Wheels vs. Gears & D/S...

[S197steve]

Hey guys, I think I can answer my own question but wanted to get some feedback from anyone with a bit more experience. Right now my car is in the 430rwhp range, with 3.31s, stock wheels and stock drive shaft. Those three components are all components I plan on changing out but as with most of us, my accountant (aka wife) won’t allow me to do all at once so I need to prioritize.

The wheels I want (TRMotorsport MT1 18x9.5) are significantly lighter than the stock 18” bullets I have on there now. By dropping about 7lbs on each wheel I know there will be some sort of performance increase but I’m not sure how much. I assume braking distance will improve the most, but how about acceleration? Will there be a seat of the pants improvement? Since I’ll be going to a wider/lighter tire I believe there should be a significant increase in mid-corner grip along with corner exit grip. Will a wider front tire hurt my turn-in feel and response?

The driveshaft and gears would be done at the same time, so I know I’d get fairly significant seat of the pants performance gain but I don’t think I’ll really get any real cornering benefits with these mods.

I’m striving to build a well balanced performance car, one that isn’t too biased towards track or strip but is a good combination of both. Right now my car is faster than most in a straight line but even with the Saleen suspension parts, it doesn’t handle nearly as well as many modern sports cars.

Assuming my ultimate goal would be to lower my lap times (don’t have any yet), will the addition of the TRMotorsport wheels help me gain a more poised and balanced car in the corners or would my money be better spent on the acceleration aiding mods such as the d/s and gears?

I currently drive the car daily (52 mile round trip) and hit the twisties a few times a month. I haven't done any trackdays in my yet (20+ on motorcycles though) but am planning on doing two with my dad over the next few months.

Thanks for any input you can provide!

 

[marksti]

If its just the wheels...then no

If its the wheels and larger tires then go for that..no doubt imho

 

[Vapour Trails]

Based on what you've said I would just get a good set of tires and go do some track/autocross days and get some experience. The biggest improvements in lap times come from getting better at driving.

 

[bigmachano]

i'd say wheels and tires. my comparison was going from 255/30r20 to 275/40r18 and it was a major difference. everything was different, now sure that was from some bullshit 20s to lightweight 18s, but still everything was different. accel/decel/cornering. it even felt like the car turned easier, not just as far as low speed steering, but at speed it feels like i don't have to turn the steering wheel near as much to get the same response. the one downside was on a shitty road bumps would pull the much meatier tires in that direction, but it just made me feel like a bad ass with 275s in the front! i'm sitting with stock driveshaft and 3.31 gears too, so i have no idea what that would be like to upgrade, but from a corner carving aspect, i couldn't imagine it would be anywhere near as much of an improvement

dane

 

[S197steve]

Thanks for the feedback guys, I appreciate it.

I'm currently using Hankook EVO Ventus 12 (255/45s) and they were a huge upgrade over the stock tires. I'd probably keep that same size for the front, but get 275s for the rear as I'd get the 18x9.5s on back.

Vapour Trails, I know more track time is going to make the biggest difference. Like I said, I've done 20+ motorcycle trackdays (also raced in club level in 04 & 05) so I know how valuable seat time is. I guess I wasn't clear enough in describing my goal, my apologies.

Between gears & d/s vs. light weight wheels... what would help a driver more around the track? With my bike, when I swapped out suspension for top line Ohlins I dropped nearly 5 seconds off my previous best once I got them dialed in. I never swapped wheels, so I'm not sure what sort of difference it would have made. I also changing the gearing on my bike and it made a little difference, but nothing too noticeable.

So, translating the back into cars, I assume that since I already have plenty of HP, the gears & d/s wouldn't be as necessary because I'm not skilled enough to fully utilize the power I have now. That being said, I feel like improving the cars handling will help me more than a little bit more acceleration. I'm just trying to find out if my assumptions are correct from those with more experience...

 

[Sleeper_08]

Going faster around a track is also dependent on good brakes - what have you changed or do you plan to change on the brake system?

 

[o0Dan0o]

Going faster around a track is also dependent on good brakes - what have you changed or do you plan to change on the brake system?

+afewmillion

My stock brakes are pretty well glazed with 40k (though a ton of pad left...)

I've only done a couple of Auto-x, it's really high on my list before I get much more serious.
Dan

 

[Cone Sweeper]

For starters.. running the same size tire all around is far better then having two different sizes - not only for the sake that you'll be able to rotate tires around, it also makes it cheaper on your wallet. ( Specially seeing you have the wife to deal with when it comes to expense on the car )
Second, the different in grip will be far more of something you'll notice coming out of corners with a bigger tire, more so then you'll notice the accel and what not. Those will come once you get the seat time and the push out of corners.
But the bigger thing to start worrying about as Sleeper_08 mentioned, is brakes.. thats right up there with tires..even past tires. I'd look into maybe some of the Carbotech( sp? and also you can search for that, i know a couple people use them on the boards ) as well as Hawk DTC series ( I run 60's up front and blues in the back ) as well as keeping up with the pad, which i'm sure you know, some race brake fluid.. other then that, theres plenty of threads made for cooling and prep besides those things. Good luck!!!

 

[S197steve]

Thanks again guys, looks like I'm going to go the route of new wheels. So I've now hear from a few different sources that differing wheels sizes isn't really the best route to go. That being said, am I better off with 8.5 or 9.5 inch wide wheels?

BTW, I do already have new drilled/slotted rotors and pads in the works as well.

 

[Sleeper_08]

9.5 x 18 seems to be the most popular for track use. I bought Enkei PF01s as a track only set. Really nice rims and both strong and light,

http://mustangforums.com/forum/s197-handling-section/589824-enkei-pf01s-and-nitto-nt01s.html

Keep a careful eye on your drilled rotors for signs of cracking under heavy use.

 

[Philostang]

WIDER!!

For the most part, the only reason the track rats here aren't running 10.5" wide wheels (or wider) is interference. If I could get wider wheel in without a custom one or much drama (read: $$$), I would('ve). A 9.5" wheel allows you to run 275 and I think some folks have had good success running a 285 on them as well. It's readily available and a nice size in general.

Also, if you haven't yet purchased the rotors, you might want to stay away from the drilled ones. Slotted are fine, but the drilled ones tend to crack sooner. Do a search and read up on them.

Best,
-j