Searched the threads on spring rates & didn't find what I was looking for (or threads weren't really answered). I currently have 500F/350R in/lb on my "DG" coilover setup. I finally made it out to a lapping event last year & I'm looking to do it more often now. I know I need more spring rate in the front, but curious what people with more lapping experience think.

Car is basically full weight, has ES bushing throughout (might swap to Prothane), currently stock sway bars but will be getting RM bars. Tires will just be "max performance" street tires (ie currently Kumho XS, probably try RS3's next, etc), in 235/40/18 size. Shock's are stock valved Koni yellows & I currently do drive the car daily in the summer as well. Currently run stock rear LSD, 4 spider center & stock front diff with TRE rip grip. I will be installing an evoVIII mechanical rear diff (with plates re-stacked in the correct order).

I know at one time people thought the limits for stock valved Koni's were ~600 mark, but seems they have since run much higher rate springs, without issues. My origional plan was swapping to 600lb/in in the front but talking with someone with more experience then me, he's recommending I go right to 700.

With that setup you are pretty much in the ballpark, depending on how low you run the car. You need enough spring to stop the car bottoming out, and the minimum necessary to allow the tyres to work.

Once you get your RM a/r bars fitted and you choose a ride height, see how much suspension travel you use up and go from there. You're already close, tweaking from here is as much a matter of preference as anything else. What geometry settings are you running ?

Thanks Charles, its been so long since my cars been stock ride height, can't say for sure, but I would ballpark about 1.5" drop. What do you mean by geometry settings, my alignment?

I know DG has the spring rate calculator on his site but I don't have/know all that info. I know there are members on here with a great deal more experience then me (when it comes to knowing all you can about suspensions, I'd be a newbie in comparison). I'm just starting out lapping & I'm just doing it for fun, not competitvely, so I don't currently need to be dialed in 100%. As said, I do currently still drive it daily in the summer (~60 miles to work & back), so I don't want something that doesn't work well on the street. I know the 350's in the rear feel much firmer/more bounce then the front. I believe even at 700 in the front, it would still "feel" softer then the rear?

On my first outing, I know with my current setup, the car felt very loose in the rear vs the front & it didn't inspire confidence in the corners. Now I'm not sure if a big part of that was my driving (likely was). At first I believe I was coming in too fast, which made the rear feel really loose (even before the apex), so I would stay off the gas for the majority of the corner, which in turn made the car basically feel unstable the whole corner, & not confident in pushing faster in the corners. I only had about 45 min lapping time, but as the day wore on, I found myself getting on the gas earlier each corner, which made the car feel much more stable & was able to push much harder. So now having to wait till the spring to go out again, I'm not sure if its typicall for these cars to feel this loose in the rear, when off the gas or if it was partially my spring rates?

My alignment was ~-1.4 rear, -1.6 front, toe 0 all around.

I'm thinking I'll probably go either 650 or 700 in the front to start, maybe not much actual "real world" difference between these too?

I too have heard that the Koni Yellow isn't valved for anything past 500 lb/in, getting into the 700s would not only blow the struts quicker, but the damping would just be ineffective. I would keep it at 500; if they blow then have the valving changed to match higher rate springs when they're being rebuilt. Koni/GC was the plan for my Evo, but I knew they wouldn't accept the 675/675 setup I wanted so I ponied up for a bigger dollar kit. Ground Control might valve them correctly for little cost (they might do it for free if you order the Konis through them), I wouldn't run a mismatch spring/damper combo.

Back when I bought my setup, something like 5 or 6 years back, 500 in the front was pretty normal. But I know guys have since been running more, I think 600 or possibly 650 may be fairly common now. I know guys have put good milage on them without issues & believe the dampening on the stock valved Konis will still be fine at these rates. I believe running 350 in the rear (some are even running 400 on stock konis), would be harder for the Konis to control vs 650-700 in the front?

