More Camber with OEM bolts

[jamal]

A while ago I put 04 STi suspension on my 1993 Legacy. It bolted up without too much trouble, but since 02+ Impreza sedans have a wider track than my car I had a bit less negative camber than I wanted. RCE camber plates are pretty sweet but cost $400. I bought a set of the small aftermarket camber bolts in the rear and ended up with -1.5° but the stock bolts only got me -0.7 in the front. I didn't really want to use the small, slippage and breakage-prone bolts in the front so I decided to drill out the struts to run stock bolts in both holes.

The oem camber bolts are 14mm with a 16.5mm cam. Since the center of the cam doesn't line up with the center of the shaft, I couldn't just drill out the hole on the bottom of the strut, although I could just drill out the steering knuckle. Lucky for me there is a small machine shop at the back of where I work.

Yeah there's some neat stuff:



Too bad my digital camera is broken and I had to take all these pictures with my phone.

For the bolt to fit I had to remove the material highlighted in red:



So here are things being setup:



The digital readout is nice. Look, the hole is exactly 2.5mm wider now.



This is from the test run I did with old parts:



Here you can see how the bolt goes through the strut:



The cam points outward, which moves the bottom hole of the steering knuckle out and tips the wheel inward, gaining me approximately 1.13° of negative camber.

Then I just drilled out the knuckle with the 16.5mm bit I had to turn down on a lathe to get to fit in my drill:



I drilled the struts out at work Thursday and then went to put them on Friday night. Then it started raining and all my stuff got all wet and it really sucked. Wooo surface rust:



While I was in there I decided to put in a few more things, like these overnight parts from japan:



Well not really it's a balljoint and I bought it from SubieGal. My right one was trashed so I decided to replace them both. Also I got these mafks:



Kartboy aluminum endlinks with urethane bushings. I should grease up the fronts and torque them properly because they're clunking. I've heard about rubbing issues on the rear lateral links because they're shorter than stock but there is plenty of room. I think it's only a problem on cars with adjustable bars set at full soft.

Yay all done:



Now I just need to get the alignment checked. I'm hoping for -2°

I'm also probably going to buy a bigger front swaybar out of a 97 GT, which is 20mm compared to my 18. I'll probably eventually go bigger in the rear, right now I have an 18mm turbo legacy bar.

[entirelyturbo]

Again, very cool stuff Jamal!

Pardon my n00bness, but what you're saying is that, in the front, a stock strut with stock camber bolts is only capable of -0.7º camber?

If so, that will not make subyluvr a happy panda, because I was hoping to get -1º if/when I get an alignment done this week.

[jamal]

No, I'm using 04 STi struts, which are made for a car with a wider track. The difference in geometry adds a bit of positive camber. With stock struts I'd think you could get like a degree and a half. One trick is to loosen everything up and push the strut top and top of the wheel inward. There's a bit of play in everything so you can get a bit more neg. camber like that.

I've driven like a block so far. I can't wait to take it for a real drive. Maybe I'll cruise up the angeles crest highway tonight...

[n2x4]

Awesome writeup!

Yeah, tell us how it worked after a drive. Now I may want to put sti bits on.

[jamal]

Well, I went for a short drive last night and it felt great. I didn't get to really push it, but the front grip was definitely higher thanks to the extra camber. I am very very happy with how much better the car sticks and I'm on RE92s.

That little looseness I felt was gone I think because of the balljoints as my right one was pretty trashed, and the car turned in more accurately, I suppose because of the endlinks. There's no more turn wheel, car starts to turn in-> swaybar loads-> car settles into corner delay.

I would have liked to just do the struts and ball joints and then try it with just front and just rear endlinks but that's a little more work than I'd like to do.

Edit: There's a 270 deg ramp I take to change freeways on the way to work and I was able to go around it about 5-8 mph faster. The car was also more neutral around it.

[jamal]

Update- I did some more driving:

A few weeks ago I went out for a drive and ended up on the Mulholland highway which is a really awesome road. Unfortunately the girl I was with does not like to drive fast (check one in the minus column for her). Anyway that was fun and I got to get a bit of a feel for the car.

Tonight I went up for another drive on the Angeles Crest highway, and then down a road called Big Tijunga canyon. I was a little short on power going up but on the way down I was flying. Big Tijunga is very fast and very smooth and I may or may not have hit 100mph. The new brakes are really grabby, my driving lights are bright as always, and the car grips so much better than it ever has. There isn't too much body roll with 224f/195r lb-in springs and 18mm front and rear swaybars. I actually find myself having to pause and be extra smooth in transitions because the car is so much more responsive.

