3dog

iTrader: (1)

I've already got the 3.76 RMM LSD and would like to get a torque converter.

I've been reading that the combination makes for real easy wheel spin and burn out.

I currently have 17" wheels and don't get any wheel spin unless it is wet out.


So here is the question.
What wheel and tire size offers the most traction for a quick launch?

2nd part to question is: I would also like to maintain excellent handling as I love to go fast thru the curves.
Is there a wheel and tire size that would be excellent for both of these functions?

I'm into smoking the tires once in a while but can't afford to do it all the time.




Thanks
3dog

RMMGS4

iTrader: (5)

If you were serious in going staight lines ONLY and willing to deal with only a few hundred miles of tire wear, then I would use the BFG g-Force Drag Radial. Size 295/35-18.

BUT, I assume you are looking for an everyday use tire and are not considering flaring the fenders. If that's the case then I'll split my answer into three parts.

First get a brand of tire with the stickiest rubber compound you can find. Selecting fat tires and then choosing a brand with poor grip is counterproductive. My current personal choice is the new Michelin Pilot Sport 2. I have read reviews saying that their straight line traction is great and great handling in turns, goes without saying.

Second, put the widest tire available, that will fit (again without flaring fenders, but maybe require some lip trimming).

There are a couple of brand tires that offer a 305/25-20 or 305/25-19, but for the Michelin PS2 they only offer a 295/35-18, 295/30-19 or 295/25-20. Any of these three sizes will provide great handling. If you are hard core about straight line traction, then you would want the HIGHEST profile sidewall available (i.e. Fat Set up). If that's the case the 295/35-18 will yield the best straight line traction, plus the lightest tire and wheel weight combination as well.

One caveat I have with this reasoning is that though the other two sizes may potentially have a little less straight line grip, the larger diameter tires will also affect the final gearing, which may be a more important consideration. There are too many variables to make a definitive recommendation. For example, knowing whether the car is NA or FI needs to be factored in. Probably can't go wrong choosing any one of them though.

Third, get the ideal wheel width that is appropriate for the tire size. On low profile tire sizes, during high acceleration (straight line) , the edges of the tread will not lay perfectly flat against the road, if the wheel is too narrow for the given size. Again, it would be counterproductive to mount a wide tire on too narrow of a wheel. For the 295 Michelins, the minimum width I'd recommend is 11 inches.

NOTE: This IS NOT stretched for a tire this size and is within Michelin's recommendations. Also note that you will need to get a custom offset wheel in order to get an 11 inch wide wheel to fit a GS. I-Forged, HRE and a handful of other wheel makers offer custom made offsets.

The limiting factor has always been the availability of tire size. There are only a handful of tire sizes available and even less brands making them. In the future, I'm sure there will be more and possibly better choices, but as of this post, IMO the Michelin was the best choice currently available to the general public. Continental makes a 305 size, but IMO the Michelin is still a better gripping tire and to do the 305 right, you would need an 11.5 to 12 inch wide rim and it would require significant fender flaring, beyond just rolling or cutting the lip. I admit I'm being picky, cause an 11 inch rim is not hurting, it's just not ideal.

I have been doing research on this topic for quite a while now and by this coming summer I hope to have a wheel / tire combo in this size range.

Oh, and you don't need to take my word for it. I just attended the SF Intl. auto show this weekend and saw the $400k + Mercedes-Benz SLR McLaren. It's got 617 HP and does 0 -60 in 3.8 seconds.

So what do you think it is running for a rear tire/wheel size????






























Tires:
Brand: Michelin Pilot Sport 2




















Size: 295/30-19























Wheel Size: 19 x 11.5


NUFF SAID

3dog

iTrader: (1)

Wow ! You have done your research.

Thanks for all the information.

I'm pretty sure I won't be getting anything wider than 275 maybe 285. If I do not go any wider than that, what would the optimum wheel size be? 17" 18" 19" 20"?

Can you give me any clues on what size wheels give the best handling on curves and such?

I"ve got the 3.76 LSD and want a torque converter. I doubt I will ever supercharge the car.


Thanks

3dog

RMMGS4

iTrader: (5)

Whether you go 18, 19 or 20, you're still gonna be able to spin the tires with a TC and 3.76 LSD.

In the past, I used 285/30 -19 Michelin PS 1's on 10" rims and the car pulled strong, but traction off the line is still a problem. Also from all the burnouts and (legal) racing I did, the centers were wearing out a lot, so a 10.5 rim would be a better fit and give more traction. A 275 size tire would be good with a 10 inch rim though.

