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what springs do you use?

Posted: Mon Oct 23, 2006 9:15 pm
by se7ensport
I currently have 130lbs x 9 on the back and 180lbs x 8 on the front.

My rear end has bottomed out a couple of times recently and i am going to go for stiffer springs, i believe that tim recommends 180lbs with his long shock conversion (beyond my budget for a while :( )

If I go to 180 at the back I calc that I would need 250lbs to maintain the same balance!!!! at the moment the front seems about right, so what do you guys run?

I appreciate that engine weight makes a bit of difference, I have a pinto which while labled a boat anker it is 135kg dry, if you could post your engine weight as well it would help (don't know your engine weight? see following link) http://www.fluke-motorsport.co.uk/weight/search.php


Cheers

Alex

Posted: Tue Oct 24, 2006 12:40 am
by Ady8077
Hi Alex

I had the same set up as yours, i've bought some new 200 lb for the front and fitted the 180's off the front to the back, seems much better

Adrian

Re: what springs do you use?

Posted: Tue Oct 24, 2006 10:45 am
by stylussprinter
se7ensport wrote:I currently have 130lbs x 9 on the back and 180lbs x 8 on the front.

My rear end has bottomed out a couple of times recently and i am going to go for stiffer springs, i believe that tim recommends 180lbs with his long shock conversion (beyond my budget for a while :( )

If I go to 180 at the back I calc that I would need 250lbs to maintain the same balance!!!! at the moment the front seems about right, so what do you guys run?

I appreciate that engine weight makes a bit of difference, I have a pinto which while labled a boat anker it is 135kg dry, if you could post your engine weight as well it would help (don't know your engine weight? see following link) http://www.fluke-motorsport.co.uk/weight/search.php


Cheers

Alex
Alex , 130lbs on the rear was Peter P's set up which I argued was wrong even in 1999 . Like you I was supplied with 180 and 130 . Mine have been changed 4 times , gradually finding a better set up , mixed with other moves to take advantage of going stiffer -- i.e. you can't go stiffer in isolation -- it will require you to make other changes. So , unless you can make the other changes , I would advise not making too big a leap :!:
You are right re - maintaining balance , so if you go 250 front 180 rear , remember that shocks need to be set around a third/total clicks front and roughly two thirds/total clicks rear. Also remember , the car will sit higher on stiffer springs so drop it on the adjusters till it sits where you want it . Added to this you will be able to run a touch lower than as is , due to the springs weight bearing increase.

General rule of thumb for shock settings is .(not in all circumstances)

LOWER LBS SPRINGS = HIGHER SHOCK SETTING
HIGHER LBS SPRINGS = LOWER SHOCK SETTING

This is quite a crude rule and doesn't account for driver weight or finer handling traits you might want to allow for. Start off with a wedge of 25mm and adjust to the oversteer :D /understeer :shock: it will create.(as will tyre pressures/spring rates/shock settings)
Wedge can be measured best on a Stylus FRONT = under bottom front chassis rail.
REAR = under last alloy floor sheet to seat pan join.(not under the tube / later models have seat pan tube underneath not inside.)
Difference set to 25mm higher at the rear. This will give oversteer unless you weigh '' a lot '' . Most people prefer oversteer. Then adjust to your preference.

Think I've gone on a bit so will leave it there unless you have any further questions :roll:

My settings = 285lbs/7 inch springs/10 inch trakspacs 3 to 9 clicks
250lbs/8 inch springs/14 inch AVO rear 16 to 22 clicks
(rear have SSC's concave trailing links)

Regards , Rob. :wink:

Posted: Tue Oct 24, 2006 4:01 pm
by se7ensport
Thanks Andy and Rob.

Rob, that’s a fair bit of info, looks like I'll be back out with the tape measue tonight. My calc of 250lbs gives rear rate to be 72% of front (same as 130/180), Rob yours are 92% and Andy's 90%, so Andy's figure of 200 is a lot closer to your front / rear balance.

Should I take in to account rocker arm ratios? I assumed mine are 1:1 which they probably aren't.


ditto: mine keeps swallowing the cash as well :wink:

measuring tonight

Posted: Tue Oct 24, 2006 4:32 pm
by stylussprinter
se7ensport wrote:Thanks Andy and Rob.

Rob, that’s a fair bit of info, looks like I'll be back out with the tape measue tonight. My calc of 250lbs gives rear rate to be 72% of front (same as 130/180), Rob yours are 92% and Andy's 90%, so Andy's figure of 200 is a lot closer to your front / rear balance.

