Well I'm in the opposite situation in that I haven't tried anything more solid than poly. I would have thought that they are closer to metal than rubber however as they don't flex much and actually crumble if they are asked to (my lower front bushes disintegrated several times for some reason - I think we got a solution before the engine went pop though we never understood why it happened to me but not Dave for example). My top mounts are effectively solid having only a Rose joint, so my guess would be that the KW is more forgiving in comparison to Billies than the key difference being in the bushes. That said I replaced the rear axle mounts with OE, so at the rear there would have been a minimal amount of compliance at the back with only the swing arm bushes being hard.
The suspension saga continues - Bilstein Escort Cup ?
- Thread starter mike220
- Start date
Well I'm in the opposite situation in that I haven't tried anything more solid than poly. I would have thought that they are closer to metal than rubber however as they don't flex much and actually crumble if they are asked to (my lower front bushes disintegrated several times for some reason - I think we got a solution before the engine went pop though we never understood why it happened to me but not Dave for example). My top mounts are effectively solid having only a Rose joint, so my guess would be that the KW is more forgiving in comparison to Billies than the key difference being in the bushes. That said I replaced the rear axle mounts with OE, so at the rear there would have been a minimal amount of compliance at the back with only the swing arm bushes being hard.
After much thought i have decided not to go for the KWs but instead take the cheaper option and fit the Koni sport adjustables (even after having a pax lap in Steves turbo S at silverstone...THANKS Steve.)...I have been wanting to take my bike test for some time and the money i should have left over after the suspension upgrade will more than pay for that....Thanks for all the advice from every one ...
This morning i took delivery of my new MO30 ARBs,castor mounts and bushes for everything, Thanks to exeter OPC for a great service....
The only thing im stuck for at the moment is Front springs, I was going to buy 968CS front springs but the OPC cant get them until mid september which a bit to long for me to wait...Having spoke to JS and seeing how is car sits at the front im tempted to purchase springs from Porsche Shop but havnt got a clue what make they are and if the £130 price tag seems a little over the top ?
http://www.porscheshop.co.uk/acatalog/porsche_944_suspension_upgrades.html
What other options do i have as far as front springs go ?
Thanks
Steve.
This morning i took delivery of my new MO30 ARBs,castor mounts and bushes for everything, Thanks to exeter OPC for a great service....
The only thing im stuck for at the moment is Front springs, I was going to buy 968CS front springs but the OPC cant get them until mid september which a bit to long for me to wait...Having spoke to JS and seeing how is car sits at the front im tempted to purchase springs from Porsche Shop but havnt got a clue what make they are and if the £130 price tag seems a little over the top ?
http://www.porscheshop.co.uk/acatalog/porsche_944_suspension_upgrades.html
What other options do i have as far as front springs go ?
Thanks
Steve.
sawood12
New member
I'm afraid not. Stiffeneing the ARB might slightly reduce body roll but also might induce oversteer on the limit. Again it's all about balance between the front and the rear as to what the end effect will be. The ARB will have no effect on stiffness of the rear end. The rear end will still squat the same under accellaration and feel the same over bumps and undulations in the road surface. ARB's are only there to react against body roll in a bend. Also a stiffer ARB reduces the responsiveness of the suspension of the unloaded wheel in a bend as the suspension spring is working against the ARB (ARB trying to lift the inside wheel and the suspension trying to force the wheel to the ground with the spring force of the ARB subtracting from the spring force of the main suspension) and can therefore reduce your overall levels of grip.
Can i put this link in here pleeeeeeeeeease......................[
]...
http://www.porscheclubgbforum.com/tm.asp?m=396636&mpage=1&key=񠵜
]...http://www.porscheclubgbforum.com/tm.asp?m=396636&mpage=1&key=񠵜
After all the trouble / discussion we created . . . . . . . . .[] . . . . . . . . . . . that's made me chuckle a bit Steve. Nice to hear you've got sorted with a track toy though none the less. What did you buy ?
I've replied to your post mate - e-mail me back and we can go from there.
