What kind of performance loss with 18's?

[BigWind330]

Im htinking about 18in cobra R's and am wondering what kind of loss i will experience in the quarter mile?

 

[FastRedPonyCar]

i just got new 00 18X9.5 cobra r's and i can't tell any speed loss. The only difference is that it handels a lot better

I figure this way: ford set out to build a no frills road racer. They musta put 18's on it for a reason

 

[modu1ar tek]

Hmmm....I didn't really notice a difference either. I upgraded to 18x9.5 Y2k Cobra R's on 275/35 on all 4-corners. The handling/braking are better, but I get alot of bump-steer when I go on bad roads. Kinda sucks, but o well.

 

[WRXracer]

um

you will have a faster top speed.. but you are going to accelerate slower.. just get gears..

 

[RedGTvert]

The biggest loss that possibly can occur is being able to hook up. 18's will spin easier then 17's.

 

[Solid Snake]

you will have a faster top speed.. but you are going to accelerate slower.. just get gears..

How is that possible? You still keep the same overall wheel diameter....

Anyways, only problem with 18"ers is the decreased traction as opposed to your 17"ers. 18" = thinner sidewall tire = less "give" to the tire = spinnnnnnnn

Just get some FAT rubber to help

 

[JonJon]

I went from 16x7"s to 17x9"s and there was noticable speed loss. Felt a little sluggish compared to the 16"s. I eventually weighed the wheels and tires, 66 lbs MORE for the 17x9"s. That's rotating mass.

 

[wickedgt70]

It all depends on the outer diameter of the tire you are going to use. A bigger tire (presumbaly used on the 18" rim) will increase your effective gear ratio and thus decrease your effective acceleration. If the outer tire diam. is the same it will not affect your acceleration at all.

 

[01BlkGT]

Like stated above, the total weigh weight difference is going to be more of a factor than jumping from 17-18's. I went from teh stock 5-stars, 245/45's to the 03 Cobra's 275-40's and I noticed a difference on the street and the track I lost .1-.2 and around 2mph. Havent weighed the difference yet, but I'm guessing it's around 10-15lbs (total) or so.

 

[JonJon]

Like stated above, the total weigh weight difference is going to be more of a factor than jumping from 17-18's. I went from teh stock 5-stars, 245/45's to the 03 Cobra's 275-40's and I noticed a difference on the street and the track I lost .1-.2 and around 2mph. Havent weighed the difference yet, but I'm guessing it's around 10-15lbs (total) or so.

Yeah, I lost 2 MPH too. Traction was a little worse too, 275/40 has no sidewall, 225/55's had a lot more
66 lbs more than the stock's!!! But I had 16" stocks. oy.

 

[wms004]

It all depends on the outer diameter of the tire you are going to use. A bigger tire (presumbaly used on the 18" rim) will increase your effective gear ratio and thus decrease your effective acceleration. If the outer tire diam. is the same it will not affect your acceleration at all.

I agree with the first part.. but if you have a wider tire and an 18 inch rim both will be heavier than stock effecting acceleration.. i want new rims really badly, but I would never spend money on something that would make me any slower. sucks

 

[ph4926]

I made the same change and lost .4 I could not believe it so I took both sets of tires to the track and made 2 passes on each all in about an hour and I did loose .4. Now my cobra R's with nitto's are for sale to be replaced with Welds and BFG. It SUCKS to spend $500 to gain .4 and spend $1500 to loose .4

 

[GotMustangs]

Just get some lightweight 18's and you'll have the best of both worlds. I think Steeda Ultra-Lites are only like 22 lbs each (can't remember what the stockers weigh, but it more than that). Go with my personal favorite, BBS RK's , and their 18x10" is only like 19 lbs. Too bad they cost like $500 each in the plasma finish.

 

[Wil]

I don't know how much slower I am now with my 18's but the looks is well worth it to me. Thats just me though. But I'm sure I'm a little slower. BTW, does anyone know how much 18x9 chrome cobras weight compared to stock bulliets?

 

[TacBear]

I ran 9.30 with stock Goodyears and I run 8.90 with 18" Y2K "R"s!

 

[Marks5.0!]

I didnt notice a difference when i switched to 18's

 

[stangman]

I ran 9.30 with stock Goodyears and I run 8.90 with 18" Y2K "R"s!

:OT: were those two runs stock & was the only difference between those two runs the wheels

 

[68 & 00 GT]

Just get some lightweight 18's and you'll have the best of both worlds. I think Steeda Ultra-Lites are only like 22 lbs each (can't remember what the stockers weigh, but it more than that). Go with my personal favorite, BBS RK's , and their 18x10" is only like 19 lbs. Too bad they cost like $500 each in the plasma finish.

That's my eventual plan too. Steeda ultralights

 

[TacBear]

:OT: were those two runs stock & was the only difference between those two runs the wheels

The only difference was the wheels and X-Pipe.

 

[JonJon]

The only difference was the wheels and X-Pipe.

My x pipe got me the 2 MPH back that I lost to changing to 17x9 Cobra's.