Tire advice

[EvanZR1]

Tire advice wanted for my 91 ZR-1. 600+HP 391 cubic inch LT5, used mainly for weekend fun, but does see occasional 1/2 Mile and 1 Mile events, as well as occasional road trip.

Option 1: Toyo R888Rs. Benefits: relatively inexpensive, Y speed rating (up to 186). Negatives: noisy, not great in the rain, only available in 275/35R18 front (currently have 285/35R18).

Option 2: Pirelli PZero Rosso. Actual street tire (max performance category), but expensive, available in "correct" sizes

Option 3: Combo of whatever brand 285/35 front (Y or (Y) speed rating) and PZero Corsa (Y) for rear. Ran the Corsas on the rear of the GS and was pretty happy with them. Very "streetable" race tire: 60 treadwear, 7/32nds tread depth, not really noiser than most street tires. Corsas are expensive, but could balance by getting a less expensive tire for the front. Would most likely do a combo ob PZero Rosso front and Corsa rear, both with (Y) speed rating (186+).

Want to stick with at least a Y speed rating as the car did 176 in the mile, and I'm still thinking about maybe adding gears or potentially a small nitrous setup. Really debating between options 2 & 3 at this point.

[-=Jeff=-]

I have pirelli Pzero Rosso on my Shelby wheels. Purchased them at Discount tire but the is a loading limitation or something on the 275, which blocked Discount tire from allowing them on the front, so I ended up with 285 in the front. They have some road noise and I need to rebalance the rears, but overall I like them so far


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[G8nightman]

Option 2

[Bob Eyres]

I have the Toyo R888’s (in stock sizes). Very sticky, yet wear well.
I’ve had numerous brands over 25 years and these are the best, and best value, so far.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

Michelin SuperSports 18/19, 285/345. Very nice and good in the wet.

[EvanZR1]

The one problem with the R888Rs is they are only Y (up to 186MPH) speed rated.
The Michelins are not available in my sizes (18/18) and I'm not getting rid of my Shelby wheels.

[DRM500RUBYZR-1]

The one problem with the R888Rs is they are only Y (up to 186MPH) speed rated.
The Michelins are not available in my sizes (18/18) and I'm not getting rid of my Shelby wheels.



Explain the problem you are concerned about with the 186 MPH rating.
The tires do not explode at 187.
Not trying to be funny, just trying to make sure objectivity, facts and logic reign supreme.
My vote would be with the r888r's which is why I ask.
Marty

[spork2367]

The one problem with the R888Rs is they are only Y (up to 186MPH) speed rated.

Keep in mind, that is sustained speed. So are you planning a lot of sustained runs in excess of 186 MPH? If so, you're really at the limit of production DOT approved tires.

[-=Jeff=-]

My ZR-1 is a fun driver.. no real intention of going to the track.. so that is why I chose the Pzero Posso, I wanted Street tire for my street car ;)

[EvanZR1]

For standing mile events, you must run a tire that is speed rated for what speed you'll be running. Right now a Y rating (up to 186) would be fine as I ran 176MPH last fall. If I add 3.90/4.10 gears and/or a small nitrous shot, I could see potentially getting up to/over that, which means I'd need tires with a (Y) rating (over 186).

I absolutely get what everyone is saying and would agree that the tires aren't going to explode for a brief run over their rated speed, but once you move to standing mile, the event organizers have absolutely ZERO give in their requirements.

It probably really doesn't matter that much as even with better gearing I doubt I'd hit 186, 10MPH in the standing mile is a HUGE change. Having said that, I guess having to buy new tires would be a nice problem to have because the car was too fast.

[DRM500RUBYZR-1]

For standing mile events, you must run a tire that is speed rated for what speed you'll be running. Right now a Y rating (up to 186) would be fine as I ran 176MPH last fall. If I add 3.90/4.10 gears and/or a small nitrous shot, I could see potentially getting up to/over that, which means I'd need tires with a (Y) rating (over 186).

