STRETCH

iTrader: (3)

I wanna run this stagger...I can either run 275 40 18 fronts and 295 35 18 in rear or change the fronts to 275 35 18s? Will this work (either combination)? I need help! Anybody have the info on this? Its about a 2 percent difference either way...Thanks for all the help!

Stretch

rockinbboy

iTrader: (1)

jeeze...why so wide? Seems overkill for the Z.

Tortuga

iTrader: (6)

Check out this thread. Subydude posted some pics of a 275/295 setup.

https://my350z.com/forum/media-share/194952-freshly-detailed-350z-w-rota-p45r-s.html

HyperSprite

iTrader: (6)

275/40R18 F 295/35R18 R is asking for trouble if you have TCS/VDC, your backs will be a smaller diameter than the fronts.

You can easily do 275/35R18 F 295/35R18 R and keep TCS/VDC happy.

Chris

edwin350z

iTrader: (23)

good find.. really nice set up

Tortuga

iTrader: (6)

Here's a link to Subydude website. Looks like the package they have uses 275/35/18-295/35/18 setup. No I don't work for Subydude, I just remembered this tire setup was being used by him.

http://subydude.com/osc/product_info...4b01ecfecd3b5e

STRETCH

iTrader: (3)

Thanks for all the help guys! I bought the wheels from Subydude, 9.5 P45R's Gloss black with red lip and did 275's all around. It fit perfectly, however, I felt the square set up made the car lean towards oversteer, so I wanna stagger it

Hypersprite - I'll definately do the 275 35 18's (I asked cuz I have 2 new 275 40 18's with one track day on them, Kumho Ecsta MX's, anybody wanna buy them for 175 for the pair?:-)
Thanks again!

dkmesa350z

iTrader: (41)

275 seems unnecessary. I would go 255 and 285

STRETCH

iTrader: (3)

dkmesa350z-
Unfortunately Kumho doesn't make those sizes. When I had 245 275 staggered my car pushed all the time on the track (although I had Nismo sways with no adjustment). When I put 275s on the front I definately had too much front tire!, but...hopefully going back to a stagger with 295's will allow me a perfect balance. Having the 3.917 gears on a tight road course makes the car very tail happy. Don't flame me, I know most of it is driving skill on the track, but Im trying to find the perfect balance for the way my car is set up

Bets,
Adam

knight_white99

iTrader: (5)

Stretch, were you at Big Willow yesterday?

I have run as big as 285 up front (and also rear) without issues. But you are right, the "no stagger" set up gives perhaps some slight oversteer - but that is faster on the track. You can dial some of this out by stiffening up the front end (either by sway bar or spring/shock settings), or conversely, softening up the rear.

STRETCH

iTrader: (3)

Yes I was. Man did I feel like a novice. How did you know? I was just getting fast with my staggered 245 275 setup...I'm not used to the square set up yet, but I'm learning...and I agree about the sway bars and track times, I don't have adjustable ones , I have the nismo sways. I'm waiting on the Hotchkis sways. I'm being told that 295's on a 9.5 inch rim is a bad idea. Is this true?

knight_white99

iTrader: (5)

I thought I recognized the car.

I was there too. Did you run in the non-competition DE run at about 12:15PM? I think you started right behind me (blue tape on your headlights?). I had silver the 350Z with the black wheels with Rotora and VRT sponsorship decals. I set off after that 911 Turbo in front of me and never got to actually see you after that.

Damn, we need to talk more next time!

Yes, the adjustable sways (heck, any suspension adjustments) can be a great help.

I know a few guys running very wide tires on 9.5" rims. I have heard of as large as 315's on a 9.5" rim! But I don't think I would recommend that. A 295 is supposed to be on at least a 10" rim, but I have run a 275 on an 8" rim and I think that was worse.

And don't feel bad. Even I sometimes feel like a novice on a new track. This was my first time to drive at Big Willow in a car. Fun track, but I still didn't get the line quite right - didn't have enough laps to test all the entry, exit and braking points that I would have liked. I know theres a lot of time to be made on the entry into turn 8, exit of turn 9, and how deep you can run into turn 1.

STRETCH

iTrader: (3)

Unfortunately it was a different person. You would have recognized my car cuz it looks like yours (same wheels, silver) but mine is also fully stripped, yellow lights,etc..I didn't get a chance to run on Sunday as I popped a tire. Hence all the tire questions. I totally agree with the line. Do you think without a wing I could run flat out in turn 8? I also have trouble with how deep to go in turn 1. Was the porsche you were after a yellow GT2? That car was on slicks on Saturday and was hauling!! You should roll to California Speedway on the 21st and we can finally meet.

knight_white99

iTrader: (5)

Oh well, not you... my mistake then.

