Widest tires fitted on a z/28? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Z/oro · 07-09-2019, 06:28 PM

Hi guys it's just about that time for my z/28 to get new tires and I've been reading around the forum to make a decision. I've settled on Michelin pss4 since I don't do much tracking to justify full on race tire compound. My question is how do 345s in the rear ride and look? I've read some guys are actually going all the way to 345s but there's no pictures posted. I had originally figured I would go 325s all around but after reading that I had to ask how wide can I go without getting camber kits or anything like that. I'm willing to do spacers but no more than 10mm to maintain a healthy stud and not need hubcentric rings. I'm really looking forward to some pictures of the 345s if it's actually possible or just another internet folklore.

pat_t · 07-10-2019, 03:17 AM

I don't have any pictures but a PSS4 at 345 should be OK on the rear without spacers.

There's a 345/30/R19 Michelin Cup2 that I've been thinking about trying for track use. Which will be quite a bit wider than the PSS4 (generally the Cup/Trofeo/track rubber runs wider for the same size than the road rubber).

Z/oro · 07-10-2019, 07:39 AM

So would you suggest going with 345 rears and 335 in front to try and maintain a closer to square setup? I would hate to go too narrow in front and have horrible understeer.

MrRaZ28 · 07-10-2019, 08:12 AM

I personally wouldn't go any wider than 325 up front.. I have 325's all the way around and while they fit with no issues, I wouldn't go wider than that up front. They have a far more noticeable bulge than the rears to the point where I'd think 335 is too much.. not to mention trying to find a shop that would be willing to put those on.

Edit: Keep in mind the original design was 305/325 but the engineers decided on 305 squared due to understeer problems at that sizing difference IIRC.

j o n · 07-10-2019, 09:14 AM

Quote:

Originally Posted by Z/oro

Hi guys it's just about that time for my z/28 to get new tires and I've been reading around the forum to make a decision. I've settled on Michelin pss4 since I don't do much tracking to justify full on race tire compound. My question is how do 345s in the rear ride and look? I've read some guys are actually going all the way to 345s but there's no pictures posted. I had originally figured I would go 325s all around but after reading that I had to ask how wide can I go without getting camber kits or anything like that. I'm willing to do spacers but no more than 10mm to maintain a healthy stud and not need hubcentric rings. I'm really looking forward to some pictures of the 345s if it's actually possible or just another internet folklore.

5mm is the max for 'a healthy stud'

Katech_Zach · 07-10-2019, 10:25 AM

Quote:

Originally Posted by j o n

5mm is the max for 'a healthy stud'

Agreed. I mocked up an 8mm spacer with 7mm extended GM studs. There was barely 7 turns on the lug nuts using this. 5mm with no studs would probably bring this down to between 4-5 turns.

10mm you will lose the hubcentric portion of the hub, the wheel was no longer hubcentric when using my 8mm spacer. The lead/chamfer on the wheel went deeper than what was left of the hub.

I ended up machining a set of 15mm hubcentric spacers, I will use ~1" extended studs.

j o n · 07-10-2019, 10:55 AM

Quote:

Originally Posted by Katech_Zach

Agreed. I mocked up an 8mm spacer with 7mm extended GM studs. There was barely 7 turns on the lug nuts using this. 5mm with no studs would probably bring this down to between 4-5 turns.

10mm you will lose the hubcentric portion of the hub, the wheel was no longer hubcentric when using my 8mm spacer. The lead/chamfer on the wheel went deeper than what was left of the hub.

I ended up machining a set of 15mm hubcentric spacers, I will use ~1" extended studs.

changing studs is simple as can be too...

ball joint tool to remove old stud

Then this seats the new stud (just use lug nut and this to pull the stud into the hub)

SS Performance · 07-10-2019, 06:26 PM

Are you planning to use the stock wheels? The stock wheel are about as narrow as you want to go with 345's. Also you will gain about 1" in height and 1.6 " in width. I'm guessing you are looking at 345/30R19 tires.

You would be better off going to a wider wheel 13" would be best from a track aspect.

pat_t · 07-11-2019, 03:22 AM

Quote:

Originally Posted by Chevy2tehBone

I personally wouldn't go any wider than 325 up front.. I have 325's all the way around and while they fit with no issues, I wouldn't go wider than that up front. They have a far more noticeable bulge than the rears to the point where I'd think 335 is too much.. not to mention trying to find a shop that would be willing to put those on.

Edit: Keep in mind the original design was 305/325 but the engineers decided on 305 squared due to understeer problems at that sizing difference IIRC.

+1 on not going wider than 325s up front.

Also - I heard a different rumour - I heard they designed for 305/325 and were testing both 305/305 and 305/325 at the Nurburgring, and it happened that 305 square happened to set the best laptime so that is what they went with...

There's another theory that going 305 square gave them better commercial bargaining power with Pirelli when ordering the tyres for original fitment!

Z/oro · 07-11-2019, 06:45 AM

Thank you all for your input it's much appreciated. Since I'm sticking to the stock wheels and mostly spirited back road driving and occasional track days (1-2 a year). I'm thinking my setup will be Michelin pss4 325 in front and 335 rears. Where do you all recommend for extended wheel studs?

Z28LC · 07-11-2019, 08:13 AM

To add to Z/oro's question, has anyone ever considered what a pair of CCW Classic Wheels would look like on a Z/28?

I've been thinking very long and hard about maybe getting a set for mine but I'm not too sure what they would look like on a Z/28 since I don't think anyone has ever put some on one.