From what I've read in the past, 600 or possibly 650 in the front would still "feel" softer then 350 in the rear, not sure how 700 compares. I know 500 is too soft in the front, just in feel alone, with the current rates the car doesn't feel balanced front to rear .

Scott, who recommended I just go to 700 is actually running 900 in the front on his stock valved Konis & I believe he still said the fronts aren't as firm as his rears (he's got 400 rear)

Talk to Ground Control, get their opinion on it. They deal with high rates day in, day out so they'll be able to tell you better than anyone here. Dodge Neons, for example, had factory Konis and would blow pretty consistently with higher spring rates and aggressive use.

A friend of mine has Koni/GC 375/450s in his Civic Si, and the ride is better than stock shocks and H&R "Race" Springs, but still firmer. It's tough to explain, but the roughness only shows on rebound over a bump. Anything else feels very smooth.

I'm running 800#/350# on my DG Koni setup and the front still feels noticeably softer than the rears.

I have a 650 front rate but it's for drag/daily, 350 rear on my DG

daren_p said:

Scott, who recommended I just go to 700 is actually running 900 in the front on his stock valved Konis & I believe he still said the fronts aren't as firm as his rears (he's got 400 rear)

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Yes, I've been running 900/400 since 2009. Prior to that I ran 750 in the front. I started with 500 front originally.

The rears have always felt more stiff / bouncy than the front, but it wasn't until I got up to 900 that the suspension started to feel more balanced.

I'm thinking 700/350 would be a good starting point for you Daren.

I've been thinking about trying 900/375 myself; but I need to keep my fat tires off the rear fenders. Would be nice if there was a bigger 2G rear swaybar than the RM DSM one...

Scott McIntyre said:

Yes, I've been running 900/400 since 2009. Prior to that I ran 750 in the front. I started with 500 front originally.

The rears have always felt more stiff / bouncy than the front, but it wasn't until I got up to 900 that the suspension started to feel more balanced.

I'm thinking 700/350 would be a good starting point for you Daren.

I've been thinking about trying 900/375 myself; but I need to keep my fat tires off the rear fenders. Would be nice if there was a bigger 2G rear swaybar than the RM DSM one...

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Ive heard if you move to over a 350 rear your rears need custom valving, but it makes me wonder because people use over 350 For the front all the time.

Scott McIntyre said:

I'm thinking 700/350 would be a good starting point for you Daren.

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This is what I am going with on my DG setup and after reading a couple threads is the most recommended Rate combination. I believe also recommend by JTMCINDER after some back and forth PM's.

If you enjoy reading about suspension then google search wheel frequency. There are an overwhelming amount of calculations you can to to determine what is optimal on paper. The 700# spring would put you around 170 cycles per minute assuming a 1:1 motion ratio. Which you don't have. Also guessing at a corner weight of around 800# with 100# unsprung. That puts you in a ride firmness just slightly tighter than a factory sports car but still well shy of a racing car set up for no downforce. Since you actually have a motion advantage over the spring the real cpm will be lower. I would recommend going up to the 900# because you have plenty of sidewall with the 40 series tires to not be bone jarring. It will help turn in and mid corner push and body roll but might be a little tight for small radius corners. 350-375 in the rear should be pretty balanced and then add some more rear bar if its not rotating for ya. Make sure your dampers are up to the task and run as much castor/camber as you possibly can.

Thanks for the input everyone (Jay, sounds like you might know what your talking about ).

Scott, I was about to place my order for the 700's, based on your advise but then second guessed, not wanting a spring that was too "harsh" in the front for the daily driving the car still see's, so I posted up this thread.

Sounds like I have nothing to worry about. I'll take your advise & go with the 700's, to start with. Since I have a few other changes that effect handling going on the car, I'll get some experience with this setup (& work on my driving) & see if I need to make further changes to dial it in.

Since you're still on stock sway bars you may just try swapping on the RMDSM rear sway bar first and see how it handles. It seems like the car doesn't rotate as easily with the RMDSM front installed, causing it to push under hard cornering.

