SCCA Solo C Street Discussion

[Briankbot]

Originally Posted by Shark_Bait88

So I installed my OEM crash bolts this weekend and took the car in for an alignment.

While the tech was working on it he found something kind of interesting. The left front wheel was able to be adjusted up to -1.3 degrees of camber, but the right front would only reach -.8 degrees of camber (although it could be adjusted the other way to +1.3 degrees).

Both wheels got set at -.8 degrees to match each other, but I'm just curious why there was such a discrepancy in how much the two could be adjusted. Any ideas?

It's possible your front sub-frame is slightly off center...

[markw]

Originally Posted by renfield90

Manufacturing tolerances and dumb luck.

If you wanna go HAM on front camber do this:
Loosen both strut bolts
Loosen the three nuts on the top hat of the strut
Place a jack under the brake rotor and jack it up a little
Take a 5lb mini sledge and smack the strut assembly inwards several times
Retighten the three nuts on top, then the two strut bolts, then remove the jack

Not responsible for anything you break

4lb dead blow works too. I just jacked the rotor up and tightened them down. 1.25 and 1.5.

[G_Ride]

Originally Posted by Shark_Bait88

I think I'll just stick with my -.8 degrees. lol

Wuss....

It does sound like sub-frame is off center, though.

[Shark_Bait88]

Originally Posted by G_Ride

Wuss....

It does sound like sub-frame is off center, though.

Lol.

So is the only way to correct that to take a sledge to my strut assembly?

[markw]

Originally Posted by Shark_Bait88

Lol.

So is the only way to correct that to take a sledge to my strut assembly?

Loosen, pry/tighten sub frame.

Loosen top of strut and push it inboard then re-tighten.

Couple of ideas.

Or like they used to do, put the car on a frame machine and pull the towers in ever so slightly.

[renfield90]

Here's the full review.

Old setup:
225/45/17 Rivals
Kosei 17x7 wheels (spaced to 42mm offset)
Crash bolts
OEM shocks
OEM springs
OEM rear bar
Hotchkis front bar (full stiff)
K&N air filter
Muffler delete
Hawk HP+ brake pads
Lotsa stickers, for all the haters in 5.0 stangs

This setup suffered from corner exit push, as you can imagine, but the car could slalom at godlike speeds. Some of the bigger slaloms would turn into straightaways with little to no lifting to get through. The corner exit problems really required you to plan ahead for any sweeper, but also allowed you to get on the gas sooner.

New setup:
TRD springs
TRD rear sway bar
Everything else unchanged

Technical info:
New spring rate: no clue. I do believe this is the Eibach Pro Kit with a rebadge, this picture here (http://www.phasteksport.com/2013-FR-...-82105.140.htm) is exactly what I received down to the shape of the new bump stops, which say Eibach on them. Assuming they are pro kit and that this page (http://www.ft86club.com/forums/showthread.php?t=8739) is accurate, that makes them ~200lbs/in front and ~274lbs/in rear. The rear looks progressive, but the tighter coils are meant to be dead coils and the spring acts fairly linear when installed.

Ride height drop: I have good reason to believe the front of the car dropped slightly more than the rear, resulting in a closer to 50/50 weight distribution than before. I have not weighed the car to verify, but I do remember seeing somewhere mentioning slightly different drop amounts (can't find it right now).

Rear sway: roughly 2mm thicker. Not a huge improvement but girth matters.

Impressions from the street:
Street testing was done with old, heat-cycled out Rivals at less than 1/32" tread remaining. You can imagine how much tail-out action you can get in first gear with tires like these (professional driver, closed course, do not attempt, etc.), but with the new setup it required significantly less opposite lock to fix the car when it got out of shape (and, to my dismay, it stopped being a challenge). This is despite the thicker rear sway bar which should push the balance more towards oversteer than initially, so I really think the f/r weight balance has changed for the better.

Otherwise the springs were extremely streetable. You almost can't tell the difference from stock. The only times I noticed were over harsh bumps (now harsher) and the fact that the car now porpoised differently over some of the street bumps I'm familiar with, due to the higher frequency of the suspension. You will tripod a bit more getting into a steep driveway, but I haven't scraped yet.

Impressions from the autocross:
It's tough to draw really good setup conclusions given the age of my tires, as I'm going to have to relearn the car with fresh tires, but here's what I noticed.

On Friday practice starts I nailed four 2.2 sixty foot times. I think across the four pros I've done in my career I can count on one hand the number of 2.2s I had. I wasn't able to pull this off in competition, but that's just poor focus and control on my part. Again, I feel this is a product of better weight balance.

As mentioned, Saturday morning we had a green course and I was pitching the car around like it was my old setup. Where the dampers had been catching the chassis movement before, they were now getting overpowered. Snap oversteer was the result for any quick double changes in direction.

We decided to drop air pressure a little in the front and dramatically in the rear. The nice part about this setup is you get a small amount of camber gain and quite a bit of roll stiffness, so we were hardly rolling over the sidewall of the tire like we used to and could afford the drop in pressure. Between these changes and the rubber getting laid down (El Toro is notorious for ridiculous amounts of rubbering in) the car tightened up considerably. I also focused on being a lot more smooth and precise in my inputs, and not asking much from my dampers.