Should I take in to account rocker arm ratios? I assumed mine are 1:1 which they probably aren't.


ditto: mine keeps swallowing the cash as well :wink:
Don't worry about percentages at this point , your 250 and 180 will be fine for developement because no way will you acheive pefection in one move. Don't forget that other people will all have different cars , handling wise , due to many build spec' differences , including their personal weight . DRIVE it , drive it a lot , think about what you beleive the car is doing underneath you before making any further changes. Set your tyres approx'ly 18 to 20 all round . Most important is to write in a note book , all set up info / date / result assessed .
Ratios of rockers only need to be calculated if just one weight of person and one type of driving are anticipated -- you don't need that info , unless you're going in blind . Tuning suspension at the first level is cheap enough at £17 or so a spring so doesn't cost a fortune to do again as you develope your car/your driving/uses ? I think it's unlikely , for instance , that if you set yours up as mine is today , that you'd like it . Mine has grown to this spec' and I probably wasn't capable of using this set up 4 moves back --- I'd have found it too sensitive. Rob. :wink:

Posted: Tue Oct 24, 2006 5:58 pm
by se7ensport
Your set up is definitely firm, I appreciate that you have gone for track set up rather than touring, but does it work in the wet? I used to run 250 front and 200 rear in my old 3000M and that weighed in at a lot more than a stylus!

Last question I hope; front shocks are 12in eye to eye with 8 inch springs at the moment and platforms are 1/3 up from bottom. Will 7 inch be about the right length to maintain a similar ride height?

in the wet !

Posted: Tue Oct 24, 2006 7:10 pm
by stylussprinter
se7ensport wrote:Your set up is definitely firm, I appreciate that you have gone for track set up rather than touring, but does it work in the wet? I used to run 250 front and 200 rear in my old 3000M and that weighed in at a lot more than a stylus!

Last question I hope; front shocks are 12in eye to eye with 8 inch springs at the moment and platforms are 1/3 up from bottom. Will 7 inch be about the right length to maintain a similar ride height?
In the wet , mines a lethal beast unless I knock off almost all the bump and some rebound but that's the cost of developing a great dry set up. I'd need to spend equal test/competition time on developing the wet set up to be really good as opposed to a compromise. My reasoning is that the proportion of dry to wet competition days is 10 to 1 , so didn't work hard at it . I'd need softer springs/more travel at the front -- all things that need a team of track mates to change on the day if the weather demanded it --- whereas all I can manage between runs is shock adjustment and connect/disconnect antirollbar plus tyre pressures ------- you have to draw the line somewhere on £££££££

Spring length wise , the important thing is ---- having lowered the car to the height you want , is there still '' shock piston '' travel in bump/rebound ??? With 250 fronts you will get away with around 15mm of shiney piston showing as well as the bump stop .You'll have to assess it now , checking with torch/mirror with existing poundage knowing that 250's will see the car sit about 5mm higher. So set the car 5mm behond where you'd like it / bounce it about a bit to settle it -------- then if there's 10mm showing , fit the 250's and 5mm will be added.
It's not an exact art so you'll need to fiddle/adjust/experiment PLUS all this assumes you have arch and headlamp clearance . Also don't forget that I'm not running 12 inch shocks with my 7 inch springs ; if I did the wheels would foul everything especially on lock :!:
Don't use mine as a guide unless you intend modding body/lamps/short shocks. To enable me to have 93mm front ride height , I've cut heaps from front/rear arches plus lower valance(in front of the wheels)also moved the front wheels forward some. That's why my car is so stiff --- it keeps it off the wheels , just a cost of drastically lowering. Hence no wet set up :!: :!: :!:

Can't complain though , it's got me a BEST OVERALL NOVICE 2002/ A 2nd in the championship 2003 / A first in the champ'p 2004 / another 2nd in 2005 champ'p and this year even faster times although not entered in the 2006 champ'p. NO DOSH :evil:

Looks like I've given TOO much info again but it's not possible to give short answers on set up :wink:

Regards Rob. :roll:

Posted: Tue Oct 24, 2006 9:11 pm
by se7ensport
Really appreciate all the info and it sounds like you have had some real results with it!!!

I've already had issue with clearance on the headlamp bowls, resulting in cutting away a fair amount of plastic.



Thanks again


alex

info

Posted: Tue Oct 24, 2006 9:42 pm
by stylussprinter
se7ensport wrote:Really appreciate all the info and it sounds like you have had some real results with it!!!

I've already had issue with clearance on the headlamp bowls, resulting in cutting away a fair amount of plastic.



Thanks again


alex
Happy to pass on a little of what's taken a while to develope if it saves others a few steps . Really enjoyed the developement equally as much as driving it to prove right or wrong :D :shock: :wink:
Rob. :D