I've been wondering what I am going to do about traction when I get a 3000rpm Edge converter and aftermarket camshaft installed, pushing 340-350rwhp.

Right now my 17x9 SS 10 Spokes hold up well to the power I am making. I can ease into the throttle of the line, then mash it and the car grips and goes. The car cant chirp gears since the change from stock size wheels. I contribute this to the LARGE amount on money I spent on Goodyear GS-D3's. But the thought of more TQ and HP shocking the tires soon has had me thinking I should go to a 17x11 rear wheel setup. Options are limited, and favor a painted or polished 17x9.5 and 17x11 setup. I'd reuse the tires I have for the front. But at the rear I would probably slap on some 315/35/17 Sumitomo HTR Z's.

In theory the wider tire should grip better, but in the case of the Sumitomo being a somewhat less "quality" tire than the GS-D3, would it be the right move? I cant run any time of Drag Radial so please dont suggest it. I just dont want to be all over the road like I was with my 245's and a few bolt on's.

Or is there no hope in the street tire catagory and just keep what I have and run some ET Streets when I need to?

Thanks.

-Dustin-

 

315/35/17 gs-d3s

 

Years ago I ran both the 17x9 ZR1s with 275 40 R17 BFG DRs and the 315 35 17 BFG DRs on a custom Centerline wheel. The 315s hooked no better than the 275s. So I went with the lighter 275s at the time....However...My new found hero is the 255 50 R16 M/T ET Radial...You're gonna need more sidewall to hook at the track and the little 16s really work great and are lasting longer than my BFGs did on the street. I would keep the 17x9 wheel/tire combo you have and get 2 16x8 factory wheels and mount some ET Radials...I made 5 passes in a row with 60's in the 1.55-1.57 range..I'm totally hooked, literally...

--Alan

 

Well I think the 315 GS-D3 is out of the question money wise, right now at least. Although Goodyear has taken care of my with my current ones. Traction is amazing. Are there any GS-D3 315's falling off the back of the truck over where you work

So the 315's didnt really help huh? I was afraid of that. See I'll probably run ET Streets at the track, but I dont go that often. So I want something that will perform well on the street so I can have good safe fun. ET Radials meaning the MT drag radials? Hmm, sounds like a good alternative to ET Streets.

Thanks guys.

-Dustin-

 

What ABA said. A wider tire isn't better if the sidewall is shorter. Plus you'd be going to a lesser tire all around. You spent a lot on the GMMG that won't give you any more power than a catback that costs half as much, don't skimp on tires.

Ditch the bigger swaybar, set your suspension up more for drags and heat the
GSD3's up. Might want to look into SFC's and a TA.

 

Alright, well I figured if the Vette's that put out around 400hp could get traction with 10-11inch 17 or 18 wheels it might be beneficial to me. But it seems like most folks dont feel thats the case.

What if I blew the extra money on good tires, GS-D3's or BFG KD's lets say. Worth it then?

-Dustin-

 

Dustin...i have the luxury of my car not being a daily driver so I run DRS all the time. I generally only put 4-5000 miles/year on the car and I like to drag race on radials so I chose that route. My not-so-scientific testing over the years show that the 16" tire will hook better at the drags over a 17" of the same diameter because of the increased sidewall and increased front to back foot print of the tread on the ground. I don't know what your priorities of the car are, but I would say that 17x11s may not do much for drag racing other than add weight. I would just stay with the 17x9s for now and just add 2 16x8s with the DR of your choice when you go to the track.

Now for handling and autocross type stuff the wider tire/wheels may help you but they didn't hook any better for me at the strip. The 275 40 R17 DRs work well, too, but not like the 255 50 16s...The key, at least for me, was to hook at the track with both sway bars and not to use drag springs/shocks, etc..I wanted a good street ride, but be able to hook and go at the track, and I finally accomplished it with my fairly basic set up...

--Alan

 

Well I always say I want to go to the track alot, but it never ends up happening. I've been to the track twice in the last 2+ years. I want something to have the most fun possible on the street but also safely. I dont want to be losing control all over the place like with my 245 16" stockers. The 275 17" SS's are working good but I figured even wider might help more on the street with a cam, stall and possible heads later. In just over 2 years my car has seen 50k+ miles, so its not ecomonical to get DR's.

Track wise I'd probably try and get a 16" rim with a good drag radial.

Thanks guys.

