I am no expert, but I doubt going with a an 18" wheel and tire over a 19" will get that much more traction when you are over 500whp. I am not talking about slicks or DR's either. My car is driven on the street (never even been to a track) so I'd rather have taller gearing with street tires then have 18" wheels with DR's. I'll keep my 19's and just fork over the money for better gears.

 

yeah IMO I'm trying to see the benefit other than people not wanting to run wider tires or stickier tires - drag radials or street legal competition tires - both with not so great wear or dealing with rain etc.

Just seems to me, the purpose of going FI in the first place was to go faster, improve accelleration, and get thrown back in your seat more. It sure isn't cheap, and some people just want the bragging hp numbers more than the fast track times

The only benefit I see these having is a 212mph top speed (if aerodynamics permit), and better gas mileage - but....why go FI if you're looking for gas mileage? Then there's less shifting in the 1/4 mile, which the 3.31's do just fine for most people. In order to get 2 less shifts in the 1/4 mile you'd need something like a 2.6x final drive or so.

So instead of gearing throwing you back in your seat, the concept is you'd have an engine working really really hard to do it instead - and 17% better highway gas mileage, and 1 less shift in the 1/4 mile

17% power loss though...at 500whp, that's like downgrading to 415whp. However I understand that if you don't have traction, it's all worthless power and drag radials/competition tires don't suite everyone's location or daily driven tires

 

I am running 285/35/19's already. How much wider do you suggest I go? I plan on getting 295/30/19's when my 285's wear, but I don't thing I can get a wider tire on there with out having issues. I am already rubbing with 285's so I do plan on rolling the fendors, but again how much wider can I get them?

As far as sticker - DR or street racing.....you said it - not so great wear and dealing with rain. I drive my car 2000-3000 miles a month. I live in Miami and it rains hard and often here.

 

well people have been able to put 315's on. You just need a wheel that can support that width with an offset of around 33-37 - or slightly outside that range depending on what brand (how thick is key) of rear dampers you're running or if you want to roll the fenders. People can use hub centric spacers, some longer nismo hub bolts, and some open ended lug nuts to get their wheels to be the desired "offset"

I've never seen it done, but some people claim you could go even wider than 315's in the rear - not sure what brand/tire/sizes you'd be able to find larger than 315 that'd fit, but who knows.

as far as 19 vs 18 inch wheels - I don't think that actually matters so much, but what does matter is what type of tires come in 18's that don't come in 19 in sizes - unless they're for another type of car with sidewalls that are too thick for a Z

 

As far as why did I go FI with such much horser power if I can't use it? Well I didn't plan on building a hp monster. My stock rod was bent on the dyno so I had to build. If had to spend so much money to re-build you can sure as chit bet that I am going to push the car to its limit. As far as wheel and tire choice. Again my car is a DD not a weekend drag car. Yes I could have choosen a wheel and tire set up that would be more ideal for strickly drag racing, but like I said I haven't even been to the track once with my car. Although I have street raced over 8 times since Sunday. 6 were on the freeway and 2 in the city. I can happily say that I did not lose 1 of those races, which by the way, 1 of those races was against a Ferrari 550 Maranello.

Here's a picture.

 

i might be interested, after seeing the result of that final drive..

 

Yeah Gman, I totally understand and say if you want the gears, go for it.

Your power in each gear will be 17% less - like on the highway runs where that might come into play, but you can just downshift to a lower gear anyway. I mean, it's doubtful anyone ever races in 6th gear with the stock FD, so better gas mileage and more grip would be nice

I'm all for having a new part developed

 

The stock 3.5 FD is way to aggressive. I have the 3.3 and it is way better. I still light em up through 2nd and Occasionally in 3rd. Its not that much of a difference with the torque but it pulls longer and you go through mph faster than having to stop your peak boost and shift. Try the 3.3 or ride in a car with a 3.3 and you'll instantly see how this should have been stock. However your cruise control doesn't work. I wonder why that happened, probably a sensor that is calibrated to the 3.5.

 

I love that picture....


but didnt you see the ford taurus in the your rear view mirrors about to smoke you?

 

I'm down, running slicks or dr's on the street is not my cup of tea and it could have a definite possibility to help useability in the lower gears with gobs of power. There's nothing wrong with wanting to run 18/19/20" wheels and still be able to hook up more effeciently - some people like to have nice wheels while still having a car that can hook up. Would definately be a cheaper option that adjusting tranny gears, or go with a diff trany & drivetrain.

Too bad the R230 isn't very similar to the R200 seeing how they got a 2.9 FD gear in one of it's configurations. I'm all up for more options. I'd figure that with a 2.9FD gear on 500+hp it'd be a much more noticeable mod in the useability over loosing anything in 5th/6th.

 

no biggy I already lost cruise control when I switched the HKS FCON V-PRO.

 

I'm interested dependant on price.....

I have the 3.3, I don't feel much difference as far as traction goes, but then I'm only running on 275's so who knows, but your right about pulling longer...

But I want to know what happened to your cruise control, I still have mine, how did this happen? Hope there isn't something going on that will make me lose my cc later on.

 

On the G35 Coupe you can run a 315 treadwidth on the rears. At present I have the following set up (tight but works). The wheel is an Enkei NT03+M 10.5 inch rim having a 30mm offset, and with a 3mm spacer. Rear camber link is Stillen at neg 2.5 degrees and the car is lowered an inch. The tire is a Nitto NT-01 315/30/18 (the treadwidth actually measures at 323mm) which is a DOT-R rated tire. The tire has very excellent adhesion in the dry but because of the wide tread blocks and siping pattern it is not good for wet conditions at all (I had a little encounter with some standing water into turn 3at Laguna Seca that resolved any question of that conclusively.) Only the tiniest little roll on the fender well was necessary with a small wooden dowel, and after several track days there is no evidence of rubbing inside or out.

 

eagle, I too am running 315's...
i noticed 2 things, that you possible noticed also.

on the drivers side, there is a bolt/screw sticking out from the inner/rear wheelwell that I cut beacuse it was very close to my rim/tire.

&

on the passanger side my tire rubbed(as I turned to the left) againt the plastic cover that protects the fuel filler hose as it passes through the wheelwell.

did you notice the same 2 things?

 

baileyrx, what offset and wheel width are you running - and what tire?

 

i had my stock 17in X 8in wide rims widened to 10 & 3/8 in.
plus I have a set of 25mm H&R spacers.
dont remember the 2003 17in rims offsets?
just need to know that & caculate in the 25mm

ps: sorry to get this thread off track alittle