scottherbert

I've added a couple recent photos of the car with 285/30 x 18 Hoosiers on 10" wide rims. It's still not in full DSP trim because I'm only running Eibach ProKit springs and stock shocks. (Obviously, I've taken the Tire Rack windshield sticker off the car for winter - scraping snow off the windows.)

IMG_2894.jpg picture by sherbert3842 - Photobucket

IMG_3106.jpg picture by sherbert3842 - Photobucket

Scott

mongorat427

iTrader: (82)

With the converted hubs you can go back to 5x110 in a few minutes by changing the studs to the other holes.

spike

subd

Spank

Scott I would be very much interested in your adapter wheel combo. In SP we cannot change hubs so John's new hubs would be of little help.

If you can run a 10 inch wheel, could you not run a 10.5 and have it stick out further, we can always flare the fenders. I agree with you the 285 is the way to go if the balt is to have a chance, however I also think weight reduction needs to play a major role.

Please do share about offsets etc. I can see by the pic you have two huge spacers to work in conjunction with the adapter. Have you looked at putting the adapter closer to the hub and getting a different offset wheel?

Have you talked to John or the guys a Kodiak to find out what wheels would cost to allow 10.5 in for better fit with 285?

Have you looked into aluminum hat rotors?

I would love to hear what you have done. Of all the cobalt guys, you are the only one who has pushed to see what can be done.

I am assuming you have spoken extensively to John Powell. How did you come about your current spring rate, coil overs and droop or rake?

Have you looked at a front splitter?

Any problems with the computer and the wheels. John feels the car needs the newer HHR steering rack otherwise he feels there may be a problem with the larger tire, wheel combo.

To all following this thread. Learn from those who are doing like Scott, the other only talk, Scott is doing.

Allan

scottherbert

Scott

scottherbert

Just installed the front suspension cross brace -- Twin Sub Frame Bar - $129.99 : Rebel Auto Worxs.ca -- and it works like a champ.

The website says is fits up to 2007s, mine is a 2009 and it fits just fine on mine too (I was prepared to do modificatoins to make it work; mods were not needed!).

Not sure how much it will help, but it can't hurt, it's reasonably priced, and SCCA now allows it.

Scott

venom09

What kind of cornering G's do you get with that setup?

Looks nice, I like!

scottherbert

I honestly don't know. I haven't gotten the rear negative cambered yet and the only chance I had to run (the photos) it was 28 outside. The front slicks got up to 72 degrees after 6 runs, the rears got to 50 degrees (Hoosier A6s want to be at 110 degrees, at least, to work well) -- so the rear end was sliding around a bunch. I won't have a real feel until it gets a lot warmer around here -- maybe next Spring.

Scott

Wangspeed

iTrader: (2)

I'm jealous. Venom, Scott, Army, and Dave are all running big sticky tires. I'm on stock wheels, like Dave, and running 235 Nitto NT01.

I might try going up to 245, but I need more camber before trying that. I wish Rota made wheels for our stock pattern. I'm not brave enough to get my hubs machined, besides I already have 2 sets of stockers.

scottherbert

About the Sub Frame Brace, I removed is yesterday and took a grinder to the sloppy welds in the inside of the frame around the LCA bolt-in components -- I ground the welds down so the brace could mount flat againt the bolt-in components, painted my grinds black, and re-attached the brace. Now I'm happier about the fit.

BTW, I'm going to inform Rebel Auto Worxs that the brace fits more then just the 05-07 cobalts. It fits my 09 just fine, which means it also fits the 08s.

Scott

scottherbert

Just had the rear hubs shimmed -- both rear wheels are setting at -1.55 degrees of negative camber. The alignment guy also shimmed the rear calipers.

The spec from GM is -0.80 and plus + or minus - 0.75 -- so the most 'legal' camber I can have in the rear is -1.55 (exactly where it sits today).

I may get a chance to play this coming Sunday -- weather dependent (snow is being forecast).

Scott

JT-KGY

I wish hub change could fall under the comfort & convenience rule... sigh

jboogie

iTrader: (3)

Wasn't there a how to thread on this somewhere? Can't seem to find it.


Thanks for bumping this thread, one of my favorites.

scottherbert

I got six runs today on my 245/45 x 17 Hankook R2Ss, on 17 x 7.5 wheels (it was 12 degrees when I got there and it warmed up to about 38) -- so I'm saving the slicks for warmer days. I had 550 lb, 6" long front springs, 200 lb, 8" long rear springs, with a Hardcore rear bar, and -1.55 camber in the rear and about -1.2 up front.

There was still oversteer at speed (mostly due to the cold conditions) but by the last few runs, I could just stay on the gas through most of the corners and the rear end pulled through. Unfortunately, I could spin the fronts at will anywhere in 1st or 2nd gear so I didn't have as much pull as I might with slicks. Even so, it handles better than ever before!

Scott

jboogie

iTrader: (3)

So, what are your (and everyone elses) thoughts on the stiff bar/ soft spring vs. soft bar /stiff springs in an autox setup? I would think the stiffer springs wound put down the power better.

venom09

Niceee!

