emoFTW

Stuck on which tire I'd like to go with, I'm leaning towards the 295/45/17 tire since the car will mainly be for "roll racing" usage. I do take occasional trips to the track, but not too many. Any reason why I should go with the 275/40/17 instead?

I will be putting these on some repo c6z deep dish wheels. 17x9.5 54mm offset. Car is an 08 base with the z51 package.

Car is currently cam only making 480whp, but will be adding a 150 shot or some soon in the next few months.

(or maybe even a 305/35/19 on the stock wheels?)

Any input is greatly appreciated.

iToast

Im in the same dilemma as you. I thought I read somewhere that the 275/40 is enough for 550-600whp cars? I've been leaning towards the 295/45 because of that reason. You can also look at the 275/50 from M&H. I think with that offset and a 295/45, you'd have to raise the car if its lowered which is the reason why I'm hesitant to buy that size.

emoFTW

Glad to see I'm not the only one.


I was leaning towards the 275/40 at first, but seeing that it is a 26in tire I'm not entirely sure that is something that I want to be rolling around with on the street. Suppose to give me "more gearing". But I believe it will throw off my speedo pretty bad. ex. I should be running 70mph, but the car speedo reads 75mph. Which will result in "extra miles". Not sure if that makes sense.


But I think the 295/45/17 is a 28in tire, which just seems tall to me. Stock is a 27in tire I believe, not sure if 1in is a big deal or not. Maybe I'm just overthinking this haha!

zemog255

I have a similar setup cam only ls3 made 483 planning nitrous after I get the clutch in. The 295/45 will measure out around 27.5. So not a lot taller than stock. I rather have the extra sidewall also. The 275/40 is too small for me on the street and I'd be impressed if it held on a 150 shot on the street. I have ran that tire on another car and its tiny. It measured just under 26 inches. Also my car is plenty low enough as it is. I think that's something a lot of people over look when running a shorter tire.

emoFTW

That's exactly what I was thinking as well. The stock tire measured via a Tire Height Calculator was 26.9in (285/35/19). The 295/45/17 is 27.5. Hopefully it won't make too much of a difference as I'm pretty sure I'll be going that route.

Joe_G

On a N/A car more gear is better. Shorter tires are better. You can correct the speedometer error with a click of a mouse with HP Tuners.

The big tires are going to slow you down. A lot. You only need them when you are shooting for an 8 second car.

Look and see what all the 9 second N/A z06s are running. Look and see what the low 10 second ls2's are running. Ask them why they chose their tires if you don't believe me.

315/35/17 if you have a wide body, 275/40/17 if you have a narrow body. About 26" tall actual measurements. 15" tires are even better on the drag strip but they are no good for street driving and you need super expensive custom mounts from LG to run them. I drive all the time on my Mickey 315/35/17. I wouldn't use them on the road course but highway and around town they are fine and even not bad in the rain if they still have their siping. No good for rain when that wears through. I think the new 275/40/17 as the same tread which is much better than the old tread for the street.

Experience talking here. I tried taller slicks and went a lot slower.

zemog255

I ran a 275/50/15 on my nitrous 5.0 mustang and ran the 275/60/15. 26 vs a 28in tall tire my 60ft times were within a few hundredths of each other. The taller tire being more consistent. The ETs and mph were the same. In theory it should make a bigger difference but a lot of the time more gear doesn't really change anything past the 60ft. Now on motor with the stock converter. There was a noticeable difference in almost a full tenth on the 60ft. The big thing there is getting past the initial bog on the launch due to the stock converter.

Also keep in mind the OP has a z51 car like myself we already have shorter gearing. In the 1-3 atleast. I do think the shorter tire would be better for a 60 roll. That's over 5500rpms in 2nd which is way too high for me and 3rd is around 3800rpms. Also in a z06 or base C6 trans for track only setups you can't argue the results like you have posted.

Joe_G

I have z51 and 4.10's and short tires. I had 3.90 and taller tower too and you want the most gear you can get for a NA build. Of course you need to be conscious of your rpm at the stripe when setting gears and tire size too. But up to 130 in the ¼ 4.10s and the short tires I mentioned are the best.

And my car is very stout on a roll...3rd gear at 60 I'm making 35-40 more HP than a guy with 3.42's and that jump gets me out front and I stay there through the gear changes. I'm always making more HP at a given road speed as my rom is higher.

And due to z51 fifth gear, I top out at 185 at redline...verified on the Miami mile airport run.

emoFTW

So even with a roll racing, you guys are suggesting me to go with the 275/40/17? Now I'm starting to change my mind. I'm here to learn guys, I'm open to all inputs. Keep them coming!

zemog255

Wow that's a lot of gear. Did you try running the taller drag radial with the 3:90's? Or was that with the slick? What did the ET difference amount to?

Joe_G

More gear is better it puts he engine at a higher hp rpm for any given speed. Only time to gear down is if you are so fast you are needing to shift to 5th before the stripe.

Check out the gear discussion in this thread for more info.

https://www.corvetteforum.com/forums...ast-heads.html

emoFTW

I appreciate it! I'm gonna check it out!

iToast

Another option is running an 18" rim. You could run a 285/40r18 NT05r and it's virtually the same height as you stock size

C6David

I let my buddy borrow my 275/40/17 hoosiers on his 700whp+ ls2 c6 and they dead hooked in first at the track. Ive had good luck with the 275/40/17 but have also ran 315/35/17, 305/45/17, and 28x10x17. Currently running the 275/40/17 hoosiers for my motor passes. On nitrous I was using the 305/45/17 and 28x10x17 so I had enough gear to cross in 3rd. I had better 60 foots on the shorter tires though.

Breze84

You will run faster with a higher mph with a 275/40/17 all day over a 295/45/17... The 275/40 will increase your rear gearing, The 295/45 will lower it. Unless you are making a lot of power stay away from a 28" wheel. You wont be happy...

Joe_G

I went from 1.8's with the tall tires and 3.90's to 1.6's with short tires 3.90's (that reduction was tires alone, it made a huge difference) to 1.4's with 4.10's and short tires.

But that's not as linear as it seems as I added 90 rwhp power between the 1.8's and 1.4's and I've learned to drive a LOT better.

I've got 497 passes launching at 5,000+ rpm and 78,000 daily driving miles on my OE clutch. NO WAY I could have had my clutch last so long without that steep lever of the the 2.97 first and 4.10 rear getting to get me off the line.

Xtremespeed

I've been debating the same. 700+ hp supercharged base with z51 manual. Very little track time. Mostly street from a dig. I was thinking the extra sidewall of the 295/45 would be the way to go on the street with a manual, but it's hard to give up the gearing advantage of the 275/40.

iToast

700+whp should be trapping near 140mph. I feel the taller tire would help keep you in fourth gear, whereas the shorter tire may put you clicking fifth. But I'm just spitballing here

Joe_G

Street from a dig is a different animal. If it's a manual car you may need the additional bite of a big tire. How is your traction on the 275? If good, stay with it.

I thought the same, I like to gear (including tire size) to go through the final trap at redline, or a little less.

Xtremespeed, what are your trap speeds and RPM?

Xtremespeed

It's a new build so I don't have any et's or trap speeds yet. I'm gingerly running around on street tires right now, but need to get something soon.