Coilover Review: DC2R, DC5R, EP3R, etc

[cordz]

Mech chris, whats the go with the GC kit? I read everybody raving about them in the US but i can't grasp the concept of assembly. Are they a complete set or do people have the koni or whatever shocks first, then implement the GC kit to the original shocks, and what do these kits include?

Why did you go for stiffer rears?

[MechanicalChris]

Cordz, GC kit is just essentially a shock absorber, spring and spring perch kit (the threaded sleeve where you do height adjustments)

It all comes seperate and you build it yourself, it's not terribly hard although the KONI instructions leave something to be desired as they're a generic instruction and not all apply.

The shock body has two slits, it determines where the threaded part sits, lowest setting is to get the car as low as possible, and highest setting is to get the setting higher if you run out of adjustment, mine are currently on the highest setting since I don't want to preload the crap out of the spring just to get the car at the desired height I want.

You can either buy the entire kit, or you can buy your own individual Koni shocks (For the GC kit) and change them later yourself. Ie - say you have KONI yellows and you want KONI Race shocks, simply buy the KONI Race and swap them over.

Stiffer rears so I can have the car rotate (oversteer) and use the throttle to control the back-end rather than understeer, I would like to go back to having a neutral balance and see how I feel with that, I've had some bad experiences with the rear stepping out on me so it makes do for a really ballsy driving style I guess..

[crashprash]

mine don't noticeably clunk - yours must have a problem?

And 'extremely stiff' compared to what? a base DC5?

they sometimes do when im reversing out of my driveway (steep angle) with full lock and stiff compared to base dc5s

i think his "stiff" is subjective tink. read on another thread that prash's cars purpose was more street orientated. Unless that has changed prash?

yep, initially it was meant to be street oriented but cant say that now :P

The pillowballs and sway bars is what gives the suspension a harsh feel.

Agree

[edfung81]

Car: DC5S

Coilovershlins DFV

Specs: F8 R10

Price and dealer: 3000 (Performance Shocks USA)

Alignment: F-2.3 R-1.5

Supporting relevant mods: Super Pro poly bushings with caster poly bushing.

Application: e.g.street every day and track occasional (not yet happen after installed)

Street rating: everyday street 8/10( on softest setting), spirited street 9/10

Track rating: N/A

Comments: Pro: well build; ride quality better than most Janpanese brands on street and pillowball bushing not cluncky like most; con: height adjustment also effect spring pre-load; limited camber adjustment; no service support in australia; adjustment knob for front shocks is at the bottom out of sight due to design

[ChargeR]

Suspension is a very complicated topic..

Car: Integra DC2

Coil-overs: KONI Race shocks, Eibach springs - on GC kit

Specs: 600lb front springs - 800lb rear springs - valving in shocks is the SPSSV3 valving not the standard koni yellows

Price and dealer: Depends on exchange rate and dealer but no more than $2000AUD for everything.

Alignment: Still being done at the moment..

Supporting relevant mods: All bushings replaced with stiffer poly items.

Application: I like to think it's a daily car but it's really not... it's like a race car on the road.

Street rating: 10/10

Track rating: yet to be done

Comments:

I'll start first by saying i've sat in a fair few Hondas with different coil-overs, be them, teins, BC's, T1R's, even shock/spring combos that are not essentially a "coil-over" as we refer to them.

The first thing I notice is that the ride is obviously firmer than standard, the spring rate isn't overly large but the damping is way off! The wheel chatters over bumps and the car continues to be unsettled over the slightest bump, this takes a very sensitive arse/little man (that guy in the back of your head that feels the car :P) to notice, a friend of mine even noticed it with the BC's in my EK.

Problem with the market is that everybody seems to concentrate on spring rates, ideally.. you want as soft spring as possible, bar the car up and run a shock that will match the spring rate given (hence the rebound/bound adjustments) on some. Some of the coil-overs, including Tein, I have seen dyno plots and their "adjustment" does absolutely nothing.. you turn it full hard, and somewhere 2/3 towards full hard it's actually at full soft! - It depends who has done the valving as Tein don't all do it in their factory, but you get the idea..

