Ok guys im going to the track tommorow night for street night. Should i take off all four of my 19's and put the stockies on or should I just change the front two? Will this effect my et. at all? Any help with this please and thanks.

 

maybe ...it depends on how much your 19wheel /tire combo weighs

 

I have 19x8" Axis Mod Se7ens with 225/35/19 tire's It just seems more light on its feet with the stocks on the front also, And I dont mind if I wear them out vs. wearing out my 19's. Im gonna see what my combo weighs whats the stock weight about?

 

Ok I just looked it up, The wheel weighs 29.5lbs. as where the tire 21lbs. Whats the weight on the stock setup?????

 

Stock rims are around 26lbs. So you should take the 19's off. I would take all 4 off.

Unless you want to run with the 19's. At least you will get a accurate time of what your car does in the real world driving everyday.

Or have a friends who's not racing go with you & load the stocks into his car & change them at the track.

 

Changing your back wheels to stock probably wouldn't do anything and you'll want to run whatever set of wheels are lighter with the smallest outer diameter.

Something else you might to try is leaving only 10psi in the front tires. It sounds crazy, but I pulled a 2.1 60' with 10 pounds of pressure on Azenis 615's. I'd start with like 20 and then let some out every run until you find the right amount.

 

Is that 26lbs including the tire? Or just the wheel?

 

just the wheel ofcourse

 

I don't know if I'd feel safe with 10psi in the front tires while trapping speeds between 95-100mph. IMO, it's risky, and if a tire blows up, you can lose control and injur yourself / others, or at the least, hurt your car real good.

With that said, in regards to the original post -> your 19's combo is over 50lbs. I'm not 100% sure what the stock rims/tires weigh but it's surely under 50lbs (perhaps around the 35 / 40lb mark).

As a general rule, for every pound of rotational mass lost @ a power wheel (front wheels for FWD), it will benefit you ten-fold. So, in your case, say you go from a 50lb rim/tire combo on each side to a 40lb rim/tire combo on each side, you save a cummulative of 20 rotational mass pounds... or 200lbs off the overall weight of the car.

In other words, expect to lower your ET by 0.2 seconds by switching from your 19s to 17s.

The rears are not as important since they are not the power wheels, however a lower mass will always help, so I would switch those too.

As far as tire pressures go, I've always inflated my rear tires to just under their maximum in order to decrease the coefficient of friction (helps acceleration).

As for the front tires, I never went below 20psi for safety reasons. Keep in mind, the lower the pressure in front, the better your traction may be, but your coefficient of friction also increases, hurting your trap speeds.

In Blazin' Si's example, what he might have gained in the 60', he could have lost in top-end due to that coefficient.

Hope this helps. I'm pretty sure most of this stuff works because I've always gotten kick-ass times out of my cars:

-2000 Civic DX on winter tires + cold air intake: 16.2 @ 82mph / 2.3 60'
-1988 CRX B20Vtec 171whp / 140ft-lbs on Falken Azenis: 13.7 @ 102mph / 2.1 60'
-2003 CLS-6 on near-bald Michelin MXV-4's: 14.3 @ 97 / 2.32 60'

Good luck!

 

I'd keep it on, the 225 series plus the extra weight vs. your stockies with 215s, you will have just enough better traction with the 225s which are probably better quality tires too that it'll make the extra 3 lbs worth it IMO, even when considering the rotational mass stuff. If you just spin the tires a bunch with your 215s, you will have shot times anyways. Unless you plan on doing a mean burnout with your 215s??? And as far as PSI goes, DO NOT drop it below 20 psi, that is just obsurd for your series tire. Maybe something with a series higher than 45.

 

keep your 19's on. it doesn't matter what you can run at the track if it can't duplicate it on the street.

 

Put all the stock wheels back on, for sure. Take out the spare/jack and run with no more than a 1/4 tank of gas. Thats how to get good times.

 

I concur!

Forgot to mention that in my post!

 

i dunno why ppl strip their cars for the track and run low gas etc. when i go to the track i go so i know what my car runs on the street.

 

Hey guys here is a link to the thread I started about my track results.
https://acurazine.com/forums/showthread.php?t=179613