15 " vs 17" wheels

[corvettejoe]

I've been thinking of going to 17" wheels with the same back space as the stock wheeels on my 81. I'm very undecided. I've read the handling is like day and night??? Is this really true? Will the car sit higher if I use the low profile tires? There's a C3 vet on Wheel Vintiques site showing the rallye 17" wheels- looks good. I would love any feed back on the pros and cons. If the pros out weigh the cons, any tire recommendations? I have about 400hp with 4.10 gears. I need more traction. Thanks for your replies in advance.
corvettejoe

 

[Mac]

To my understanding, traction for launch depends on what kind of tires you install as opposed the size of the wheels. The tread design, rubber compound and tire pressure are all factors which can be considered but the wheel size itself isn't a big part of the equation.

If you mean cornering grip, the key advantage to going to 17" wheels is you can use lower profile tires altering the total circumference of the tire. This allows you to reduce sidewall flex without changing the cast & camber or otherwise throwing out the geometry of the suspension. The engineers spend a great deal of time and effort designing the suspension to be 'neutral' in handling. Tires are the most cost effective means of improving handling and the feedback is immediate.

The cons are that reducing the sidewall means a rougher ride where every bump is immediately evident and, in extreme cases, wheels can be damaged by bumps that might otherwise be absorbed by sidewall flex.

I hope that helps!!

-Mac

 

[corvettejoe]

Mac, thanks for the reply. That's helpful. It seems that manufacturers don't make 15" hi performance tires? That's one reason I'm leaning towards the 17" set up.
corvettejoe

 

[67HEAVEN]

Joe,

Here's more to think about...

 

[lnirenberg]

Its important that you stay within a close tolerance of the OEM tires' diameter when you plus size as you can run into clearance issues as well as a wheel well that doesn't fill up (not to mention screwing up your speedometer). I agree, after extensive web search real 15" performance tires are a thing of the past. Its all a matter of personal taste as I went with 16" as there are still some decent speed rated tires at this size. I went with a 60 profile vs the 70 that was stock in '71 as my car is otherwise stock looking and I wasn't looking for anything too radical. I expect if the snow ever melts I'll get to test out the new found corner grip. Back to tire height--go to this link and it will calculate tire diameter so you can find a plus size match:

http://www.net-comber.com/tirecalc.html

 

[patsnitrovette]

Just a couple things for sizes for you ..i run nitto nt-450 255/50/17 in the front which are 27 inchs tall,and 275/50/17 on the rears which are 27.8 inchs tall,they fit the wheel well perfect.MOst guys run 255's all the way around and are happy.

 

[pgtr]

corvettejoe,

Mac makes excellent points in his post...

IMHO Virtually all tires are pretty darn good at 17".

The overwhelming majority of 15" tires are pretty pathetic. There ARE however a 'few' 15" tires that can deliver darn good performance. Look at V rated A temp 15" 225/70-15s w/ treadwear in the 300s or lower. They have pretty good tread compounds and sidewall construction and can deliver respectable performance.

But otherwise go to 17 where you just can't go wrong unlike 15" tires where it's almost entirely crap for tire selection and you have to scrounge for decent tires.

good luck!

 

[Glensgages]

To my understanding, traction for launch depends on what kind of tires you install as opposed the size of the wheels. The tread design, rubber compound and tire pressure are all factors which can be considered but the wheel size itself isn't a big part of the equation.

For 'traction', as termed by straight-line / drag-racing, you might want as-MUCH side-wall height as you can get, as-opposed to a shorter side-wall height....

All things (over-all tire-height, compound, and tire-construction) being equal (let's consider a 28" tall tire), a 15" wheel offers 6.5" of side-wall per side, where-as a 17" wheel offers just 5.5" per side:
on the initial "hit" of the tire, the 15" wheel has 1" more tire (per-side) to 'flex', or 'wind-up', softening the blow, over a 17" wheel/tire combination, before 'springing' the car forward down the strip.

