Aesyrin

I'm still fairly new to cars, at least in an enthusiast aspect, and this is also my first Honda (and oldest model vehicle) so please take this into consideration if I'm unaware of anything I probably should otherwise know.

I have a 96 Del Sol S that I've had for almost two months now. It is also my first manual vehicle and project car. Since getting the car, it's ride has felt rough over any road imperfections (but otherwise great on flat surfaces). And when I say rough, I mean I feel like I'm taking the brunt of the shock from the dips in the road and you can hear/feel the car shaking/thunking as it hits small pot holes. From what I had read, most people attribute that issue to blown shocks. Since I had also been planning to drop the height about an inch or so since the factory ride height is pretty tall, I decided to replace the original coilovers with a set of Progress CS-II 350F/250R coilovers. However, after getting them installed, the ride quality over road imperfections hasn't gotten any better - if anything it seems harsher, though the handling otherwise has improved. Since this is my first Honda, which from trying to research my problem, people say Hondas ride pretty stiff, and also the oldest vehicle I've owned, I'm not sure if I'm just expecting too much. But I've also driven my friend's 2012 Genesis 2.0T which has Megan coilovers (7kg/8kg) while I was trying to learn manual, and the ride on the Genesis is several times smoother than on my Del Sol and no where comparable when going over bumps and holes.

I did the install myself, which seemed pretty straightforward after I found out how to reassemble the new coilovers with the required parts from the original shock (instructions weren't particularly friendly for someone who didn't know what the names of the parts were called yet). But aside from it being my first time putting these together, I'm fairly certain everything is installed correctly. I do have the springs put in properly (I didn't mix the front with rears as I've read has happened in some posts) and I do have more than sufficient pre-load, since I only wanted a minor drop in ride height. I've also let the suspension settle and have gotten an alignment, which has been over a week ago, but the ride quality is still the same.

I've read that worn bushings can also affect ride quality, but I wouldn't think replacing them would affect holes and bumps to a great extent, would they? One other thing that I noticed is when my friend, cousin and I tried replacing the clutch plate ourselves (which we eventually did, but was a pain in the ***), was when we were trying to disconnect the LCA from the knuckle ball joint to get the axle out, it was seized on and looked rather squished and worn. Driver's side was no problem to get off, but we eventually had to just do a work around to remove the axle on the passenger's side. Would that be a possible culprit? Would replacing the suggested suspension bushings make a world of difference? Or are there any other things I should be looking at?

I appreciate everyone's help and insight!

GiantDad

Sounds like shot control arm bushings, when going over a bump you'll hear and feel metal to metal contact.

Aesyrin

Thanks Giant. Haven't noticed the metal to metal contact since I've been driving with the top down lately, but I'll try to take it out with the roof on and see if I can hear it. I definitely plan to replace any bushings I can when I go to work on the suspension, but wanted to see if there are any other possible parts I should replace while I'm down there.

I did try to pay attention to the bumps when I went out today after starting the thread. For smaller imperfections and ones that have smoother transitions (rounded bumps and dips) ride quality actually did increase compared to the stock coils. But it seems like at more sudden or dramatic imperfections, it doesn't react the same way you would expect it to given how it reacts to smaller ones. It feels like it's stiffer than it is or that it doesn't respond quickly or smoothly enough. It's kind of like if it goes above certain threshold of turbulence the ride quality just goes out the window instead of being a gradual decrease.

GiantDad

Sounds like your suspension is bottoming out, which does severely decrease handling characteristics.

You have three options.
Stiffen the suspension
Raise the ride hight

Or a combination of both.

Then as stated before, completely shot rear and front suspension will also cause the death wobble.

eghatch9295

iTrader: (1)

these cars aren't particularly smooth. never were. OP, what were your previous vehicles?

