wantboost

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So I posted over in suspension, lot of help that was. And I've searched with little result

I have a 97 ex coupe I'm currently building. Mostly a street car but I do my fair share of aggressive mountain runs and will be doing lots of driving at Atlanta Motorsports Park, given our membership

Drive train will be a fully built turbo ls/vtec, based on a gt30r turbocharger with 450hp as the goal.

I'm not bothered by overly stiff suspensions, I have an s13 that I drift and it could knock out fillings (still daily drove it) and our C6 Z06 is slowly becoming a full fledged circuit car and has a suspension system that rivals any back massage.

Right now the car is on stock shocks and GCs. (Got it that way) with 8" front 400lb and 7" rear 300lb springs. Car rode soft in my onion but I cannot find anyone that's using stiff/custom rate springs.. even the autox guys are pretty mum about it.

Now I would like to get a set of custom konis (looked through all models) but I have a high end set of Penske coil covers sitting around from another build and wanted to use them on the civic, clearly they won't be bolt on, so I was going to do a pushrod/cantilever setup. I already have the rear figured out and am sorting out the front right now.

They are double adjustable (each circuit won't affect the other)
The fronts set up for a 5" 2.5od spring
The rears are setup for a 6" 2.5od spring

Having worked at a local suspension company that handles a lot of Penske units, I can play around with the shim stack, piston, fluid weight and nitrogen pressure all I want, as well as having access to the shock dyno.
So I can basically make these work for any spring rate, application, etc, so I would really like to use these on my car, I'm just looking for a starting spring rate for setup and baseline... I won't be able to truly dial the setup in until I get the car together, as well as decide on a front/rear sway bar setup (i won't run with stock bars or without any, period) as well as finalize the break setup

So I'm just looking for some advice, if anyone has some to offer... again I'm not shy of stiff ride quality.. I could need a 1000/800 spring setup and I'd still drive it to the doctor. I don't care if it rides like a steel pole as long as it handles

Thanks in advance, I really need some guidance. I can setup a racebike suspension system in 5 minutes, but I get lost with cars a little lol

chargeR

What's your motion ratio going to be with your pushrod setup? Or do you just want people to recommend spring rates assuming OEM spring/damper location and you'll work backward from that?

Before someone else says it, everyone's preference is different and people will like different spring rates on their cars and get different results with the same springs.

That said, what tyres are you going to use? No point having ridiculously high stiffness in pitch and roll if you're running street tyres in my opinion. I ran 900/1600 on my DC5, not sure what would give you the same wheel rates in a '97 Civic somewhere around 1200/900 I'd guess without knowing motion ratios, and it was skittish to say the least on street tyres. On Hoosiers it was great though, and I daily drove that setup for 40,000km without a problem.

VTECIntegra9

Completely agree to the above - you need to know the motion ratio so you can find the wheel rates and ride frequencies. This is a basic vehicle dynamics problem and can all be done with math to get you into a good ballpark figure. But the wheel rates are going to be a tradeoff based on tire compounds, the smoothness of the track, and make sure it still makes it down the road (but you've written off that it doesnt matter to you). For race tries calculate back from about 2.4Hz, street tires prolly closer to 2Hz.

Xian

For a track car, assuming stock shock/spring geometry, I'd start in the 800f/1000r range. Stock or smaller front bar, very large rear bar (look at the ASR/Speedway stuff). This is also assuming R comp tires. If you're on street tires, go softer but try to maintain the same percentage front to rear bias.

Christian

wantboost

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Yea I'm fiddling around with the ratio right now, I just figured spring rates for a stock style damper would be a good starting point. I need this info to at least figure out the shim stack, fluid weight, and nitrogen pressure (which can obviously be adjusted down the road)

The rocker arms will be machined with multiple attachment points so I can play with motion ratio as needed. I am thinking about some stiff and direct, as 1 to 1 would yield a little more wheel travel than I like.. I would prefer to have the spring/damper move more than the wheel.

