Wheels, tires and brakes.

[TomsGarage]

17x9's on all 4 corners.

These wheels are xxr 17x9.75 +25
245/40/17 fronts
275/40/17 rears

With 50mm bolt on spacers on the rear. The car has 4x100 normal civic size hubs.

http://www.arielatomchat.com/forums/thread1176.html

This is around the size I plan on running. 350whp/420wtq is gonna need a lot of rubber. What are your thoughts on staggered rims?

 

[northvibe]

I did see some talk that recommended tires with a 200 treadwear or less for the best traction on these light car.

The R888 are 100 treadwear and considered a track or autox tire, but Atom guys were running them on the street.
A guy said they kick up a lot of rocks so be sure to have your fenders on. Oh, and that if you encounter rain, the grim reaper will be staring you down in your rear view mirror. LOL

Can confirm, running R71r's on my daily LNF and it sucks...

 

[PHerder]

Also remember the Goblin only weighs ~ 1500 lbs., not the 2500+ that the original Cobalt is at. Too hard a tire will NEVER wear out and will not give you ANY traction.

I was running a "normal" tire on my Stalker and found that I was all over the place on the road, never mind the autocross track. Was taken aside by another racer and was told that 140 TW would probably last as long on the Stalker as the original tire lasted on the S-10 pickup (original Stalkers were built using a S-10 as the donor) and due to the much lighter weight, I should be running a lot less pressure in the tires. The ratings (i.e. 32 psi) was for a vehicle that weighed ~3500 lbs.

The fenders on the Stalker were little use when running 13" x 10" RR slicks. One area the Wichita SCCA ran at was a sandy parking lot. It looked like I was running in a sand storm and if I wanted to have a passenger, I would have to have them wear a full face helmet due to the amount of "stuff" being picked up and thrown around. The workers also hated my car when it ran due to the "stuff" I was throwing around. They gave me a WIDE buffer. Also it was a mess to clean after an event. Sand, pebbles, etc. all covered the interior!

 

[rallyracer]

Yea, the Atoms running on R888 have the tire pressure set at 18psi front, 20 psi rear....according to the owners manual.

 

[rallyracer]

From an email chain with Adam around the end of March. I was looking at SS donors at the time, so this info is for SS donors.

-------------
""We aren't going to use the big brakes on any of our cars and don't recommend them on everyone else's cars. Since they are designed to stop a fully loaded Cobalt SS at a track, they are overkill for the Goblin. On the original P1 and P2, we use the stock rotors all the way around but when we rebuilt P1, we decided to use a rotor in between stock and SS on the front of the Goblin. We really like how it balanced out the braking front to rear.

So instead of supplying base model rotors (10.08 inch diameter) with the kit for the front of the car, we are supplying the smallest 5 bolt front rotor (11.02 inch diameter). It uses the same caliper but it is mounted further from center, increasing front brake force a little bit.

On the rear you will use stock Cobalt 10.08 rotors. With 11 on the front and 10 on the rear, you end up with a great balance without a bias adjuster. Since you don't have stock brakes to put on the rear, they will have to be purchased (you can get them cheapest from RockAuto.com: http://www.rockauto.com/xx/cart/?cartid=0df4030809368b14ef9ae7eb7f6c79e0.

We didn't make this very clear on the website because we've been figuring out the SS stuff as we went. Now that we've figure out that extra calipers have to be purchased, custom shifter cable mounts have to be fabricated and other changes must be made, we've raised the price of the kit when using SS donors (you can see this change on our site).

On the SS cars, we are recommending the wheel bolt pattern be changed to 5x114 so that finding wheels is possible. We can redrill your rotors and change the studs in your hubs (you'll have to send your hubs to us).""
------------

Hope that info helps and is still correct.

Quoted you to this thread to help keep some info in the right place to be found.

Thanks for this info. I figured something was up as I keep hearing different things. The image in the first post on this thread shows what the Atom's are running. The standard package is with the single piston Calipers and the upgraded brakes use 4 piston. Even Clarkson in his Top Gear video said to be sure and opt for the race brake package. Maybe the setup the DFkit is going to run will be just fine, but I'd not want to find out the hard way coming in hot into turn 5 at Road America

 

[smithvmi]

Well I always try to keep in mind, this kit is engineered toward a compromise of cost and performance. I'm sure they could have made an inboard suspensioned, race brake-equipped, fully aero'ed ST1-classed monster, but then its not an 8-10K kit anymore, more like 15-35k.

You can always upgrade your brakes later, but I think its good to start with smaller brakes, especially with no ABS or TC. They did say the bigger SS brakes were too grabby, which might lead to a lot of front-end lockups into turn 5 at RA.

 

[TomsGarage]

Well I always try to keep in mind, this kit is engineered toward a compromise of cost and performance. I'm sure they could have made an inboard suspensioned, race brake-equipped, fully aero'ed ST1-classed monster, but then its not an 8-10K kit anymore, more like 15-35k.

You can always upgrade your brakes later, but I think its good to start with smaller brakes, especially with no ABS or TC. They did say the bigger SS brakes were too grabby, which might lead to a lot of front-end lockups into turn 5 at RA.

