Gentlemen,

Ever since installing the Cattman headers I have been losing traction in second gear after hitting 6000 rpm. That pretty much makes my extended redline useless, since I never get that high in third gear in the type of driving I do. Of course, in first gear I have to feather the gas pedal pretty early on if I don't want massive wheelspin, but I'd like to stay WOT all the way to redline in second. Kind of a nice problem to have, but I'm wondering what to do about it.

Will having a Quaife or Vitek type of limited slip differential help?

Wider, stickier tires? Right now I have Kumho Ecsta Supras, 215R55-16.

 

how tight is your rear suspension? Spining is no good, second is that im outa here gear too. You would prob benifit from some softer tires and maybe wider wheels to. I wouldnt think you would break loose on the top of 3rd.

 

dam, losing traction at the end of 2nd gear when u had traction in midrange? that must be the best feeling in the world

 

Just try some better tires first off, you haven't skimped on a single thing on your car, it's one of the cleanest and most immaculate and thorough SC installs there is, and yet you are running on crap tires. I suspect some good tires would cure your 6000+rpm problems. They will also help with your first gear problems, not to mention improve overall grip both in the dry and wet. My suggestion would be Toyo T1-S they are in the top class for dry and wet traction, not horribly expensive like S-03s or Michelin Pilots, and as an added bonus they are the lightest tire on the market (yes tires vary significantly in weight just like wheels do.)

 

I would say a Quaife would be your best bet. The peg leg is a prime suspect to the car breaking loose at the top of 2nd gear. Im not sure what power Im making but I've only had the car break loose on slicker surfaces at the top of 2nd and I have the Quaife and 235-45-17 meats. My current setup is 3.125", JWT, MEVI, and full 3" catback. Im hitting 11.5psi peak so Im sure I within 15whp or closer to your current dyno. I would try wider softer tires first bc its a cheaper option, but IMO a Quaife would be your best bet.

 

drag radials that you can run on the street, bfg makes good ones or gs rims with 245/45 tires

 

You still trying to sell yours, Ken?

 

Like Neal said, tires are the key. If you want the best of both worlds, get a set of light and wide 16X8 rims (RX-7 or 300ZX) and 225/50R16 Toyo T-1S. Traction shouldn't be a problem after that. I had Kosei K1 16X8s with 225/50 Sumitimo HTRZ tires and that setup was by far the best handling, most traction, and lightest setup I ever had.

The Quaife is also a nice option, but it sucks out power (~15-20whp) and it ain't cheap. Tires should be done regardless. If you're still having traction problems, then consider the Quaife.

 

Yes and no. I think I will have an answer by this weekend. I was originally going to sell them to a friend for his IS since I just put some new tires but now he is checking into buying my car with them on.

 

i have the same problem, but i'm auto.

I have my winter tires on, so I'm not going to change anything until spring.
Steve

 

Like everyone said try other tires. Curious, do you have the V or W rated Kumho's? I would think the V's to be way too hard at 340 treadwear. Don't go too low on the profile as that I'll hurt the contact patch. 55->50 series sounds ok. And heavier rims & tires might hurt the accel but reduce the spin.

 

i would say since you live in a dry climate drag readials would be best but i have gone through 2 sets since may and they seem to only last about 4-5k miles so it getts kinda expesive

 

Are you using BFG or Nitto DRs subs. I'm thinking next spring I might need to start running DRs all the time. I'm thinking nittos because they aren't so soft that I will wear through them in a week, but they are definately stickier than the stickiest "normal" street tire.

 

i had BFG comp T/As (i still have one on the front but its showing belts and im going to replace it and the spare this weak with some winter tires)

i know alot of mustang guys running nittos with good luck. the problem is that nitto does not make a drag radial that would fit a stock 6.5width 15in rim so i had to get a bfg 225-50-15

the tires hooked great for N/A use. in order to spin them in 1st i would have to drop the clutch above 3500rpms. they would beg for traction in 1st with the nitrous but they held second on most dry pavements (although still fighting pretty hard for traction)

 

The one time I drove on the street on my G-force DR's I did not like it

 

The toyo's are good.. I had them and liked them. But @ $200 per tire for 235/40 18.. I went to dunlop.

I and jaime, have the same problem. Jay has the Quaife.

Jay was thinking about DR's

 

I have also been having this problem for the last few days ever since I got my PF TB put on. I do not have the MEVI, and I run 235/35/19s tires. I think some of it may have to do with the temp drop as well. It is getting around 40 at night here now.

 

I believe I have the V's.

What's the widest width tire that will go on the oem SE five spoke wheels?

 

I've heard of people running 225-55s on the SE 16" wheels.

 

Toyo's website also shows a 235-50-16 which will fit on a 16x6.5" wheel.

 

Neal whats the widest tire you can run on your SSR's 245 or 255? I would look into BFG KD's; they hook very well. The only drawback is price. Greg's vette hooks a lot better with them vs. Pilot sports and F1 goodyears.

 

I had the same prolem with my old tires. Partially because my 18" Rims are only 17lbs.

Went to Yokohama parada Spec 2's and now I don't spin at the end of 2nd very often - unless I hit a bump just right.

