Pompiuses

I'm doing road racing in a Civic EG chassis with a B18C swap. I recently upgraded my front springs from 450lbs to 800lbs. I like the stiffer springs a lot better. More grip, better turn-in and more rotation. I've got the Koni Race dampers, and ended up full soft rear and full stiff front for best rotation. I feel like upgrading the front springs even more to get more grip as the car still feels a little pushy. But exactly when do I know I got enough front spring?

My current setup is:
Front: 800lbs, 0 toe, -3.5 camber, 24mm bar, 225/45-15 R888
Rear: 600lbs, 0 toe, -1.5 camber, 22mm bar, 195/55-15 R888

Also the rear feels too stiff as the rear of the car bounces a lot over small bumps in the track. I feel like going down to 450lbs in the rear but I'm not so sure.

FPR

Do whatever feels good to you man!

Pompiuses

I know there is no right answer for everyone when it comes to suspension, but I was hoping maybe someone could give a few pointers when it comes to dialing in the suspension. I.e. what will too much spring feel like?

ScottBell

iTrader: (1)

Obtain and learn to use a tire pyrometer.

Do a shock sweep. Fronts full hard, rears full soft, then the other way, then both in the middle, and so on.... Do the same with disconnecting the sway bars. Don't do this on a track with limited runoff.

Remember if those are single adjustable shocks, you are only adjusting rebound.

Pompiuses

I did a shock sweep. I liked it best when full stiff front and full soft rear. Does that mean I need more front spring? If so what would be a reasonable increase in spring rate?

solo-x

You have enough spring when:

1. Chassis bottoming is minimal at desired ride height
2. Terminal roll angle is acceptable
3. Ride quality/grip is poor (tires chatter, skip over the surface, or break loose too easily)

How much does your car weigh?

descartesfool

The answer depends on the track surface you are running. On smooth tracks, you can run very stiff dampers and springs, while on bumpy tracks, you need softer springs/dampers. Like Nate said, if car is bouncing around a lot over bumps and loosing traction, your setup is too stiff. Otherwise, you can go stiffer. I run 850F/1100R on a DC2, and that is fine for smooth tracks, but it is really too stiff for bumpy tracks. I am lazy so I just drive it the way it is on bumpy tracks.

You are too soft if car is bottoming out its suspension, or you are too low or both.

MBellRacing

There is too hard for the dampers and too hard for the tire. If you are "skipping" as has been said, or are "flat sliding" more often than you feel acceptable, it is likely the spring too stiff. As was also said, if there is excessive bouncing that you can't get rid of with use of rebound and compression (more the former), then your dampers need some new valving.

Excessive spring can also feel like a lessened ability to trail the brakes or roll on power early in a corner. This is because the tires are experiencing so much more direct load that they can individually become overloaded easily. The "overloading" thing is controversial, but I am on that side and have definitely experienced it in testing heavy spring rates.

I would absolutely recommend getting a pyrometer and learning to use it. Your camber settings seem a bit off, I would try to optimize them better, then play with springs/dampers, then recheck your tire temp spreads.

FPR

You just want find that perfect balance, not so stiff so the rubber just skids when you take off, or loose so it feels like your gonna flip at a turn. What kind of driving fo you do, like style? Cause that makes a big difference also

Pompiuses

Including driver and gas my car weigh 690.5kg over the front axle, and 378.5kg over the rear. Total of 1069kg.

My front camber is adjusted when I had the 450lbs springs. I may need less camber now. I'll be sure to bring a pyrometer with me next time I'm at the track.

The tracks I'm at aren't super smooth. I can definately feel the rear bounsing sometimes. The front feels pretty good.

solo-x

bah, my first post is confusing as hell, got interrupted part way through and didn't get back on the same line of thinking when I finished it.

You have enough spring when:

1. Chassis bottoming is minimal at desired ride height
2. Terminal roll angle is acceptable

You know you have too much spring when:

1. Ride quality/grip is poor (tires chatter, skip over the surface, or break loose too easily)
2. Tires overheat easily, run hotter, but lap times aren't any better

What I've found with super high spring rates is that the grip curve is pointier. The peak is higher, but it harder to hit that peak without overshooting/undershooting. You end up sliding a bit more, which puts more heat in the tires. The car gets harder to drive in that small mistakes are more costly and happen more frequently. I experienced this very smooth surfaces. A little softer spring resulted in a bit less grip, but I can get to that grip more easily.