Cheers,
Mike
] . . . . . . . . . . . that's made me chuckle a bit Steve. Nice to hear you've got sorted with a track toy though none the less. What did you buy ?I've replied to your post mate - e-mail me back and we can go from there.
Cheers,
Mike
No worries Nick. Money's tight at the moment, and it's due to go into Hartech in the next month or so for a 34k plus belts and a proper report etc. etc. and unless I find someone to send them over for me at the right price it won't be happening - Lindsay want $440 to ship !! []
I'm working on it, but may update all the other bits and bushes for now along with my service and stuff and see how it feels after that. Budget will determine the rest . . . . . . . . .
Mike
PS - stay away from the shiny bits Nick, you know they hurt your wallet []
]I'm working on it, but may update all the other bits and bushes for now along with my service and stuff and see how it feels after that. Budget will determine the rest . . . . . . . . .
Mike
PS - stay away from the shiny bits Nick, you know they hurt your wallet [
]Mike just sent you a PM (let me know if it dosnt work)Just updated the suspension parts add with part numbers .....
Thanks for all your advice on this subject even though i did hijack the original posting a bit but im Sorry to say i spent my money on another car.....i know its not a porsche but its i have to say its a lot of fun....
http://i232.photobucket.com/albums/ee119/spicster1974/643647-1.jpg []
Thanks .
Steve.
Thanks for all your advice on this subject even though i did hijack the original posting a bit but im Sorry to say i spent my money on another car.....i know its not a porsche but its i have to say its a lot of fun....
http://i232.photobucket.com/albums/ee119/spicster1974/643647-1.jpg [
] Thanks .
Steve.
appletonn
New member
Mike, the PO couldn't find the details so I went straight to Lindsay Racing who were more than helpful and managed to track down the PO's original order!
So it turns out that I have 250 lb springs at the rear (in addition to the t/bars) and 450 lb Hypercoil springs at the front.
I am seriously considering putting some fractionally softer ones at the front in a bid to improve the front end bite and feel still further. The Hypercoil site lists 400, 350 & 300 fronts, so may well give the 400 ones a go.
Hope this helps[
]
appletonn
New member
Does anyone else with uprated suspension know what their front spring rates are?
I am going to order some different Hypercoil springs for the front, but I need some guidance on how much of a drop down from the current 450 lb/in will give me the better front end bite and compliance that I need.
I am going to order some different Hypercoil springs for the front, but I need some guidance on how much of a drop down from the current 450 lb/in will give me the better front end bite and compliance that I need.
appletonn
New member
OK, since I appear to be having a conversation with myself (not for the first time[8|]), I may as well continue in that same vein!
I have now calculated what I believe to be my front and rear effective spring rates and they go a long way to explaining why my car handles the way it does!
At the rear, I have 25.5mm torsion bars which equate to an effective spring rate of 175lbs/in plus the 'helper' coil springs at 250lbs/in to give a combined rate of 425lbs/in. This compares with the standard car's set up of just the 175lbs/in.
At the front, the supplier in the States sold the PO some 450lbs/in springs, which compare rather drastically with the original set up of 160lbs/in![]
So, whereas the original car set up had the front being slightly softer than the rear in terms of springing, which would have promoted a slightly o/steery balance, my car is not only far too stiff at the front, but the whole balance of the car, front to rear, has been upset by somone fitting the wrong front springs.
I can understand that they wanted to stiffen the suspension, as it was destined to be a trackday car, but at a stroke they have also destroyed the handling balance![8|]
Since I had the geometry, corner weighting and negative camber work done, it improved but it still never used to give me the confidence in the front end bite - now I know why!!!
So I now need to buy some softer front springs (unless my logic is flawed, in which case, someone please tell me quickly!![]) and I am talking to a handful of people who have either the same Bilstein setup as mine, or are racing/sprinting/trackdaying their cars and have found a great balance.
Will report back, once I have chosen and fitted the new springs - hopefully with a happy ending!![8|][]
I have now calculated what I believe to be my front and rear effective spring rates and they go a long way to explaining why my car handles the way it does!
