Suspension suggestions welcome

[AZmike]

Right now i'm still fixing leaks and replacing belts etc. on my Accord. But once I get everything working correctly, I was planning on modifiying the suspension. I don't care very much how the car looks yet (I got a deal on it since it has a sagging front bumper), but I was hoping i could improve how it handles for not too much money. I was considering getting basic sport springs from H&R or Eibach and running the original shocks (which are still in decent shape). Later on I might also get thicker front and rear sway bars. I don't want to lower it very much since many of the roads around here are rough, have 'speed humps', or are dirt.

Has anyone else done something similar? How did it turn out? Do I really need aftermarket shocks too?

My goal is a car that can autocross well without scraping the ground as my daily driver and without taking me into debt.

Thanks in advance.

[Jims 86LXI HB]

Originally posted by 89LXi4dr
Right now i'm still fixing leaks and replacing belts etc. on my Accord. But once I get everything working correctly, I was planning on modifiying the suspension. I don't care very much how the car looks yet (I got a deal on it since it has a sagging front bumper), but I was hoping i could improve how it handles for not too much money. I was considering getting basic sport springs from H&R or Eibach and running the original shocks (which are still in decent shape). Later on I might also get thicker front and rear sway bars. I don't want to lower it very much since many of the roads around here are rough, have 'speed humps', or are dirt.

Has anyone else done something similar? How did it turn out? Do I really need aftermarket shocks too?

My goal is a car that can autocross well without scraping the ground as my daily driver and without taking me into debt.

Thanks in advance.

I have the H&R springs. They are excellent, buy them, they're that good. And they will work well if you want to autocross for fun. I have driven down country mountains road for no other purpose than to test my set up out. The H&R's give the car a very nice balance.But if you want to have a chance to be competiive you'll need something stiffer. Now you may find that to go stiffer may not suit you, you might not like the ruff ride.

I have called all the spring makers and I know the spring rates for all of them. The best spring with a 1.5" drop for autocrossing would be B&G springs from www.shox.com for $169. A even better choice would be ground-control coil-overs. The Ground-Controls do not have progressive springs on them, they are linear. Linear springs, unlike progressive springs do not have a weaker initial spring rate. They are firm thoughout their travel and are more responsive. Plus for a extra fee you can choose to get stiffer than usual springs with them.

Don't fool yourself into thinking that you can use your stock struts with stiffer lowering springs. And don't listen to anyone that try to tell you it'll ride just fine, WRONG! Those are people that don't want to admit or don't know how a screwed up suspension acts.
All lowering springs are stiffer and you need to have a strut that's likewise stiffer. Having a lowered suspension that will drive as well as if it came directly from the honda factory cannot be done by installing struts that aren't firm. I'm runnig koni struts for that reason. I tried Bilstein struts, but removed them because they were not stiff enough. They let the suspension behave in ways that would get a honda suspension designer fired. The koni's are expensive but unless your willing to except lower performance levels and a certain amount of bounce and other weirdness, get the Koni's, they are worth ever penny. Now if we want to kick it up a notch higher than the koni's, get Bilstein struts and send them back to Bilstein and have them revalved stiffer. That's what I'm running in the front of my car.

If you really want to pinch you pennies you can cheat and run Koni's in the front and Tokico's in the rear.

If you have any questions, feel free to ask.

[RCracer]

I will agree with Jim that the H&R springs combined with konis is a nice set up.
Its soft enough not to make your teeth rattle over every bump in the road but hard enough to make it drive pretty much spot on.
I didnt want to go too hard/low due to the state of the local roads etc and it is pretty much what I had hoped for.
Even lowering it just 1.5in it still catches speed humps and stuff if you arnt carefull.
I am going to uprate the sway bars at some stage in the future but that is just personal preferance

[AZmike]

Thanks guys, I feel a lot better about putting money into something that i know is going to work.

Jim, I noticed you didn't mention anything about sway bars. I know my car comes with thicker (than LX, DX) bars standard. Do you think aftermarket bars would make a big difference? Last time I autocrossed after I turned the wheel I would have to wait for the car to lean way over before it would start to move in the new direction. I'm trying to get a more immediate response. Would the springs and struts alone do that? I don't plan on being seriously competitive at autocross since I'm planning to stick to my stock 14" wheels so I can run tires that will last through all the highway miles I put on the car.

Thanks again

[Jims 86LXI HB]

Well I didn't mention it because I felt it was more important to see where you stood on springs and struts. Well the suspension techniques sway bar set would only give you a 1/16" greater thickness in the front and yes they would have urathane(ms) bushings. The rear bar would be 1/8" thicker than stock. Yes I do think they would make the car lean less, but with their thinkness being hardly bigger, I'd sure hope their steel is much stronger than stock. Problem is, how know's if it is. My plan for myself was to purchase a custom made sway bar for the rear and test that alone, if it worked I'd then order another one for the front. I thought 1 1/16" for the front and 7/8" for the rear, cost is $175 each. But with you want to do, I'd say just stick with the suspension techniques bars, if at all.

[AZmike]

Jim,

All steels have the same elastisity (or Young's modulus, or modulus of elasticisty, whatever you want to call it). The only difference between 'stronger' steels is how much they will bend before they permanently deform. With that in mind, for a given sway bar geometry, the only way to alter the stiffness of the bar is to change it's cross section. You could increase it's diameter some and leave it solid or increase the diameter more and use a hollow cross section to save overall weight. The stiffness of a bar in torsion is proportional to (outer radius)^4 - (inner radius)^4.

