NinetySevenDC2

I have been reading a lot on this forum about spring rates and swaybar thicknesses. It seems to me that these are the first and second things to directly affect a cars characteristics as far as how stiff it is for the track.

Besides spring rates and swaybar thickness, how does changing suspension component bushings from rubber to polyurethane compliment the stiffness of a car? Would it make more of a beneficial change then say a different swaybar setup or a change in spring rates?

Thank you in advance for any input,

Sev.

Johnny_9

Yup. Make sure the lower front control damper fork bushing is changed - Big difference

Also foam-up the side sills and use a 3-point strutt bar and fender bar

The 3-pt front strutt bar, fender bar and foaming the side sills (equivalent to a side lower bar) will stablise the front rear weight transfer - with a PU bushing, you will enjoy the car

This suspension form is a bit limited; need to discuss on the chassis as well...

PIC Performance

How does a front tower bar, fender bar (?), and foam in the side sills (??) stabilize (???) f/r weight transfer? I think you have one or more ideas mixed up.

rmcdaniels

I would say "search", but............

It didn't help me, and the poly RTA bushings actually hurt me. At most of the turns at Roebling Road or VIR 14A for example, I did much better after I switched back to rubber. Some people have also had them permanently deform under stress. Some people have had them work fine though, especially if they zero the rear toe. I found that the faster I got the less I liked them and eventually went back to rubber, then to sphericals and Delrin when I built a dedicated track car.

I'd recommend driving the car on the track with the stock bushings (as long as they are in good shape, if they are cracked then replace them with stock bushings). By the time you are able to feel the limitations of your stock bushings you will know what you need to do.

NinetySevenDC2

Wow that was good piece of advice. I am currently in the very very slow process of building an H2 honda challenge car. Most of the arms on my car have been replaced by new oem counterparts from honda. I agree with that last statement about feeling the limitations of your stock bushings. I will definitely take that into consideration.

As far as PU bushings, would the particular location of where you change the bushing to PU say for instance the rear trailing arms, have more of an affect than some other arm?

Thank you,

Sev.

NTCustoms

i disagree on your statement on the strut bar. strut bars are a "fine tuning device" and should be the last part of your suspension to mod.

rmcdaniels

I had the relatively common RTA binding problem on some turns, the arms go so far, then bind up, getting me quickly sideways. Switching back to rubber fixed it. I did VIR two months in a row so I had a chance to switch them back to rubber and see the effect that it had and it was dramatic. I have heard that changing the rear toe will alleviate that, and different people have had different experiences with them, but I prefer to avoid them. Changing different bushings will have different effects, the smaller bushings should make relatively less difference, the difference in deflection will of course be less with a stiffer bushing the smaller it is in diameter. At any rate, I never had any problems with OEM bushings (other than routine replacement of older ones that were deteriorating, but that's just normal wear) and I don't know anyone else that has, but I have had problems with polyurethane bushings and I know others that have, so I prefer to avoid them on a track car.



I wish search worked, a guy here had some really good pics of his polyurethane bushings that permanently deformed, and they were a mess. They were on his front LCA's though, and those see a lot of stress. Like everything else, as I get better at driving, move to stickier tires, etc, things (or my limited driving skills) that worked fine last time I was at the track will suddenly no longer stand up to the situation, and it snowballs sometimes. I get a little faster through turn X, which is great, but then I'm suddenly moving a whole lot faster when I get to turn Y, which presents a new set of exciting opportunities to work on my off-road driving skills. I had a catch can setup that worked really well for a couple of years until I learned to drive better and switched to r-comps, then one day at VIR it puked hot motor oil all over the place (all over the engine bay, my header (big smoke cloud), through holes in the firewall and over my instructor (Riding with me is always exciting!). My brakes have been the same way, as I get faster they get less adequate, but I generally try to keep the car at a level that I can drive it at until it becomes obvious that I need to change something because it no longer works for what I am doing. And even at that I probably am too eager to change stuff with the car vice changing stuff with the driver, but I'm kind of stupid about that sometimes. I've been changing less car stuff as I progress as a driver though, so maybe there's some hope for me. The exception to that is my engine, which I am always tinkering with because I enjoy it, even though I know the car already has more power than I am capable of effectively using, but as indulgences go it beats spending all of my money on hookers and blow, although that's a judgement call sometimes. At least if I did that my wife would understand why I spent so much.

