Talk about a night and day difference. I installed my Perrin PSRS (Positive Steering Response System aka ALK) last night. First off what a pain in the butt to install by yourself with absolute no air tools. It wasn't that bad of an install but very time consuming and the transverse link is a PITA to get the bolt through. I had to take a jack with a wrench on it to push the transverse link up enough for the bolt to go through. Plus it got dark on me so I was fumbling in the light. Anyways I love this thing. There is a road I turn onto every morning on the way to work. Usually I will take it at 45 mph because any faster or sharper and the front tires will push and slide. There is a huge runoff so this morning I figured I will take my chances and try out the new toys. I took the turn at 60 mph and the car instantly went "Okay" and turned. No effort and absolutely no squeal or pushing of the front. It just turned like it was on rails. You can turn WAY sharper and WAY faster than ever. Plus the car hasn't even been realigned so I most likely am not getting the max caster possible. I say get this but be ready for a tough install but it is 100% worth it. The car is getting aligned right now....can't wait to play this weekend.
I wonder how much of the difference is due to increased castor or actually changing the suspension geometry. I felt the same way after adding camber plates; you can really feel the front end tugging the back end through the corner.
Yep the front stays planted and I can swing the back end now. Now I just need some sways to compliment the ALK and Tein Flexes.
i have them as well... actually a similar setup as you rex, and i can swing the back end of mine. only thing that is diff. is i have a rear sway. i've been thinking of getting a front sway. but i was wondering how it would effect the handling. would it reduce understeer, increase oversteer & increase turn-in???
The perrin kit as well as the whiteline ALK adds caster. The whiteline offset bushings do the same thing. the three items add about 1.0 to 1.5 in positive caster. Caster alone makes the largest difference in dynamic handling and response in the front end of the car. However, the ALK and Perrin kits are NOT LEGAL for any stock class, street touring, street prepared or street modified autocross classes. They will bump you straight to F-Prepared. The SCCA rules see the bracket that the bushing is in as the 'suspension mounting point' as that item does not move with suspension deflection. The offset bushings that whiteline has are legal for street touring/street prepared/street mod. Obviously they are NOT legal for any stock class. I have the offset bushings on the WRX (well, next week they go on) and the outback. I did have them on my RS, and with some other modifications allowed within the class rule sets, I was able to get +7.5 caster. There sure was a TON of front end grip. We're talking 85 mph thru turns on street tires that most subies on race tires couldnt touch (except STi).
WJM, could you describe the difference between the Offset bushings and the ALK a little more? Do the offset bushings only replace the actual bushing within the bracket, where as the ALK replaces the Braket and bushing?
The ALK and perrin kits replace the bracket and come with spacers for the subframe. Since it replaces the factory bracket...its illegal as mentioned before hand. The offset bushings are pressed into the stock bracket in place of the stock bushing. Therefore being legal in the classes mentioned.
WJM is correct...I have 2004 Aspen White WRX. I love this ALK. The only warning I have is that it absolutely will transmit bumps and vibrations more. I however like this as I can 'feel' the road even more. Steering seems to be much tighter and crisp...need to get the steering rack bushings to make that even better. I personally think that this is hands down the best bang for the buck suspension mod out there. Like I said it's a night and day difference. But it is also a PITA to get installed....patience goes a long ways.
+7.5 caster... i wish i had on my wrx. i`m planning on getting cusco camber plates (i`d like to get PDE, but way too expensive for what i`ll be using my car for), and ALK. how much caster/camber should i be able to pull off from those two mods? also, is a roll-center adjuster a must have when you lower your car for an improved handling, or would it not affect it as much as the camber plates and the ALK? also, is a there a difference as far as how much caster you get from the comfort ALK to race ALK?
I've not see any need for the roll center adjustment. the race vs non race is just different bushing materal. With those mods w/out anything special...you could see about +4.5 caster.
i`m guessing since the ALK will yield additional caster, it will get rid of wandering right? i hate it when i`m coming to a stop on an uneven pavement, and my car jumps left and right everywhere... because of this, i thought at one point that my rack is toast, but i guess it is a common problem. hopefully ALK will get rid of that feeling.
i`m guessing an alignment is needed after you install this piece? man, i guess i gotta install the camber plate, springs, and the ALK all at the same time so i only need to align it once.
Yep just got mine aligned this morning. 4.8 caster from what was previously 0! The toe was off a bit so it's important to fix the alignment ASAP after this. Now I have a freaking clunk when I go in reverse and turn the car. It sounds like it's coming from the passenger side....I did that side first and removed the ball joint bolt before realizing it really wasn't needed to be removed. WJM should I hit that nut with the impact since it spins when trying to tighten it with hand tools? I'm thinking that is where the little play/clunk is since I didn't even touch that nut on the drivers side and it doesn't clunk. The nut I'm talking about has that cotter pin through at the end of the transverse link.
is there anyone that has had the racing one and the comfort one? how big of a difference in performace? if there is a huge difference and the NVH isnt too bad, i`m probably going to get the racing one.
all this is great but why dont you guys save a little longer and get the sti control arms with built in alk? and you have less unsprung mass with the sti control arms.
Why did I go with the Perrin ALK? It was a direct trade for something I didn't even pay for and never used so essentially it was free....why not? I was saving for the STi aluminum arms but shoot if I can get something for free I will.
i can totally understand your thinking. i wasn't really trying to pick at anyone. i was just wondering why it was never brought up that the sti control arms have alk already and is a better option than just the alk for about a hundred dollars more.
I am doing STi control arms AND the offset bushings on Ashley25's car so i can get about +8.5 caster. There is no 'built in ALK' in te sti control arms...the arm is physically molded for that extra +1.5 caster. The 07 sti control arms are the same as the 06 WRX arms...and they are supposed to do away with the AL arms on the 07+ WRX... Coolrex: air tools work best...when it starts turning...air tool it. Also, stock caster for your car SHOULD be 3.0~3.5 in stock form.
thanks for clarifying that. i knew it adds about the same amount of caster as the alk does. i didnt know it was molded tat way though.
could someone explain the advantages to less unsprung mass/disadvantages to more unspung mass & how these factors effect the suspension/handling?
There's a book on that...and google it. Basically, the MORE sprung weight you have, the more overall control you have on the car. The unsprung weight is basically weight that is nearly 'uncontrollable' during suspension deflection (movement...say, over bumps and curbs and stuff like that)...the more you have, the worse the car feels and responds over bumps and sometimes it its bad enough, can become very unpredictable over bump events. The less unsprung weight you have...the better it is overall. its like wheel weights vs acceleration times on an 80hp car. Put heavy ass (say 40lbs a peice) wheels on the Civic...and its SUPER slow. Now, replace those 40 lb wheels with say...12 lb wheels. That loss in weight (112 lb difference) is SIGNIFICANT. Not only do you have less rotational mass affecting acel times, you have also dropped the overal weight of the car AND unsprung weight. make sense?