If you look at the C4/C5 (and probably soon, the C6) drag-racing guys on this and other Forums, they have a tough time hooking-up on today's "street-slick" type of 16"-18" tires (granted, NO Corvette-chassis is designed or built for drag-racing), and I think that having so-little side-wall is a reason for this problem.

If you will be drag-racing your C3, and wish to be competitive (especially at bracket-racing, where consistency is more-valued than balls-out going-fast), this might be something to consider.

 

[Badass95]

I'll try to go easy with you. Mac & the guys are right on target with all the technical stuff, if you're planning on racing next season on the grand prix circuit. My 16" Firehawks did just fine at 172 mph on the H-3 (highway) last Saturday, then I raced on the M/Ts that night.
Glensgages, I will summarrily disagree with you. My '95 runs high 10s. The drivetrain is custom, but it's still a vette. If you think a vette can't run with the big boys, you can kiss my ass.

 

[Badass95]

Oh, and I forgot to add... I race bracket

 

[pgtr]

For 'traction', as termed by straight-line / drag-racing, ...SNIP

... or handling/traction as in sports cars, precise steering, good tactile feedback, windy roads, city driving, etc..

(granted, NO Corvette-chassis is designed or built for drag-racing),

Yet any Corvette with respect to the era and engineering available when designed/manufacturered is better purposed for sports car competitive type driving.

If you will be drag-racing your C3, and wish to be competitive (especially at bracket-racing, where consistency is more-valued than balls-out going-fast), this might be something to consider.

... or a spare ragged out dime-a-dozen Camaro for this purpose.

 

[Vettehead Mikey]

I'll try to go easy with you...............
If you think a vette can't run with the big boys, you can kiss my a**.

Don't really appreciate your foul language.

 

[pgtr]

Don't really appreciate your foul language.

Yeah OK but you didn't say anything about his moniker...

 

[67HEAVEN]

Ahem.... ;squint:

 

[Glensgages]

Glensgages, I will summarrily disagree with you. My '95 runs high 10s. The drivetrain is custom, but it's still a vette.

If you re-read (or CAN read) my prior post, I said:
" granted, NO Corvette-chassis is designed or built for drag-racing ", then you prove my point by saying YOUR "drivetrain is custom", validating my statement.
:confused

If you think a vette can't run with the big boys,

ANYBODY can go-fast on A particular run:
I'm talking about back-to-back-to-back runs with-in .02 on marginally-prepared tracks.

Care to show me somebody who has repeatedly won, in either IHRA Modified Eliminator, or NHRA Heavy Eliminator, or finish repeatedly in the Top 3 in points at their respective home-track (not some Corvette-only series, either), ANYWHERE, with a stock-chassised (I.R.S. rear-end) Corvette?

you can kiss my ass.

Ya gotta get yer head outta the way first.


On the bright-side, you ARE just 2 letters shy of being called " class ".....

 

[67HEAVEN]

Back on-topic please gentlemen - we hate closing threads. There's no need to exchange insults, however well disguised.

 

[67HEAVEN]

Badass95,

It seems that "pulling your head out......" is one of your favourite phrases. You've used it in another thread here today. No more.

We pride ourselves on running a civil site here. Please find a way of participating without the putdowns or find another site.

 

[Badass95]

My apologies

I feel I must apologize to those whose fragile constitutions cannot bear the impropriety of my use of the English language, including the devastating aspect of "slang". My apologies. I shall refrain from causing any hate or discontent in my future postings.

Dan

 

[photovette]

There is another point to consider--17" tires are expensive as heck and don't last worth a darn. My last car was a 3000GT VR4--a set of tires was an eye-popping $1200. I had to do it twice during 42K miles. When I put tires on my '77, I was pleased to pay $300 total for a set of TA's.

As for the handling difference, a C3 with TA's can still corner fast enough for your passenger to sink her nails into your seats...

 

[corvettejoe]

Thanks everybody for all the replies, very helpful. I'm planning on taking it to the strip only a couple of times.
corvettejoe