I think you'll find that anything you do to firm up the suspension will make your track experience better. It's going to take a lot of track time to figure out how to use the awd to your advantage. You can get your car to over rotate with stock suspension by trail braking past corner entry. Be careful ramping up your aggression but the harder you drive awd the better it performs. Work on smoothness, braking zones, entry points and controlling dynamic weight transfer. Figure out what the car absolutely won't do no matter how you drive it. Then make changes that effect that aspect. What track are you running? Have fun and be careful because 4g63's can make tons of power and get you in trouble quickly!

I've only lapped at Cayuga/TMP so far. Other tracks that are fairly local to me would be Mosport DDT (think I need a lot more practice before I go on their "real" track) & Shannonville.

Yes, I found out quickly, you don't need a ton of power, especially when your just learning. I turned down the normal street boost (32psi) a few notches my first outing but quickly found out it was still way to high for a first timer (I spent most of the time feathering the throttle). Guy came up behind me in a current 911 turbo that was lapping quickly, signaled him by on the long straight, wasn't flat out & he still wasn't able to pass, had to really get out of it for him to pull by. Yep, I think the boost can still be turned down a bit further

It was a very steep learning curve, looking back probably should have started with the boost even lower but by the 3rd & 4th session I was getting a lot more confident. Think I'm hooked, can't wait to get back out

Ok that's just rediculous. Your probably have enough power to annihilate your brakes, cook your engine bay, and destroy any exotic that shows up. I know you want spring rate feedback but your really just need to drive it more. Softer springs make things happen a little slower and make the car more forgiving. The suspension soaks up more of that dynamic weight transfer and it will be slower to overload a tire. Get a feel for what makes it push on entry, mid corner and exit. Your tires are the only thing that really matters. Understand what they like and what spring rate changes do for them. Figure out also what your driving technique does to them. Think days of thunder. "His way... [slaps a ruined tire] my way... [slaps a lightly worn tire] I was 6 seconds faster."

Just make sure your engine and brakes stay cool out there.

I do have the Wilwood factory big brake kit but for the 2g's, its not really all that "big". My winter plans include a bigger Wilwood kit thats more suited for lapping use. I was just running their BP10 pads, since it was my first outing, thought they'd be fine. Once I got more into it, didn't take long before I got them to fade.

Running my daily power, think I need to invest in some aero to actually take advantage of it Strange in a DSM to actually have too much power. I believe I got the boost turned down to about 25psi, which was more manageable.

I tried keeping the sessions short, ~10min, & that would keep coolent temps under control. If I want to get more serious, I'll probably have to look at better cooling in a few areas.

While my current turbo would probably be considered by most, to be much to laggy for serious lapping, the one benefit is at the reduced boost levels, it should be right around its max effiency, so the turbo itself won't be producing as much heat.

Well you started on trying to find a better rate for your springs.

1- You found out you had more power available than needed for your level.

2-You found out that your upgraded street brake system is not enough.

3-You found out that you need to improve your cooling system, brakes and engine

4-You found out that you are not spending enough time driving your car for all the above reasons.

You have made the most common mistakes that a beginner makes when going lapping or just a track day.

arrowhead said:

Well you started on trying to find a better rate for your springs.

1- You found out you had more power available than needed for your level.

2-You found out that your upgraded street brake system is not enough.

3-You found out that you need to improve your cooling system, brakes and engine

4-You found out that you are not spending enough time driving your car for all the above reasons.

You have made the most common mistakes that a beginner makes when going lapping or just a track day.

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Am I missing something, what is supposed to be the point of this reply?

