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tires for racing????

7K views 15 replies 9 participants last post by  Ludachris 
#1 ·
I currently run 225/40r18s, at the track last night other rex pilots were telling me I should go back to stock 16s for dragging. Honestly, most of these guys now s@#t about mods. Ohh, they talk like they know, but I ask them if they go online, like to this site or the others, they all said no. One dude cracked his a/m headers and blamed it on the txs utec. But he had no guages other than boost, and 22psi out of the stock turbo. So, I ask y'all are 16s better than 18s :confused:
 
#3 ·
Yes 16" rims are better then 18" rims for racing. Going to a bigger wheel and tire combo basically makes your gearing taller, which is great for top speed, but crappy for acceleration.

The rule of thumb is for every inch bigger you make your rim, you should drop 10% in aspect ratio. So basically going from a 205/55/16 you should be running a 225/35/18 which is still going to be larger then stock.

Here's a helpful link:
Tire Size Calculator
 
#9 ·
lol

i dont thing basic laws of physics have been proven wrong becuase you had a bad ET at the drag strip.

it has to do with surfice area and rotational mass like the man said.

why would you run 18's when you have 16's? tires for 16's are usualy cheeper. what would i do if i gave a damn about drag racing? id have drag wheels and street wheels. i would keep my nice street tires on my nice 18's and i would have crappy k mart tires on my 16's for draging. or if you really take the drag thing seriously, you could have your nice drag tires on your 16s, and what ever you have for street on your 18s. and just swap em off when you get to the strip.


but seriously, the diference in times between a 1" diamater diference is two or three tenths of a second with a consistant driver.
 
#10 ·
you always want to use the smallest diameter possible without compromising the grip you need. And you always want the lightest weight possible at that outside diameter

these two things combine to tell you that none of this makes a difference. Stock 16" vs 18x40 is virtually identical weight and outside diameter. The only thing it increases is grip. It has no effect on acceleration.
 
#11 ·
a bad day lets see I started with a 15.6, 15.4, 15.2, 15.1, 15.0, 14.8. Now my times were getting faster as is cooled down. Last time 16.1(1st run ever), 15.2, 14.8,14.8,14.8,14.8. And, I am positive it was the tires because my reaction times sucked, because the 18s grab alot faster. :mad:
 
#12 ·
yelljack said:
a bad day lets see I started with a 15.6, 15.4, 15.2, 15.1, 15.0, 14.8. Now my times were getting faster as is cooled down. Last time 16.1(1st run ever), 15.2, 14.8,14.8,14.8,14.8. And, I am positive it was the tires because my reaction times sucked, because the 18s grab alot faster. :mad:

ok thats fine if your 18" rubber is better then your 16", but dont say they are wrong, they answerd your queston. you asked if running 16" wheels is better then 18's and it is, not by much but it is.
 
#13 ·
dude why are you trying to get in a p@#$ing contest w/me. you come across trying to make me look like an a#$hole talking about how I am trying to prove physics wrong. well, because my 225/40r18s are only .2" larger (radius) but the 18s are enkei and significantly lighter than my stock 205/55r16s maybe the 18s have slightly less rotational mass. and I am not sure how long you have been a member, but we are allowed to blow off steam, usually w/out someone else trying to make us look stupid.
 
#14 ·
yelljack said:
dude why are you trying to get in a p@#$ing contest w/me. you come across trying to make me look like an a#$hole talking about how I am trying to prove physics wrong. well, because my 225/40r18s are only .2" larger (radius) but the 18s are enkei and significantly lighter than my stock 205/55r16s maybe the 18s have slightly less rotational mass. and I am not sure how long you have been a member, but we are allowed to blow off steam, usually w/out someone else trying to make us look stupid.
na man, im not out to get you or make you look like anything, its just ticks me when you say everyone is wrong.

So, I ask y'all are 16s better than 18s
they answerd the question you asked corectly.

and you come back saying

y'all were wrong, I put the 16s back on and ran like s#$%. and it wasn't the weather, 'cause it was only a couple deg warmer
well thats got nothing to do with your wheels.


like i said before, the diamater of the wheel is practicly moot in street car drag racing, you probably have softer rubber on your 18's or any one of a thousand difernt things hapend when you went back to your 16's.

the only reason i made the physics remark is because you where making it sound like the ONLY reason you ran worse was becuase you put yer 16s back on, and thats not the case.
 
#15 ·
May I ask you what is your Enkei wheel size, because I know the Enkei RPF1 17x8 is weight 15.5 but as I know the 18x8 is more than 17, and stock is 16.5. I am not wanna to say any thing bad about you, I just want to find out the reason why you got that time in 1/4 mile.
Is that track you ran is in a level which is higher than the sea level? Did you shift too early? Did you burn your tires on first gear, second gear or even the third gear? Did you had a good reaction when the light turn green?
We are not trying to make you feel bad in any purpose, we just try to answer and solve the porblem and question.
 
#16 ·
yelljack said:
a bad day lets see I started with a 15.6, 15.4, 15.2, 15.1, 15.0, 14.8. Now my times were getting faster as is cooled down. Last time 16.1(1st run ever), 15.2, 14.8,14.8,14.8,14.8. And, I am positive it was the tires because my reaction times sucked, because the 18s grab alot faster. :mad:
Your 18" tires may have grabbed better, but it likely had more to do with the tires than the wheel diameter. Better tires will grab better. And reaction times have nothing to do with tires grabbing - that's your 60 foot time. Most serious drag racers use small diameter wheels, 15-16" in fact. Theorectically, 18's are not ideal. But you probably won't see much difference unless you're running 11's or faster. I wouldn't worry about it too much if I were you.

Cosmo knows a thing or two about drag racing, you should really pay attention to what he says.
 
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