How would 19 inch volk ce28ns be for road couursing and autox? I have 18 inch rota p45rs. They will be daily driver wheels as well as racing wheels. Or would I be better off keeping the rotas and putting some r compounds on them and use them only on the track. And daily drive the volks?

 

18" for GO, 19" for SHOW

 

i auto x on 19 nismo lmgt4s. but there are no r compounds for the 19s that i want. or something in between like the falken rt615s which is wat i really wanted. it also depends on how competetive u want to be in auto x. r compounds are a must if u want to win those auto xs.
although i think 19s will be fine for track days. with ultra high performance tires.

 

If you take the Super GT series into account and look at the Z's that are running in it, they all run on 18" wheels. Although their wheels are a foot wide, it seems that there is something about the 18" wheel size that is the sweet spot for the Z's performance on the track. Also, it's not that 18" wheel is the limit that the rules allow, there are cars w/ large wheels. Not that any of us will be doing the type of racing on the level of Super GT, but it seems to provide some 'rule of thumb' insight.

 

19s for show 18s for performance. I put 19s on my G35 and went to MSR to run. The car did well, but the car liked to hop more over bumps and was a bit more rough. With my 18s wheels/tires I used the 2nd time I went, the car was more stable, and I was able to push her much harder.

 

I have 19" Work S1 Meisters and have tracked it twice with T1Rs. Im scared to mess em up, get em scratched dented or somethin, so I bought some cheap 18x9.5" P45Rs for track so I can run on some great Nittos. At least with the P45Rs, I wouldnt worry about breakin em and have even MORE fun at the track. I can just keep the S1 for daily drivin.

 

I sometimes use my 19" CE28N's on the track. I don't see any problems with them. I bought the CE28N's before I ever considered tracking the car. Now that I have them, I use them. However, I wouldn't buy a set of 19" wheels now that I do track the car. I'd stick to 17's or 18's. For DE's use whatever you deem inexpensive. I happened to come accross some deeply discounted 19" Continental sportContact II's a while back, so I don't have any problems with tearing them up.

 

For performace, you want the smallest diameter wheel that will fit over your brakes.

Smaller rims are lighter, cheaper and will improve your gearing to help with corner exits.

Not to mention there arent too many R compunds available for 19's.

 

Axelerate, smaller wheels will not improve gearing. Because you still have to put a taller tire on it to meet the factory specs.

 

Well you dont have to meet factory specs.

My 275's on 17's are about a quater of a inch smaller in diameter overall.

 

Bestmotoring did a back to back run using an 05 Z to test whether 18s were faster than 19s. It turned out that the 19s were actually slightly faster than the 18s because of improved turn-in response. I think in the end, it was good for .3-.5 seconds around Tsukuba (I don't remember the actual amount).

HOWEVER, the driver commented that a normal person would go slower in the 19s because it's trickier at the limits, and you have to have the reflexes of a pro driver to get any advantage out of the 19s.

 

Magazine tests like the one mentioned above are deceiving. They generally look at the fastest lap achieved when comparing items but running one fast lap is not how a race is won. Running consistent fast laps over the duration of the race is more important. A little forgiveness is a nice thing to have when running a 30 lap race.

 

Excellent point. I remember a mag test a few years back where they were having one of their shootouts. I remember the Viper eventually got the fastest lap. The driver who did it said he had to man handled the car to get that lap but wouldn't want to try and get that time consistently. I don't remember the car that came in second (I think one of the Porsche's), the comment was every driver got in it and instantly turned a fast lap and then can consistantly run them. That wasn't said about the viper. I aslo remember Montoya's run of poles driving the William's a few years back.

Plus, you need to remember the saying, "horses for courses." It's like a recent thread comparing an mr2 to a Z. The Z will win when horsepower matters.

I got question though. I see a lot of Z's on these boards with huge tires all around. What I want to know is where is the crossover point at which these tires become detrimental to performance? Especially with Na's.

 

When they wont fit.

I dont feel the need for anything bigger than a 275, the grip for the turns is more important than straight line speed for me.

 

Tire factory specs are not relevant on the track, nor on the street. You can mount whatever size tires you wish, as long as you don't have any issues (rubbing, VDC, etc).

 

The crossover point is different for each car and driver, you can only determine this through testing.

I did a test for a Solo2 DSP BMW 325i and we compared 245/35-18 on 8.5" rims and 285/35-18 Kumho V710s on 10" wide rims. The 245 setup was 4 lbs per wheel lighter with a .4" smaller OD. It accelerated faster to 60 and to 100mph. The 285 setup braked better, turned in better, and gripped better. The end result was the 285 set quicker times by about 3% over the 245s. Later, testing a set of 315s on the back of the car created an understeer problem that could only be worked out by making the car's overall times slower. We couldn't fit the 315s on the front of the car.