'95 Civic EX Coupe running in ITA. I'm looking for ways to increase cornering grip. I'm currently running 205/50-15 Toyo RA-1's on 6.5"x15 Rota Slipstreams. The coilovers are Skunk2, I think 10k up front and 8k in the rear (it's whatever setup comes for the 2001 Integra I used to have, and they fit, so I'm using them), and AGX adjustable shocks (don't flame, I know these are totally unacceptable for racing, just haven't gotten around to doing the GC/Koni setup yet.)

I've got the car lowered to the minimum ride height (5" to the rocker panel), and only have about -1.5* camber up front (not sure what the back is). I was researching my Toyo tires the other day, and discovered that they work best with between -2.5* to -5.0* camber. Not to mention I think I've been running them at WAY too low a hot pressure (35-37psi, where I've read their optimum hot pressures are around 40-42psi).

Anyways, back to the camber issue. I've read the rules. You can slot the upper mounting points if it's a MacPherson strut, but that's not what I've got. Eccentric bushings or shims are the only things I'm allowed to use, per the IT GCR. So:

1. Are adjustable upper ball joints for the fronts legal, and is this an acceptable way to decrease camber on a track only car?

2. How would one "shim" more negative camber into a double wishbone suspension such as mine?

3. I spoke with Lyonel Kent's wife a few years ago, regarding eccentric delrin bushings, which they were having custom made for them. Is there someone out there now making these as a stock item, and if so, who?

Tangent question: Can I run 225/50-15 Toyos on my 6.5" wide rims, or are they just too narrow?

Oh, and if the numbers I've posted in my first paragraph are incorrect info, please set me straight. I don't recall exactly which website I got that info off of, but I think it was from 1010tires 'dot' com.

TIA

 

Adding grip- I would start with a tire from Hoosier/Hankook/Kumho. ie R6/C51/V710. Those are all stickier than the RA1. Get it in a 225-width, with whatever offset/spacers are necessary to make it work.

Shock- lose the AGX. They just don't have enough rebound control for a stiff spring, but at the same time they have a good bit of high-speed bump. They're not a bad shock, they're fine street shocks, but they're not ideal for most roadrace or autox applications.

As for your actual questions-
1. adjustable upper balljoint a la SPC would not be IT-legal. Additionally those take up suspension travel. I don't know if your fenders are flat above the UCA like a EF Civic/CRX, or if they have a bump in them like a DA Integra. The control arms will bottom against the body in the former, where in the latter you have more clearance. For a flat fender, the adjustable ball joint takes up more real estate and you'll bottom against the fender sooner than you do now.

2. To my knowledge, you can't. You could gain a little by loosening the UCA-to-body mounts, yank them in, and retighten.

3. Try OPM Autosports for the eccentrics.

You CAN run a 225 on a 6.5" wheel, though a 7" would be better.

 

This is an eccentric bushing:

http://www.jazzproparts.com/Eibach_C...its_s/2613.htm

 

With the shim placed between the shock tower and the UCA subframe bushings. I think doing so would be more detrimental than beneficial, since it would change the camber curve, RC location, other stuff I'm not aware of, etc...

Bend the knuckles. No illegal parts that way.

 

wouldnt bending the knuckles also change the camber curve and etc?? and wouldnt shimming it be more accurate than bending the knuckle??

 

No then yes, respectively.

Bending the knuckle won't change its length much, nor the angle of the control arms much, but will change the angle of the hub relative to the chassis. No pivot points are relocated.

Using a shim there will be relocating the UCA pivot point down. This changes the suspension geometry.

Which is legal to do though?

 

I can't quite figure out why these are not legal. Don't they use an eccentric to move around a stock type ball joint?

Or at least any more illegal than the UCA eccentric bushing. Those change the locaton of the stock pickup points, correct? I know you can not do that.

 

And I can certainly vouch for sliding of offset ball joints destroying available suspension travel.

I ran with flushed tires with stock UCAs, and only bottomed out occasionally. With SPC sliding UCAs and raised to a "2 finger gap" I bottom out regularly, only this time its the UCA introducing itself to the shock tower instead of the shock fully compressing the bumpstop. I have dented shock towers, both sides.

I can't speak on rules. I'm only a lowly autocrosser.

 

Thanks for the discussion, guys. It doesn't sound like there's a readily available, IT legal way to do this. I'm thinking about making my own delrin bushings with an offset hole that would replace the upper control arm onboard pivot (since bushings are openly replaceable in the IT ruleset). I think the change in geometry would be minor, since the lower pivot points would remain in the same location, but I need to get in there with some measure devices and see just what can be done, and how much offset on the hole will change the degree of camber by how much, etc, etc.

Good food for thought, though. I was hoping enough people had done this for Honda's in IT that there might be something off the shelf, but I guess it's to McFadden-Dale's and my friend's lathe I go.

 

Not so much "offset" per say, but would a sliding busing be legal?

 

I don't believe so, under the "if it doesn't say you can, then you can't" rule. I don't see anything in the ruleset that talks about "adjusteable bushings", unless it falls under "bushing material", which is unrestricted.

I just looked at the suspension section of the ITCS again and in section D.5.d.2 you've got this rule:

"2. On other forms of suspension <not MacPherson strut>, camber adjustment may be achieved by the use of shims and/or eccentric bushings."

and then for the rear, it says this:

"4. Independent rear suspension mounting holes may be slotted and reinforced for purposes of camber and/or toe adjustment. Material may be removed from the top of the strut tower to facilitate installation of adjuster plate."

#6 says bushing material is unrestricted, and #8 says no other relocation or reinforcement of any suspension component or mounting point is permitted.

I'm reading this as, I can slot the rears UCA to Shock Tower holes (and upper shock hole) to increase negative camber in the rear, but not the front, since I don't have Macpherson struts.

I think #'s 2 and 6 make it pretty clear that I can have delrin bushings with an offset hole machined for both front and rear UCA's to acheive a static, non-adjustable increase in negative camber (and I now know someone that can make them for me), and I don't believe it defies #8, as the mounting point (i.e. UCA to Shock Tower attachment) hasn't changed. Now, I just need to take some measurements from my current setup to determine what increments of offset will affect increments of camber. Once I figure this out, I might have several sets made with different degrees of offset to be able to try different camber settings to see what works best.

I'm curious, though, about the effect offset bushings will have on the suspension geometry, as it will change slightly. I think there is a way to adjust camber with offset bushings, and maintain the current geometry, but it would involve changing the length of at least the upper control arm to compensate, which isn't allowed in the rules, so it's not an option.