I'm hopefully going down to the shop tomorrow and dyno them as they are configured (pretty basic shim stack, equal on compression and rebound. Linear valve, .500" shock shaft, roughly 2.5-3" of travel from fully extended to bottomed out. I don't think I'll need more travel than that,

Most of the driving will be street surfaces.. not the best roads around here but I know where every dip andhole is. Now, road Atlanta isn't too bad, working for FormulaDrift I examine the track for debris and such etc, and I literally grew up in the pits RA has some rough spots where they patched things and I know for a fact our drift events lay down tons of rubber and make 10a/b and under the bridge super slick

AMP is brand new and the racing surface is supremely clean and level.

So I'm just looking for a starting point on springs, not something concrete. I know playing with the motion ratio will allow me to fiddle around with the current spring being used and such, just need a base.

The car will probably stay relatively full weight... but no ac, PS, a lot of misc crap gone but I want to leave as much of the full interior in as I can (I'll remove sound deadening as well)

Although right now I'm debating a cage, but that might be down the line if I start to do competitive events as opposed to ***** out track days

Xian

I've done a ton of races over the years at RA and the rates I referenced above will work fine there... the track itself is really pretty damn smooth IMO.

Christian

wantboost

iTrader: (2)

Sorry I didn't even see your post (tired when I replied)

Doesn't having 1000lb rear (assuming you have a dc2) make the car more rear biased? Any push or under steer issues?

I have a spare complete em1 subframe, so I was going to put the larger front Si bar on my ex to start and was considering the asr stuff

If I can find the means, I thought about hollow bars and blade adjusters to change bar stiffness on the fly but I think starting with a static setup will be more beneficial in the setup/shakedown phase.

I'm just worried that on a civic coupe (with very littke weght back there) putting 1000lb springs in the rear will promote a setup that's oversteer prone/snappy rear although its not really a bad thing, a car that pushes/plows is a slow one lol and I guess the chassis weight calls for it, as I don't think I'm going to gut my interior and cage the car just yet. Although I could do some super awesome tin work in the back

"Power is nothing without control"

Now have you driven on surface streets with that setup? Just curious

Thank you for your advice sir, maybe pm me a few more details/advice?

Xian

Not that I've seen. Crank the rear rates up until you get to where you like the balance. There are a ton of ways to skin this particular cat. You could also get there with rear toe or camber but I'd go with spring/bar for a track car.

I'm not a fan of big front bars on a track car... decoupling the front, in my experience, helps the front end (and specifically the inside front) put down power better.

IMO, having an adjustable rear (or front) bar would be the bee's knees but I'd play around with a single setup before introducing that level of adjustability. It's not like this is a new chassis so you should be able to get pretty close in the fist couple setup iterations. Once you've got the setup close, you can use the adjustable bar to maintain the balance over the course of an on-track session/race.

Meh. I ran 700/1000 on my 90 EX which was under 2300# including driver. I thought the on-track ride was plenty fine and the balance was exceptionally good. This was with no front bar and with a large Speedway rear bar.

Thought you weren't "bothered by overly stiff suspensions"?

I wouldn't particularly suggest driving on 1000#+ rear rates but you could do it. A big part will come down to shock valving. My current car is remarkably comfy on the street... setup for autocross with 850/500 and Moton DA's it's not really much worse than it was on the stock springs and revlaved Bilsteins. Then again, I live in a land that's largely free of potholes...

Christian

wantboost

iTrader: (2)

Very helpful sir, I appreciate the post

I'll try the spring rates, as I can re-valve my coil covers in about 30 minutes without issue.
I'm not sure about sans front sway but I guess time and seat experience will tell.

The streets are fairly tame, no potholes. But if I go to downtown Atlanta, its the I'm not drunk officer, I'm just avoiding pot holes game. I actually broke the drivers side upper mount in half going down spring street. I guess that's the price of race car/hellaflush ride/height stance on the street. Although I have no issues anywhere but downtown Atlanta and my dads house, he has those damn gutter curbs so I have to drive through the yard lol

I'm trying to work on the car but its been *** cold, the car is outside and I'm xleabif the garage out. Maybe soon I can make progress.

Xian

Re-reading what I wrote previously, my experience with no front bar has been limited to the EF chassis. Everyone that I know with an EG/DC track car is still running a front bar of some sort. I believe it's most often a 21/22mm front bar though so they're not going up in front bar rate.

