Elistan

The official word from Honda about 2003 to 2004 spring changes:
Front: Increased spring rate 6.7%
Rear: Decreased spring rate 10%

http://www.hondanews.com/categories/898/releases/1501

Please correct my math if needed, but assuming 250 front / 250 rear for AP2, that would imply 234 front / 277 rear.

bigteninch, if I was in your situation I would put the AP2 fronts on, and leave the AP1 rears.

RED MX5

Yes, the AP1 has roll understeer built into the rear suspension geometry, while the AP2 either has none, or has less. Softer springs would mean more roll, and more roll understeer. Roll understeer also manifests itself as bump steer when one wheel hits a bump or dip, and softer springs would allow more movement over bumps and dips. Since the idea is to get some more understeer the additional roll would be a plus. If bump steer is causeing a problem there are other ways to eleminate it (but of course you have to give up the roll understeer in the process).

My guess is that a change in roll rates will overshadow the other effects, but the only way to be sure is to put the srpings on the car and do some testing.

bboixtc

I was wondering the same exact thing as the OP. As my Ap1 is a daily driver and I've taken it auto X a handful of times.

zeroptzero

I just put low mileage 2007 springs and shocks on my 2002 which had 55k on it. I had the car aligned at my dealer with the old suspension on it, I have not changed any alignment settings since putting on the new parts.

In my opinion the car now handles better. There is less overall body roll in hard corners. In straight line daily driving conditions the ride on the rear end seems softer over larger road undulations, but pretty similar over hard sharp bumps. It almost feels like I got softer rear springs but firmer rear shocks ?, though I haven't seen any official numbers to support that.

I love the feeling of the front in hard cornering now, I think most of my body roll was coming from the front end on my factory setup. While I expected to have more body roll in the rear end I can't say that I feel it, it might be present but I just can't detect it. I can definitely feel the difference in the front.

I don't know if my factory shocks were in poor condition or not, they looked fine. I found the ride on my factory suspension to be rough and clunky feeling over bumps, but my new suspension feels smoother, whatever that indicates. I do prefer the new suspension and ride qualities. I haven't experienced any bumpsteer situations since putting on the new parts, so it is hard to comment on that aspect. I was concerned about the effect on bumpsteer, but I haven't been in a situation where it has manifested itself yet. I've only had the setup on for a few weeks. I thought that I had more understeer with my factory setup, with the new setup it feels like the car is more neutral, the rear end feels pretty planted in hard cornering and the front end feels much sharper overall. These are all of my subjective comments whether they make sense or not based on reported suspension rates. hth.

thielepr

The best suggestion above I think it's to put the front AP2 and leave the rear AP1. I will put The CR front (spring/shock) when my shocks require to be replace.

bboixtc

Ok so I just picked up some ap2 shocks and springs together and was wondering if I can just drop these in and not worry about getting an alignment?

zeroptzero

I didn't get an alignment on mine after the swap, because I had one done only a short while ago - 2 months prior.

If you haven't had one in over a year it would be worth doing regardless. If by chance you've had one done in the last few months then you might be able to skip it. It shouldn't affect the alignment settings very much, perhaps camber very slightly if the ride height changed, but on my car the ride height appears to be very much the same.

bboixtc

Do you agree with thielepr about only swapping the fronts?

jyeung528

perhaps you haven't pushed it hard enough to notice the understeer?

but i know the ap2 suspension understeers a lot more than the ap1.

zeroptzero

well it depends on what you are looking for, if you want outright handling capabilities then yes because the ap2 fronts are a good bit stiffer (depending on what year) than ap1 fronts. And the Ap1 rears are stiffer. So the two should be the best combo for handling.

But I wanted an updated ride characteristic, the ride on my car seemed like it was pretty hard over rough surfaces. I didn't like getting jolted around. I don't know if my oem shocks were worn out or not. But I like the overall feel of the ap2 suspension, better handling on the front with a better riding (less rough) rear. Lower body roll on the front, without much of a sacrifice in the rear. Keep in mind I'm comparing 8 year old springs and shocks with 55k on them to parts that were used less than 2 years with 12k on them.

I will admit that I don't push the car to it's limits on a daily basis, but for the amount of hard driving I do it seems to be perfect. I wouldn't go back to the other setup or any combination of the two for my tastes. For some reason my ap1 never exhibited tail happy oversteer characteristics, it always seemed to understeer, I found that to be strange based on what I had read from other owners.