Handling gripes

[Vidospace]

Hi,
I have a 97 Del Sol with some 17inch rims and 215x40 Kumo tyres. It has stock brakes with semi-metal pads. It has some coil over shocks with hight adjusters and non adjustable shocks. It isnt too low but is about 2cm from the guard at the front (very seldom scrapes though, even at full lock!).
All sound meh! BUT!
It brakes terribly in the wet, and is bottoming out (hitting the bump stops) when hitting big bumps etc.
So I am after a better ride, and better braking. I also want to keep the rims I have.

After doing a bit of research on these forums I can see that the KYB adjustibles or Koni Yellows are a good choice for a shock. But I am concerned about getting the right springs to suit. I am happy with the ride hight (it sits nice and never scrapes the front or back). So what spring rate should I be looking at for good ride quality for a daily driver?

In terms of the brakes I am thinking DC2 front rotors and calipers but will I need a different brake booster to suit? If so which one?

Any other suggestion to improve the ride, braking, handling and overall drivability of the car?

[fatboyz39]

AS for brake, upgrade to the type R calipers and rotors. It would be good to use ITR MC and booster as well. You'll need the rotors redrilled to 4x100 and shave the caliper bracket by 3mm. Pm me for more info.

Note: dc2 brakes are the same as Delsol's.

[JohnL]

Koni yellows work very well with springs from stock to quite stiff. If you want stiffer springs too then maybe about 20% to 30% stiffer than stock shouldn't be too stiff for reasonable ride comfort. Keep in mind that typically you'll get more harshness from a stiffer damper setting than a stiffer spring, but with a stiffer spring you'll generally require a stiffer damper setting to control the stiffer spring (catch 22). I have Koni yellows on my CB7 Accord at the stiffest settings on stock springs, the handling and response is very good considering my cheap tyres and stock rear ARB, the ride is on the harsher side, but only on rough roads.

Koni are the highest quality damper you can fit to your car (along with Bilstien if they are available for your car). They'll last longer than cheaper dampers, and have very good characteristics including that they'll give a fairly soft ride at softer settings and much more responsive and 'sporty' handling at stiffer settings (at the expense of some harshness, but they will still be supple enough over savage bumps).

The only downside of Konis (other than cost, and you get what you pay for) is the lack of bump damping adjustment, but rebound adjustment will have the greatest affect on your car's handling. Some other adjustable dampers may have bump adjustment as well, but often the actual range of adjustment isn't all that great in either bump or rebound (despite some dampers having a large number of adjustment 'clicks'). Konis are also fully rebuildable, so when they eventually do wear out (and all dampers do, its just a matter of how long it takes) they can be relatively economically made as good as new.

Konis may or may not be compatible with your existing springs, which might also be the case with the AGX dampers, you'd need to check this out.

Before I considered uprated springs I'd be thinking about an uprated rear anti roll bar, which often will have a better affect on handling balance than a full set of uprated springs.

Good quality front and rear strut bars should also be on your list (but not cheap ones that aren't stiff enough, typically the attachment brackets are weak on cheap strut bars, which means they're next to useless). I have front and rear strut tower bars, home made and very stiff, quite a noticable improvement to chassis dynamics.

Increasing caster angle as much as possible is also very worthwhile, but is a bit involved and you need to know exactly what you're doing (yes it can be increased, despite what some people say). I have double the stock caster angle, which significantly improved steering response and feel, also improved front grip in tighter corners due to the increased steered camber changes that are caused by higher caster angle.

Increased neg camber helps a fair bit, but if you're lowered with no camber decrease with aftermarket camber adjusters then you probably have as much neg camber as you need.

Bottoming out may well be caused by soft dampers, or if the dampers are good (and they need to be stiffer than OEM for a lowered car, if for no other reason that lowering springs should be stiffer than OEM to prevent bottoming out), then perhaps the dampers are too long in the body for use with the springs you're using (a shorter body damper will allow more bump motion before bottoming out).