I run larger rear spring rates on mine since I want the rear to rotate and throttle steer the car, I think it's abit too sensitive as I can get it to do it around roundabouts if I get a little keen late at night lol.

The ride itself, it's firm, very firm I'd say, but it doesn't "bounce" around as such, the rear will over bumps but that's because of my large spring rate - the shocks are actually designed for spring rates up to 1000lb/in - I would definitely not run that on the street...that would be for some high speed/highly developed aero cars.

Another thing I should mention is that it's probably a very very personal choice when it comes to "ride" - My car is essentially a circuit car in nature so I can deal with the harshness of everything, some others may not like it - in that case, I would advise Koni yellows with 400lb springs or something similar.

I don't understand how roll-bars can give a car a harsh feel though, it would definitely increase the jacking effect which is more of a traction issue rather than harshness, there is no force transfer to the chassis apart from reducing roll when it comes to "bumps" - it would simply refrain from allowing the wheel to droop as much as it should. Bushing material will play the largest factor in the NVH dynamics of the suspension.

Oh by the way - some of the "tramp" you guys get with wheel-spin is actually from a too soft a shock, not too stiff a spring...

Don't mean to say someone is wrong or anything, it's a forum and I'm just expressing my opinion

Good review MechanicalChris, be sure to post up again when you hit the track. Coming to Honda Nats? I am looking at the Koni race for my other car, and would like to have a chat in person about them. By the way I don't fully understand what you mean by sway bars having no effect on performance over bumps, a sway bar effectively adds spring rate when measured as single wheel bump, though not as an axle pair over bumps that affect both wheels obviously. Or have I just misunderstood you?

[lukits01]

Coil-overs: KONI Race shocks, Eibach springs - on GC kit

So these are re-valved Koni Yellows, yea?
not the 28XX series?

[MechanicalChris]

By the way I don't fully understand what you mean by sway bars having no effect on performance over bumps, a sway bar effectively adds spring rate when measured as single wheel bump, though not as an axle pair over bumps that affect both wheels obviously. Or have I just misunderstood you?

No, what you are saying is correct, I was assuming in the general case of a "bump" in the road that both wheels absorb.

So these are re-valved Koni Yellows, yea?
not the 28XX series?

Correct.


I've attached a photo of the kit; take not OEM top hats are being used, you can actually get spherical top hats now. Also, extended hats don't need to be used as the "race" shocks have already been shortened to allow for travel. If you re-valve sport shocks, you will need the spacer or cut the shock.

[cordz]

do you blokes recommend any 'must' modifications to accommodate a coil-over upgrade?

i.e - extended ball joints? their descriptions always say a must have when coilover lower your car.

[szymonsta]

Car: DC2R
Coilovers: Zeal Function XS
Specs: revalved by Zeal to suit Zeal Xcoils 12kg/mm(F) 8kg/mm(R) (10/6 std rates)
Price: ~$2800 a while ago
Dealer: Centrax Auto
Other suspension modifications: Vision adjustable camber arms front and rear, Honda strut tower brace front and rear
Alignment: can't remember exactly. approx 2.8deg negative camber front, 1.6deg negative camber rear. 5mm toe out front. standard toe in rear (2mm i think or maybe 4mm)

Comments: Very happy with these. Easy adjustment of ride height independent of spring preload. easy access to damper settings (1-6 clicks). i daily-drove the car plus regular winding road use and a few trackdays. great compromise and about as firm as most people would tolerate on a daily, though actually a lot less crashy than many other coilover setups ive experienced. I think it comes down to the valving being well matched to the springs. excellent on winding road, and matched well with 15" RE55s as well as high-spec road tyres 205/40 17s. very good on circuit, great body control over bumps. i guess if i was to have a pure track car i would consider something even stiffer, but then it wouldn't be suitable for road use.
..oh and my wife hated them. too hard and bumpy. :P

[cordz]

