Race wheels and tires

[thebigjimsho]

I find these items are as important as any suspension mod you can do. Does anybody have any lightweight wheels on their SHO? Also looking for feedback on some of the newer competition tires out there. I still have older R1's, looking to replace soon.

 

[noSHO]

nm me, I can't read...

[This message has been edited by noSHO (edited 01-29-2002).]

 

[ThrillSHO]

I ran BFG R1s for years and was very disappointed when BFG quit making them and then pulled completely out of the autocross and roadrace market. Heck, at one time BFG sponsered the North Carolina Autocross Championship Series as well as the National Series.

Yokohama makes some great tires for street and track. So if you don't have a second set of wheels or don't like to carry a second set and change them at the event Yokos are a good choice.

Members in our local club praise the performance of the new Kumhos as well as their attractive price and available sizes.

Another option is Hoosiers. Most people consider Hoosier more of a roadrace tire than an autocross tire. They also seem to work better on higher HP rear wheel drive cars than Kumhos. And finally, they are more expensive.

I currently drive to the track on my Kumho rain tires and have sticky Yokos to change into when I get there. When the Yokos wear out (early to mid-season) I will likely buy sticky Kumhos. As for wheels, there have been lots of wheel lists posted with weights if you do a search. I have three sets: 16x6 slicers, 16x7 continental wheels and 16x7 steel OEM wheels (hard to beat'em at $45ea new).

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ThrillSHO Racing
93 ATX SHO
UDPs, LPM, 80mm MAF, K&N w/CAI Snorkle, 8mm Taylor wires, Koni Struts, IPT Coil-overs, Camber plates, Adjustable rear control arms, Touque box brace, Poly bushings, 24mm front SB, 26mm rear SB, Shaved Alum SFB, Full-length SFCs, Front & Rear STBs, SS Y-pipe, Borla Cat-back, TransGo Shift Kit, Relocated battery, Five point harness, Five 2" gauges below the CD player, 225/50s on 16x8s, 96 Brakes
Very Low Very Fast

 

[DeaconBlue]

I understand the TireRack carries some fairly light weight wheel comp rims for the Taurus fitement now. The ASA JS5 rims in the 16 x 7.5" with 225/50-16 Kumho V700's
weight in at about 38 lbs each per Sergio P. That's about 4 lbs lighter than the stock 215/60-16 tires on the 6" wide slicers, not too shabby.

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95 MTX
with a few mods

 

[1fastsho]

i've been running the Toyo T1-s's on the street now for a couple of months and like them a lot....these are the same tires that the speedvision touring series run on the track(but shaven ofcourse)

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Shawn Pasley
Innovative Performance Technologies
770-725-4631
www.iptech.tv
92 SHO red/grey
3.2L(bored) Lowered compression(9:1)
stageII cams, Ported/Polished heads,Ported/polished Intake manifold(runners, endtanks, and behind the throttle body), big bore butterflies,80mm maf, LPM,equal length Long Tube Headers and custom Y pipe, Dynomax cat-back, Koni/coil-over suspension, poly-bushings everywhere,26mm FRONT sway bar, 28mm REAR sway bar,rear strut tower brace, solid subframe bushings,subframe connectors, tubular aluminum adjustable rear control arms,shortened shifter,235/45/17 Toyo Proxes T1-S's on TSW VX-1's. 15 lbs of boost here I come!

 

[NJshofear]

Originally posted by DeaconBlue:
I understand the TireRack carries some fairly light weight wheel comp rims for the Taurus fitement now. The ASA JS5 rims in the 16 x 7.5" with 225/50-16 Kumho V700's
weight in at about 38 lbs each per Sergio P. That's about 4 lbs lighter than the stock 215/60-16 tires on the 6" wide slicers, not too shabby.

damn my 17" alessio turbos and 225/45/17 falken grb fk451's weigh 40lb's only (thats 2 more lb that the 16") and my old 17" mim asti (same tires) weighed in at 42