CandyRedRC46

A quick read through this post and I didn't see any mention of rims/tires? What brand/model are your tires and what size are your rims/tires? This plays almost as big of a role in NVH as suspension. Generally the higher the aspect ratio (tire sidewall height), the better the ride quality, this usually has a direct relation to rim size, as you usually want to maintain about the same overall wheel diameter with any given tire choice. EG civic tire choices below, ranked in softer ride to harsher ride, from top to bottom (note how the side wall will get smaller as the rims size goes up):

175/70R13
165/70R13
175/65R14
185/60R14
195/55R15 (Integra)
205/50R15 (Aftermarket)
195/50R15 (Aftermarket)
205/45R16 (Aftermarket)
215/45R16 (JDM ITR)
205/40R17 (Aftermarket)
215/35R18 (Aftermarket)

Basically a 13in or 14 inch should offer much less harshness. A 15 inch rim would be a nice compromise. 16 inch will be a little harsh. 17 very harsh and 18 would probably be ******* awful.
Of course tire choice would have an impact here as well, whether they are old/cheap/race/economy tires or high end expensive luxury tires.
By the way, what PSI are you running in your tires? 28psi would ride smoother than 44spi, etc....

Aesyrin

Gotcha, that was one of my thoughts - just hard to know without having knowledge to compare it to. Previous to this the only car I've owned was an AT '08 Lancer GTS. And the sportiest car I've driven is probably the Genesis I mentioned in the OP.

Ah yes I thought about this but forgot to mention it. I was debating between 15 and 16 but ultimately went with the 16's. I'm running 205/45R16 and the original tires it was running on were 175/70R13. Wheels are Fast Shibuya and the tires are General G-Max. I was intending to get Continental ExtremeContact 215/45R16 but the place I bought the wheels didn't have that as an option, so figured I'd roll with the G-Max and see how they were at that tire size before eventually changing over to the Continentals. I also had them at 32psi from what I was finding was a good pressure for Del Sol tires, but I just rechecked and they're at 34psi right with the 20+ degree jump in temp we've had the past two weeks in DE. But I searched again and now what I'm finding is the thinner the sidewall than original the lower the pressure should be?

Also this is the height its currently riding at:

CandyRedRC46

Wow thats a great looking del sol, but unfortunately the 16inch and 45 series tires (Though they look great!) is not helping your ride quality. Steping down to a 15" with 50 series side wall would help. I also don't think the gmax tires are built with comfort in mind. You mentioned having "more than sufficient preload", how much pre load did you add? Are the springs being compressed or did you simply take all the slack. Preload (depending on how much was added) can make the ride harsher and feel like a higher spring rate than it actually is. Oh and what about dampening, is the dampening adjustable? Maybe if you get lucky, you can loosen up the dampening, loosen up the preload a bit, let some air out of the tires and get some ride quality back.

Chance EG

Del Sol looks good, ride height looks reasonable, and your shock rates aren't overly stiff at all. I have 450/350 CS-II on my car and it's riding pretty great on the street. 225/45/15 tires as well on mine, summer performance tread (spacing out on the tire make/model right now).

Check your RTA (rear trailing arm) and rear LCA (lower control arm) bushings. Something doesn't really sound right here, the car shouldn't be riding too rough with the rates you described.

Aesyrin

Thanks guys!

Candy - I'll definitely consider that when I have a chance to switch out the wheels. I was hoping to have a little more sidewall than I currently have (hard to tell just how much sidewall you get between 15" and 16" since pictures online all vary) so not a change I'd be against at all. In regards to the coilovers, unfortunately the Progress CS-II have no damping, and is only one way adjustable where it only has the spring perch which you lower or raise to change ride height. I mentioned having "more than sufficient preload" because one thread I came across one poster wanted a lower ride height and had the perch so low that there was no preload when the wheel was off the ground. The CS-II are I believe a 1"-2.5"(or 3") drop and I have the perches for all 4 corners up to to within the last 1" thread before hitting the highest ride height of 1" drop. I can try dropping my pressure to 28-30psi and see if that makes any difference.

