Anyone konw the spring rate vs wheel rate, movement or lbs on the 2nd generation or third generation Integra?

 

-------------------------------(F/R)----------------------
Mfgr--------------------------Drop----------Rate-------
Eibach Pro-Kit__________1.4/1_____457/171-257
Eibach Sportline________1.8/1.5___457/171-257
H&R OEM_____________.75/.75____315/170
H&R Sport____________1.8/1.8____340/186
H&R Race_____________2.25/2____400/285
Neuspeed Sofsport_____.75/.75____340/230
Neuspeed Sport________1.8/1.8____340/230
Neuspeed Race_________2/2_______500/450
Suspension Techniques__1/1_______354/149-180
" " " " Speedtech 2/1.8____________425/215

This is the best I can do. Look at the H&R OEMS for an idea of what our factory spring rates really are. As for the "wheel rate," I'm not really sure what you are asking. These were taken off of Loc's site at b17a.com when he still had this info up. You could always try emailing him, as I'm sure he'd know or could find out for you.

 

That's not what he's looking for. He's looking for the ratio of spring rate to wheel rate. Let's say you have a 400 lbs/in spring. Well, that is not the rate that actually applies to the wheel, due to mechanical leverage. Scott has posted the ratios and stuff, but I unwisely did not save it.

So let's all beg Scott to repost for us

Warren

 

Yeah, I figured it was something I hadn't learned about yet, but thought I would post something that had a good chance of being relevant. Looks like I've got a little reading to do. I know a lot, but I sure as hell don't know it all, and I'm just now really starting to get into auto-xing and finer suspension tuning and such. Thanks anyways.

PS - I love the sig. Sounds like you've had a great Audi under you. As for the R, true choice is about 5 minutes away from my parent's house in Columbus. All of them are really great people. What stage coilovers did you buy?


[Modified by mojoGSR92, 5:24 AM 8/19/2001]

 

Rough (Averaged Approximations) Integra G3 motion ratios:

Front: 1.5:1 (for one inch of shaft travel you get 1.5 inches of wheel travel.
Rear: 1.35:1

Wheel rate = (spring rate / (motion ratio squared))

Front wheel rate = spring rate / 2.25

So 400 lb front spring gives a wheel rate of 180, and a 600 lb spring gives a wheel rate of 270.

Rear wheel rate = spring rate / 1.82

So 250 lb rear spring gives a wheel rate of 140, and an 800 lb spring gives a wheel rate of 440.

Scott, who noticed that the archive is now not very deep. Is all our old stuff gone?

 

ok
RR98ITR: how do u aplly that to get any imporvements??
or to setup the suspension ?

 

Thank You Scott!

 

There is no formulaic answer to your question. Knowing the wheel rates tells you the static deflection which can be used to help setup close initial ride heights - leaving aside questions of geometry affected by changes in ride height, and assuming you know what you want and why.

Selecting spring rates is an art best practiced within a meaningful test program. Application of general rules the origins of which might be in cars of a different configuration is a hopeless place to start. Such rules might be: limit natural frequency to 2 cps, or start with wheel rates equal to corner weights. Each type of car is different. There seem to be a few useful generalities: wheel rates are typically lower on the driving end of the car is the only one I can think of right now.

When starting from relative ignorance, with practical prospects of remaining there, the single best thing a person can do is to buy a widely acknowledged off the shelf setup and live happily ever after. Between relative ignorance and thoughtfully developed competence is alot of expensive learning by trial and error. If you just can't stand to be ignorant, then you have alot of reading to do. You'll need at least several hundred dollars worth of books to start - assuming you have enough background to understand them; if not then you'll have to provide yourself with that prerequisite knowledge. You'll need to develop a circle of similarly commited friends - preferably smarter and more deeply involved and connected than you but still willing to accept you, and you'll need to sacrifice alot of primitive visceral pleasure for hard intellectual work on the maddeningly complex interrelations of a chassis. Most of the time I think this is worth it.

Scott, who honestly tried to answer your question....

