I'm trying to figure out what the optimal tire width would be for Track and AutoX events for the Z...I'm planning on running all 4 wheels the same and on 17" rims.

I see that some ppl are running 275's for autoX- is the biggest tire width the best for the Z? (I would think that as you increase the tread width - traction will increase to a point, but as the tread width increases - the weight also increases...where's the best balance for a non-FI Z?)

*I'm looking for a midpoint between track and autoX use.

if you had to choose, would you go with:
1) 235/40/17s Toyo RA-1 on buddy club, P1, QF, 17X8, 28 offset, (13.6 lbs)

or

2) 255/40/17s Toyo RA-1 on MB Motorsports Competition, 17x9, 27 offset (18lbs)

**this is for track/autoX and driving to and from events...no other street use.

thanks!!!! (btw, I tried searching and couldn't find anything this specific...)

 

I would say 275s are the best way to go for you application, but you can easily do 285s. I am running 285/30/18s on the front of my Z now. 235s are way too small IMO.

 

i agree,
after a couple hot laps the 235s will show signs of grip loss while the 275/285s will stay fresh...

 

I'm pretty sure the MB Comps weigh more than 18lbs. I was recently looking for a light 17x9 - 275 combo, and ruled the Comps out pretty early in the search. I talked to Discount Tire and they said the wheels were around 20 lbs. Can anyone confirm?

Also, Enkei RPF1's weigh 15.9lbs in 17x9. They're not cheap tho.

BTW, I run 265 r-comp rubber for A/X and could use more grip.

 

wow, thanks for the info guys! I thought 245's would be the biggest I'd need...looks like I'll be getting a set of 17X9 rims - I'm leaning towards the buddy club rims b/c of the weight (unless I get a good price on the MB Comps...someone on the forum is selling it w/ Toyo 255s)

thanks again!

 

I just ordered a set of MB's comps with 275 Azenis.

I was worried about the weight, but for the price, I cant complain. I rather have the wider tires than the lighter wheels. As I used to with my old track wheels.

 

They are 20 lbs. I also have 275X40X17's V710 for track. You just can't beat this combination. Great balance and traction from the 710's

 

I have run 275/40-17's all around for both auto-x and track on 5Zigen FN01R-C 17x9" wheels. These wheels weigh only 17.5 pounds each, and are cheaper than the Enkei wheels. I have been very happy with this combo for time attack events.

 

Knight - have you weighed the FN01R-C's? I was trying to confirm the weights listed on edgeracing.com regarding these wheels.

 

I'm running 275/40/17 Avon Tech R r-comps on MB Motorsports Weapon 17x9 +27. Has been a nice combo for AutoX. Have yet to hit the track, but plan to do that this season...

 

Has anyone tried these rims:

Buddy Club, P1 QF, Forged 17x9, 14.5lbs

I think I'll be going with these...what offsets are you guys running with 17X9 rims and 275 tires?

thanks for the all the input!

 

Keep in mind that although a huge tire will probably help grip, it will slow you down during turn in and will cause drag on the straight. Unlesss you are pushing a ton of power, you have to find that medium of where is too big?

 

I totally agree...what size do you find that middle ground to be? 255s? Initially I was thinking that 275's seemed rather wide for a non-FI Z, but it's sounding like a lot of ppl think that 275's are a perfect fit for the traction and power of the Z

thanks

 

On my 17's I went with a 255/40 up front and a 275/40 rear (Yokohama A032R soft Compound) and it has handled very well after it was corner balanced. I was going to try to go for a 245/45 and see how that felt up front, but I still need to burn through the 255's

 

I ran 235f and 255r for my dual use Street/Track Azenis. I liked the balance.

This year, I'm going with 255/40r17 and 275/40r17 for the track only wheels (RA1)

I don't to AutoX so I didn't want to go same size all around.

 

Why do track ppl like staggered tires? I assume the AutoX ppl like extra grip in the front to help with cornering, so they go with the same tires all around - right?

I guess I'll get the buddy club rims and just mount the Toyo RA-1 235/40's on and see how I like it. (at least the smaller 235's will give me a better gear ratio)

-Peter

 

Okay, I was just about to order 1 rim...I saw the pricing and for some reason thought that the buddy club rim for $570 was for a set - nope (I thought it was weird that the one of the lightest rims would be sooo cheap). Looks like I'll be going with the MB competetion rims @ 20.4 lbs [17X9 +27mm offset]

 

Sounds you know about the local guy selling the MB comps. I think the 255's are a good starting point. They're really only marginally narrower than the 275's and will have a little less sidewall flex. I offered to buy just the guys tires but he wants to sell them as a set with the wheels. Jritt is also selling a great set of track wheels and tires.

 

I’m assuming you’re referring to those of us who do HPDEs and such?

Staggered 235/255, my Z will have a slight understeer but it’s still easy to get the rear end to swing wide with throttle induced weight transfer. I also use trail braking in most corners (view points diverge on TBing, some say we should not have to use it if the car is setup right (zero understeer), I say I’ll set up my car so I can keep my speed up as long as possible into the turn.).

Knowing that I’ll brake deep into a corner, it’s good to have more tires on the rear to keep the car from fishtailing. The bigger tires will also help get the power down on corner exit.

So, more tire is needed on the rear for the type of balance I like. 295 might be pushing it a bit. 275s are a bit cheaper and will clear the fender/suspension in the rear. I go with that as a base and go down one step for the front tires, ending up with 255 wide in the front.

255/40R17(f) and 275/40R17(r) with RA1s is the setup I’ll use this summer. I’m still 235/40R18 and 255/40R18 for the street.

AutoX will be different. The speeds are not as high, leading to less overall weight transfer, so less chance for the rear to give up. Plus, tires will be cold for most of the run. You would want as much cold grip you can get right from the start. So you fill the fenders with the biggest front tires you can get to compensate the lower grip and get less understeer. The rearend braking loose will be a good thing on tight circuits as it helps you turn with less steering input.

My 2 cents…

 

I agree, on a road track, it is easier to correct understear than overstear, I really don't want to slam my car into a wall.
Yet ,on AutoX you want a more balanced set up, since the biggest risk is you will hit a cone .