 

Toyo T1-S in 235/45/R17 weigh 23.8 lbs
(http://www.toyo.com/tires/tire_specsheet.cfm?id=2)

Kumho Ecsta MX in 235/45/R17 weigh 20 lbs
(http://www.kumhousa.com/Products/Ptn...=1&PtnID=KU-15)

I'm certainly not saying the Kumhos are better tires, but over 3 pounds at 25 inches out from the center point is significant, and the K-hos are much cheaper.

 

Not that I have ever weighed them, only tires I have ever weighed were my nittos, and my T1-S, but I find it strange that fully half (13 out of 26) of the tire sizes listed on the Kumho MX page weigh 20lbs exactly... That is a little fishy... 205-50-15s and 275-35-18s weigh exactly the same according to that site... I find that incredibly hard to believe. I guess we'll never know if anyone is telling the truth though unless we start weighing tires all the time heh. The info of T1-S being the lightest that I am quoting though is from a few years ago so the game is likely to have changed.

 

I can't wait till I have more traction issues

 

A buddy has a ~500 WHP supra and swears by the Kunho MX's

 

Tires are certainly the major issue here. The lack of a LSD is also but... Your running stock sized tires. That contact patch is barely big enough for a stock 5Spd. For those that suggested 225's I really don't understand why. Do it right. At least an 8" rim is required. This is one situation that I think a larger overal diameter is called for. I'd say a 245/45 is good. I'm running that now and the gearing certainly isn't benificial for an N/A car but it would cure your problems in anything below 300 treadwear with that monster patch.

MAX2000JP, I'm currently doing 245/45 on my SSR's with zero problems except the extreme weight and bad gearing. I'd say that 255 has a high probability of fitting. If you want stock sized gearing you can't have it with 245. .6" too small for 245/40 and .3" too big for 245/45. Your making me contemplate my next purchase of rubber. I was set on 245/40 for the longest time but now... Anyone else want to confirm if a 255 will fit on a 8" rim in like a 40 series.

OD's are as follows excluding tread depth:
215/55/16 = 25.31
235/45/17 = 25.32
245/40/17 = 24.72
245/45/17 = 25.68
255/35/17 = 24.01
255/40/17 = 25.03

This makes me wonder. Is a 255 capable of being stuffed on an 8" rim? For Stephen I'd say the taller gearing of the 245/45 is benificial. Maybe if you really want a lot less spin in first and no spin is second the 255/45 is the way to go for you. This has turned into a tire only post. Sorry.

Neal, I'd agree that it is a bit fishy but there isn't any good way to estimate weight of a tire. The comparison you pointed out, 205-50-15 = 275-35-18s seems extreme but it could be possible. Sidewall is very tough and sturdy these days. The 205 only has ~131.2 sq in. of sidewall while the 275 has ~518.58 sq in. That is a huge difference but one must remember that the taller the sidewall the studier is has to be to resist rolling on itself. There are so many factors that its impossible to account for without a tire and scale right in front of you. When I order my next two tires I'll compare them to the site. Then we'll know if they're crooks.

I'm sure the tire guru will step in to straighten us all out(TopElement).

 

FWIW - Kumho MX's have a softer sidewall than most Max Perf catagory tires like Azenis, KD, Pilots, etc. We've found they need extra air to support ultimate cornering loads. Their compound grip however is some of the best available anywhere.

 

There was a GRM article about Max performance tires and they showed the MX's were the best bang for the buck. The KD's are minutely gripier than the MX's. Toyo is going to be coming out with T1-R's, which is the replacement to the T1-S. Supposedly, they are improved in the wet and a lot stickier in the dry. More info below.

Toyo Proxes T1R

The latest high performance tyre from Japanese tyre manufacturer Toyo is the Proxes T1R. Designed exclusively for sport sedans and coupes, the Proxes T1R is a new generation Vshape UHP tyre which has been designed to meet the demand for high-speed stability and excellent handling under dry and wet conditions, while retaining low noise and optimum driving comfort.

The new tyre takes advantage of modern design technology and provides stable steering response and traction thanks to an improved tread pattern design compared to the tyre's predecessor, the Proxes T1S, resulting in exceptional braking performance as well as improved wear resistance.

A key feature if the Toyo Proxes T1R is a newly designed silica compound, which effectively minimises heat-build-up. The silica provides a rigid tread hardness, which delivers excellent ground contact on dry surfaces and therefore helps optimise wet handling. Meanwhile a higher wet-µ means that excellent wet handling is also achieved. The Proxes T1R also incorporates an ultra-high molecular polymer, which helps increase wear resistance. These compound developments, together with an improved casing profile provide effective resistance against irregular wear and structural stress, resulting in extended total wear life.

The Toyo Proxes T1R features a unidirectional tread pattern with V-shaped main grooves for exceptional resistance to aquaplaning. The tyre also features a rigid shoulder rib pattern, which ensures excellent dry handling and anti-irregular wear as well as making a significant contribution to noise reduction. The stiffer shoulder blocks compared with the Proxes T1S also help assure improved braking performance.

The Toyo Proxes T1R is available in a comprehensive range of V, W and Y rated tyres in wheel diameters ranging from 14" to 19" and in aspect ratios from 30 to 55 series.

 

Thanks for the great tire info, guys!

If the MX has less sidewall reinforcement, that would make sense that they're lighter. Excellent tread compound plus a little extra inflation pressure adds up to an excellent and light performance tire, it seems. Cool.

T1-R sounds amazing.

 

I agree that T1-R does sound fantastic. We must remember that compressed air weighs something too. I know it isn't significant.