[ChrisF]

I've heard differing opinions on this topic. Can anyone tell me if the STi can benefit from an ALK in the same manner as a WRX? I drove a WRX with one installed and really liked the feel. If it would do the same for an STi, i would install one.

Thanks.

[Slowride]

Everyone who has one will tell you it makes a big difference. I put one on my '02 wagon and it was a noticable improvement. I haven't put one on my STi because (a) I'm autocrossing in Stock, and (b) it looks to me like the STi already has roughly the equivalent.

[lupohki]

I'd like to know too. I've read conflicting opinions. I have yet to install mine.

[lalartu]

I have the Perrin P.S.R.S. (ALK) on my STi. The difference is very noticable. The front of the car felt like jello in comparison. The improvements are the most noticable in Auto-X. Before the P.S.R.S the steering wheel was all over the place when pushing hard in sweeper turns and now it is solid as a rock. The steering feels almost as stable as on my old ZR-1 corvette.

[ValvetrainEngineer]

I've been considering this mod also. The more I read, the more I wonder if people are feeling the increased vibration from the stiffer bushings and equating that with better handling. Whiteline themselves say the ALK only helps with braking and accelerating (especially accelerating out of a turn). Hmmm..... :-?

[mindchatter]

Bumpo for any more experience w/an ALK on an STi. 8)

Stu

[Snax]

Just keep in mind that the ALKs will bump you into either modified or prepared classes in SCCA Solo competition as per the exclusion for altering suspension mounting locations. Apparently they don't look at it as an alignment adjustment despite using the same hardpoints for the mounting bolts. It's not right IMO, but as I understand it, that's the current interpretation.

[fg1quest]

the whiteline ALK was one of the first things i did to my 04, not only did i notice a big difference on initial turn in but friends who had been in the car before i did this comented on how the front end stays so much flatter and smoother on initial turn in, and under heavy breaking. the car felt like it wanted to be thown into turns, go cart like. I now have Hotchkis sways so i dont really know how much of a difference the ALK would make to people with sway bars already on as i dont feel like taking the ALK off just to see if it makes as much of a difference when the swaybars are on as it did with them of, although im sure it is till doing its job of stoping front end lift/ nose dive

[Slowride]

Originally Posted by fg1quest

im sure it is till doing its job of stoping front end lift/ nose dive

The ALK doesn't "stop" lift, it reduces it. And it doesn't stop dive, it increases it...according to Whiteline, anyway.

[zeke]

I've posted about this before.

From my understanding, by altering the caster angle of the wheel at the suspension link point not only are you altering caster but you are giving a different leverage point to the suspension.

The strut is slightly more angled which means less leverage to lift the front under hard acceleration and when you are braking hard and the nose starts to dive, the strut is actually getting more leverage to work against dive by the change in angle.

As far as the caster increase, it's well known that some increased caster (you can go too far) will make the wheels track straighter when you hit bumps and so on instead of deflecting. Another effect of increased caster is that during turns, camber angle is increased which could mean increased contact and better turn in.

Now, if everything is engineered properly those are all the benefits you will see from this mod.

As to what the negatives are? For a four wheel drive vehicle, I imagine that the increased caster angle means less driving force applied to the front wheels during turns for offroad and since subys are primarily raced offroad maybe that is the compromise they made. I don't know for sure.

These are all opinions based on my knowledge of vehicle dynamics that I've managed to pick up so far.

[Slowride]

A couple years ago, when I bought my ALK, Whiteline said the ALK reduced lift but increased dive. I just checked their web site (a real disaster) and they've withdrawn all the ALK-related papers. A google found a magazine article on their website that says:

Before getting down to it, we should clarify a question that Whiteline have recently investigated - does their ALK really increase anti-lift geometry? Taking into account the position of the instant centre, wheelbase length, centre of gravity, percentage front torque and percentage front braking, the WRX's anti-lift and anti-dive dive characteristics can be found. With fitment of the Whiteline ALK it has now been discovered that the factory anti-lift and anti-dive geometry is reduced to virtually zero. In other words, the amount of fore-aft pitching will actually increase.

http://www.whiteline.com.au/articles...on_rails_3.pdf

So it sounds like it adds both lift and dive--as well as camber. But probably the biggest benefit of the kit is due to the stiffer bushings, which maintain much better dynamic camber.

[Snax]

That backs up what my intuition about the ALK has always been. I never really looked at it and just trusted to a mild degree that it had an anti-lift effect, but it's like $3 bills. If you didn't know any better, you would be happy to have one vs. a $1 or $2 bill - until you tried to reap the implied value from it. The geometry for anit-lift just doesn't make sense with that kit, whereas the change to caster and dynamic camber does and should provide a noticeable benefit.

Perrin's kit FWIW is called the 'Positive Steering Response Kit'. That seems much more appropriate.

[surlysinglespeed]

So when I charge thru the apex and hard out of a corner
I notice the front wheels kinda skate across and irregulars on the road (even when it appears smooth)
re these kits supposed to "fix" that?

thanks

[Antimullet]

OK from what was explained to me the term Anti-Lift Kit is misleading. The ALK kit does decrease lift, but the meaning in terms of the kit is this: In a hard turn the front inside wheel will tend to lift and lose traction, the ALK kit allows for more droop in the suspension and keeps the inside wheel planted and avoiding lifting (OFF THE GROUND).

This is not to be confused with anti-lift, as in launching at a drag strip and the front suspension tops out (IE front end lifts up). That's a different type of lift and one this ALK kit does not address...

[zeke]

Thanks for the info. Now I just need to digest it all. heh.