I only ran on Sunday morning. I was chasing a silver 911 Turbo.

Running flat in turn 8 will depend as much on tires and suspension as on horsepower. I don't think I could run flat out in 8 in my car on anything but slicks (I was running on Hoosier DOT tires), and maybe not even then - its pretty fast. Plus I am now pushing 400+ hp to the wheels, so we are talking some serious speed there. I am entering turn 8 in 5th gear and I need to brake on the entry for a moment. Certainly that is something that needs to be worked up to carefully. The pucker factor there is something to consider.

If you are running an NA motor with under 300whp, I think you might be able to do it, but it would still be something to work up to. Certainly a wing might help. I was talking to a guy from Tucson who had a fast Corvette there with an APR GT300 wing. He said the wing helped him tremendously; made the car much more stable in the big turns. But he had so much rear downforce that he had to add a splitter to the front end since the car wasn't balanced any more. So you need to consider some front end downforce if you are going to add a wing.

Somewhere (either Speed Ventures webiste or Willow Springs website) I read that turn 8 was a "120mph corner." Of course, every car is different. So I would use that as a general guideline when working up to that corner.

Can't make it to Cali Speedway on the 21st (though I would like to be there). Have to work - that's on a Friday.

Hope to meet you at some event in the future though.

STRETCH

iTrader: (3)

Yeah, I was thinking the wing too, for turns like 8 and the Roval part of Cali speedway. The guys at Speedventures don't think I should drive the Nascar Oval flatout without some kinda downforce, but I wouldn't know what kinda splitter to put on front. The Nismo front lip isn't enough? I wanna go faster, but I don't wanna look rediculous! Thanks for all your advice knight_white99!

knight_white99

iTrader: (5)

I am considering adding a wing to my car as well. I have the power now to push it through the air and overcome some of the added drag.

I can't say if the Nismo front lip is enough or not. Depends on you as a driver, the car setup, the tires, the conditions, etc. Only you can read the feedback that your car is trying to give you. Conditions on any given race track can change from lap to lap. You would need to do some testing, play with tire pressure, suspension and wing angles, etc.

I would not be setting "flat out" on any corner of any track as my goal. I would set trying to improve my overall lap times as a goal. If the wing helps you achieve that, that's great. But there are probably other areas that can help you just as much. Can you take any more weight off the car? Can you change your ride height? Improve the balance of the car?

Setting up a car for track use is as much an art as a science, and every driver has a different idea of what feels "right" for them. You just have to experiment to find out what works for you.

Just to let you know, I am on my 4th aftermarket suspension (there is another thread about this). I am still thinking about tweaking it again. I think suspension is where the most can be gained with these Z cars.

STRETCH

iTrader: (3)

I never felt unbalanced at 140 on the roval, but that could be due to my inexperience. I feel with my suspension and adjustable sways and if I mess with ride height and tire pressures I can at least get to a point where I know what I need, instead of just throwing parts at my car. With my 275 40s in front however, I was limited on ride height. Im rethinking tires size. I'm thinking of going 265 35 front and 275 35 rear to help with the balance and give me more ride height adjustment. With 275s in front, is it due to the 30 series being the reason you are able to adjust your suspension? I have camber arms, but still had rubbing issues if I went too low...and it wasn't that low.

MoodDude

Stretch -
I run 265 in front and 295 in rear. When these track tires are done - I will probably move up to 275 & 305. I really don't feel that your 275/295 will be to much tire for your Z! Yet, I have twice as much power as a stock Z and all my suspension is aftermarket.
I know Kolia has a problem on track with the stock suspension and his wider track tires.
And as far as downforce - I have mine sitting in my house waiting to installed on my Z (rear wing and canards for the front). After Road Atlanta in August I will be installing it since I have about 6 weeks than before Sebring. I just don't have any time right now with all my track events and work. The only thing that scares me about installing it, is people will start saying my car looks "ricey". I guess until they see me go around a corner.

STRETCH

iTrader: (3)

MoodDude- thanks for the input..I agree that its not too much tire, but I think my rims might not be able to handle that size tire. Plus I have 270 rwhp compared to you guys with 400+ ...I might just stick with 265 35 fronts and 275 35 rears and mess with my suspension pressures and sways(once I get them) where did you get the canards? Any suggestions on hot pressures for Kumho Ecsta Mx's on the track ? Thanks for all your guys advice!

MoodDude

I spent to much money and bought a Top Secret front bumper w/ canards and their rear wing. Yet, they where the only company I could find that there aero products actually do something and is not made out of cheap fiberglass.
I don't run Kumho's, but my Cup's like 40 to 42 psi hot pressure.