 

I wanted the numbers to get a true starting point for corner balance and comparison issues related to other vehicles. Spring rates will only allow you reference vehicles with the same “Spring Rate VS Wheel Rate Ratios”.

 

Marc is right about the usefulness of normalizing spring rates into wheel rates. But in such comparisons, between similar and dissimilar cars, that's not the end of it. One of the biggest reason we are interesed in rates is to appraise front to rear roll stiffness balance. To get an accurate picture of that we need to have pretty accurate values for roll center heights and cg location - and I'm oversimplifying at that.

Imagine two different FWD cars where one has a much higher rear roll center than the other. If both cars have the same wheel rates front and rear, the one with the high rear roll center will have more rear roll stiffness proportion (all other things being equal).

Imagine two different FWD cars where one has a much higher rear roll center and that car has lower rear wheel rates. It might have a similar roll stiffness distribution to the other car. It might or might not also have other desirable or undesirable effects which may or may not be more critical to getting the lowest lap time out of that car on a particular track.

Time and money is consumed at an exponentially increasing rate as you chase chassis performance. And the ability of the average competent fast driver is probably rapidly overshot in the process. At that point your hobby has changed dramatically, and a reasonable person might step back and ask what their goal is.

It's not just to be a toady to Scott Zellner that people like Andrew and I recommend the Mugen Lowdown setup to people, and currently drive the standard King Mugen N1 setup. They are systems with well known attributes and performance - we knew what we were getting and we could see who used it and to what result. We have learned alot over the last couple of years from our own experience about how our different setups drive, how easy to live with they are, what the costs associated with the next step are, and what drivers at relatively early phases of the learning curve can cope with. When you can take your existing setup to the point as a driver where you can't get anymore speed out of it and your consistency is measured in hundredths or better, not tenths, then you might be ready to take the next step without it being a waste of money.

I write this not to insult anyone or to force a fundamental lecture, but to describe the next step or two down the path. My car is now very sensitive. Box stock the car was relatively numb and benign, with the Lowdown setup the car became more responsive and faster but a little more temperamental in terms of tires, with the N1 setup the car is of course not streetable anymore and very fussy about tire and brake setup - it's now alot more management work. With a good initial balance I can find after a few hot laps that I might like the rear looser, then I might rotate tires and be off a couple of lbs from where I should be on a hot rear, and I've got a car that's hard work to keep on the track - but when it's right...it's soooo right. This has fundamentally changed the nature of a day at the track for me. It's a tradeoff I have willingly made - but I didn't fully appreciate the consequences of each step until I took them.

I am extremely grateful to Honda and the man who developed their culture for building a car the rest of which has performed flawlessly thru more than three years of flogging, allowing me to focus on developing myself as an amatuer driver/engineer for my own pleasure. These Honda's spoil us pretty rotten you know. As you move further along the chassis development path you leave some of that security behind you. That's why I chose to do business with King Motorsports - to stick close to the Honda culture thru Mugen and to take the opportunity represented by the fact that King is a full service retail Race Shop that actually prepares and fields serious road race cars. There are only a couple of other Honda shops I know of that do this. I know that for alot of guys on this board OPM fills the same slot, and I personally know Tom Fowler to be a very nice guy.

I guess the biggest reason I wrote these last few paragraphs is to set up this point: If you're serious about this stuff, associate yourself with one of these outfits. Be considerate of their time, put up with their idiosynchrosies and shield them from you own, be loyal to them and realize that if they don't make money they can't answer the phone when you call, and realize that even if they give you the best advice they can, they may not be right or there may be no right answer. You and I are probably not smart enough, rich enough, or committed enough to do all this stuff on our own - we need help. That doesn't mean you don't have to study. If you don't raise your level as a driver/engineer about all you can do with these guys is call them, ask what you should use, and then give them your credit card number. And that may be alright for you. But if you want to talk to these people and get into this deeper, you have to acquire the vocabulary, and the knowledge as a driver that you must have to speak thru it.

Scott, who can't even remember what the question was now....uh-oh, I think I blacked out again...hey, I don't remember logging on....oh, there's another post from that RR98ITR guy.......