If I limited myself to the 19 x 10 wheel I currently have, I'd say the PS2 in 275/35-19 might be the next tire I'd choose. I'm thinking a little taller tire diameter plus a little more sidewall would help the traction problems I currently experience.

There are a lot of choices in brands at the 275 tire size, so you might wanna research other options. I'd say the PS2 is the tire to beat though.

redgs4

The rim/tire size are only part of the suspension equation. Your handling can vary dramatically based on tire choice as RMMGS4 hit upon. And I have to agree with RMMGS4, the PS2 will be my next tire [I have gone through Yoko's, S02's and am currently running GSD3's]. But there's so much more to ultimate handling in the curves -- you really must consider the rest of your suspension and how you tune your car, including such things as spring rates, compression and rebound damping, lowering, sway bar selection and adjustment, corner balancing, and simple things like tire pressure.

IMO, get the lightest/strongest 18" rims you can and run fat. Unless the roads you drive on are smooth, the 18" give the best balance of handling/acceleration while still offering taller sidewalls for ride quality/rim protection.

rominl

iTrader: (4)

if you talk about rims and tires, i think for common use, get some 10" wide in the back with 285, that's your best bet for best performance and handling.

now if you wanna do super wide, get some 11" wide wheel and get some 305 in the back, that's almost the widest you can run on the GS

3dog

iTrader: (1)

I've got all the Toms braces, Daizen sways and JIC-Magic FLT2A coilovers set really stiff.

Hey thanks guys you offer up alot of experience




3dog

FutureGS400

I'm going to go with a 285/35 18" (up from 275/35) very soon. I would also like to try the PS-2 but they only come in 275/35. I really like the Goodyears I'm running now anyway, and they added width (and slightly more diameter) will only help. I know I'll still be able to spin them, but hopefully not quite as easily! Should be no problem fitting I think with my rear rim width and offset (45).

morris

iTrader: (2)

ARe you sure about smoking the 285's ? I am moving to 285 30 19's and was hoping for significantly more traction

redgs4

Oh yeah! More traction does not mean enough traction - you will still have to fiddle with your launch technique and things like tire pressure. Can't recall - Do you have a high stall torque converter?

morris

iTrader: (2)

Yea PI 2800 rpm

I am working on a 15psi cogged pulley setup right now so I should have even more HP by the mid winter.

3dog

iTrader: (1)

The roads here are pretty smooth. I noticed when I went from 16" to 17" there was a vast improvement in the way the car handles. Does this continue to improve when you go to 18" . If so, does it continue to improve with 19" or 20". I would think at some point the improvement would stop.

I also noticed when I put the 16" wheels back on last winter for a snow storm, that the car seemed a little quicker off the line. So I'm guessing that the bigger the wheel the harder it is to get them rolling. But of course with the torque converter you want a large patch of rubber in contact with the pavement in order to get max. traction.


One more question what if I left my 245/45/17 Michelin Pilot Sport A/S on with the Torque Converter and the 3.76 LSD. Would that combination result in smoking tires every time I leave a stop light. Or is it possible to feather the throttle and not burn out?

This seems like it could drive someone nuts trying to figure out the perfect setup. And there probably isn't a perfect one seeing as how I seem to be trying to accomplish two very different things.


Hey thanks for all the input I'm learning alot.



3dog

redgs4

With a 2800 stall speed it's possible to drive perfectly normal. I drive in stop and go traffic every day and only smoke the tires when I want.

morris

iTrader: (2)

I agree you should drive perfectly fine, the only difference is that you will accelerate faster and shift harder

RMMGS4

iTrader: (5)

Of course a little width and increased diameter should help, but it's all relative. I have run 285/30-19 PS1's and I am still complaining. The PS2 is rated a couple of ticks better in traction than the Goodyears. Even at a smaller tire width, the Goodyears will be challenged (IMO). Also remember a 275 tire on a 10 inch rim will better utilize its contact patch, while the 285 contact patch will not be optimized. On paper this puts the 275 PS2 ahead of the 285 Goodyear.

I wouldn't blame you if you still choose the Goodyears. Certaintly still a great tire, but IF you find any value in reading the Tirerack reviews, the PS2's sound pretty impressive. It might be a good time to transition.

http://www.tirerack.com/tires/tires....ilot+Sport+PS2

I have done ton's of 0 to 60 runs, practicing my launch technique. With the current tire set up, I either do it right grabbing at launch or I spin em slightly, losing about 3 to 4 tenths in my 0 to 60.

I'm hoping a little better traction will allow me to do consistently quick 0 to 60 times and be easier to do. Right now it's difficult to be consistent, usually only getting a great launch around 1 out of 4 times.