raceboy

Getting these from Todd at Discount Tire for $225 each in 17x9x35mm, shipped. They are "rim rolled" which is almost as strong as forging, but a lot cheaper. They are really light as well. I am assured they fit the Z track model, but I know for sure the RPO2's fit, so I doubt there will be any problems.

Tires are going to be Toyo RA1's, heat cycled and shaved. Watch the lap times drop baby!!!

For full specs, see here:


Enkei RPF1 specs.

SchoolZin

Got the same ones dude, but I run a 17x8 front, 17x9 rear for autocross with victoracers. Good wheels, lightweight, good price.

raceboy

What tire sizes are you running?? I am wondering if I should just run the 17x9's all around with 255/40's all around. That way I could rotate my tires since the RA1's aren't directional unless you are running them in the wet. Or should I get 17x8F with 235/40's and 17x9R with 255/40??? Any help would be appreciated.

2003z

iTrader: (7)

Nice, even lighter than the rpo-2js! I suggest 275/40-17 all around. My 255s are great, but could still use 'just a little more' rubber.

GaryK

Are they supposed to come out with this wheel in 18"? It seems like I read that somewhere, and I'd like to have a set in 18".

raceboy

Hmmm, I was also trying to shorten the gearing a bit over my rear 255/40/18's. The 255/40/17 would shorten the gearing about 5%. I could go with a 17x9.5x38mmR and a 17x9x35mmF. Tires could be 275/40R and 255/40F, what do you think??? That would be a lot of tire for track days!!

EnthuZ

iTrader: (2)

I'm spending way too much time debating the same questions.....we need MUCH more front grip, so maybe the 275's are the hot set-up?

Would there be a problem with the ABS running the same size F & R?

Raceboy, will the Toyo RA1's, heat cycled and shaved still get me to & from the track OK? I heard about an event at Mosport that is VERY tempting.....AWESOME track. Would these tires get me there & back?

BTW....those wheels , are(as the kids say)SICK!

D'oh

I remember you saying that even with the S-tune there was still some understeer, so maybe going to the same size tire all around would help?

I currently have 245/40-18 (Yokohama AVS ES100) in front and 245/45-18 (stock RE040's) in back and the balance seems slightly better. I've only had a single AutoX to try them out but the intial impression was positive.

Therefore, maybe running 255's or 265's all around would be good.

My friend runs his S2000 with 7.5" rims and 245 race tires, so you should be able to fit quite a bit more tire with 1.5" more width (about 40mm more). I'd say that 265 all around would be a good size.

I like the 9" wide rim all around with 265/40-17 all around.

That gives you nice wide tires and the ability to rotate if desired. You'll also get the 5% shrinkage in your overall diameter on the rears (based on your 255/40-18 example) and about a 2.5% shrinkage on the front (based on stock front size).

EDIT: Ooops, the 5% shrinkage was based off the stock rear tire size. It's actually about 2.5% based of your 255/40-18 example.

-D'oh!

J Ritt

iTrader: (4)

Steve,
Sweet wheels. I'll be getting a set of those or the RP02's in the spring for next season's racing. As for size, I've been debating the same thing...

Up until this past weekend, I had been running the stock 17 wheel/tire combo at autoX. This week, I decided to drive my street wheels to see how the car would feel with wider tires...so I could make a better race tire decision. I ran Kumho Ecsta MX's 245/40/18 on 9" wheel, and 275/40/18 on a 10" out back.

I have to tell you that the car felt much, much better. I was concerned that the car would understeer even more than with the stock 225/235/17 stock setup, but it didn't. We drove my buddy's Z on stock 17's back to back with mine. He was very impressed with how much better the car felt, as was I. There was less understeer overall. I think part of the reason was the lower aspect ratio (40 vs. 50), which makes the car feel sharper all around...but the front end grip and turn in was much better on the whole with more rubber up front. One of the keys will be your tire pressures. When I first put those wheels/tires on my car the other week, the steering felt heavy, and it didn't want to turn all that well. I've done about 6-7 autoX's with the car now, and I've found a 5lb tire pressure stagger front to back feels best. I ran 39lbs cold pressure in front, and 34 back. Obviously, you'll be getting a lot more heat in them on the track, but I think the 5lb stagger is a good place to start. The car turns soooo much better.
Now back to the tire widths...the 245's felt good on the front. IMO, I don't know that we need a whole lot more tire up front. 275 in front seems like overkill to me. My guess is that steering will be sort of heavy and less precise, even at speed.

I was also afraid that the 275's out back were going to be too much for the car, and that I wouldn't be able to break the back end loose. With street tires, this wasn't the case. I was able to get the power down earlier and harder than with the 235's...that's for sure. I could get the back end out and around on the throttle when I needed to.

Now with race tires and their added grip...I'm not as sure. As he mentioned, 2003z has been running the 255's all around, and seems to think we could use the 275 in back. The problem is, I don't know that you want to cram 275 race tires on a 9 inch wheel. That wheel comes in 9.5, but the offset is +38...should probably be ok, but not sure. That would be much nicer for 275's.

At this point, I'm leaning towards that wheel in 9" front with 255s and 9.5" rear with 275 kumho V700's. Being able to swap with 255's all around is very nice and cost effective though.

