lt1z350

iTrader: (2)

Maybe got new wheels and found out needed another back spacing for that size or didn't like look on the car and now see these. Just looking for some help. 1992 formula I am totally changing around all tube framed suspension big ctsv brakes so the cross lace I really like won't fit now. So in an 18 to fit the big brakes looking for an open style lighter side type wheel. Like the forgestar f14 look or esr sr01. Just one area I am not very familiar with on these cars and know a lot of guys have done the homework I need to do. I build transmissions for a living so like to give back maybe need help have a question so trade up info since some guys like to say go use search button which I have just looking for opinions more then anything. Thanks

paul_huryk

Depending on the wheels and brake system, 18" may be too small to work for you too. Anything over 14" brakes is just overkill (you won't ever have enough tire to exploit them) and those can be fit under 17" wheels.

lt1z350

iTrader: (2)

Guess l should have put in question I just put ctsv 14 inch setup on the car and why I am looking for rims now as I was fine with my stock web style wheel.

paul_huryk

You may face the dilemma of not having enough 3rd gen specific options to make you happy with the design of the wheels.

What are the exact specs of the brakes?

Chuck!

I have the 4 pot CTSv breaks and run TSW Nurburgring. They have a 18x9 +50mm offset and the correct 120.7mm bolt pattern. There are not a lot of choices with the right offset and bolt pattern unless you go custom.

lt1z350

iTrader: (2)

Yea finding that out. From what I read on the forum 18x9.5 15mm-20mm offset gives the 5.5-6.0 back spacing the car needs. Of course corvette 4th gen camaro and bmw all run a larger 22mm-40mm offset where a spacer is needed to make them work and see plenty of options there. Why I started this thread for guys to tell me well I am running this rim size and spec with a spacer but know now should have went this route and so on. Or I got this rim and now know this model looks the same but 5 lbs lighter and only 50 bucks more. There are 100s of similar models looks for anywhere from 75 each to 500 each. Some 15lbs some 26lbs and price doesn't always lead to a good wheel. Some garbage is just expensive. Found some brands in forged that are very affordable. Just wanted some opinions and examples and no one is getting on board. It is one a 800rwhp car so I need some tire under it now that brakes are covered with the 2004-07 ctsv brembo 4 piston calipers and 14 inch rotor up front and 14.5 in rear. They are actually 2010 camaro ss rotors. I got the brackets from bigbrake.com Scott is great to work with on this stuff. Just got to get wheels now that are light strong and look good with that brake setup on a formula. Rims is now becoming the hardest decision I have made on the car. Easier to look at someone's car and say that looks sweet and copy it. I wouldn't if lived around me but being most of us don't here I see it as a compliment to copy a guys wheel or look.

lt1z350

iTrader: (2)

I am finding now some of the places that sell wheels on eBay will custom do a set with your offset. I just don't know if a 24lbs wheel is considered a heavy rim or not. I see some are 17lbs most that light are 300 each and up. Seems like the bmw rims are very available but not all will fit. Found a place on eBay that whas esr sr01 in a 18x9.5 22mm offset which is pretty close and a good looking rim 23lbs each. Waiting on a member that has some for sale apec arc8 like the look just waiting to see what he wants. 10.5 in rear and said will have to hammer a little not sure what a little is though. Lol

BrianChevy

I have done lots and lots of homework on 18x10 front / 18x11 rear Forgestar F14's and I have placed an order, they will be in within 3-4 weeks and I will report back here with a full writeup. I expect they will be very very close and might need a 2 or 3MM spacer to be in the "nice" range. yes, this is very hard fittment and every car is a little bit different, but I will be sure to share my experiences and mods that are needed to make it work. There SHOULD be a less expensive lightweight wheel for our cars, i'm trying to PROVE that.. More later!!!

lt1z350

iTrader: (2)

Are you running a coil over up front? I got that setup since went all tube front end arms k member and didn't want to put the factory style coils back up under it since a coil over seemed like a much better option. Didn't think about how it limits the tire adding to diameter of the strut. Seem so many with huge tires road racing with cool overs didn't ever consider it until someone brought it up. What offsets did u order? I was thinking 20mm -22mm to get away with no spacer making it 5.5-6 inch back spacing.

lt1z350

iTrader: (2)

I was pretty hell bent on going forged due to strength until started reading about guys that drift these ls powered 240z and they abuse the hell of of the wheel and tire hit stuff bumps in roads and parking lots smack walls and most run a light cast wheel and don't have any more issues then a forged doing that with them. Guess new casting techniques have come a long way and stronger now. Finding pretty light stuff in a pressure form cast I think is what I read that adds strengths and not the big cost like forging. Enkei has some raijin forged wheels that run 250 each and are pretty light 23 lbs for 18x9.5 so very reasonable for a forged wheel and looks good similar to a forgestar f14. I looked at a gt500 we had in the shop yesterday and had 255/40/18 fronts and 285/40/18 rears and I liked the look. Tires up front were a little narrow for the rim and think they are 9.5 for factory wheel on that cobra so maybe a little more tire up front of a 9 inch rim.
I started this quest due to these big *** brakes and not to put a huge tire on it but now want the look and going for a touring theme on the car daily driver that is track capable. Last thing I want to do is drop all this on a rim put it on the car and not like it.

paul_huryk

9.5" wheel with 5.25"BS is 0mm offset. Every 6mm added to that is going to be another 0.25" BS. 25mm is going to be 6.25" BS as an example.

