SageMoonblade

Ok all I know this will odds are get me a bad reaction but I have to know, is an air ride kit something that works well in a road race application? I am looking into building a car to run in the NASA PT class so I am here looking for advice and exploring options. Mostly I have been trying to figure out my best suspension setup to run with, IE: shocks, springs, struts, sway bars, other. I have read through a few of the other road racing posts but they are about 6 years out of date. Any help I could get would be appreciated.

Guest

I do not care what anybody, or any company will try and sell you on- They are CRAP for handling.

Now if anyone else wants to dispute this, then show me any racecar in this world that is winning circuits on air ride suspension. 99.999999999999% of racecars in this world are running conventional springs or torsion bars. Even the leaf spring cars are notorious for dribble, but are class restricted to keep spec performance and cost down.

Airride will dribble you accross the road- trust me, I know first hand with years of experience with them on a vechile I own and drive daily. I have taylored three different systems on it over the years (I owned this car 20 years- air bags have been on it in some form or another for about 16-18 years.

SageMoonblade

Vetruck, what would you suggest I use for springs and shocks as well as the front struts?

kukerdan

iTrader: (1)

how much do you want to spend?

If you can afford it, go Bilstein Sport, Koni Sport, Koni Special,

If you cant afford that much, go tokico Illuminata, or KYB AGX
(all aboce are adjustable except bilsteins, but they are sick)

Go with moog stock springs,
build up the rest of your car
Panhard / Lower control arms, sub frame connectors, sway bars, wonder bar

Guest

Go to FRAXX.com and ask them. You will be running with alot of them and you will have to develop your car yourself after that to suit your driving style.
My car is set up different than anything anyone has seen. but what works for me would have to be absolutely 100% duplicated and would aalso not fit your driving style nor wouldl you like the small motor I left in it.

If you are going to be racing it and stripping weight, their really is nothing anyone on these boards can help you with in typing but not actually having hands on your car with data aquisition. You spring rates will vary on track paving conditions, track speeds, tire choices and grip coifficiants, etc.... the list goes on.

If I were starting a road race 3rd gen car stripped of weight to about 3000 lbs I would start with spring rates around 900lbs in front and 175lbs rear with moderate to high compression/rebound valving in the front and high rebound med comp shock vavling in the rears with a 2" drop ride height and the roll centers reworked to fit those spring rates. Then taylor in a lighter set of swaybars aprox 32 from 21mm rear- then start fine tuning with spring rubbers. after you have all other perameters set to you driving style and braking favors.

Stephen

iTrader: (12)

I don't wanna get into a "I'm right/You're wrong dispute" I personally have no air ride experience. Unless you count over load bags on my old lowered Tahoe for towing.

BUT, that race cars are running on conventional coils vs air, has more to do with class rules, than anything else. Even IF air was PROVEN to be better, that wouldn't mean air would be allowed, thgerefore still not class legal.

Guest

Lets get into a fun friendly debate on air.

We all in fact ride around on air suspension daily- our tires. Tires have spring rate so to speak. It is why different tire sizes and quality demand different pressures to withstand the same vehicle weight.

It is also why a car will feel much better or much worse on a sset of tires because the better the peformance tire the generally stiffer the sidewall. However, too stiff a sidewall and the suspension frequency has to be refigured.

Airbags work in essence like a 75 series tire. lots of sidewall. Does that rate go up linear when compressed? No. It swells and bulges in other deflection surface areas until the rubbberband effect bounces with an abrupt recoil like a basketball bouncing. It only compresses to a point then bounces back. A spring however will compess alot further in travel until coil bind. Car spring setups are engineered in a way that the spring does not travel to coilbind. Airbags will reach "coilbind" or bounce very quickly because the rubber outer surface only gives so far then rubberands back. You do not have the consistancy and smoothness a coilspring has.

Let me give an example of a full airbag type setup on a vehicle alot of us know and experienced in the dirtbike word. Remeber the little 50cc ATC 3 wheelers with absolutely no suspension but the big balloon tires it rolled on? THose are equivelent to an airbag suspension. When those tires hit smaller speed bumps they were fine, but when higher speed impact of the suspension shock loaded them they bounced when the tire air quanity inside was pressured from the impact. Now of course you might say this is because the tire was not dampered with a shock. Well, to absord the leveraged impact blows of high speed suspension leverage, the shock damper rebound rate would need to be so high that the low speed contact quality would suffer. Diriving speeds and road conditions change constantly.

The other factor of the tire is it actually absords shock impact far better because it is rotating with centrifical load to distribute the impact reducing shock loading recoil. The airbags do not rotate. best way I can discribe this off the top of my head is its like stopping abruptly and heading back in the same direction like hitting a wall and bouncing back as opposed to rotating direction around a radius and deflecting load impact maintaining speed. Tires stay more constant and do not shock load because of rotation. YET- I will reiterate the point above how even tires make a difference on ride quality if they are larger ballooned tires and wallow about.

It is the best I can explain this. It is something I have taylored and manipulated with in-cockpit controls for years on a truck I have with 3 different setups. All end up acting the same and bounce the living heck out of ou if the rates of the shocks are not increased also- I have in-cockpit controls on shock dampering also in sequence with the bag psi changes. I also do varying load or chassis weight changes (Yes this is a truck, but one that is built bigtime with custom suspension and frame work I did as well as my own engineered suspension mount points. pic attached)

Guest

I will also add that this is my worktruck. I drive it daily. It will carry 2 tons payload in the bed but is limited to 3200 instead of 4000 because of the wheel load restrictions of the C6 Vette wheels I chose to run.

SageMoonblade

Anyone know where I can get springs that are about 900 lbs? Also what about coil overs anyone ever raced with them?

Guest

SSS, Eibach, any # of performance racing spring companies. Just search on the web. You need aprox a 13" coil at free height for about a 0-1.5 inch max drop based on car weight.

Coilovers are not good on a 3rd gen strut frontend in "my opinion" becasue of the force exerted on the spring and seats during steering rotation of the assembly.

Coilover rears wouild be fine as long as you use reinforment plates up in the top of the shock pocket. Spohn sells the reinforment plates as well as the top shock adapter but i do not see them listed individually on his site. You may have to call Steve direct to see if he would part with them individually.

For rear coilovers, Steve also sells decent kits or you could go with some upper scale QA1 coilover adjustables or fix valve rears in the 67 series style with a 5-8 aprox valving. these can be self rebuilt and revalved to suit your needs in the future. We run these on my NASCAR supertruck I crewcheif for great shocks for the money. I but alot of my parts through Lefthanderchassis.com .
(ps, I'm the tall guy in the middle with the hang loose gesture)
https://www.thirdgen.org/forums/atta...ndale-st18.jpg

topless89

go to http://www.ground-control.com/ and look at the weight jacks.