I wouldn't be thinking about brake modification at this point to address poor wet weather braking problem until I had some tyres on the car that worked better in the wet. You may well find in this case that your wet braking problems disappear.

[SeverAMV]

if its using the same bump stops that im thinking of, you could always modify/cut them so it doesnt bottom out as easily. short of that, follow johnL's advice.

[nd55]

Any idea what camber you are currently running?

Negative camber due to to lowering will reduce your tyre contact patch under straight line braking/acceleration.

Nick.

[Vidospace]

I would bet its standard camber. So off to Whiteline for adjustable camber? I dont get any camber wear on the tyres though so it might not be an issue.

[JohnL]

I would bet its standard camber. So off to Whiteline for adjustable camber? I dont get any camber wear on the tyres though so it might not be an issue.

Well then it probably isn't an issue. What nd55 says is quite true, but it takes a fair bit of camber to make much difference (and in theory ought to slightly improve resistance to aquaplaning). Still, it wouldn't be a bad idea to have the alignment checked so you can put a number on the camber angle (hopefully only one number not two!).

If the car is significantly lowered it won't have the stock camber angle, you will have gained some neg camber, just how much depending on how lowered the car is. A camber angle of about -1.5° is generally considerd OK for road cars, though some people use more (which isn't to imply that I think this is necessarily a good idea, it may or may not be depending on the car and particularly the tyre).

[vinnY]

johnl, increasing castor angle, is it a diy sort of job or is it best to take it to a sussy place?
the improvements you've listed that it can achieve makes it sound like a very worthwhile mod

[JohnL]

johnl, increasing castor angle, is it a diy sort of job or is it best to take it to a sussy place?
the improvements you've listed that it can achieve makes it sound like a very worthwhile mod

It's DIY depending on your skill and whether or not you know what you're doing. If you aren't (justifiably) confident about this then you'd need someone with a good understanding to do it for you.

You have to 'shorten' the radius rod part of the lower wishbone. If you pull the radius rod (RR) out you'll see that where it fits into the front bushing the OD steps down from the diameter of the main part of the RR. This smaller diameter end section needs to be made longer either by turning the RR in a lathe (best) or grinding and filing (OK if you're careful, this is how I made my caster mod on my CB7). Avoid making the inside corner of the 'shoulder' very sharp (make it a little rounded) as a sharp corner is a stress riser. Both RRs should be shortened by equal amounts.

Shortening the effective RR length in this manner will 'pull' the lower ball joint forward (by more than the degree to which the RR is shortened), thus increasing caster angle. It also increases the wheelbase a little, making the wheel look somewhat 'forward' in the wheel arch, you have to decide whether this will irritate you or not.

There are other things you need to be aware of, i.e. pulling the outer end of the lower control arm forward in this way changes it's angular relationship to the chassis mounting bolt, so the bushing now has to operate at something of an angle. Rubber bushes will tolerate some angular displacement such as this but there is a limit to how much. Poly bushes will tolerate less angular displacement, less the harder the bushing material is.

To get a feel as to how much angular displacement you might get away with, remove the two RR bolts at the control arm, then push the ball joint forward until you feel the resistance at the now misaligning control arm bush start to strongly increase, this is as far as you should go, don't really force it. Measure how far forward you can push the control arm forward at the RR without using excessive force, it may be something like 1cm give or take at the RR (i.e. the RR would need to be 'shortened' by 1cm). If you really force this then expect bushing life to be substantially shortened at the very least, or chassis damage at worst.

You also need to make sure that this mod won't cause the axle shaft to 'bottom out' on the inner sliding splines at any angle of steering input and / or suspension travel. To do this you need to disconnect the lower ball joint to see just how much 'spline plunge' you have at the stock caster angle, if it's a fair bit then you're probably safe, if it it's only slight then be careful! Try 'plunging' the shaft again at the estimated 'forward' control arm position, if the plunge seems the same then it's probably OK, but be aware that this is all a matter of estimation and judgement, it's not really possible to accurately measure this in any reasonably easy manner.