If you are talking 3rd gen specific offsets, a 18" x 9.5" wheel that is 23lbs is pretty good. Some BMW specific wheels may weigh a bit less due to the weight advantage of their offsets.

In terms of size, go no narrower than 275 (on the right width wheel), 285 and 295 will also fit on the right wheels. Wider is going to give you a big advantage in terms of braking and cornering ability.

BrianChevy

i have been running 275 on all 4 corners for years and years with no issues on 16x10 real race wheels.. This bigger wheel and tire combo should be much better out back. As far as what I ordered, i had do so some things to make sure the front hub could clear, so please don't copy my configs until I confirm they will work. IF they work, i will post a lengthly writeup on 18x10 wheels and give everybody the configuration so that lightweight 21 pound cast wheels can be ordered for $1600 (that is what I paid).

I have done a lot of research on Forgestar, the NEW compound they are using and the NEW materials have a much higher load certification than the 2012 wheels which had a higher failure rate. I am told that they've had no failures of 2014 or newer wheels due to racing loads. we will see.

As far as the Enkei commments, i agree whole heartly, we wanted Enkei because that's what we run on our Subaru racecar, but Enkei won't do a Chevy bolt pattern (i have asked many and was told "not possible".). So this F14 solution is a proposed compromise.. I'll let you know.

paul_huryk

On a side note - we are gauging interest in CTW Motorsports 18" x 10" wheels for the 3rd gens - same design and construction at the 22 to 23lb/wheel weight target. The brake clearance should be able to swallow up almost any 15" BBK as we already get the largest 14" kits into our 17" offerings. Price would be in the $1,300 to $1,350 a set price point if it goes into production.

lt1z350

iTrader: (2)

Why not use the 5x120 that a lot of guys run the bmw pattern with enkei wheel. That is what I was looking into as they are mat forged and like 245 per wheel for raijin which I really like. Enkei actually recommended that I run a 5x114 wheel with a spacer that converts our pattern over to that rather then the 5x120. Just didn't think about it or didn't want to run spacers? They said go with 30mm offset then the spacer which is 1.5 or 2,I think. Just more to spend though and I am trying not to do

BrianChevy

Because I race my car and I don't do ANY spacers or things that don't fit properly. If a failure occurs it's NOT because I took a shortcut or tried to make something fit. 5x120 is NOT the same as 4.75inches, i don't believe in spacers (though some swear by them, I won't put my safety or my competitors safety on the line by bolting something 'almost' right. PERIOD.

I am very conservative about things in the garage, so that I can be very aggressive on the track.

Stepping off the soapbox.

EDIT: I certainly wanted to go with Paul's 18 inch solution, but it doesn't exist at the current time and I need wheels NOW. Thank you for supporting thirdgen.org Paul, good luck with that project, i know people will be eager to buy them.

lt1z350

iTrader: (2)

Some of that makes total sense. I will say though in dirt racing which has huge loads on the wheels I have seen centers break out we used spacers to change the stagger when didn't have the wheel we needed and never has issues. Also seen them on cars like corvettes and camaros when I walked the pits in Daytona during the 24 hour race. So that end it is safe if the product is well made. Honestly some spacers are stronger then the actual hub surface when compare the thickness of it.
I know the 120 isn't exact but so many guys do it on the street and just didn't know u were straight up racing. I haven't tried it so not sure if it is so close a trip to the Bridgeport can make it correct or not.
I really like that enkei wheel and wish is was gm specific. Not sure why a company that big wouldn't make them.

paul_huryk

Welcome to the world of high sales volume. If they can't sell enough to offset the development cost, warehousing, and marketing - they won't make it.

And not every GM specific wheel will fit every GM application - 3rd and 4th gens have incompatible offsets, which are the same f-body models. That is why spacers are so popular and useful...

lt1z350

iTrader: (2)

Yea guess I just like spending other people's money. Lol even to offer just the bolt patten and have it special made to order.
With what u said on spacers I am assuming your opinion on it is they are fine.

Base91

iTrader: (1)

like the sound of the 18 x 10s. Are they likely to fit with 2 inch drop spindles?

paul_huryk

Doubtful.

Drop spindles are a nightmare for wheel fitment - they move the tie rod the distance of the drop into the bottom of the wheel barrel.