-Dustin-

 

Going wider isn't going to be better if you're not going to spend the money on the right tire. I've got 315 htrz's on the back of mine, and with the 4.11s, you can spin 1st anywhere, anytime, although 2nd will hold unless you're just trying to spin them. Nitto just came out with a new tire that seems really good, and they said they would be offering them in a 315/35 17 size, but I don't know if that size is out yet. That would be my preference, or else the gs-d3s. The sumitomos are a great street tire, but they just can't grip quite as well as tires that cost twice as much. - and the sidewall is important too, of course, a taller one will allow more flex so slippage is less likely to occur. However, the actual size of the sidewall is basically identical between the 315/35 and the 275/40 since the width of the tire is part of the equation. I guess what I'm trying to say is that the compound of the tire is just as important as how wide it is, probably more in a lot of situations.

 

Well I understand I'd be going to a bit of a lesser tire in the rear, which would mean less performance. Which most everyone is explaining well. Man I was hoping to get away with that

Here is my main issue. I want/need new rims, I like my 10 spokes, but I'd prefer some polished ZR1's since they go for a bit less and I like the look. Now with the ZR1 wheels I could go 17x11 in the rear for a minimal increase in price, which is the main reason I made this post.

Ultimately after my last pair GS-D3's run out and until I get a wonderful job I'll probably be switching over to the cheap Sumitomo's on all 4 corners and just run DR's at the track.

With that being said would 315 Sumitomo's grip better than 275 Sumitomo's? I think that will give me the answer I am looking for.

If not, why do many cars with major amounts of HP/TQ have such wide tires in the rear? Does it not benefit their traction?

Thanks guys.

-Dustin-

 

Yes, the 315s will give you more traction than the 275s when you're using the same tire. The point I was trying to make is that it's not the only consideration you should make when deciding what to go with.

What isn't important in 315 vs. 275, but is on the dragstrip, is the profile of the tire, or the size of the sidewall. For instance, a 245/60 15 tire will outperform a 245/50 16 tire of the same compound on the dragstrip because the sidewall will flex more and absorb some of the intial shock- which is why you will see a drag tire wrinkling the rear tires. Sidewall flex is extremely important on a car with a manual transmission because of how quickly the rear tires can be loaded and unloaded.

Of course another reason the big sidewall tire performs better is that the rim is smaller, so the tire/rim package weighs less, and it also keeps as much weight towards the center as possible. A large rim will have a lot of weight on the outside, and the farther the weight is from the centerline of the axle, the harder it is to accelerate.

So the real reason you see high performance cars with huge tires on the back is because if you want handling you need a low profile tire, and if you want to accelerate quickly with a low profile tire you're going to need a lot of width because of how prone the tires are to spinning once their limit is reached.

Anyway, it sounds like that with your decision you can have the best of both worlds, with a 315 for the street with a decent treadlife, and then a dedicated drag tire. Are you sure you don't want to go with the chrome rims, though? Ever since I got mine, polished aluminum just looks dull and boring. Plus I don't have to do any polishing, just clean them like you were cleaning windows and they look brand new again.

 

Yea, I must have worded my comments different than what was in my mind. I know all that good stuff about tires, it's just a matter of 315 vs 275 with similar tires. Thanks for answering that, my intuition told me go bigger for more traction, but I had to be sure. I also like the handling aspect which is why I am also doing some springs/shocks.

Yes since I have alot of miles each year the straight DR's dont work for me. I am in the process of buying some polished ZR1's or Torque Thrust II's. I like Chrome like I have, but I like the look of polished like my fathers Cragar SS's on his 57' Chevy. Hopefully I can come out of this with some nice TT II's like I have always wanted.

Thanks guys.

-Dustin-

 

Urrr... Wider is always going to give more grip...


Oh, and I'm really happy with my HTRZ IIs. And my TT2s.

 

Do they make the HTRZ II's for the rear in a 315? I know they make the standard HTRZ's. How much did they run you for rears and where did you get them?

BTW I am driving to pick up my TT II's tomorrow. 17x9.5 and 17x11 They currently have some broken in Nitto DR's and I now have 4 pair of 275/40/17's to use up on the front. I was thinking of selling the new pair of GS-D3's I have to pay for some 315 Sumitomo's and keep the Nitto's for the track. Even though a 35 side way Nitto DR isnt exactly prefered.

-Dustin-

 

Ahhh apparently they don't make the HTRZ II in 315... I could have swore that they did, but looking on Tire Rack they don't list it.

I got my 275/40/17s at my local Americas Tire. I mistakenly told them that I had seen them for $88 a piece on the net (that was actually Tire Rack's price for the original HTRZ) so they matched the $88. I like the tires, awesome bargain for the money, really attractive tread pattern and sidewall, and I don't feel any remorse if I decide to lay a patch or two. If I did that with a $600 set of rear tires, I'd probably be depressed the rest of the way home.