zze86

Finally, had the opportunity to take the S for some spirited driving the other day including a nice on-ramp with a banked sweeping S turn where you can apply throttle early on and get a feel for the suspension work through it's motions.

I can see where the S, and specifically the AP1, gets a reputation for snap oversteer from, getting up to the limits it's fairly predictable. Once there though things ramp up pretty quickly.

So turning into the turn, I was slowly applying throttle and being careful not to enter vtec. Things felt really nice and predictable and the car felt like it wanted more so I kept giving more and more throttle and steering input. Went from the top line along the bank to the inside line of the curve and felt something switch, like it kind of hunkered down. Car felt like it wanted even more throttle and steering input. Applied juuuuust a little more throttle and I could tell the rear wanted to step out. Modulated the throttle with some steering correction (countersteer would be too strong of a word) and it settled down.

Like I said getting to the limit it felt predictable and progressive, however things ramped up really quickly. With relatively sticky and non-audible Hankook Ventus tires, there isn't much warning about when it wants to go. At WOT reflexes would have to be fairly quick to catch the rear end.

From what I have been reading, the S toes out during rear rebound. This is what I suspect happened as I went from the banked outside line to the inside line. The outside rear unloaded and toed out causing the sensation that it wanted to turn more. If you have ever driven those cars with AWS, like the Prelude or 3000GT, it felt a lot like that. Slightly weird sensation if you're not used to it.

Now that I'm wiser I tend to drive fairly conservative on the streets but this behavior un-nerves me and is of concern when pushing it and hitting bumps or potholes. Not unheard of on upper Midwest roads.

How do I correct this at-the-limit, non-progessive behavior?

I have read this thread: https://www.s2ki.com/forums/s2000-brakes-suspension-249/ideal-rear-toe-curve-1153521/page2/ which appears to address my concerns. From what I understand from the thread it appears I will need rear adjustable toe links with a bump steer kit. I will need to shave one of the bushings that comes with the kit. I will need to play with the eccentric bolts at the rear.

My questions: do I do this before or after an alignment? If after, how do I tell the alignment shop to not mess with these settings? How did he go (or how do you suspect he went) about measuring the toe range? Compressed the suspension with a jack?

Car Analogy

Another option, buy an ap2 rear subframe. Bolt in. Get a standard ap2 alignment. Done.

zze86

Yeah, that doesn't sound like a good option. I rather like the balance now. By all accounts the AP2 is not as playful as the AP1 and the AP2 still suffers with the dynamic toe changes, just to a much lesser degree.

I don't particularly mind a loose car or a sliding rear end.

I just don't like it when the car is dictating when it happens versus me.

ZDan

This is wrong. You shouldn't be giving MORE throttle *and* MORE steering input at the same time. You should drive a line such that as you apply more power on corner exit you are unwinding the steering. Applying both more throttle and more steering is very bad technique and you shouldn't be doing both of those things at the same time, ever. Nothing creeps me out much more as an instructor at the track as when a student keeps the steering cranked in while applying power on corner exit. Just unnatural, car doesn't like it... Cranking in MORE steering while applying more power? Even worse!

Well, unwinding the steering a bit and giving the car its head was the right thing to do (given room on the outside). Lifting off the gas woulda been a big mistake...

Drive a proper line and never be adding more throttle and more steering at the same time. At the limit at the track, you'll BRAKE for a turn, then turn in while trailing off the brakes, trading braking pressure for steering angle, you'll be at max steering angle as you transition from brake to throttle and then begin to unwind steering as you apply throttle as you exit the corner.

I don't think you should need aftermarket toe links to get static toe where you want it (IMO 0.2 degrees total rear toe-in). I wouldn't bother machining bushings to custom thickness unless you are measuring the toe curve yourself to ensure you are getting it to zero toe change with bump.

Of course you'll need an alignment after suspension mods. If you figure out how to measure the toe curve yourself then you can probably set static toe, but you'll want to be able to measure camber as well to ensure that stays in desired range and symmetric. Or you could just install BSK with recommended bushings/spacers which should at least tone down bump steer significantly, and then get alignment and see how that goes...

ZDan

IMO it's the best option.

??? If you like the handling balance now, don't change anything at all...
AP2 experiences a lot less dynamic toe change specifically because of the relocated pivots in the subframe.
By going to the AP2 rear subframe while keeping ap1 springs and sway bar, you aren't fundamentally changing the handling balance, you're just *fixing* the bumpsteer/dynamic toe change problem, which is *specifically* what you originally said you wanted to do! And this is IMO a better way to do it than a BSK.

rpg51

Just out of curiosity - are you driving, or planning to drive, on the track? If so fine, I'll just lurk and read.

Otherwise, this characteristic you are describing is a non-issue in my humble opinion. I NEVER bring the car to the limit of grip driving on the street. IMHO it is very dangerous to drive any car in this fashion on the street. Just sayin'. To me this creates an unacceptable risk of serious harm to the driver and anyone else in the area. I will say that wet roads change the place where the limit is reached, and I learned that real fast one day when I did some stupid stuff and nearly lost it on a wet interstate highway. Fortunately, I learned the lesson, and I have had zero issues since. Lessons learned? I need to to slow down on wet roads, and NEVER use cruise control on wet roads.

Emil St-Hilaire

^^^

Jah2000

Easy fix... installed a thick MY01-02 FSB (similar to a CR FSB) and a thin MY06+ RSB on my 03... sticks like glue and drives like a 4WD now lol.

zze86

OK, I see where you guys are going with this. I obviously didn't think it through; I thought we would have to switch EVERYTHING from the AP2 subframe over. I do like the idea of keeping the car as OEMish as possible and I like the 16" wheels. Also, I see from the post I referenced that "Long Acre" is a brand and reading through their instructions, I see how he went about it now. From some research then, it appears I will need the AP2 subframe, AP2 upper control arms and AP2 rear knuckles to complete the conversion.

Question: Do I also need the lower control arm? From https://www.s2ki.com/forums/introductions-21/changes-between-2003-2004-2005-a-483593/]this post, under the suspension and chassis section it sounds like BOTH control arms were lengthened but that doesn't appear to be the case, just the upper control arm.

Thanks for the driving tips as well all. I am actually quite comfortable with a sliding rear end, initiating and controlling it. In my misbegotten youth, I had a stable of AE86s that I drove year round rain, snow, mud and shine. Autocrossed, tracked, off-roading and a bunch of hooligan stuff. I was sliding the car around before drifting was even a thing. I'm no drift king but I'm not exactly shy about it either. Comparatively, I'm pretty conservative nowadays (my DD is an awesomely reliable minivan) and I do plan on non-competitively tracking/autocrossing the car.

flanders

Lower arms are the same, it's pretty easy to find out if you just compare the part numbers.
https://www.hondapartsnow.com/parts-...lower-arm.html
https://www.hondapartsnow.com/parts-...lower-arm.html