unusual71

Honda-Tech bringin' me the Lols this mornin. if i wanted a quote in my sig this would be it haha


OT: this was good information because i was debating between ordering PU and hard rubber bushings. Do you think this kit would be on par with OEM quality?
http://cgi.ebay.ca/ws/eBayISAPI.dll?...2BSI%26otn%3D4

kommon_sense

Hardrace is an excellent hard rubber option.

prkiller

If you guys asking the question about bushings are building cars for Honda Challenge or other forms of racing, then the answer is simple.
Go with Spherical bearings first! Don't bother with the Poly!
Reason being, you WILL end up switching to the mono-ball stuff anyway, so you might as well save yourself some money and a lot of time in the long run and do it right away!

If the car is street driven, the Hardrace stuff is fine!
If you'd rather not deal with changing the bushings, you can pick up a new set of arms with the new bushings or sphericals pre-installed here!
http://specialprojectsms.com/index.php?categoryID=39

rmcdaniels

I've heard a lot of good stuff about the Hardrace bushings. As someone said, sphericals are the best though, I'm running mostly sphericals with a couple of Delrin, but that's on a dedicated track car. They made my car incredibly noisy though, and I wouldn't recommend them for a car that will be street driven. The guys at SPM in the above link are great to deal with; I've bought stuff from them before and been very happy with the transaction and the product.

NinetySevenDC2

Alright I think I understand better what Im going to do as far as my bushings are concerned. I dont see the value in buying arms pre-fitted with sphericals for such a high price.

Right now I'm just trying to get some seat time, which I understand is the best thing you can do. But as RMCDaniels explained about progressing, I wanna know what is out there as far as upgrading my car when that time does come.

From what I have seen, this season's H2 cars are gonna be awesome. I would love to be a part of it on the track but unfortunately I'll be on the sidelines!

Thanks for all the advice,

Sev.

NinetySevenDC2

Ok I did some research and it seems that if you want spherical control arm bushings you are going to have to buy the pre-fitted arms.

Are you able to buy individual sets of spherical bushings and press them into your control arms?

rmcdaniels

I bought all of mine individually. Progress sphericals from Summit for the rear LCA's, RTA sphericals from Special Projects, front LCA sphericals and front UCA solid bushings from Orijin Motorsports.

sgallagher

I'm running Mugen bushings on my entire car, HUGE difference, although Im comparing to stock 17 year old bushings. Haven't had any experience with the PU however.

*Boostwerks*

Anyone run sphericals in the trailing arm, LCA, and toe link? It seems like the toe link would be obsolete if both the control arm and trailing arm had sphericals...?

I'm thinking about swaping to a spherical trailing arm joint and have always thought the OEM rubber TA bushing would be best because of this.

NTCustoms

many people run spherical RTA bushings. PCI/Special Projects makes very nice pieces.

mlrmotorsports

I agree

*Boostwerks*

I realize that, but that doesn't really answer my question. In other words...how do you adjust the toe if you have sphericals in both the TA and the rear LCA?

DB2-R81

Same way it was done before the rear lower control arm spherical and the trailing arm spherical. The trailing arm sphere is not fixed on its axel and is allowed to slide laterally.

fiero87

can someone explain to me or point me in the direction of a fender bar, and what and where one would foam the side sills?
thanks

hayabusa160

its special body foam that hardens really fast.

Stinkycheezmonky

Are you just curious, or do you want to follow that knucklehead's advice?

fiero87

was curious never heard anything about that so was just inquiring about what he was talking about.