I don't know if I've actually helped or given any answers...just some of my perspective and things I've been thinking about. Let us know what you decide. I'll be curiuos to hear your report.

ps Keep in mind, this was all on the stock suspension...My S Tune kit will be on soon with my 350Evo bars...we will then be able to share setups more easily!

2003z

iTrader: (7)

Well, I guess I come from the auto-x perspective more, where the 275s up front would offer a little more grip in the corners, and in the back would keep me from hitting the rev limiter in 2nd quite as fast. The 275s would fit on a 9" just fine, 275 wimd ridths are 9-11" and a nat'l champ autox'er I met is running 275/40s all around on his stock 7.5" and 8" 17s.

Keeping the same size all around will allow you to rotate, but I'm not sure how many track days you will get out of those tires anyway. I would say go with the 9.5" rims if you feel they are better for the 275s, and start out with 255s all around. If you want more rubber, get 275s the next time.

In the latest Sport Z magazine, They have a paragraph in the motorsports section that says "4 time nat'l champion Guy Ankeny is developing a Track Model for SCCA nation tour and pro-solo competition. He solved the cars natural understeer problems with huge 275 Hoosiers up front and 245s in back. Ankeny also added 34 lb/ft of torque and saved 40lbs of weight with a custom 3" single pipe catback exhaust."

J Ritt

iTrader: (4)

Thanks for the input...275 in front, 245 rear may be fun for getting the car to rotate at autox, but I sure as hell wouldn't want to go through a 100+mph sweeper on that setup!

also added 34 lb/ft of torque and saved 40lbs of weight with a custom 3" single pipe catback exhaust."

I believe the weight savings, especially since the muffler itself weighs over 30lbs, but that power increase # is absurd.

2003z

iTrader: (7)

someone selling these wheels on 350zfrenzy for 1100 with barely used race rubber. 17x9 and 17x9.5

EnthuZ

iTrader: (2)

I saw that post too...got me thinking.......I like RaceBoys idea of better gearing with 255's all around, but I'm not familiar with the sellers tires.....

I was impressed with the Falken Azenis I drove at the Mazda Rev It Up event....VERY quiet.....and stickier than my 040's.

Has anyone tried different brand tires F & R? It MIGHT be another way to our desired balance! R compound up front, with Max Performance street tires rear. Still in the thinking mode..... I haven't broken traction in 3rd gear exits YET! Sooooooooo it MIGHT work.

Back to the drawing board.......

GaryK

Do you guys really think the z pushes noticeably on an autox course? I've autocrossed mine only once so far, but it really seemed well balanced to me. I was running bone stock, including touring 18's with 040's, on a wet course, but usually any bad traits of a car will show up worse in the wet. I never had more than a hint of understeer on turn in, and I was able to compensate with a little trail braking. Overall, I'd have to say I was very impressed with the handling. And no, it wasn't because I was under driving the car...I ended up with fast time of the day (it was a local PCA autocross).

BTW, in my opinion stuffing wide tires on rims that aren't quite wide enough to support the tread isn't the best way to go. I know that some of the fast national guys do it, but in my experience I've always had better results with a properly sized tire. For example, my stock class Camaro had to run 16x8 rims. People were running anything from 225 to 275 tread width. I tried almost every tread width available at some point, and it always worked best with a 245 tread.

raceboy

Well, the wheels are coming so there will be no more excuses at track events! I went with the 9"F and 9.5" rears. I went with Toyo RA-1's, 255F and 275R. The 9" and 9.5" rims are the exact Toyo recommended wheel sizes for those tires.

I now think that gearing won't be as much of an issue. I should be able to carry more speed through the corner therefor I should be in a sweeter part of the powerband exiting the corner.

I still need to get adjustable front "A" arms ASAP. I really need to dial in LOTS more front negative camber to really get these tires to perform their best. I have been trying to contact 350EVO, but no luck yet.

At the next track day I will also be running sans passenger seat and I myself will also be about 20lbs light (makes my wife happy!). That is about a 70lb saving. We shall see.

raceboy

BTW, I should be attending about 2 or 3 SoCal track days in August. They should be on weekends so I hope to see a bigger turn out from the 350Z guys. See:

Speedventures

Blue Liquid

Does anyone know if the 275 width tire in the front will require any fender modification? Will this rub with the suspension compressed or in a full lock turn?

raceboy

You don't need a wider front tire, you need more front negative camber. My front tires are worn on the OUTSIDE edge from heavy track use/abuse. Extra -camber up front will help increase front grip without going any wider.

Blue Liquid

According to Tirerack, the only race rubber I can run with a 17 inch wheel is the Hoosier with 245/45-17 front, and 255/40/-17 rear on a 8.5 inch front wheel and 9.5 rear. Otherwise, I'd have to run 275 all four corners. The Z has so few R compound choices in the 17 inch size, I can't believe it. Any other tire size combo and my wheel diameter is off enough to alter the electronics of the car, i.e. ABS, TC & VDC. This is frustrating.

EnthuZ

iTrader: (2)

I don't think we need to worry about all the electronic sh*t, since it should be turned off for track use. Trust me...I forgot to turn it off a couple times, and it REALLY .....screws up the car......like killing RPM's to 3K......