A small increase the the diameter of a sway bar can significantly increase the torsional stiffness of the bar.

Do you know the stock LXi sway bar diameters and the spring rates for the stock springs, the H&Rs, the B&Gs, and the springs on the Ground Control coil overs?

I've heard that www.shox.com is a good place to save money on struts. Any other places I should check? Right now I'm thinking about getting the H&Rs, Konis front and Tokicos rear and running stock sway bars and see how that goes.

Thanks,
Mike

[Jims 86LXI HB]

All steels have the same elastisity

I'll take that to mean your not talking about alloy's, such as chromollybedilum or chromollybedilum & magnisum such as reynolds 531 or 853. And arent' they many ways in the manufactuering process to add strength to steel's. Wouldn't a forged piece of steel have less elastisity than one that isn't? (yes I know sway bar surely aren't forged).

http://www.bikindex.com/guru/steel.asp

What is the relationship between elastisity and tensile strength?

[Jims 86LXI HB]

Stock sway bar sizes

86-87 LXI
front 20.5mm or 13/16"
rear 12mm or 15/32"

88-89 LXI
front 22.5mm or 7/8"
rear 13mm or 1/2"

LX's and DX's do not have rear sway bars, their front diameters are the same or slightly smaller if at all different.

Stock spring rates are 211 front 117 rear
H&R* 265 165
B&G 350 240
Ground-Control 340 250 or whatever you want for
I think $65 more. I don't
think you can go softer.

*H&R flat out would not tell me what their spring rates are. But then I talked to them recently and had a simular conversation with Bilstein, we concluded that they are the same stiffness as the Neuspeed springs.

For prices on tokico's you really can't beat shox.com. But for the koni's check and see what it would cost you to get them from www.tirerack.com including shipping, write that figure down so when you call shox.com you know who's cheaper. For H&R springs shox.com is way out of line with their price. Get them from www.optauto.com . Shox.com does have the best price for the B&G springs, everyone else is about $20 higher.

[AZmike]

Thanks again for the info Jim, I see how you've developed your reputation around here.

Not all those spring rates are linear, right? Do you think that the manufactures would have spring rate/deformation plots available if i asked? those are (pounds force)/inch right?

I noticed that the H&Rs aren't much different than stock. Have you ever ridden in an accord with the B&Gs, or something similarly stiff? Do you think that the Tokicos would still work in the back if i ran something as stiff as the B&Gs?


All steels (stainless excluded, which is ~10% less stiff) have the same elasticity. It is completely independent of tensile strength. Although forging and alloys can increase the tensile strength of steel, they have no impact on it's stiffness. A piece of steel with a higher tensile strength can handle higher stresses without permanently deforming (so in many situations you can get away with using less of it). For example a spring's shape changes a lot during use, but the deformation is not permanent. On the other hand, if you drive your car into a wall, the hood will deform permanently.

Generally the 'stronger' steels (those with higher ultimate tensile strengths) will take more stress to permanently deform, but will only deform a little before breaking (they're more brittle). Weaker steels can stretch more before coming apart, but it takes less stress to start the permanent deformation.

From your link:
the next topic on the agenda is stiffness or young's modulus. another name for this property is modulus of elasticity. the modulus of elasticity of steel is 30 million pounds per square inch or 30 msi for short.

(note how there is no differenciation between types of steel)


Did that explanation make sense? I'll clarify any confusion.

[Jims 86LXI HB]

Thanks again for the info Jim, I see how you've developed your reputation around here

Ut oh, I can just imagine

1.Not all those spring rates are linear, right? 2.Do you think that the manufactures would have spring rate/deformation plots available if i asked? those are (pounds force)/inch right?

1. No they are not. 2. I doubt they would feel the need to keep such information in a business sense, wheather that be a need to keep such information a secret or they doubt anyone outside of engineer would know what the figures mean and how to apply them. Let me they you the secretive thing was a HUGE roadblock for a couple of the companies. I had to really work my people skills to get them to talk. Eibach would be the only company that might have that kind of info, but likely only for their race spring line.

I noticed that the H&Rs aren't much different than stock.

Yes but with 26% more stiffness than stock and 42% greater stiffness than stock in the rear they do offer a noticeable difference over the stock springs. And like the B&G's they increase the rear rates more than the fronts, theirby reducing understeer. Only when I push the car really hard do I find myself wishing for stiffer springs. I feel that if I had the spring stiffness I really want, from the B&G's that quite a few people would feel that the car rides to stiff. But as a performance minded soul that I am, I would rather have the performance they would offer at the higher limits that I so offten get to. And I do think that the B&G's would be a little much for tokico's in the rear. But a number of members are running tokicos on the rear with suspension techniques speed tech springs. Their rear spring rates are very close to the B&G, but they are 2" drop springs. I haven't heard them mention anything about them in the rear. We do have a member that is running the B&G's, but I don't remember who he is. I don't think he posts much if at all.

Thank you for commenting more on steel and its elasticity. I'm left wondering why when I rode several racing bikes that each had different types of reynolds tubing. 501, 531 and 753. All were constructed using the same frame geometry(ms). Yet they all differed in how much flex I felt. Maybe they used different tubing thicknesses.

[AZmike]

I'm not sure if it was Jim, or someone else, but i think i remember recently reading that using coilovers and maintaining close to stock ride height makes for best handling. Is this true or did i just read something wrong the other day?

Also, what makes the Ground Control coilovers the best? I usually do a lot of research before making any big changes so I was hoping someone could explain some of the differences so I'd know what I should be looking for. It's not just a matter of different spring rates is it?