Car: DC2R
Coilovers: Zeal Function XS
Specs: revalved by Zeal to suit Zeal Xcoils 12kg/mm(F) 8kg/mm(R) (10/6 std rates)
Price: ~$2800 a while ago
Dealer: Centrax Auto

Comments: Very happy with these. Easy adjustment of ride height independent of spring preload. easy access to damper settings (1-6 clicks). i daily-drove the car plus regular winding road use and a few trackdays. great compromise and about as firm as most people would tolerate on a daily, though actually a lot less crashy than many other coilover setups ive experienced. I think it comes down to the valving being well matched to the springs. excellent on winding road, and matched well with 15" RE55s as well as high-spec road tyres. very good on circuit, great body control over bumps. i guess if i was to have a pure track car i would consider something even stiffer, but then it wouldn't be suitable for road use.
..oh and my wife hated them. too hard and bumpy. :P

good stuff. Do you mind adding these categories to your template??

Alignment: e.g. "stock" or "-1"

Supporting relevant mods: e.g. poly bushings, shperical bearings etc.

Application: e.g.street every day and track once every three months

Street rating: e.g. /10

Track rating

[szymonsta]

there ya go, edited

[szymonsta]

do you blokes recommend any 'must' modifications to accommodate a coil-over upgrade?

i.e - extended ball joints? their descriptions always say a must have when coilover lower your car.

for dc5r roll center adjustment due to the characteristics of the mcpherson strut front suspension, ive heard is a good idea if the car is lowered more than 15-20mm.

for dc2r, no real 'must haves' imo. i got camber adjustment kits mainly to try and reduce the negative camber at the front at my ride height, however i wasnt able to reduce by more than a few tenths. however it did alow for more accurate alignment which i wanted anyway.

[ChargeR]

do you blokes recommend any 'must' modifications to accommodate a coil-over upgrade?

i.e - extended ball joints? their descriptions always say a must have when coilover lower your car.

The only modification I would say is essential is to ensure that every suspension bush and ball joint is in good condition, and replace anything that is necessary. Particular items that might need attention are the rear trailing arm bushes, I haven't seen it on many DC2Rs but lots of other 90s Hondas I have seen have wrecked RTA bushes. Speaking from experience this makes for interesting handling.

I see little point in trying to improve the handling of the car if you are starting from a worse than OEM base due to damage or wear. Treat RCAs, inverted tie rod ends and *insert well marketed suspension cure all here* with caution, a stock car with the right spring, shock and swaybar choice with a good alignment will out-handle a car that has had every random spherical whatsit etc. added to it without thought or testing.

[cordz]

The only modification I would say is essential is to ensure that every suspension bush and ball joint is in good condition, and replace anything that is necessary. Particular items that might need attention are the rear trailing arm bushes, I haven't seen it on many DC2Rs but lots of other 90s Hondas I have seen have wrecked RTA bushes. Speaking from experience this makes for interesting handling.

I see little point in trying to improve the handling of the car if you are starting from a worse than OEM base due to damage or wear. Treat RCAs, inverted tie rod ends and *insert well marketed suspension cure all here* with caution, a stock car with the right spring, shock and swaybar choice with a good alignment will out-handle a car that has had every random spherical whatsit etc. added to it without thought or testing.

I have on my list to do 1. coilovers, 2. camber arms (F&R) 3. bushings 4. 25mm rear sway bar upgrade.

Do you recommend stock-piling the parts and installing them all at once with the coilovers and a corner weighting/ alignment? Was wondering whether coil-overs is a potential DIY.

[EG30]

Did mine in stages for our dc2r.

Did the 25mm cusco bar 1st, great improvements over stock 22mm bar works well with stock suspension even. Surprising still forgiving in wet conditions even on gripless S drives

Installed GC/Koni coilovers next, another step forward

Planning to install front and rear camber kits next, then corner weight , then wheel alignment.

New hardrace engine mounts set to replace the flogged out ones that came with car at some stage.

As much as it's more ideal to do everthing in one hit you dont get to feel the changes of individual components. The sense of which I find is valuable data you build up for your own benefit and over time makes you more informed to make future decisions in parts selection and problem solving.