240baja

OK, here it goes!!, I now our cars have 160 of Torque, which means our engines are strong, ok?, so i have a frend who have a Civic b16, and he told me he have Cams and Vtec controller and sprockets and ****!, and at dyno, he said he had 206 hp at the wheel and 146 of toque?, is that posible?, and i talk about this because he said that if he race whith 17/205/50 tires he's car it's a lot slower than using 15/205/50, why?, is it for the torque?, if this is the reason, then we can switch to 17" and have no problems?, I spin in 1st gear a lot whith the 15" wheels, and I'm thinking of the 17", but I have never tried that...in R/C racing where i race to, if i have motor whith high torque i can switch the gears up and have a faster car....but I don't now in the real thing...

Thank's.......

Catharsis

no way he has 206 whp from just Cams and Vtec controller and sprockets and with a 146ftlbs to the ground he would step on us a 200whp jond runs in the low 14s at least even lower

EvilCerealBoX

heres what i think about that problem..... HONDA SUCK ...

well for starters its probably because of the fact he has so little torque and the 17s are alot of heavier... but a thing about ricers (mainly honda drivers) ... they have a bad tendency to lie (or extremely exaggerate) just about everything...

but if you want a choice of wheels i'd probably go with the 17s because larger tires equals more distance per full spin thus you can go faster....

kaos

Two things about the bigger rims. One they are heavier. Two Honda's rely on high reving engines. Therefore a 17 inch has 2 more inches to spin than a 15 inch causing slower acceleration. Everyone knows that Honda's are not meant for high speed cause they have no torque. 17's will give you better highway speeds but slower 60' times. And I really doubt he is pushing 206hp with only those mods although he could be. It all depends what the an "****" stands for. Besides honda of course

Chad

spitz7985

when you get 17s, you get a lower profile tire and keep the same wheel/tire diameter that you had with 15s.

Limited240sx

15's are lighter. Rotational mass is less.

leiferik1

i was under the impression that this the way to go....i'd always heard that this was what you were suspossed to do.....let me know if i'm wrong 'cause this is what i plan to do kinda soon

Dave41079

Ok, but he has the same width/profile tire on a smaller wheel he is A.) losing rotating unsprung mass, and B.) changing his final real gear ratio to a quicker accelerating/lower top speed setup. A larger rim with low profile tires can actually have LESS overall height than a small rim with tall tires. Overall height is what you need to calculate. Also, if you vary too greatly it will affect your speedometer.

kaos

so the new guy know some stuff.... Just playing. Yeah but just like he said. I know when I had 17's on my civic the speedo was off by about 3 or 4 mph.

Chad

Dave41079

Amazing isn't it!!!! Here is a cool page for doing calculations. It has one on there for adjusting your speedometer for new wheels/tires, but you have to know the overall height. I'm not going into how to do that because I'm lazy.

Catharsis

Welcome Dave.. and you are correct also...

is your DSM turbo?

Dave41079

Unfortunately not, I am the king of 420A though evidently. Everyone comes to me with their problems. It's a good engine, and has lots of potential, no one ever uses it though.

Catharsis

i dont know much about the 420A.. please do tell ina PM....

Chikara

wait so would my car be slower if I got the same TIRE size as the stock, just a lower profile? I heard 18s or 17s would make my gear ratios larger, but doesn't the size of the wheel and tire matter not just the wheel? so wouldn't a 17 incher 205 be the same as an 18 incher 205? just like a 15 incher with 205?

Plus no matter what wheels I get they will be lighter then stock. So wouldn't 18s with stock sized tires not really make my gear ratios larger?

I want 18s not because I am some show ricer, but because I love the Endless 4 POT brake system, the way they look and I want brakes that are good and its between endless and brembo. The sales reps all told me I need 18s to runn endless 4pot brakes.

Dave41079

About what wheels you need with those brakes...I have no clue. You are right, 205 is 205 is 205 no matter if it is on a 15 inch wheel or an 18 inch wheel. 205 would be the width, then you have a second number that is the aspect ratio for the sidewall height. If it's 205/45, then the sidewall height is 45% of 205mm. you then double that number and add it to the wheel diameter and you get the overall height of the wheel/tire combo. What gets even better is that one tire manufacturers 205mm may actually be 201mm and another might be 209mm. Most tire manufacturers can tell you what the overall height is on the tires they sell. Lighter/heavier has nothing to do with your final gear ratio. It's the overall height of the wheel/tire combination. If you have a 15" wheel with 3" of sidewall, you get an overall height of 21"(remember you have two sidewalls in the overall height). If you have an 18" wheel with the same width tire and same aspect ratio(in our imaginary case, a 3" sidewall), then you would have an overall height of 24". The smaller the overall diameter, the quicker the acceleration, the larger the overall diameter, the higher the top speed. It works just like gear ratios. Once you go above a certain size wheel, you can't get the aspect ratio small enough to maintain stock parameters on your overall height. Then you adjust your speedometer, and deal with slightly slower acceleration.