I will be running the SS/TC brakes on mine. True that they are probably overkill, but I would rather have more brake power for track days. They haven't tested the SS brakes yet, but said that they might get around to it. I will also be trying to implement ABS/TC to see if that might be beneficial on wet/slippery days.

 

[rallyracer]

I will be running the SS/TC brakes on mine. True that they are probably overkill, but I would rather have more brake power for track days. They haven't tested the SS brakes yet, but said that they might get around to it. I will also be trying to implement ABS/TC to see if that might be beneficial on wet/slippery days.

I believe the smallest wheel you'll be able to run up front with the Brembo SS/TC brakes is a 17", that's designed for big brakes.
You probably already know this, but may be helpful info for someone else down the road.


Now to run ABS and TC, you'd need SS/TC hubs up front too, and I'm not sure what hubs there custom knuckles are be designed for.

 

[TomsGarage]

I believe the smallest wheel you'll be able to run up front with the Brembo SS/TC brakes is a 17", that's designed for big brakes.
You probably already know this, but may be helpful info for someone else down the road.


Now to run ABS and TC, you'd need SS/TC hubs up front too, and I'm not sure what hubs there custom knuckles are be designed for.

Yeah I'm planning on around 17x7 for the front, 17x9-10 in the rear. I was told that the SS hubs will mount up just like the non SS ones.

 

[Lonny]

We use the OEM rear hubs from our donor cobalts as front hubs on our Goblins.
The bolt patterns on the knuckle side are the same for all cobalts. The hubs that have a speed sensor plug will not clear our steering arm.
If someone wants to try using factory ABS and TC they will need steering arms with more clearance.

 

[BAR-AIR]

Just my uneducated opinion but wiring the ABS/TC would be a challenge. Actually getting it to work properly would be a nightmare. First the weight difference between the factory Cobalt and the Goblin, then would come the weight distribution differences (which sensors would you mount where, front stay in the front or move to the back with the front suspension?). Then just the space to put it all in the Goblin and a lot of extra room to play with.

 

[Jungle Gym]

How would the weight and weight bias be of any factor? All the abs and tc does is compare the speed of each wheel to the rest and make adjustments accordingly. The brake proportioning valve is what will determine brake bias, but that's a fixed value. To change the bias ratio, you'd need an aftermarket adjustable proportioning valve.

 

[Lonny]

You will likely need to adjust the sensor ring inside the wheel hubs on either the front or the back to allow for unequal tire circumference or it may think you are experiencing tire spin all the time.

 

[rallyracer]

Saw this, thought I'd share.

"Just wanted to make this post to say how thankful I am for Enkei Wheels. I run their RPF1 for track and time attack. This weekend I was trying to break 1:40 at Laguna secato best my 1:41 lap time. I cut the apex at turn 6 a bit too hard and too soon and hit the inside red curb (that tactic only works in video games) lol the curb is actually raised off the ground and can cause serious damage, which is weird because the regular apex line comes within 6 inches from the curb.


The Enkei wheel shown took a direct impact on the curb at 110 mph. Did not shatter, etc. if this were a cheaply made wheel it would have probably cost me my evo, and possibly more.

I will continue to endorse Enkei wheels as they have proved themselves time and time again. I will take this over a catastrophic failure any day. Time to get the car back together and break my PR."

http://www.mx5nutz.com/forum/index.php?showtopic=244810

 

[kalishek]

In case anyone is interested Flyin' Miata, 949 Racing, and other Enkei Wheel dealers are having a close out sale on 15x8 & 15x9 four and five hole silver wheels with machined lip as it is being discontinued.

 

[rallyracer]

TR-42 kit car.

Wheels:
18x9.5 ET22 FRONT
18x11 ET25 REAR

AdaptitUSA adatpers (standard thickness. 1.3" I believe)

Tires: Toyo R888
275/35/18 FRONT
315/30/18 REAR

 

[rallyracer]

Lonny's 2010 Turbo SS

WHEELS: ????
16x? ???? FRONT
17x? ???? REAR

TIRES:
205/45/16 FRONT
245/40/17 REAR

 

[rallyracer]

BAR-AIR's Cobalt LS supercharged.

WHEELS: - Rota V
15x7 with 15 offset + 3mm shim FRONT
15x8 with a 0 offset REAR

TIRES:
Kumho 195/50R15 FRONT
Kumho 225/50R15 REAR

He had clearance problems with the calipers up front. Ended up re shaping the caliper and adding a 3mm shim.

If he did it again, probably would have went with 16's in the rear there are a lot more tire choices with the 16's.

 

[smithvmi]

Wheels:
18x11 ET25 FRONT
18x9.5 ET22 REAR

AdaptitUSA adatpers (standard thickness. 1.3" I believe)

Tires:
275/35/18 FRONT
315/30/18 REAR

Toyo R888's

You sure its not 18x9.5 Front and 18x11 rear?

 

[rallyracer]

You sure its not 18x9.5 Front and 18x11 rear?

Thanks! Yeah, I was still trying to clean a few of these postings up. I hope to get most of the cars posted up as they come. I think it helps to have these other kit cars up as well for inspiration, as we don't have much to go off of so far.