Short stroke suspension
|
08-25-2012, 06:35 PM
Post: #1
|
|||
|
|||
Short stroke suspension
without running very stiff springs, is it possible ?
My current front suspension is using 190lb springs and I would like to lower the car by about 40mm using short stroke dampers. My concern with using short stroke and 190lb springs is that it will run out of bump travel very quickly, I do not want to use stiffer springs. Anyone have any thoughts on this or have any information on short stroke damper lengths ? Thanks An analogue brain in a digital World |
|||
08-25-2012, 11:41 PM
Post: #2
|
|||
|
|||
Short stroke suspension
The question of how much stroke you require is directly related to how
much energy dissipation you need. And energy dissipation is dictated by how big the bump is, and how fast you are going when you hit it My car is around 40mm down with 3kg/mm springs and AGX shocks. The front struts had 40mm removed above the perch, and I am using full size lowering springs. Bump stops are shortened one lump This works fine around town and faster driving on good roads. Where it falls short is faster driving on poor roads with lots of dips and bumps. The faster the car is travelling, the harder you hit the bump, and the greater the energy the spring/shock combination has to dissipate. Note for the technically inclined; I may not be explaining this in the correct scientific terms, but you will get the gist of what I am trying to say When you have limited travel, the result of hitting a decent bump at speed is "bottoming out" and a sudden upward acceleration of the vehicle as the spring rate of the bumpstop approaches infinity. So yeah, if its just for a daily driver, you can go low without rock-hard springs. But for a race car, the less travel you have, the harder the spring you need. Cheers... jondee86 |
|||
08-26-2012, 07:46 PM
Post: #3
|
|||
|
|||
Short stroke suspension
I will try to evaluate how much travel I have with my
suspension as it is now, do you think a cable tie around the damper rod would work for this ? The question is then, is the lowered ride height worth the increase in spring rate ? Thanks by the way. An analogue brain in a digital World |
|||
08-26-2012, 10:21 PM
Post: #4
|
|||
|
|||
Short stroke suspension
jondee86 Wrote:My car is around 40mm down with 3kg/mm springs and AGX shocks. The I'm having a hard time wrapping my head around this.. if you lower the top of the damper (car body) by 40mm. Then lower the top of the shock body by 40mm, shouldn't you now have the exact same bump stroke as stock? I know mine does with a very similar setup. You might be having some trouble with spring-bind perhaps? Twin tube dampers like the AGX also have small piston area's and as a result take a longer time to devellop damping forces. A wheel to steer the front of the car A pedal to steer the rear |
|||
08-27-2012, 12:44 AM
Post: #5
|
|||
|
|||
Short stroke suspension
NoHachi Wrote:I'm having a hard time wrapping my head around this.. if you lower the Maybe I'm more than 40mm down ? I know the Espelir springs were rated 40mm down when I bought them. After I installed them I was only about 20mm off the bumpstops before I cut the struts. I'll have a look in my notes to see how I assessed the bump and rebound travel when I fitted the AGX inserts. I know I had to cut the bumpstops to get adequate bump travel. EDIT: Thinking about it some more, I spent a lot of time trying to set the front up to function within the total available operating stroke of the AGX inserts. There is not a lot of working stroke to start with, and cutting the bumpstops unlocked another 20-25mm. Then I aimed for 60% bump and 40% rebound. Cheers... jondee86 |
|||
08-27-2012, 03:04 AM
Post: #6
|
|||
|
|||
Short stroke suspension
totta Crolla Wrote:The question is then, is the lowered ride height worth the There is a set of AE86 coilovers complete with new front spindles, that ships with 8 kg/mm springs for the front. I fantasised about fitting these to my car All I would need to do would be to get some 4 kg/mm springs to soften the "drift style" spring rates for normal road use. Wrong... the front shocks only have about 60mm total travel !! Fitting softer springs would mean hammering the bumpstops. So I had to give that idea away. Spring rate and ride height/suspension travel is always going to be a compromise. Go low and take the big hits, or go high and put up with the body roll. If I get round to spending more cash on my suspension, I will go to a slightly stiffer spring, say 4.5-5.0 kg/mm, and invest in some Bilsteins valved for the application. Quality shocks will improve the ride when you are using stiffer springs. Cheers... jondee86 |
|||
08-27-2012, 08:21 AM
Post: #7
|
|||
|
|||
Short stroke suspension
Totta, is this for your rallying efforts?
If so, just look at the Escort Mk2 setups. Their chassis in GP4 spec is 99% similar to the AE86 in places where it matters. They have decades of rally devellopment behind them. Whatever works for the front running escorts will work on an 86 too. Always easier to learn from the pro's. A wheel to steer the front of the car A pedal to steer the rear |
|||
08-27-2012, 11:15 AM
Post: #8
|
|||
|
|||
Short stroke suspension
Here is the deal, yes the suspension is for my (tarmac) rally car and
yes my suspension for that application is very very good at the moment. I'm very much a function over form kind of person but I have been offered some short stroke dampers and Corollas always look good low. The idea was to lower the car whilst keeping everything else as it is now, it seems my suspicions about this are correct though. You are of course correct in what you are saying about Escorts and sometimes I wonder if Toyota got hold of a copy of the "Ford Escort rally preparation" manual published by Boreham Ford in the 1970's when they designed the AE86 Most of the Escort design weaknesses picked out in the book appear to have been deliberately over engineered on the '86 a good example is the way the steering column attaches to the body. RAS motorsport have made the whole book available to download free and here is a link to one of the pdf's. Interesting stuff http://www.rasmotorsport.com/Billeder/Mo...n-Rear.pdf An analogue brain in a digital World |
|||
08-28-2012, 02:58 AM
Post: #9
|
|||
|
|||
Short stroke suspension
Aha... I had a feeling yours was a leading question, and that you already
knew the answer If you have suspension that works well for the speeds that you travel on the roads that you use... don't change it just for the sake of looking cool. My suspension is fine for normal driving, but it does not handle big hits well. So I drive within its limitations and suffer the odd kick in the a$$ from dips or bumps that I don't see early enough Cheers... jondee86 |
|||
10-11-2012, 08:56 AM
Post: #10
|
|||
|
|||
Short stroke suspension
need info and axperience on this.
i have been planning to build coilovers all around for an 86 with adjustable konis, ae92 insert on the front, ae86 oem stroke on the rear. but i dont like tha fact that i have to push and turn the rear shock to adjust damping, as i would have to disassemble the coilover every time i need to make an adjustment. so im questioning, what if i would use ae92 front inserts for the rear too? lenght is good, mounting eye not a problem. whats your opinion guys? |
|||
« Next Oldest | Next Newest »
|
Possibly Related Threads... | |||||
Thread | Author | Replies | Views | Last Post | |
TRD Short Shifter Rattle Noise, It's Normal? | Mattolo | 19 | 19,303 |
04-27-2024 10:04 PM Last Post: banpei |
|
Bilstein short strokes | Grant | 1 | 4,198 |
05-15-2012 07:32 PM Last Post: NoHachi |
|
Does anyone know where to buy a short steering hub/boss? | krullibull | 6 | 6,584 |
10-12-2011 10:26 PM Last Post: krullibull |
|
Long Stroke Springs - Espelier 40mm Tokico ??? | juantonwan | 20 | 16,884 |
05-11-2010 10:31 PM Last Post: jondee86 |
|
fc3s front brake conversion, short report | speed-inc | 18 | 15,834 |
10-09-2009 06:32 AM Last Post: aussiefan |
User(s) browsing this thread: 2 Guest(s)