They look just about good on most cars I've ever seen them on i.e. Corvettes, Mustangs, Supras, etc....I have never seen any on any Camaro model ever Gen 5 and up.

Mark_Z28 · 07-11-2019, 10:18 AM

Yea I've been looking at the Classic 2s for a while. If you do get them I'd love to see them on the car!

Only thing that has me held up is that I don't think there is any wheel that looks as good as the stock wheel on this body style.

Z28LC · 07-11-2019, 11:40 AM

Quote:

Originally Posted by Mark_Z28

Yea I've been looking at the Classic 2s for a while. If you do get them I'd love to see them on the car!

Only thing that has me held up is that I don't think there is any wheel that looks as good as the stock wheel on this body style.

Yea for sure man, The 2's are what I'll probably go with too, if I pull the trigger.

But you're right, I haven't seen wheels on a Z/28 that look as good or better than stock yet.

Biergut · 07-11-2019, 11:44 AM

Quote:

Originally Posted by Z28LC

But you're right, I haven't seen wheels on a Z/28 that look as good or better than stock yet.

Agreed. It's the only car I've ever had where I had zero interest in changing the wheels... love them. Everyone else seems to as well.

07-09-2019, 06:28 PM	#1
Z/oro Drives: Camaro z/28 Join Date: Sep 2017 Location: Texas Posts: 37	Widest tires fitted on a z/28? Hi guys it's just about that time for my z/28 to get new tires and I've been reading around the forum to make a decision. I've settled on Michelin pss4 since I don't do much tracking to justify full on race tire compound. My question is how do 345s in the rear ride and look? I've read some guys are actually going all the way to 345s but there's no pictures posted. I had originally figured I would go 325s all around but after reading that I had to ask how wide can I go without getting camber kits or anything like that. I'm willing to do spacers but no more than 10mm to maintain a healthy stud and not need hubcentric rings. I'm really looking forward to some pictures of the 345s if it's actually possible or just another internet folklore.

07-10-2019, 06:26 PM	#8
SS Performance Drives: 02 Camaro B4C Join Date: Nov 2016 Location: Cape May County NJ Posts: 749	Are you planning to use the stock wheels? The stock wheel are about as narrow as you want to go with 345's. Also you will gain about 1" in height and 1.6 " in width. I'm guessing you are looking at 345/30R19 tires. You would be better off going to a wider wheel 13" would be best from a track aspect. __________________ A man's garage is his castle 1969 Camaro SS 1970 Camaro SS 2002 Camaro B4C 2014 Camaro SS Dedicated Track Car 2015 Camaro 1SS 1LE 2008 HHR SS 1996 Silverado Crew Cab Long Bed Dual Rear Wheel

07-10-2019, 03:17 AM	#2
pat_t Drives: . Join Date: Jun 2016 Location: . Posts: 589	I don't have any pictures but a PSS4 at 345 should be OK on the rear without spacers. There's a 345/30/R19 Michelin Cup2 that I've been thinking about trying for track use. Which will be quite a bit wider than the PSS4 (generally the Cup/Trofeo/track rubber runs wider for the same size than the road rubber).

07-10-2019, 07:39 AM	#3
Z/oro Drives: Camaro z/28 Join Date: Sep 2017 Location: Texas Posts: 37	So would you suggest going with 345 rears and 335 in front to try and maintain a closer to square setup? I would hate to go too narrow in front and have horrible understeer.

07-10-2019, 08:12 AM	#4
MrRaZ28 @MrRaZ28 Drives: 2014 Z28 #80 Join Date: Oct 2009 Location: Cincinnati, OH Posts: 590 View My Garage	I personally wouldn't go any wider than 325 up front.. I have 325's all the way around and while they fit with no issues, I wouldn't go wider than that up front. They have a far more noticeable bulge than the rears to the point where I'd think 335 is too much.. not to mention trying to find a shop that would be willing to put those on. Edit: Keep in mind the original design was 305/325 but the engineers decided on 305 squared due to understeer problems at that sizing difference IIRC.

07-11-2019, 06:45 AM	#10
Z/oro Drives: Camaro z/28 Join Date: Sep 2017 Location: Texas Posts: 37	Thank you all for your input it's much appreciated. Since I'm sticking to the stock wheels and mostly spirited back road driving and occasional track days (1-2 a year). I'm thinking my setup will be Michelin pss4 325 in front and 335 rears. Where do you all recommend for extended wheel studs?

07-11-2019, 08:13 AM	#11
Z28LC Drives: 2015 Camaro Z/28 Join Date: Mar 2019 Location: Dallas-Fort Worth Posts: 42	To add to Z/oro's question, has anyone ever considered what a pair of CCW Classic Wheels would look like on a Z/28? I've been thinking very long and hard about maybe getting a set for mine but I'm not too sure what they would look like on a Z/28 since I don't think anyone has ever put some on one. They look just about good on most cars I've ever seen them on i.e. Corvettes, Mustangs, Supras, etc....I have never seen any on any Camaro model ever Gen 5 and up.

07-11-2019, 10:18 AM	#12
Mark_Z28 Drives: Black 2015 Z28 #457 Join Date: Sep 2016 Location: Dallas, TX Posts: 214	Yea I've been looking at the Classic 2s for a while. If you do get them I'd love to see them on the car! Only thing that has me held up is that I don't think there is any wheel that looks as good as the stock wheel on this body style.