Saturday afternoon we started getting a lot of confidence in the car - I think my codriver (never touched my car before, and actually I think he's never autocrossed anything except his S13) pulled himself up from 8th to 5th, one spot out of the trophies. A little bit more power-on oversteer than my old setup, but way easier to fix. I can't emphasize this enough, the car was just much easier to handle. I think once I pinned the throttle with the wheel turned, rear steps out, I keep it pinned and don't unwind at all, and the car just caught itself and took off. At most, maybe you straighten the wheel.

There weren't any issues with the rear bar causing too much weight transfer for the Torsen to quit working and the e-diff to kick in. That's probably thanks to the lower CG which keeps that inside wheel firmly on the ground. On my old setup I could occasionally get e-diff to activate, which isn't ideal since it's braking you while you're trying to power out of a corner.

All in all it ended in a good result and the new parts definitely helped. With more seat time and better damping I think there's more time to unlock. What I like most is that I've kept most of my godlike slaloming capability while fixing my corner exit push - it's basically driving like I've wished it would for the last couple of years. There is still going to be some course dependency between us and the 8, and getting our driving up to the level of Fenter and Harvey is a tall order, but with a max prep car and an awesome driver you will be in the conversation come September.

As far as BS competitiveness goes: check out Guy Walker's time's in BS compared to me. Yes, I'm on old tires and stock shocks, but I beat him last year at El Toro when the 370Z was still in CS. These parts are good, but they are not pixie dust.

[TrqlessWonder]

Originally Posted by markw

Loosen, pry/tighten sub frame.

Loosen top of strut and push it inboard then re-tighten.

Couple of ideas.

Or like they used to do, put the car on a frame machine and pull the towers in ever so slightly.

Mostly good ideas. Re-assembling the subframe is how you clear up the L/R camber stuff. Loosening the top of the strut and taking advantage of that slop is also easy. Top tip: Just like using a jack on the rotor to hold the strut in the right spot while doing the crash bolts, wedging something small between the tower and strut to hold the strut over while tightening at the top will help you make sure you got everything legally available to you.

I wouldn't advocate for hammers, sledges, or tugging on the towers. Displaced metal and tool marks are both easy to spot, and solid evidence for an upheld protest.

[renfield90]

Originally Posted by TrqlessWonder

I wouldn't advocate for hammers, sledges, or tugging on the towers. Displaced metal and tool marks are both easy to spot, and solid evidence for an upheld protest.

The Adrian Peterson rule applies: don't leave permanent marks.

[qoncept]

Originally Posted by TrqlessWonder

I wouldn't advocate for hammers, sledges, or tugging on the towers. Displaced metal and tool marks are both easy to spot, and solid evidence for an upheld protest.

But you're not breaking any rules..?

[TrqlessWonder]

Originally Posted by qoncept

But you're not breaking any rules..?

RTFRB

[7thgear]

Originally Posted by TrqlessWonder

RTFRB

I'd rather read the bible than the SCCA Solo 2 rulebook.

[qoncept]

Originally Posted by TrqlessWonder

RTFRB

Read it front to back several times. Don't remember a rule that said you couldn't push the top of your strut toward the center of the car before you bolted it back in place.

I should stop being facetious. I assume you're saying you can't bend things or some such. No one is saying that. Or maybe I'm wrong, but I don't think they are. Just suggesting that you can use tolerances to your advantage.

I'm hardly the kind of person looking to push the rules - I want to show up and drive and have a good time, period. But I did take 5 minutes to make sure I got all the camber I possibly could in front.

[TrqlessWonder]

Originally Posted by qoncept

Read it front to back several times. Don't remember a rule that said you couldn't push the top of your strut toward the center of the car before you bolted it back in place.

I should stop being facetious. I assume you're saying you can't bend things or some such. No one is saying that. Or maybe I'm wrong, but I don't think they are. Just suggesting that you can use tolerances to your advantage.

I'm hardly the kind of person looking to push the rules - I want to show up and drive and have a good time, period. But I did take 5 minutes to make sure I got all the camber I possibly could in front.

Correct. It's actually specifically allowed. Taking advantage of tolerances is totally above-board. Pushing the struts inward as far as the factory studs can in the factory holes (all 1/32" of it) and then tightening down does that. I was just cautioning against using more than a bare hand to do it. Striking it with a sledge or mallet does run the risk of moving metal, whether intentional or not. If that happens, you've changed the hole size or strut shape, and that's where the line gets crossed.

Take a 5lb mini sledge and smack the strut assembly inwards several times

4lb dead blow works too.

Or like they used to do, put the car on a frame machine and pull the towers in
ever so slightly.

tl;dr - Don't use a hammer on the top mounts, it's completely unnecessary and might put you afoul of the rules. And maybe damage the bearing on the strut shaft, if that's what you swing at.

[Laloosh]

If anybody cares I did some testing today with HR 5mm spacers. I just wanted to confirm you need to install longer studs to run these spacer...and you do. On the stock setup I get about 10.5 rotations unill the lug is torqued. Add the 5mm spacer and I get 6.5 full rotations. The minimum recommended is 8 turns so proceed at yor own risk but I am going to install the longer studs that came with the spacers.