!

Not only the weight drop, but you're also looking at less resistance going down the track from a drag-specific front tire.

Derek

358chevycamaro

iTrader: (10)

Drag brakes lose most of their weight in switching from cast iron calipers to aluminum calipers, which is stationary and does not revolve like the rim or wheel does. Losing weight with drag brakes is cool, especially on the front, and you stop better, but it is not the same as losing weight in your rims and/or your tires....

**Disclaimer - I am sure with drag brakes the rotors may be lighter which would equate to rotational weight, but the largest majority if not all of the weight lost in a drag brake setup is in the caliper. (Correct me if I am wrong.)

358chevycamaro

iTrader: (10)

I agree!

Where is Madman, and Steve Burkhart and all of the guys with the big shops to put their $.02 in on the subject?? I would really like to hear what they have to say about it, especially since they have more experince with changing race car setups than anyone...

joelster

I did exactly what you are talking about. I don't have any track times but I do have the exact weights. I took off a Kumho 165/85r/15 and had installed the Moroso 2-ply Drag Special tires (MOR-17050). Each wheel/tire combo went from 29.5lbs down to 19.5lbs. It was virtually 10lbs each. 20lbs total.

358chevycamaro

iTrader: (10)

Thanks for the info! I know my cheap 165's were supposed to weigh right at 20 lbs when I had a friend weigh one in the tire shop he works in, and the Morso Drag Specials only weigh 10.

It's nice to know that will drop 20 lbs off the front for sure though! Someone should add this to the weight reduction sticky, as bias ply front runner vs radial front runner.

Demonicbird00

iTrader: (17)

its already in the weight list


Villain, i dunno if you refering to me, but i am/was staying on target, the topic is about rotation mass. thats why i brought up the axles,spool and such

-brandon

358chevycamaro

iTrader: (10)

It just says...

17ea...Skinnies

I think it would also be informative to see it say.

17ea...Skinnies (165 Radial)
27ea...Skinnies (2-ply Drag Front Runner)

You see what I am saying? There is more to be lost than what the list shows, and it would be nice for people to glance and see the difference in weight of a radial vs. bias ply front runner.

358chevycamaro

iTrader: (10)

Well my bad I was looking for "skinnies". lol

Also wouldn'tyou save more with the Moroso over the 165's? haha

Anyways, back on topic. What is everyone else's thoughts and opinions?

pmbmax

The other thing to look at most 165 tires (most not all) are not high speed rated . So 150mph or so is somthing else to consider, I think it is worth the change to get the weight off. any time you get ride of unsprung weight is a good thing

STEEPSS

iTrader: (30)

i've been looking at the greg weld fronts from summit. right now they're $99 each for a 15x3.5 with 1.75 in BS. if i paired that with a mickey thompson front runner 26"x4.5-15 (if that's the right tire), how much could i expect to gain et/mph over my 17x9.5 AR TTM's with 275-40-17 nittos? (they weigh ~45lbs each as they sit) i would plan on pro star rears in the 15x8-10" variety. i would use the Greg Weld rears if they would fit. did the 8" GW's ever get fixed?