04' STi Struts, recap and a couple ?'s

[skid542]

I recently bought a sweet setup that is based off of 04' STi struts and upgraded springs. I know this isn't the ideal setup with regards to alignment and track width, but I just couldn't pass up the deal.

So I've been doing a lot of searching on the experiences that Jamal, Thawa, Brat4x4, and some others have had. I think I have a feel for the situation but wanted to recap my understanding so those that are experts can correct me if needed.

To be upfront with my goals in regards to performance and how I drive - this car is my daily and I do put a fair number of interstate miles on it. I do Auto-X it though and also enjoy the windy roads on occasion. So I will need enough negative camber to keep it exciting, but not so much that I kill my tires if I'm not taking a lot of corners. I still have a bit of learning to do on what settings I'm after but thinking around -1* up front and -.7* in the back?

Fitment into the strut towers -

The fronts will bolt right in, no problems here.

The rears will not go in stock and here I have two options. First is file out the holes in the strut tower to allow the wider bolt spacing. I am opposed to this for two reasons, first is I don't want to do this and have my struts mounted in elongated holes. I know it's been done and works, but a personal preference says no. The second reason I don't want to do this is I have a nice Cusco rear strut bar that I'd like to continue using and have no desire to try and file out those holes. The solution to this, as I understand it, is to source a set of 90-91 tophats as the 04' springs are tapered. So if I get the 90-91 tophats then everything bolts right in.

I am assuming that the rubber the spring seats against will transfer from the 04' tophats to the 90-91 tophats?

Alignment - Here is where it starts to get fun and I'm looking for confirmation I have things right.

Since I was just talking about the rears, I'll start here. The STi track is wider than the BC, so swaping in these struts induces a positive camber. Filing out the holes reduces this though - but I don't want to go that route. I know Jamal uses Intrax camber bolts in the rears. Will this be enough for me to get my car setup the way I want or will I need a set of camber plates as well? If I put in camber plates, do I loose the extra bolt height on the tophats that I need to mount the RSTB?

Upfront I know I'm facing just as many issues/customization. Jamal has milled out the holes on his struts to allow the use of two camber bolts per side, using stock camber bolts. This has gained him some room but not as much as he was wanting. The bottom hole is already cammed and just the top needs cammed? Do you have any dimensions that I could use? I do have access to a milling facility. Should I just look at camber plates off the bat? I know the RCE's are ~$400 but I think there are a few others though they don't offer the same degree of adjustability.

I hear a lot about Caster, and truthfully do not understand this variable. I can see the tire being aligned with regards to two axii, longitudinaly and perpendicular to the axis of rotation within the horizontal plane. What is caster?


So yeah, I'm trying to get everything figured out so that when I go to install these it's a one time ordeal and I don't have to mess with my suspension for 30k+ mi., outside the occasional alignment. Please fill me in on where I am in error and any other items I've missed.

Thank you in advance.

[skid542]

Nobody? I know the whole STi swap is an issue that's been covered a fair bit and is usually a 'search' item, but I do have a few specific questions I'm looking for answers on.

Perhaps I should state just my questions instead of making everyone read the recap?

[jamal]

I'm putting the 04 front lowers on some newer STi parts, and I'm going to just slot out the other side of the front lower hole and use the regular bolts. That should get me something like -2 degrees.

In the rears with a set of bolts you should get plenty of camber. I was at a little over -1.5. Then I bumped into a curb sort of and ended up with a bit of cross camber.

With the 90-91 stuff you'll need the rubber perches and stuff from them. The 04 tops are different:

[skid542]

Cool, thanks for the reply Jamal. I was hoping you would chime in.

I must be pretty dense, and this might make more sense to me when I have the struts in my hands to look at, but when you say you are going to slot the other side of the front and use a regular bolt - I'm just not following you. Can you elaborate any more?

On the rears, so if I use the 90-91 top assy, rubber and all, I won't have to mess with anything else and the stock setup will still allow me plenty of adjustment? This is assuming I get a set of Intrax camber bolts. Just wanted to make sure I was understanding you right.

Thank you much.

[jamal]

when I milled my struts, I only did it to one side for the cam to fit into maxed out:



So I'm just going to use the same housings, slot the other hole with a dremel, use a standard strut bolt, and jam the upright to max negative.

[skid542]

Ah that makes a bit more sense. You aren't worried about the strut moving under heavy loads since you are relying on the 'bolt compression' to hold the strut in position on the hub?


Thanks again for the help, I know we have had our disagreements on braking system dynamics... but it is nice having a real suspension guru around.

[jamal]

yeah, it won't slide around. The tension of the bolt is what actually holds things in place anyway. There will be a little more clearance on the one side than I'd like, but it shouldn't cause a problem.

The nice thing is that a the hole only has to move about 1mm to create a 1 degree change in camber. mine will be slotted enough to get over 3 degrees I think.

[rally370]

Well I'm a lazy bugger and just slotted everything! It all held up to 2 years of CA rallying. Plus I tighten those bolts really well.

Interesting deveplopment with my rear STI set up was this strange problem: The suspension had thi knocking noise. I thought it was the bushes etc The noise sounded metalic. Then last week I felt the suspension lock up for a second. Turns out the grease inside the struts had dried up and the tube was binding. $7 worth of grease and a strut rebuild now all is well. Infact the car handles way better. Must have been getting worse and I didn't notice.

Good luck Lee with the build

[jamal]

Well I'm a lazy bugger and just slotted everything! It all held up to 2 years of CA rallying. Plus I tighten those bolts really well.

Interesting deveplopment with my rear STI set up was this strange problem: The suspension had thi knocking noise. I thought it was the bushes etc The noise sounded metalic. Then last week I felt the suspension lock up for a second. Turns out the grease inside the struts had dried up and the tube was binding. $7 worth of grease and a strut rebuild now all is well. Infact the car handles way better. Must have been getting worse and I didn't notice.

Good luck Lee with the build

Slotting is the way to go if you don't want to buy camber plates. I wish I'd just done that in the first place.

Clunking is really common with the inverted rears. Even when I pulled apart my fronts there was a fair amount of scoring on the shaft. So yeah, make sure they stay well greased.