I knew all of these would be issues before I even went out. I went out for fun, the car was not purpose built to lap, otherwise I would have gone a different route from the start. No point in building a lapping car to find out I don't even enjoy it

It's pretty obvious what he, myself and almost everyone else that's spent time on a track is saying. You need seat time. The parts you've assembled are only good for a short burst of straight line acceleration. Your brakes fade, engine overheats and your just starting to learning how spring and dampers effect weight transfer. If you enjoy lapping and want to improve your abilities and times then save the suspension tuning dollars for upgrades that will keep your butt on the track. I have literally run down and passed a modded 400+hp Audi s6 on slicks in our chumpcar on dunlops during a practice session. So take it from me and everyone else, the most important modification is to the nut behind the wheel. Once your car is safe and reliable that is. We run 24 hours straight with the turbo and front rotors glowing. We also have to run OEM brakes and cooling systems. If we overheat, lose brakes, have turbo bolts back out, or wreck the car, we lose the race. Almost all of our resources have been put towards making the car reliable first, then to the extremely limited handling mods.

Keep you stick on the ice and have fun. You may end up building a track whore some day but just remember that firmer springs and dampers will make a quicker responding car with better roll control but its up to you to be able to make it faster. Seat time grasshopper, seat time.

Oh, I'm well aware of the driver mod & that this one still has a lot to learn The car was built to be a fun, summer, street car (jack of all trades, king of none).

My car isn't the typical DSM build, my buddies were shocked that I actually went out & "beat" on the car a bit. I wasn't having actual over heating issues, after 15 min of lapping I got up to 213-216deg, I cut the sessions short just because I'm still getting use to not babying the car

The current brake setup could be pushed much further with a real set of track pads, but I plan on lapping again in the future, so figure its a good time to upgrade. Don't think worrying about your brakes will help with your driving at all.

I hope my post got you and many others thinking, it is not meant to put you down but to make you think.

The least you could have done was replace your street pads for something more becoming to the track, since you will get faster with more practice, you will be running out of brakes in your first lap.

If you knew before hand that you had issues why did you not do something about them?

You dont have to have a purpose built car to enjoy a day at the track, just think about the basics.

Evo mechanical rear diff? for what?, spend your money somewhere else that would make your car more enjoyable for you to learn and get more seat time, instead of going out for just 10 minutes and having to come in. you dont even get into a rhythm in the first 10 minutes.

Hope you find the point of my reply.

Guys... He's only asking about front spring rates. What's that... a $100 upgrade? It's a cheap & easy modification that will make the car more enjoyable to drive on the track.

I'd agree with you on the brakes... I've tried to convince Daren to experiment with some proper race pads before before laying down cash on a big brake upgrade, but he likes to spend money.

And the EVO8 diff... Well, it's such an awesome upgrade; if you have the means then why not. It transformed my car and made it way more fun to drive. And fun is what he is after.

But we're getting off topic. Daren just wanted input on 2G spring rates.

We've been way off topic for awhile now Scott, but I already got my answer & this is in the Road Course section, so figure, what the hell

arrowhead said:

If you knew before hand that you had issues why did you not do something about them?

You dont have to have a purpose built car to enjoy a day at the track, just think about the basics.

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If you look at my profile, you'll see the car is already fairly well built for lapping (does have some downfalls for parts that were purchased when lapping was never a thought).

I think the first portion is an easy answer for most, cost. A set of proper race pads is common sense for someone thats going to spend time lapping, but I went out for fun, not knowing if I'd ever go again in the future. Living in Canada, we don't have the luxury of cheap parts & shipping. Do you think most will want to spend $400 on a set of race pads for something they may never do again?

To be honest, I thought I could get away with using my current pads, while they are listed as street pads they are also listed for light lapping duty. Being a beginner, I thought I would be alright, obviously, thats wasn't the case.

My current brake setup is also fine for occasional lapping & superior to anything that came on DSM's from the factory, but by no means a HD track setup.

Cooling, well my cooling system is already upgraded. Large rad, properly ducted from FMIC to rad, etc. If I want better cooling I either hack holes in my bumper & hood (not a chance that will happen), or I buy a carbon hood with large venting (again a large cost & not somthing I'm currently willing to do to a daily driven car). Then I can add in a tranny & external oil cooler.

What have you got me up too, $3K+ in upgrades, at the time, not knowing if I'd ever do it again