Since it sounds like this will ultimately be a street/track car, there's likely to be a compromise somewhere in the setup... and that's not a terrible thing. My current setup is absolutely a compromise. I'd be waaaay higher in rear rate if the car didn't see street miles and autocross use.

Hit me up if you want to compare setup/balance/subjective feel sometime. I'm typically at most of the seat-time.com DE's @ Roebling instructing.

Christian

dirty19

iTrader: (1)

^^ X2

Xian

Oh, and on the part in bold... if you're bottoming out that hard, it sounds to me like something is "wrong" in the current setup. Maybe you need more spring or more travel or you're just getting into the bumpstops too soon or the upper arm is hitting the chassis (bumpstop too short)? There's definitely something not right with that though if you're hitting hard enough to break an engine mount. My $0.02 and all that...

wantboost

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Well my subframe is about 2" off the ground..... without a motor in the car

I simply hit a chunk of **** stuck to the road in downtown Atlanta with my oil pan, I definitely don't need anymore travel.

I did the old zip tie to check shock travel trick and honestly, on smooth roads I saw less than an inch of travel. It's just how low I am, I will obviously raise the car up a bit for track events, as I'll need a proper tire size for the power I'll be making, but street car status will always be low. With a motor in the car, my front bumper with a lip is less than an inch off the ground,

I just happen to have really good roads where I live and I've never had a problem riding low. Its only when I go downtown that things happen, like when I pull into my favorite restaurant downtown, sometimes if I didn't get the right angle I would actually drag floorboard lol. One night's in another low car I had at the time, I was leaving a night club and high centered on something. It took two Atlanta cops to stop traffic and two of my friends pushing

So I've basically determined that when I go downtown to do most things, I take the element.. if I don't have to go down spring Street I can take the civic, I'm just paranoid the whole time,

wantboost

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So I dropped the penske shocks off at my old shop, going to be dyno'd, revalved and reshimmed and all that goodness, luckily hyperco stocks the springs I need which is good.

I have my old 99-00 Si front subframe, I though about taking the LCAs and the stock (26mm) sway bar with some decent end links, I've been looking at ASRs 32mm rear kit, trying to find people that have used it and get some feedback

I'm also looking at building adjustable tubular arms for every possible arm, even flcas... I have an idea in my head just need to see how it works. I plan on having as many spherical bearings/heim joints as possible, that way the suspension is 100% rock solid and the suspension does what it's supposed to, as opposed to having arms deflecting.

Figuring out a good way to do the front uppers is still beyond me for the moment.

Xian

Kingpin does the front uppers... And basically every other spherical you could need.

wantboost

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Kingpin doesn't offer anything for an ek chassis

wantboost

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But I have access to Aurora bearings super cheap due to the quantity we used at the shop I worked at, so I can machine the lowers to fit the bearings (that kingpin was nice enough to list past numbers for)

I just wanted to get away from a cast 2 piece lower. I need to figure out what to do with the trailing arms, I definitely don't want to run something like a bloc spherical unit

Xian

Ahhhh... Forgot you had an EK. I think he may be working on some stuff now... saw some posts on FB about prototyping parts?

chrisb

I have some old H&R coilovers that I would love to have dynoed to see if they are even doing much of anything. I make spherical front LCAs (straight part only) and spherical UCA mounts for the EK. I have a set of EK rear LCAs that I can prototype whenever. Anyway, I am always open to working with people that have connections. I need to sort out something as far as shocks on my race car. Don't over think the front LCA. I have 1100 WHP Honda drag cars running those arms. They are fine. I would encourage you NOT to reinvent the wheel. There is not that much point IMO.

Here are my EK spherical front UCA mounts for the Skunk2 arms.

Also, I am about half way through prototyping spherical RTA bearings. Just need to get back on that project.

wantboost

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I like what I see.

Pm me with everything you can make spherical lol

We can dyno your shocks, I just need to bribe martin to do it but it shouldn't be an issue

wantboost

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And I was thinking about tubular arms for the sake of saving weight, the front arms weigh entirely too much IMO