Did you take any pics? Or do you know the thickness of the shims he used. I fooled around with mine last week also

venom09

I never liked too stiff setups. You can over load a tire pretty quick when too stiff...

scottherbert

I had a friendly local tire/repair shop (that sponsors SCCA regionally) do the rear shimming. I told the alignment guy I wanted -1.5 to -1.55 negative (-1.55 is the absolute legal max by SCCA rules for the Cobalt SS) -- and he gave me exactly -1.55 on each side (he's a racer too). The factory spec - according to the factory manual - is -0.80, plus or minus 0.75 -- so if you add it all up, it comes to -1.55, which is where SCCA says it has to be.

When we first measured the factory stock rear setup, the car was sitting at -0.23 left and -0.60 right. He fiddled with shims until he got exactly the right about -1.55. So there's no way I could tell you what shims he eventually used. He did say he had to modify shims to work because there were none (out of the box) that would fit around the Cobalt SS rear hub bolts -- so he made mods to the shims - a little filing - to make it all fit.

I'm huge a fan of stiff swaybars and soft springs. However, since I'm running the really wide tire/wheel combo (285/30x18 Hoosiers on 10" wide rims) and the tires are outside the body line about 2", I have to run stiffer springs to avoid rubbing fender against tire. I posted some photos earlier of the car with the big wheels/tires, Eibach Prokit springs, and OTTP hardcore bar, and I discovered that I was rubbing rear fender against the slicks -- just barely, but enough to leave rubber layered inside the rear fender edge - not good.

BTW, the Eibach ProKits with stock struts and the OTTP hardcore bar is a GREAT street setup -- not harsh, very compliant, quite quick, and the car will still oversteer. It isn't what you want if you're only interested in 'slamming' the car, this isn't for 'looks', it's for performance, it is what you want if you're interesting in handling.

It also isn't a happy maintenance setup with the OTTP CABs because the amount of 'drop' on the LCA is much less than with the stock rubber bushings -- so you have to compress the struts to mount them -- a huge pain in the butt to do! It's such a pain that I've considered getting another set of LCAs with stock rubber mounts to use with the Eibach's -- it would be easier to change LCAs and struts than to deal with the strut compression problem.

But I didn't get the OTTP CABs for street use so I'm not complaining -- they're absolutely great for their purpose -- thank you OTTP!!!

With current setup, which I ran on an airport SCCA event two weeks ago, I ran 8" 200lb rear springs with the OTTP hardcore and 6" 550lb front springs - Konis front and rear -- cambered at -1.55 rear and about -1.5 front -- no tire rubbing at all. If you measure from the ground, across the wheel center, to the lowest part of the front fender edge, it's 26" -- about 1.5" of clearance between slick and fender. If you measure ground to rear fender edge, it's about 1/4 to 3/8" higher (remember, softer rear springs) -- about 1.75" clearance. I've had no tire rubbing so far. It's lower strictly to get the roll center down as low as possible -- to keep the car as flat as possible -- to keep the slicks as flat as possible -- to get the most possible traction for cornering, accelleration, and braking.

I'm planning to get a set of 6" 650lb front springs to experiement with before this coming year. Various of the racing Cobalts have run springs as high as 1000lbs - most of my fellow SCCA racers in DSP are running springs in the 650-850lb range.

Scott

venom09

With current setup, which I ran on an airport SCCA event two weeks ago, I ran 8" 200lb rear springs with the OTTP hardcore and 6" 550lb front springs - Konis front and rear -- cambered at -1.55 rear and about -1.5 front -- no tire rubbing at all. If you measure from the ground, across the wheel center, to the lowest part of the front fender edge, it's 26" -- about 1.5" of clearance between slick and fender. If you measure ground to rear fender edge, it's about 1/4 to 3/8" higher (remember, softer rear springs) -- about 1.75" clearance. I've had no tire rubbing so far. It's lower strictly to get the roll center down as low as possible -- to keep the car as flat as possible -- to keep the slicks as flat as possible -- to get the most possible traction for cornering, accelleration, and braking.

I'm planning to get a set of 6" 650lb front springs to experiement with before this coming year. Various of the racing Cobalts have run springs as high as 1000lbs - most of my fellow SCCA racers in DSP are running springs in the 650-850lb range.

Thanks for sharing Scott!

Dart_SI

iTrader: (1)

good thread. this is also one of my favorites.

im going with some bigger wheels as well.

vannstoen es 2.2.1

18X9.5 with a +30mm offset custom drilled to 5X110 bolt pattern. havnt ordered yet due to a backorder but im pretty much set on them. pic:





my only worry is wondering if they will clear the brembos. everything else should be fine tho, except the center bore i believe, which is an easy fix. btw, whats the hub bore on the LNF?

the wheels have a concave look to them, so it appears that it will clear the brembos. also seen a picture of the same wheels on an evoX. those cleared brembos but had a +12 offset.

any help would be appriciated. im learing a whole lot about wheel fitment lately.

jboogie

iTrader: (3)

I would be very concerned with the way those spokes curve about the brake clearance

08ssedan

iTrader: (1)

Are 245s too wide to run on stock tc rims?

madcitySS

iTrader: (4)

i run 235 star specs, and i plan on going with 245-35 r-comps.

Dart_SI

iTrader: (1)

what about the curve looks bad for break clearance? i really want these wheels, lol, just hope theyl fit, but yea, brake clearance is a huge worry. these would clear with a +22mm offset but thats just too little offset for me. (they clear 350z and genesis coupe brembos with a +22mm offset)

jboogie

iTrader: (3)

Just the way they curve in at the outside. That's just a heck of a gamble but, they do look good.