I'm kinda vexed by an issue in the rain. I've got 19x11.5 CCWs in the rear with BFG KDW2 295/35R19 tires and in the rain, I swear to god it's like driving on ice. They're not the drag radials either. Supposed to have great wet traction but I have practically none. Tires are a couple months old. It did it with the bald *** nittos it had on it when I bought the car and now still with brand new tires.

It tracks and finds every groove in the road dry so I expect that but in the rain I've probably almost lost it two dozen times. Driving over painted crosswalks or even changing lanes is a terrifying prospect. Yesterday got caught in rain and had the rear slide over while changing lanes (drove over line) about 2 inches then grabbed.

Could it be something other than the tires? Suspension or rear end issues? It's got a new set of Tein CST coilovers on it as well.

Any pointers or if this is a known issue on SCs with wide tires, please let me know, it's much appreciated!!

 

Could be due to bad alignment, but I doubt it. A friend of mine has the same tires on his G35, and complains about the same thing..Now provided he is on the stock G35 wheels, so they arent as wide as yours..But, I am on stock TT Surpa wheels (9.5'' wide in rear) on Kumho Ecsta SPT's, and get excellent traction in the rain, but same issues with the painted lines cause those are slick when they are wet regardless of tires.

I would check the rear alignment just to eliminate the problem, but I dont think it has anything to do with your suspension itself. Any mods done to the engine/drivetrain? From my experience with things like this, it usually comes down to the tires, driving style, and performance modifications, BUT an alignment can (but not always) effect wet driving.

 

other than the suspension and wheels, it's bone stock. I'm about to swap to a V160 and a TT LSD rear however.

In the rain, I pamper the thing. Trip home yesterday from work I was doing 45/50 in a 65 getting passed left and right. lol. I'm thinking just going with the continental contact 2s or whatever but it's a $700 gamble if that will fix it.

thanks for the reply

 

I've always been told that the wider the rim/tire, the less traction you will get on rain and snow.

 

Anytime you mess with the stock suspension or stock tire arrangement you enter into an unknown zone. The engineers spend a lot of time designing automobiles that are safe to drive. Obviously when you take off the stock 16's and throw on some 19's, plus whatever else you have done to the suspension, the car is no longer predictable.

This happens with all cars.

That's the price you pay for modding it. Either take it back to stock or keep your speed to 25 mph in the rain.

 

This is true in some cases..but again all comes to tires and finding the right ones. In rain, its tricky cause of the different materials used. Concrete, black top (very slippery when wet), and then the hybrid mixture of the concrete and tar-based black-top. But if running a wider tire in the rain hurt performance, then when it rains in Europe during the F1 races, they wouldnt continue to use 12''+ wide rear radials for rain..but then again if you look at the cars used for ice racing or even the rally cars on snow courses, they opt to use a slimmer tire than normal..but they also spend thousands of dollars on specific tires for each specific condition, and that does not include the time for research.

If you put a new Continental tire on your stock 16x7 wheels, and I put the same tire but used with 50% tread wear on a 17x9.5'' rim, your going to get better traction..BUT, flip the 2 around, new tire on the 9.5'' and a worn tire on the 7'', in THEORY, the 9.5'' rim will have better traction..

I hope that made sense.


I am at a horrible disagreement with you on this cause its not true. IF the suspension is setup properly, the cars handling is improved and this has been proven for many many years in all different applications from bicycles to trucks with lift kits..not to mention lowering a vehicle will lower the center of gravity, providing better handling and control of the vehicle provided camber and toe adjustments were made properly.

If what you stated above had ANY fact at all, there wouldnt be street classes for drifting, drag, or autox cause everyone's car would be unpredictable and hundreds of people dead, and the Motor sport world itself would barely exist.

Adding performance parts to a car properly WILL improve the performance. But since the performance of the vehicle in "normal" driving conditions was not the topic on hand, its irrelevant.

He is simply trying to figure out why he gets horrible traction in the rain. In this case, alignment (toe and camber) can have a negative effect, and if a proper alignment was done after the suspension was installed and set to the desired specs, the suspension has nothing to do with it.

The fact that he is on 19x11.5 rims would tell me he has a much better tire-to-ground contact point over the stock 16x7 rims which in turn, even in rain SHOULD improve wet road condition performance by a significant amount. But in this case even with an 11.5'' contact patch he is getting little to no traction at low speeds, or while cruising when the road surface is wet.

Now, providing the alignment was completed properly after the suspension was installed and set to desired settings, the only thing I can think of that would be causing a low traction problem is tires. KDW's have excellent ratings across the board, but as I stated from first hand experience in my friends car, the wet traction rating is a little FUBAR..

SCereal, I would find someone local that would let you borrow a different set of tires with as close specs as possible to your wheels to see if that will help remedy the issue rather than going and taking a $700 risk that might not be the problem. I am assuming that you had an alignment done after the suspension, so the only thing I can think of is it has to be your tires. Another thing to check is tire pressure, make sure it is at the TIRES recommended specs, and if needed let out 1-5 psi at 1psi increments until you feel an improvement. A little less tire pressure in the rain never hurt anyone, F1 and Indy drivers have been doing it for years.

 

Thanks guys, I'm going to bring it my guy tomorrow and check it out. Probably see if I can throw on a set of some wide mustang wheels and see how they behave. I have an awesome suspension tuning shop here in town but no point dropping the coin on getting it checked out there when the whole rear is going to be swapped out soon.

The car was already done when I bought it and it seems like the tread is wearing pretty quickly on the rears so I'm hoping it's just out of whack and causing it to be squirrelly.

Fortunately working from home is an option. LOL

 

I am assuming that your tires are directional. Are they mounted on your wheels correctly?

 

Changing tire pressure should be where you will find your best improvements the common misconseption with wider rims is that you are extending your contact patch to the asphalt which isnt true. The contact patch is staying the same just getting distributed differently, wider rims long skinny rectangle where as a thinner rim just a big box.

 

Tire pressure is spot on, I get a full even tread pattern, they're wearing evenly and mounted appropriately as far as directional wise.

We'll see what the suspension looks like but these tires probably just suck something fierce.

 

SC are RWD there isn't enough weight on the back to get traction, otherwise you will fish tail alot in the rain and snow. That how most SC end up dead cuz rear panel damages.

That why you don't see much FWD getting drifted cuz all the drive power is being used in the front where most of the weight is.

 

I had the same thoughts about weight on the rears but I know wayy too many guys with vettes & stangs with even wider rear tires that have no such issues.

 

True, and when you put larger tires in the rear you shift more of the weight forward, which is why I stated that you enter an unknown zone when you start modifying the suspension and tires without knowing what you are doing.

 

Damn, I live in Miami and still have not driven in the rain for the first time with my SC400... All these threads are making me kinda nervous...

 

I got my traction issues resolved. Alignment was out of whack. Camber was fine but toe in was dorked up. Now, even with bald tires, it's solid in the rain. New rubber on its way (315/25/19) then I should be golden.