The idea of drop spindles is good in theory, but it really limits wheel and tire choices. Performance-wise a set of 275-35-18 tires is going to give top-notch performance with the right brakes and suspension. Can't compete on a 245 tire, no way - no how...

lt1z350

iTrader: (2)

Wow good to know I cam so close to buying them just for weight loss and ease of brake install. Glad I didn't now.

paul_huryk

I wasn't trying to steer you away, but only to let you know what can happen with wheel & tire fitment.

If your primary focus is weight, go for it, some lightweight brakes, suspension parts and other items. If you are looking to put the max amount of rubber on the road (for handling and braking), skip them.

Beater79TA

Would love to see some thirdgen specific options that would fit a 275-25-18 tire.

But you can successfully compete on smaller tires. We've done pretty well this year running a 255-40-17 BFG Rival S tire on all 4 corners.

lt1z350

iTrader: (2)

I am building this up like a touring car I guess u can say. Something capable for it all. Fast quarter mile times and they have a drifting and road course here local and I have some big ones close too that would be fun to go to at some point. Just looking for an all around capable car tired of the drag race specific build they are never fun on the street. I have a 1994 z28 rotting in my garage with a full drag setup. Brakes no ac full cage 9 inch spool skinnys up front just not street friendly at all.

paul_huryk

A 3rd gen specific 18" x 10" would cover that.

We have collected some data from our CMC racing teams that run our 17" x 9.5" wheels (moving up to 275-40-17 tires from 255-50-16 ones) and they all picked up a second or more per lap. Pro drivers were in the 1 second range and less experienced ones were in the 2 to 4 second range as they could not consistently push their cars as hard on the 255-50-16 sized tires. So putting a 275-40-17 Rival on your car would be at least a 1 second reduction compared to the 255-40-17 ones you run now. In a 45 minute race, you might end up 1 lap behind...

Beater79TA

Except the largest BFG Rival or Bridgestone RE71 in a 17 is a 255-40-17. To go to a 275 I need to go to a 18 inch wheel and run a 275-35-18. The best 200 treadwear tire available in a 275-40-17 is the Falken 615K

kairles

iTrader: (2)

I want a set.

paul_huryk

The fact that there is no 275-40-17 Rival shows everyone how short-sighted BFG is - there are millions and millions of cars that run that size and are in competitive driving. Ditto for every other tire not in that size.

I have a set of the Falkens - they are really good, but probably not as grippy as the Rivals in the same size.

Beater79TA

I've had that conversation with both BFG and Bridgestone already. For events that get recorded and tire sizes looked at, no one runs a 275-40-17. But the argument can be made no one runs them because no one makes tires not that no one runs them because they don't want to run them. But unless lots of people call in asking for them and complaining, the size choices aren't going to change. It would also help if more 3rd and 4th gens needing that size ran events other than drag racing.

And having run practically every 200 treadwear tire available in a 17, the Rival S in a 255-40-17 outperforms the Falken 615K in 275-40-17 and lasts longer before grip does drop off. Nitto NT05's aren't even close in performance or durability to either.

paul_huryk

CMC is limited to a spec tire at 275-40-17 max, the next series up, AI can run a 275-35-18 as long as it is on a wheel that meets the minimum weight. Other racing series have different rules of course. 255-40-17 is a 3 series BMW rear tire (with sport pkg) and I'll bet that over the entire e46 run, less of those tires were mounted than a single year of LS1 f-bodies.

Think of the millions of 4th gen f-bodies and Corvettes that had 275-40-17 sized tires coming from GM - so their argument is BS. Then again, Toyo stopped making 255-50-16 race tires, even though there was a spec tire series that ran that size - the rules had to be changed for the tires. Also realize that the 245-50-16 tire is on its last legs - the 275-40-17 is a great option due to cost and road concerns (ride, damage, grip) - so there are probably thousands of sets of the Rivals in 275-40-17 to be sold yearly.

I've already contacted BFG regarding the Rivals and they blew me off. Typical corporate BS.

lt1z350

iTrader: (2)

So after sooooo much looking and advice I got the esr sr05 in hyper black. 18x9.5 front and rear and +22 offset front +35 offset rear. 20mm spacers all the way around and puts me about factory offsets. 265 35 18 front and 285 35 18 rear for tires as a friend has some nitto 555s cheap. Will post how it works out so to help others.

dannyboyemt

Thats a good looking wheel, i was also considering picking up a set for my 4th gen. Be sure to post up picks when u get them mounted!

lt1z350

iTrader: (2)

Yea I will. I picked up 285 35 18 rear tires bran new nitto 555s from a buddy for 150 for pair so couldn't beat it. Too big for his Sylvia and was stuck with them. Got 265 35 18 for front and believe this I found them 75 percent tread at a Salvation Army here local. Lol 40 bucks for both and excellent shape. They are a continental tire. So 200 in tires and was expecting over 600 easy so got lucky. Also they place I got the rims modwerkz on eBay already takes and cuts them from 120mm to 120.65 so they are correct pattern for 12 bucks a wheel so really can't beat that and not having to mess with cutting them and on a 4th gen no spacers at all as have bigger offsets then I got.