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**NoHachi** · 04-26-2010, 12:25 PM

No its the other way around. The chassis needs to be at least 7.5-10 times as stiff as the springs. So you would need a caged car to effectively use stiffer springs, but running springs with lower rates is fine since the ratio will be more then 7.5/10.

Basically you want the combination of car and springs to fall into the green area of the graph.

Uzelac · 04-26-2010, 12:36 PM

Can sway bars do the job for not-serious-track-racing AE86 ?

As much as i've seen, standard cars go up to 30 000 Nm/deg and none of them have cages.

So, presumably cages are really hard core, and they are needed for real serious use/suspension stiffness.

boo50 · 04-26-2010, 12:42 PM

NoHachi Wrote:The chassis needs to be at least 7.5-10 times as stiff as the springs.

understand, thnx.
I think I've choosed propper ratio for my car (caged + F8/R7kg springs).

and what I mean in previous post - what if you've a cage, even with this rule, you can go with smthng like 20kg's springs and still body will be 10 times stiffer than springs.

**NoHachi** · 04-26-2010, 12:49 PM

Hmz, I've added a further remark to the text to make things more clear:

To summarize:
*To run more then 5kg/mm springs on an AE86 you need ideally to stiffen your chassis through seem welding.
*To run more then 6kg/mm you really need a cage.

You could run with the stock body, but realise that it will be doing a lot of the suspensions work (a compromise). Roll-cages, if designed well and integrated into the chassis, will bump stiffness numbers well into the 30.000+Nm/deg

Newer cars run up to 30.000Nm/deg. This is relatively new thing that's made possible through CAD and FEM software (this is also where the numbers come from and why you won't find many older vehicles in the list). My estimate is that cars from the 80's will be somewhere between the figures I posted. 6000-14000Nm/deg.

These outcomes further confirm my suspicion (and until we've looked at all numbers it is just that: a hunch) that the popular 8/6 rates are truly a race only set-up for use with all out caged race cars.

[edit: Sway bars are a whole different topic that we'll cover some other time. Basically they are just another kind of spring.]

TeZe · 04-26-2010, 10:36 PM

Very interesting info's, keep up posting them.

I also would like to share my experiences with my car. It's a caged (full FIA homologue weld in custom cage) 3 door Levin. Suspension has(had the following mods: Cusco F+R ARB's, poli bushes, front Pass Racing coil-over conversation with 6kg/mm Swift springs and Tokico HTS, RCA, Tein camber plate. Rear had rose joint pan-hard, TRD 4,7 kg/mm springs and the Tokico's. It was ok, a tad soft for track use, and drifting, but my car does regular duties as well, and sometimes amateur rallying. Basically I was happy, it was sweet handling and had a good neutral balance. It has a Quiafe QSR and a Yaris electric servo, and it is as easy to drive quick as it gets. But I was not happy with the dampers.

I really don't like to say it to loudly, but I was not happy with the performance of the Tokicos. They were not as good damping and holding the car, as I would liked to have. So last autumn I sold them and got the sport Bilsteins with the standard springs for the snow fun. It was perfect, and I did learned a lot during the winter times.

I also tried to figure out what to buy for this summer as an update. I wrote e-mail to a lot of suspension companies (10 or something) with my current (old) setup, and that I would like to have something more race oriented, high adjustable, and in damping 3way adjustable suspensions. No or not useful answer from Koni, Bilstein, Tein. Freindly answer and good customer care from Intrax, AVO UK, Proflex, KW Motorsport. In my price range (tbo it's a bit above, with ~3000 euros Smile

at the moment I would choose between AST or Proflex - they are rally proven is Hungary, and have local support.

Your topic, and specially the race Konis you mentioned before caught my interest. Would you recommend them or anything else? Have you any experience with the above mentioned companies?

Thank for the answer, and cheers, TeZe

**NoHachi** · 04-27-2010, 08:54 AM

Hi, Teze
Wow, our cars sound VERY similar in setup. Although yours has a few mods that are still in the future for mine (like the powersteering setup). Do you have a link to a project thread?

Regarding decent suspension setups, If you can wait a little bit longer I was hoping to post some details in the near future. I have AGX's on my car and hate them. Hoping to go to a short stroked race bilstein setup, with the larger 36mm pistons and custom valving specific to the 6/4 AE86 setup. Once I have those damping curves it wouldn't be difficult to come up with the needs for different cars and setups.

I have some small experience with the development of new products with AST. If you choose to go with them send me an email and we can see if can be of any help in the development of the AE86 setup. I don't think they did anything for a hachi before, but they have a new product for the E30 BMW. You might be getting that setup (which is nice but on the stiff side for a hachi). Let me know and I can give the owner a call.
No experience with proflex, but everything I hear is good.
If you are in a hurry then take a look at Sellholm. They also make some very nice Bilstein rally setups and I am certain that they setup several 86s.

**Jan Pedersen** · 04-27-2010, 11:58 AM

Teze, what didn't you like about the HTS?

My setup is quite similar as well: Front coil over using 6 kg/mm TRD springs and adjustable TRD dampers. Rear has 5.1 kg/mm TRD springs and adjustable dampers. And the usual poly bushes, camber plates, QSR, stich weld ect. I never felt that this was too soft but if you are running better tires that might be it.

I quite like the TRD dampers - comfort is tolerable, the car settles quickly and its easy on the limits. I went for TRD back in the days because most danish rallydrivers use them. But since then I know some tried Bilstein and proflex.

Bilstein was the "cheap" non TRD option. As I recall the dampers wheren't adjustable. They where upside down and the driver quite liked them.

Proflex can setup you car just the way you like but it won't come cheap. A complete setup is €4-5k (I was told).

TeZe · 04-27-2010, 02:33 PM

TeZe · 04-27-2010, 02:54 PM

@NoHachi:

to answer your other questions, yes, I can wait, worse, I have to wait because the lack of $ at the moment. Smile

My goal would be to have a suspension fully adjustable (3way damping, height and spring preload), once I even want to change to Whiteline adjustable sway bars, and "play" with them a lot, to have experience and better understanding of how suspension, specially dampers work. I'm a car jurno, and very much interested in this topic due to some racing experience (Clio 182 Cup driver for a year, and rally navigator for 2 years). But I'm doing it mostly on my own budget, there are very few sponsor, so sometimes money is thight.

If you could help me to contact directly AST, I would be very happy. I did wrote them, but there came no answer. My ex-rally-driver is supported by the hungarian AST company, but they were not really helpful. Even so, that I could give the dampers some promo..

TeZe · 04-27-2010, 03:04 PM

Jan Pedersen

My english is just to week to explain what I did not liked on the Tokico's. For start they were blowing away on the first 2 meters - I bought them new. It was not a good start Smile

Then they were repaired, but on track I had the feeling they are overstressed. Sorry, I can not explain it better. A non adjustable Bilstein can be a very good damper, but for me it's not an option. I want to play with them and adjust them, and learn how to set up a car for special demands, tracks, wetter etc.

Proflex Hungary give me a price offer: a set would be 3200 euros. KW Motorsport 3way would be 5200. Huh