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Jeremy
Red 89 SHO
MODS:
-Upgraded brakes,
-17x7.5 Alesso Turbo(hyper black) wheels W/falken GRb fk451 tires (225/45/17)
-Custom bent single exhaust exiting under SHO on the back bumper
-Coilovers from IPT
-Pioneer head unit, with 2 Rockford Fosgate 12inch subs, and RF amp, Alpine amp.
-Two row copper radiator
Coming soon: SFC, LSD, forced induction (twin-turbo or a S/C)
AIM:Tiedie6683

 

[jprinesho]

Are there any stock 17" rims that will fit a sho? (That you could find in a junk yard or cheap somewhere) I've heard some volvo rims will fit. I need 17" rims to clear my front rotors.

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90 MTX Black/Black - Tons of mods - Previous SHO Shop test mule.

 

[NJshofear]

Originally posted by jprinesho:
Are there any stock 17" rims that will fit a sho? (That you could find in a junk yard or cheap somewhere) I've heard some volvo rims will fit. I need 17" rims to clear my front rotors.

how much u looking to spend?

 

[94shoboy]

Originally posted by DeaconBlue:
I understand the TireRack carries some fairly light weight wheel comp rims for the Taurus fitement now. The ASA JS5 rims in the 16 x 7.5" with 225/50-16 Kumho V700's
weight in at about 38 lbs each per Sergio P. That's about 4 lbs lighter than the stock 215/60-16 tires on the 6" wide slicers, not too shabby.

whats the point in spending all that money just to go to a lower profile tire, only gaining 10mm width of tread and staying with 16s? the 18s i just bought weigh in at 21pounds each, that a pount lighter then my 17s i am selling.

 

[drivinhard]

One thing to remember, is rotational weight. Ie, how close the weight is to the centerline of what's spinning. A smaller wheel keeps the weight of what's spinning closer to the centerline, reducing the centrifugal load. This is why, for instance, a same weight 14" wheel and a 17" wheel, all things being equal, the larger wheel will have less wheel hp, due to centrifugal force. Same idea as x amount of force out on a 6" ratchet, and the same force 16" out on a ratchet. Same applied force, the latter will produce more force at the centerline.

The above 225/50 16" set up provides better "gearing" and keeps it's weight (sub 40 lb) closer to the axle centerline (more wheel hp).

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White 92
SR71SHO - racer '89

 

[AutoXSHO]

Why spend money to go to a wider, lighter wheel? I would ask why bother going to 18" wheels, with the significantly more expensive tire cost and higher rotational intertia.

In terms of autocross, the SHO is fairly competetive when properly prepared for STS. Maximum tire width in STS is 225mm and maximum wheel width is 7.5". Does that answer your question? In the future I would like to run something in a 17" wheel, 7.5" wide, with 225/50-17" Bridgestone SO2s for summer/autocross use. This keeps almost the exact same height as the stock tires so the speedo is still correct. If anything it is slightly shorter (improving gearing). The wider wheels provide a performance benefit by giving more sidewall support. In all honesty running 225mm tires on 6" rims is pretty miserable.

Going to a plus two size is, IMHO, overkill for autocross. My personal opinion is that 18" rims look a bit gaudy.

JV

 

[94shoboy]

i understand rotational mass. i just don't like the smaller 16s, i understand that the smaller wheel is better for racing, but damn it looks sooo small on the sho. i personally just like the 18s, i think the looks depend on the wheels, my anthracite i am selling just look small, even compared to the slicers. thats why i went to an 18, that and they are lighter and look better. well, as most things i guess thing comes down to a matter of opinion of bigger wheels.

 

[thebigjimsho]

If you look to get specialized wheels/tires for autocross only, you're better off going with 16" rims w/225/50 race rubber. Less weight, rotating mass is closer to the hub and with the overall diameter, those suckers can get up to speed quickly!

 

[AutoXSHO]

Except that the increase in sidewall stiffness of the 17" tires provides a performance increase on most cars. 18s will provide benefit as well, but not as drastically as switching from 16's to 17's.