Mid-corner it's really easy to control with the throttle. It's very neutral when I turn in, and with a little bit of lift or braking it will start to rotate. Naturally there is understeer when accelerating hard out of a corner but it isn't much and I really like how the car is balanced.

I'm starting to wonder about my decision to run a 20mm front swaybar. It's the corner or my room right now though so I should try it out at least and if I don't like it I guess that means a bigger rear bar. What I really need are some real tires, but I have lots of tread so I think I'll wait until after ski season for that.

[n2x4]

I was unaware that a leg gt bar was larger. Sounds like something that needs to be in the suspension sticky.
Any idea what size the LGT rear bar is?

If you did run that 20mm in the front, how big were you thinking of going in the rear?

You said the STi springs didn't give you much body roll, are you happy with them or have you thought about some that would give you a drop and even less roll?

[Brat4by4]

Mid-corner it's really easy to control with the throttle. It's neutral when I turn in, and with a little bit of lift or braking it will start to rotate. Naturally there is understeer when accelerating hard out of a corner but it isn't much and I really like how the car is balanced.

I'm starting to wonder about my decision to run a 20mm front swaybar. It's the corner or my room right now though so I should try it out at least and if I don't like it I guess that means a bigger rear bar. What I really need are some real tires, but I have lots of tread so I think I'll wait until after ski season for that.

Do not wonder at all and get that front bar installed. You really reduce the amount of understeer with how much better the wheel is placed in the camber-curve. If you think the car settles quicker and changes direction quickly now, wait until you get that 20mm bar on (you are only up to stock turbo swaybars) . If you are getting understeer with the 20mm you honestly need to look at how agressively you are going into corners turning and speed wise.

One of the only downsides to the bigger front bar is that you must be much smoother with your inputs. But that can also be considered an upside, depending on who you ask.

I had inside wheel spin with my Legacy at BeaveRun with the stock sway bars on... pretty bad actually. One set of corners I spun the inside front wheel halfway through third gear til redline (~89 mph ). I was worried that I was going to start roasting them with the bigger front sway bar. The worry was completely unneccessary. Wheel spin was gone and traction was on! Both times were with STi suspension.

I will admit that I got a 20-22mm rear bar (set to 22) on the car before that track day, but I rolled around with just the front sway bar for over a year and loved it. The rear bar was hardly noticeable compared to how much the front bar changed the flatness of cornering. In fact, I rolled around with the rear bar disconnected to actually see what kind of change it was making one day.

So bigger bars are track tested and given a definite A+.

[Brat4by4]

You said the STi springs didn't give you much body roll, are you happy with them or have you thought about some that would give you a drop and even less roll?

Dropping the car puts you in a worse part of the camber-curve, so should be done only moderately.

You really want to control roll with swaybars. Trying to control it with springs will lead to a car that hops and skips bumps in the turns = not good. The softest spring possible will let the suspension follow irregularities.

Unless you plan on running glass smooth pavement, then go ahead and throw 1200 lb springs on there like auto-x'ers.

[jamal]

I was unaware that a leg gt bar was larger. Sounds like something that needs to be in the suspension sticky.
Any idea what size the LGT rear bar is?

If you did run that 20mm in the front, how big were you thinking of going in the rear?

You said the STi springs didn't give you much body roll, are you happy with them or have you thought about some that would give you a drop and even less roll?

I think the LGT rear is still 18mm. As far as being in the compendium I mentioned it toward the end and I think Scott just hasn't added it. He should probably wait until I comfirm it fits anyway. For one the stock bushings that came with it seem to big for my mounts but the guy also included the brackets. If I can't make them work I'll see if I can find some p/u bushings. I think I saw some on e-bay.

I will most likely go to the Whiteline 20-24mm rear bar. Of course that will probably make me want a bigger front bar. Heh.

Like Brat said, more drop = bad camber curve. I posted a graph in a thread somewhere that I will try to find. Right now I'm around 3/4" lower than stock and I like it. I went through all this work to get an extra degree and if I were to lower the car any more I would lose most of that while cornering.

I would not mind something a bit stiffer but I think they only thing that will do that without lowering the car is a set of ground control sleeves. These struts are definitely capable of handling a stiffer spring.

Camber vs. bump on an STi:


(made by nhluhr on nasioc)

You can see that after 2" of compression the negative camber starts to decrease. So, lower the car an inch or so and you don't have a lot of bump travel before it starts to go the wrong way. Although it's really not so terrible; at full compression the camber is still where it was statically.