Suspension is complicated

[Shad]

Just spent an hour reading up on D2 suspension. This seems like the way to go for a CRX at the moment (they were fitted to the winning TOTB FWD car after all).

But there's so much to think about. Spring rates, preload, rebound... all I've fathomed so far is that 730/620 lb/in F/R springs should make a stiff and neutral track setup.

Does anyone have anything worth reading regarding suspension setup? All I really understand is how the damper and spring work in conjunction, and the effect of differing spring and damper stiffness. The rest is all Greek to me

[5lab]

have a look on good ol autozine tech pages. theres loads about sus in there - its more to do with what design you have than naything else.

[Butuz]

D2 coilovers are good you wont go wrong with them though they all seem to be imported from yapan - thus getting them serviced if anything goes wrong is not as easy as with say tein for example.

Butuz

[IainB]

all I've fathomed so far is that 730/620 lb/in F/R springs should make a stiff and neutral track setup.

730 730 !!
Thats stiff as a stiff thing, is this going to be a track only car or are you still going to use it on the road?

[Shad]

I'll still drive it to work occasionally and to tracks for racing, until I've got a trailer.

I'm happier to put up with a harsh ride on the road for an improved setup on the track

[5lab]

thing is, the sus also protects components in the car from too much abuse, run your sus too hard on the road and it'll shake itself to death.

[Shad]

Another set of springs is only about £60 so I'll probably order 2 sets, one for road (about 560/280 F/R) and the others for track. Just means I'll have to do 2 lots of setup work

[Konan555]

The odd drive into work might turn into a bit of a challenge. Might be nicely set for a well maintained track, but show it some good ole British highway and it'll be a handfull.

[Zak33]

that will be HORRIBLE in the wet! Man you need compliance not bricks for springs!

Tell you what you need first on a Honda...SHOCKS....not springs.

Get proper shocks/dampers..... and see what a huge difference that makes BEFORE doing springs. Springs, as you said, are cheap to change. Shocks need to be right.

Do Bilstein or Pro Flex do any for your car?

[Jiff Lemon]

You sure about that front rear ratio? Typically with a FWD drive car, the front springs are softer than the rears.

[Shad]

There's more weight over the front. I think the weight distribution is something like 65/35 F/R. 13/11 (kg/mm) has been tested by several track day drivers and had good feedback.

Zak... it's a coilover kit so dampers will be replaced too. The opinions given by those who've used the kit are all very highly respected

730lb springs are still softer than the 800lb springs the challenge cars used to run.

Back to the original question...

[5lab]

could you not get an adjustable spring rate setup? that'd allow you to play with your stuff by just taking a wheel off, rather than having to unbolt the suspension.

[Shad]

I can adjust the preload with the kit... does that equate to spring rate adjustment?

[Rave]

No. Adjusting the preload is likely to adjust the ride height of the car as I understand it but it'll still have the same level of compliance when it hits a bump. If the springs are progressively wound then increasing the preload would also affect the spring rate to some extent.

[Butuz]

I can adjust the preload with the kit... does that equate to spring rate adjustment?

No - not generally, unless as Rave says the springs are progressively wound (which would mean the more they compress, the harder they get)

Really, what you need for trackuse is no body roll - stiff Anti Roll bars provide this without compromising an individual wheels suspension movement which is what you want if your going to use the car on the road as well.

I have gone for uprated dampers and slightly stiffer and lower springs, plus stiff anti roll bars. (havent got the ARBs yet though). If you slap super low, super stiff coilovers on you will find that off track use will be seriously compromised and you will end up getting your ass kicked by cars with body roll and soft shocks when it gets to the twisty off camber rutted and potholed B roads.

Pure track car, go for coilovers and ARB's
Mix of both, go lower and a bit stiffer, just get good ARBS
Pure road car, just lowered should do.

Oh and if you do go too stiff by accident on the back you will get more oversteer than normal this is the way to tell.

All IMHO of course.

Butuz

[Konan555]

ARB choise is quite complex as I remember it aswell.

I'd assume you'd pick it out to induce a slight lift-off oversteer charactaristic on a FWD?