Chance - That's what I figured. I didn't think it should feel as stiff as it does during those certain moments. I do have an Energy Suspension Bushing kit which I plan on using to replace most bushings so hopefully any that needs to be addressed gets replaced. I guess my biggest concern is whether or not anything aside from bushings might need to be replaced (I ordered new front upper/lower control arm ball joints to do them just in case), since while I am a little concerned about ride quality, I'm more concerned whether or not the lack of absorption I felt would lead to any part of the suspension getting damaged over time if it wasn't addressed.

eghatch9295

iTrader: (1)

light car + stiff suspension + rubber band tires= harsh. no bushings will save you.

CandyRedRC46

You really think 350/250 is that stiff? I wonder if maybe they accidentally shipped him something higher like 450 or 550?

Aesyrin

The rears were marked 250 on the spring. The fronts were unmarked so maybe it's a possibility?

Chance EG

When I got my CSII springs in, both the fronts and rears were labeled.

CandyRedRC46

hmmmmmmmmmmmmmmmm

eghatch9295

iTrader: (1)

in comparison to what he's used to, definitely.

Aesyrin

I might have to contact them and double check to see what they say about it possibly being heavier than 350 then.

True, but like I mentioned I had driven my friend's Genesis. Granted it's about 800lbs heavier than the Del Sol, but the coilovers on it were also 7kg/8kg which is higher than the 350/250 that I have, and the ride quality isn't exactly similar.

eghatch9295

iTrader: (1)

del sol= 2302-2522 lbs. genesis= 3495-4541 lbs. a behemoth in comparison, https://www.edmunds.com/hyundai/gene...alkaround.html
the suspension engineering and design is beyond comparison. we are talking 25 year old go-kart vs a brand new car with an entirely different suspension and steering setup.

Aesyrin

Cool, and if that's the case I'm completely fine with that. Since I had nothing to compare to I wasn't sure what I should be expecting. I was more concerned that whatever was causing it was something I'd need to tend to that could hurt the suspension. But otherwise I'll double check the spring rate with Progress, check whatever bushings and ball joints need replacing and get those done, possibly change to 15's down the road, and live happily.

I appreciate the suggestions and feedback everyone, thanks!

CandyRedRC46

You can not compare spring rates of one car vs spring rates of another car with obvious different suspension design. The geometry and therefore leverage and "effective spring rate" at the wheel will be totally different. This is why the DC5's spring rates are double that of the DC2 (McPherson strut vs Double wishbone).

Aesyrin

So today I figured out what was causing the harshness, just in case anyone makes the same dumb mistake I did. Apparently the kit for the Del Sol needs to be run without any dust cover/shields over the dampeners, even though it reuses almost all the other small parts from the original coilovers. I was checking the coilovers today and saw that the metal dust shields had been deformed at a few places. The original instructions that came with the coils didn't have the exploded view of how the pieces went together (remember, this is my first time taking apart/assembling coilovers) so I had done a search and I guess mistakenly found instructions for Progress coilovers for a model that did reuse the dust shields. When I put it together, the dust shields went on fine and I thought nothing of it since it didn't seem to get in the way of anything else. But after seeing their shape again today, I decided to do another search and found the correct instructions/exploded view which did not have any dust shields whatsoever. So I disassembled the coils, removed the shields, and reinstalled them and now everything is running as I was expecting them to!

CandyRedRC46

Oh okay so nice and relatively smooth now? Hopefully nothing was damaged. I didn't see this issue from a mile away,but I am glad you figured it out lol.

Aesyrin

Yup, the difference is like day and night. Nothing damaged but the dust shield which isn't being used now. But yea I wouldn't have thought anything either since they're assembled and fit completely the same. Apparently it was keeping the dampener from compressing though, thus the harshness. Appreciate your suggestions throughout with the process!

nagami

subscribed, this seems like a very interesting thread

CandyRedRC46

Youre welcome, glad it worked out.