Celica Forums General Discussion Engine and Performance WHP gain by changing tires?

On my celi I have stock 195/60/15 tires. I was thinking of going to 195/50/15 in hope of getting a little more punchy car (I never drive above 90 mph anyway). Would there be any gain by this, and how to calculate (roughly)?

Thanks!

I dunno about any HP gains to the wheels maybe if their lighter. it probably will give you alittle better accelleration cause it'll change your final ratio. you could figure it out if you got your gear ratios and final gear ratio and then make a ratio comparing the diameter of the two tire sizes.. the 50 series tires are going to be about 20 mm smaller in diameter so if you take the two diamters Pi * D to get the circumfrence of the two wheels then divide the two wheels sizes to get the ratio difference then applie that to the final drive and then you can compair that to your gear ratios to see what kind of new differences you'd have. you'd cut your top speed and increase your throttle response and accelleration alittle probably.

as a rule of thumb, the 50 series profile is usually lighter than the 60 series profile, but it doesnt have to be so watch out (a lot depends on the materials that make up the tire).

as far as whp gain..absolutely and utterly 0.

the lower profile tire will increase your car's cornering ability though.

After you get your huge gains, I've got a performance chip to sell you. NORMALLY I sell them for over $100, but I can let this one go for $60. I've also got a few GT-R emblems left, but because they give such huge power, I can't sell it to you until you build your engine .

J/K pal, you won't expect any additional power, but it just may hid the ground quicker.

I guess there are a lot of people out there thinking they know about improving the performance of a car, one way suggested is to reduce tire size (to improve whp), another is using (electric) grounding kits How stupid can one be...

^^ lol

one thing though..i dunno how in the hell it works..but grounding kits do consistently add 1 or 2 whp on a dynonameter for our cars. granted 1-2 whp is within the margin of error for dynonameters anyway, BUT the gain is consistent time and time again.

electric grounding kits though? i dunno..i think apexi makes one of those for like 250 bucks. whether it does anything at all is up in the air. either way i dont think its worth it

you can make one for like $40 with some four gauge wire and ends, anyway, it makes your spark more effecient by allowing the engery out of the engine and to the frame and battery, so less resistance just like better spark plug wires

Tires are just rubber material that goes on your wheels, not you engine. So don't expect any gains. It will however help you grip the ground for better traction if you get drag radials.

yes, that would be a regular grounding kit..which obviously has to do with electtricity. what i was reffering to about apexi though was that they make an 'electrical' electric grounding kit...or something. i forget it's exact name. anyway its like $250 and the gains are SUPPOSEDLY better.

most grounding kits only cost around $30-$50.