The geometry that affects axle shaft 'plunge' is to do with at what lateral / longitudinal angle the axle projects from the inner end outward to the hub (change in caster doesn't affect the horizontal / vertical angle of the shaft).

If this lateral / longitudinal shaft angle at the stock caster is exactly 90° to the chassis centreline then any movement forward or backward of the outer end of the axle will pull the axle slightly outward on the spline thus increasing the the inward range of 'plunge', but if say the axle is angled backward at stock caster then moving the outer axle end forward will cause the axle to move at least slightly in on the spline, thus decreasing the inward range of plunge.

I'm probably being anal retentive about this plunge thing, Honda is likely to provide a reasonable range of plunge to avoid such problems, but be aware that a change in caster can affect plunge in much the same way as lowering ride height can, and that some people have had problems in this respect with substantial lowering.

Also, pulling the control arm forward may affect alignment of the ARB linkages making it a little more difficult to attach the linkages, and in some cases could require modification of the links themselves (such as placing a slight 'S' curve / bend in them etc.) I didn't have to do this on my car, but it was obvious that I only just didn't have to.

If you change caster then you'll need to re-align the front end as it will affect toe, and also may very slightly affect camber angle (not enough to worry about I'd think).

If you significantly increase caster angle you should notice an increase in steering weight, on and off centre steering feel, steering response, and straight line stability.

Since increased caster increases steered camber angles (increasing steered neg camber at the OF and increasing steered pos camber at the IF), increasing caster in theory will mean you don't require so much static neg camber to keep the OF wheel near zero camber when cornering (i.e. to counteract camber change due to body roll).

Increased caster angle is actually better than running a lot of static neg camber because while static neg camber tends to improve 'roll camber' at the OF, it actually makes camber worse at the IF wheel. Increased caster improves steered 'roll camber' at both front wheels. You might notice that many stock high performance cars these days aren't running much static neg camber, and this is because typically they will be running a lot of caster angle instead.

[nd55]

Another thing which can affect wet handling, is mounting directional tyres backwards. Just a thought.

Increasing castor on EG/EK platforms is kinda easy.

EG front upper control arms are offset, so swap them left to right to get some increased castor. I think this doesn't wok on EK's because the upper control arm is symmetrical.

EG/EK two piece front lower control arms can be split and some washers placed between the the pieces to increase caster. One piece arms obviously can't. (but they're lighter).

Offset bushes, and upper ball joints can all be purchased for both these platforms.

Whiteline will be heaps of help, as they manufacture most of these components for EG & EK civics and can generally back it up with strong technical knowledge.

Ingall's for offset upper ball joints.

EG & EK civics do not have a radius rod.

> Any other suggestion to improve the ride, braking, handling and overall drivability of the car?

for the ride, anything stiffer than stock is not going to improve it.

RE Braking: installing front DC2R brakes, will change your brake bias from 36% rearwards to 27% rearwards.

In other words, the fronts will do more of the work and the backs will get lazier. It might feel better but braking distances will go down.

Installing bigger brakes will improve resistance against heat induced brake fade, but are you seriously experiencing that on the street?

An engineering certificate will require brakes equivalent to the orginal vehicle your larger motor was in. ie B18C will need ITR brakes (282mm fronts).

> I am thinking DC2 front rotors and calipers but will I need a different brake booster to suit?

Depending on what size your current MC is, 13/16, 7/8 or 15/16. It's cast into the side of MC and easy to find.

You will prefer (not need) a 1inch master cylinder and brake booster.
A 15/16" master cylinder will bolt on and might be good enough, but if you gonna do the work go 1".
Alternatively, I think you get use just the 23T caliper bracket and the original caliper but I havn't confirmed this. No need for a new MC or BB then.

The 1" is not completely bolt on, though, the hard lines will be different and need some attention.