Lo-Buck EF

I have yet to hit the 'too much front spring' point on my car. I have seen over 1000in/lb up front with no front bar and it still picked up the rear tire. More shock tuning was needed, but the driver liked it better than what was on it previously.

Drive 4 fun

Pyrometer was mentioned a couple times. After a cool down lap information can be confusing. I am running Nitto 01's at about 3 degrees neg camber and still find the inner edges hot. That could suggest too much neg camber, but is probably from running on the inner edge on a soft cool down lap because tire wear if slightly more on the outside edge suggesting that I need more neg camber. 10k front and 8k rear. Are you measuring tire temp at a quick stop before cool down?

lwnslw

you are pushy cause your rear end doesn't have enough spring. 450 for the back is way to soft.
With 800 in the back I would go for 800-1000 in the back.
Have to make the car rotate at one point, you don't want the back to follow the front , you want the back to turn to help the front turn. crank that camber more in the rear also, and use the same tires front and back. We are not in Japan here.

Lo-Buck EF

To properly check tire temps, come in on a hot lap

Pompiuses

That theory has been debunked a few times:
https://honda-tech.com/forums/road-racing-autocross-time-attack-19/my-suspension-quest-looking-advice-2790878/

lwnslw

I'm talking for what works for me, and everybody else I know that race with me. Rear is at least the same as the front or more.
I have seen spreads of 600 lbs. 650 front 1200 back, for me a little too much but I have seen them out there.
Loose car is a fast car, at least that is what some of the fastest drivers say.
Debunk, I would hardly call it that. Show me on the track with same car a comparison.

beanbag

Rear is probably underdamped. Get somebody who knows suspension to ride with you and turn the *****. Get your springs properly damped first, then worry about which end is too soft or stiff.

ScottBell

iTrader: (1)

This.

Especially in a car with no bump travel

MBellRacing

You'll want the inside edge to be pretty warm compared to the outside, probably 15-20 degree spread. If you're aim is better braking and power-down, then run less camber, if you want good apex speed, run more.

As has been mentioned, pyro readings should be taken as hot as possible, keeping in mind that the last corner before the pit will be really what you're seeing. If there is a long straight that you must accelerate down or heavy braking is required to meet your pit stall, you'll also see some higher inner temps.

Spring rates can be tricky. Try things out and see what's best for you. In our Grand-Am Camaro we'll go from 300s to 850s in the same weekend (sometimes in the same session!!!) to chase our ideal balance, so saying that "whatever" will work for anybody all the time is narrow minded. It is more than just understeer/oversteer as well-- it is driveability, ease of transition, braking, power-down, etc. The spring is the main component of the suspension and therefore has a huge impact on the handling of the car.

chargeR

Good advice. If my understanding of the way the Koni Race dampers adjust is correct then if you are at the extremes of adjustment at either end of the car then something else is wrong. I don't think shocks should be used as a bandaid.

Questionable advice. What does Japan have to do with it? Is there only one way to make a car handle? Does he really need to saturate the outside rear tyre with vertical load, and lift the inside rear a foot in the air just to get it to turn? Your advice might work, but don't make it sound like the absolute guide to going fast.

Lo-Buck EF

?

ScottBell

iTrader: (1)

Even at relatively stock ride heights my DC2 has very limited bump travel on the front. I run a "weird" super stiff front setup, and with the right surface I could see using 1200b or more on the front.

lwnslw

I wish that you would read what I posted . I said it is what works for me not everybody else , you can try , doesn't mean you have to and is not a guide to go fast. And as far as I know small tire in the back and bigger tire in the front is what they do in japan to make the car rotate because they use less spring in the back. Just saying. I'm sure you can find it in google .

lwnslw

And yes there is only one way to make the car handle , at least to make it fast . That one way is what the driver has to determine and is particular to that specific driver