Wheel size and acceleration.

[HijackTheLeft]

How much of a difference does wheel size make when it comes to acceleration? It seems like smaller tires would give you better launches, because it would be like a lower gear. Granted, it would kill your car at high speeds, but it seems like if small enough, it could make a difference.

The only thing is that when you look around, nobody races with little tires. I know the big drag racers need the big tires for traction, but traction isn't that big of a problem when your pushin about 160hp.

[hannibal]

Good question.

Maybe the tradeoffs arent worth it. You'd hit redline sooner, have to shift more to reach a given speed, etc

[240DRFT]

weight also comes into play some. less rotating mass is better.

[HijackTheLeft]

That's something else I thought about. And I know I'd have to shift more, but I just reach the top end of third gear in the quarter mile anyway... maybe hit fourth depending on how I shifted early on. I wouldn't put em on for everyday driving, just at the track. Maybe I'll get some from the junkyard and try it out, and let everyone know how it goes.

[naed240sx]

alot of people here are using much smaller tires than stock, like mounting 205/50 azenis on the 7-spoke s13 wheels. I have a different rear end ratio in my car, which definately helped with acceleration alot. Dont do anything drastic, like mount some 45 ratios on the stock rims or anything. Generally it will help acceleration, unless you are making alot of power.

[hannibal]

I assumed you meant running a smaller wheels with slightly thicker tires that would give you an overall smaller diameter. I think lowering the profile is a poor way to test this theory. Not to mention how expensive narrow (205) low profile tires are. I'd try smaller tires AND wheels.

Try to find a set of base Sentra wheels. They are probably 13x5.5 or something. Tires are dirt cheap too. Of course if you go too small, you lose traction even with your 'underpowered' KA.

I'm curious to see your results.

[tonynalli]

and you will also get terrible gas mileage, youll be at interstate speed(80) with your motor winding around 4-5k

[HijackTheLeft]

tonynalli,I wasn't planning on running them on the interstate. Just at the track. That would be hell on my engine. The RPMs needed to maintain a highway speed would be way too high.

IWannaS15,yeah, I was planning on going to the junkyard and then I can get wheels and tires for like $8-10 each. And you're right, I was talking about smaller wheels to get an overall smaller diameter. I'm gonna try to find some old 12s that they used to put on metros... or even a couple spare donuts. And if I lose too much traction, then I'll just play around with em until I blow em up. I win either way!!

[hannibal]

I forgot a few cars had 12" wheels. 12" wheels on a 240sx, haha.

I dont think your local drag strip will let you run with four donuts. If they do, that would be a funny site.

Where do you drag? Not sure where Hopeville is, but do you know if VIR or MIR have good amateur drag racing on Friday/Saturday nights?

[naed240sx]

tonynalli,I wasn't planning on running them on the interstate. Just at the track. That would be hell on my engine. The RPMs needed to maintain a highway speed would be way too high.

IWannaS15,yeah, I was planning on going to the junkyard and then I can get wheels and tires for like $8-10 each. And you're right, I was talking about smaller wheels to get an overall smaller diameter. I'm gonna try to find some old 12s that they used to put on metros... or even a couple spare donuts. And if I lose too much traction, then I'll just play around with em until I blow em up. I win either way!!

12 inch wheels? are you crazy? Trust me it is not gonna help in any way in a track condition, because you will have some rediculously high aspect ratios on those tires, and you will be cornering on the sidewall. My engine is pretty much stock, and I run some 225/50/16 in the rear, and I can break them loose easily. your car will handle like **** if you do that, and shorten the gear ratios way too much.

[hannibal]

He's not trying to turn...

[naed240sx]

He's not trying to turn...

ahh. even more reason not to get tires like that. way too much torque to the ground on some extremely skinny cheap tires will yield horrible times.

[Kenrik]

get some 8.5 inch wide 12 inch rims... Lol j/k

[HijackTheLeft]

HAHA yes!! Some of those little gold 100-spokes some people put on those old 80's Camrys.

IWannaS15, Hopewell is about 20 minutes south of Richmond. I race at the Virginia Motorsports Park in Petersburg. I've never been to VIR or MIR, but I've heard VIR is awesome.

And I was pretty much joking about the donuts. You can't race on those anyways. But racing on some Geo Metro or Ford Fiesta steelies would be fine. It's worth a shot. I'll just bring a trunk load of different sizes and see what works. For some reason though, I have a sneaky suspicion that nothing I try will be better than my stock wheel/tire combo... but I won't know til i try. Cuz that's the scientific method, and I am a physics nature, so it would be educational. Maybe if I take good enough measurements and calculations, I could use it in some research project.

[naed240sx]

The fact is, you cant get any good tires for those sizes, so the lower gear ratio is not gonna help because you will get terrible launches. you want wide, sticky tires.

[HijackTheLeft]

so i'll spin em til they're smooth, run real low psi, and spin em in the water pit, like racing slicks. lol... I know they'll be much harder to stick. I know, in reality, that all variables taken into consideration would lead to slower times, hence the "I have a sneaky suspicion that nothing I try will be better than my stock wheel/tire combo" comment. But what I was wondering was, traction aside, if smaller tires would lead to quicker launches. I understand they would need to be wider to get any traction. I was just wondering if the diameter had much of an effect.

[unfortunatepenguin]

http://www.csgnetwork.com/multirpmtirecalc.html From what I gather this Calculator should give you the results you want, personally it's a little to confusing to me but give it a shot and let me know.

[HijackTheLeft]

lol... im not too sure about that one either. I don't know what all my ratios are. It looks like it has the potential to be helpful though. lol

[hannibal]

The fact is, you cant get any good tires for those sizes, so the lower gear ratio is not gonna help because you will get terrible launches. you want wide, sticky tires.

Yeah, the race between wide (195) tires and skinnier, smaller diameter tires will go the wider tire. You would need to run 195/60-15 vs 195/60-12 to make an accurate comparison. I doubt you can find a set of 12" tires in that size.

[HijackTheLeft]

Then I'll strike out the racing idea, and just do burnouts... cuz i wasn't trying to "look" for anything. I was just gonna go to the junkyard and "get." haha... I'll be sure to take pictures.