> Any other suggestion to improve the handling of the car?

26mm front sway bar. (Look at 98 era CRV's)
ASR rear sub-frame brace and ITR rear sway bar.

Call Yonas at JDMYard.

>RE overall drivability:

everyone's different here. I like the non-power steering feel myself. I forget why I like it, though, everytime I need to park. he he.

Nick.

[JohnL]

RE Braking: installing front DC2R brakes, will change your brake bias from 36% rearwards to 27% rearwards.

In other words, the fronts will do more of the work and the backs will get lazier. It might feel better but braking distances will go down.

Moving brake bias toward the front may improve braking in the dry when you can get a lot of forward weight transfer under hard braking and thus the front wheels become more loaded and the rears lighter. However it will increase the likelihood of locking up the front brakes in the wet when forward weight transfer will be less, and the rear tyres will have a greater % of the total grip under brakes and thus should have more of the braking bias.

The ideal set up would be to have a choice of braking bias that could be switched (by means of a button, knob or lever etc) for wet or dry conditions. The car manufacturer will set the car's braking bias as a compromise of the ideals in dry or wet braking, if you change it you may tend to improve braking performance in some conditions but worsen it in others.

I think most manufacturers seem to bias more toward dry braking performance, why it can be so easy to lock the fronts in the rain with so many cars. It may in this case be unwise to increase front bias even further, you may possibly decrease braking performance in the dry as well as the wet. Personally I wouldn't mess with it unless I knew exactly what affect it will have.

Having said that, some changes to the car may make more front bias desirable, I'm thinking in particular of fitting much grippier rubber that increases forward weight transfer under max braking effort (as long as the brakes are actually strong enough to test the limits of adhesion in the dry). On the other hand, a significantly lowered car will transfer less weight for the same braking 'acceleration' (all 'G' forces are an acceleration), and thus require more rear bias for ideal braking performance...

[Vidospace]

Thanks for the detailed help so far guys!

[crx51]

My mate had kumho's on his ss commodore.. They were appalling in the wet. Tyres are a massive deal. Dont be cheap when it comes to tyres. Buy some sumitomo htrzII or goodyear f1 gsd3 if wet weather is your big priority. Otherwise just get some higher quality tyres and you should have gains wet and dry weather. Many honda's dont have huge suspension travel so when you drop them on their guts you run into problems with hitting bump stops etc.
Also 17inch wheels look great on del sol's but thats what should be expected from them. When you have a light car losing two inches of rubber is going to rough up your ride. Having said that though, choosing a quality damper set up can help compensate. I think the advice thus far has been pretty good. If you are keeping the wheels then invest in some koni's and probably go with good quality springs such as eibach or whiteline. Whiteline would be good as they are made for the road and they used to be paired with koni yellows by whiteline themselves as their suspension package so they are tuned perfectly spring rate wise...
Good luck mate

[JohnL]

Many honda's dont have huge suspension travel so when you drop them on their guts you run into problems with hitting bump stops etc.

If you run out of suspension travel when cornering then you will get a very abrupt and potentially dangerous increase in weight transfer at that axle line (of the bottomed out suspension).

For the OP, if you have a substantially lowered car, and as a result have the OF suspension run out of travel when cornering then you will get a possibly abrupt and substantial weight transfer from the IF to the OF, and at the rear you will get a reversal of some % of rear weight transfer from the OR back to the IR. This will cause understeer, possibly with a sudden onset as you approach higher lateral acceleration.

[Vidospace]

Pleased to report that I now have Bridgestone G009 Potenzas and the ride is a lot better. Just have to test them in the rain.

[JohnL]

Pleased to report that I now have Bridgestone G009 Potenzas and the ride is a lot better. Just have to test them in the rain.

That should be pretty easy to arrange at the moment!

[Vidospace]

Well well. Wet weather grip is heavily improved. Not even spinning at the lights (if AC is on that is).
Next is Konis!