I absolutely get what everyone is saying and would agree that the tires aren't going to explode for a brief run over their rated speed, but once you move to standing mile, the event organizers have absolutely ZERO give in their requirements.

It probably really doesn't matter that much as even with better gearing I doubt I'd hit 186, 10MPH in the standing mile is a HUGE change. Having said that, I guess having to buy new tires would be a nice problem to have because the car was too fast.



Well said, Indeed!
Good luck with your tire purchase and your further mods!
Marty

[spork2367]

For standing mile events, you must run a tire that is speed rated for what speed you'll be running. Right now a Y rating (up to 186) would be fine as I ran 176MPH last fall. If I add 3.90/4.10 gears and/or a small nitrous shot, I could see potentially getting up to/over that, which means I'd need tires with a (Y) rating (over 186).

I absolutely get what everyone is saying and would agree that the tires aren't going to explode for a brief run over their rated speed, but once you move to standing mile, the event organizers have absolutely ZERO give in their requirements.

It probably really doesn't matter that much as even with better gearing I doubt I'd hit 186, 10MPH in the standing mile is a HUGE change. Having said that, I guess having to buy new tires would be a nice problem to have because the car was too fast.

Makes sense. While I'd agree that 186+ is ambitious, it looks like the Pirelli P Zero Rosso is going to be one of the only (Y) rated tires in the size range you're looking for, at least for rears. On the Corsa, the smallest rim size is a 19" and at that diameter, the widest tread width is 265.

[EvanZR1]

Corsa is available from Tirerack and Discount in 335/30R18 in a (Y) speed rating. Thinking about Rosso in front and Corsa in the rear.

[spork2367]

Corsa is available from Tirerack and Discount in 335/30R18 in a (Y) speed rating. Thinking about Rosso in front and Corsa in the rear.

Ah. Not the "Corsa," but the "Corsa System". Why name two different tires so similarly...

That looks like an awesome tire.

[EvanZR1]

Yeah, I used these on my supercharged 2013 GS in the rear, and they worked very well. Best of the "streetable" track tires I've ever used. Handled the 700rwhp in my GS pretty well, so thinking they should handle 391 motor's power pretty well.

[XfireZ51]

Evan,

There’s a standing mile HP calculator at the bottom of this page.

Just playing w some SWAG figures, u would need another ~ 100hp to jump 10mph in trap.

Give it a play:

https://www.rbracing-rsr.com/aerohpcalc.html

[EvanZR1]

Well 100HP is certainly doable, just throw a small nitrous setup on it. :mrgreen:

[EvanZR1]

Evan,

There’s a standing mile HP calculator at the bottom of this page.

Just playing w some SWAG figures, u would need another ~ 100hp to jump 10mph in trap.

Give it a play:

https://www.rbracing-rsr.com/aerohpcalc.html

Interesting calculator, more of a potential top speed calculator, not standing mile as it doesn't account for gearing, but I've got a separate calculator for that. Looks like fully loaded (driver, fluids, roll bar, etc), with cd and frontal area for C4, I should actually be able to hit 200 with perfect gearing, since I should be over 600HP with the 391 engine can cams.

[USAZR1]

Evan, what 18" rear tires are your competitors running, for those speeds? I'm assuming you are running 335/30/18's, now. Still have a 3.45 rear gear?

[EvanZR1]

Yes, I'm on 335/30/18 rears, and still running the stock 3.45 rear gear. No real competitors in C4s that I've seen at the events I've been to. Most Vettes at these events are C6/7, with a few C5s, and almost no C4s.

[USAZR1]

I wasn't necessarily referring to competitors, with just Corvettes. If others are using a big 18" rear tire, just curious to know what tire is popular and also legal.

It might not be a bad idea to have a set of dedicated wheels w/race rubber, for those mile events, if you're gonna shoot for 200mph.