JV

 

[Diameg]

AutoXSHO,

Why is running 225 tires on a 6" wide rim miserable?
Is it miserable because there are problems, poor performance compared to stock, or poor performance compared to wider rims?
I was considering getting 225 tires. The only Autocross and track stuff I would do are for fun with the local club, so it's not like I'd be trying to gain every little bit I could. I would prefer better performance than stock though, but retain my slicers.
Should I avoid 225 tires on stock rims like the plague or was that just your observation from a performance minded aspect?
Thanks.



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Mike

94 MTX (Rare Green model)
Hi Flow Y-Pipe, Dynomax, UDP's, 80mm MAF, K&N panel, Ted B LPM.

 

[sho_dwn]

I run 225/50ZR16 on my slicers and love them. They are Dunlop SP8000s. Before them I had Yoko A520 of the same size, but they wore too fast for my wallet. I have had no problems with this width on the slicers and they handle much better than the ole' basketweaves and 215/60s ever did.

Alan

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1989 SHO
80mm MAF,UDP's,y-pipe,
NOS,Warlock muffs,slicers
[email protected]

 

[AutoXSHO]

I run 225/50 on slicers as well. It can be done, but that tire is 20mm too wide for that rim. The sidewall is not supported tremendously well, so it's best to get tires with very stiff sidewalls.

The solution is to get a rim that's the proper width for a 225 tire - 7" or wider.

John V

 

[ThrillSHO]

Generally speaking, the criteria for selecting wheels and tires for track use is different than for street. That being said and since the topic says "race" here are some observations:

1. True competition tires (not high performance street tires) are not available in many 17" and 18" sizes and those that are available are quite pricey. In contrast 15" and 16" tires are available in almost every imaginable width and aspect ratio at reasonable prices.

2. For autocross, wider is not necessarily better. A narrow tire will heat quicker than a wide one; and a hotter, stickier tire works better than a warm one. Keep in mind that autox courses are usually around a minute. Not alot of time for a tire to heat up.

2. Conventional track wisdom says - run the widest wheel you can, then select the narrowest tire that will fit on that wheel. This keeps the tread as flat as possible and provides maximum support for the sidewall. A 225mm (8.86") tire on a 6" wheel will not sit flat on the track and therefore reduces the effective working width of the tire. You can easily confirm this with tire temperatures - the center will be much hotter than the edges. I have run 205s (8.07") on 8" wheels with much success. Definately not a combo you'd see on the street, but very effective on the track.

 

[DeaconBlue]

Another way of looking at it is the ratio of rim width divided but section width. The higher the number, the better the handling, within the maximum manufactures limits on rim width for any given tire size. Anything over 0.8 is very good.

I run a 245 tire on a 8.0" rim. The ratio is 8.0 / (245/25.4) = 0.829. If I were to drop down to a 235 tire (still with the same 45 aspect ratio) for better gearing, the ratio would be 0.865, even better.

A 225 tire on a 7.5" rim is 0.847 very good, while a 225 tire on a 6.0" rims is only 0.677, not good at all. Maybe this is why the SCCA Solo II (Autocross) limit for STS/STR is 225 on a 7.5" rim.

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95 MTX
with a few mods

 

[thebigjimsho]

Originally posted by AutoXSHO:
Except that the increase in sidewall stiffness of the 17" tires provides a performance increase on most cars. 18s will provide benefit as well, but not as drastically as switching from 16's to 17's.

JV

If you are not an experienced racer, you can run into a problem by running 17 or 18in wheels at the track. With BFGoodrich R1's, you will notice the sidewall is unbelievably stiff. 225/50 16 will give you enought tread to "feel" when you are about to lose traction. Going to lower profiles will make it much more difficult to feel that limit before breaking free. Like what's been mentioned, go with a wide wheel and not so wide tire. Also, sticking with a 16in wheel still gives you a little sidewall for increased feel. I feel this tire size gives you the best chance to succeed at an autocross.