At the rear, I have 25.5mm torsion bars which equate to an effective spring rate of 175lbs/in plus the 'helper' coil springs at 250lbs/in to give a combined rate of 425lbs/in. This compares with the standard car's set up of just the 175lbs/in.
At the front, the supplier in the States sold the PO some 450lbs/in springs, which compare rather drastically with the original set up of 160lbs/in![
]So, whereas the original car set up had the front being slightly softer than the rear in terms of springing, which would have promoted a slightly o/steery balance, my car is not only far too stiff at the front, but the whole balance of the car, front to rear, has been upset by somone fitting the wrong front springs.
I can understand that they wanted to stiffen the suspension, as it was destined to be a trackday car, but at a stroke they have also destroyed the handling balance![8|]
Since I had the geometry, corner weighting and negative camber work done, it improved but it still never used to give me the confidence in the front end bite - now I know why!!!
So I now need to buy some softer front springs (unless my logic is flawed, in which case, someone please tell me quickly!![
]) and I am talking to a handful of people who have either the same Bilstein setup as mine, or are racing/sprinting/trackdaying their cars and have found a great balance.Will report back, once I have chosen and fitted the new springs - hopefully with a happy ending!![8|][
]Actually Nick to do the rear rates with Torsion bars and helpers is not just a matter of adding them up. It's more complicated than that. I will post an email I received from Karl of Racers Edge in the US when trying to figure out my own rates on the KWs. Also understand that this was in context to some questions I asked of him and told him of someone else's calculations. Anyway, it's quite interesting. Oh and there's spring rates and wheel rates too. Be nice if it was just a matter of adding things up.[]
"Patrick,![[FONT=verdana,geneva"]](/forum/styles/default/pcgb/space.gif ". [FONT=verdana,geneva\"]")
I have not spoken with X, and actually don't know who he is. But believe me, my numbers correct (or close to it - see the following explanation). The info on Paragons site is stuff they got from me a few years ago. In any case, the 47% is a number that I have calculated By taking measurements. I am now pulling out one of Porsche's own Motorsport sheets that shows all the rates of their Turbo and "Cup" cars back when they ran competitively. Porsche lists the 25.5 mm bar as 31 N/mm which is 177 lbs/in. They also then give the variable rate coilover helper spring rates at 34-65 N/mm which is 194 lb/in - 371 lb/in. They then give the total Rate at the wheel(T-bar plus coilover) as 45.4 - 58.5. Back out the rate at the wheel due to torsion bar which they list as 31 and you have 14.4 - 27.5 at the wheel due to the coil over. So take your pick, 14.4 / 34 is approx 42% or 27.5/65 is 42%. X is right about them being inboard but his numbers are off. Actually they are correct I think in that the motion ratio is about 65%. But when calculating wheel rates from spring rates it is the motion ratio squared that is uses. So 0.65 ^2 is , guess what,... 42.25% which is the number that Porsche's own sheet claims as I outlined above. So your torsion bar is 177 at the wheel, and your helper spring rate is a 285 which is 119.7 lb/in at the wheel. So working backwards 177 plus 119.7 is 296.7 pounds per inch at the wheel. Divide this by .42 and that is you equivalent coilover, or 706 lb/in coilover (initially I had 661 lb/in which is attributable to my measurement error - I had 47% and Porsche lists it at 42%). So it may be a bit stiffer in the rear than I might run but with the ability to tune sway bars etc... you should be Fine. Your setup is actually much stiffer in the front than the Porsche cup setup which ran progressive front springs (200 - 371 lb/in) with the rear setup I described above which is not that far from what you have( yours is 296 at the wheel and theirs was 259 - 334 lbs/in at the wheel). Hope this make sense, but believe me, what is above is 100% correct. I can fax you the Porsche motorsport sheet if you think it will help.
]"Patrick,
I have not spoken with X, and actually don't know who he is. But believe me, my numbers correct (or close to it - see the following explanation). The info on Paragons site is stuff they got from me a few years ago. In any case, the 47% is a number that I have calculated By taking measurements. I am now pulling out one of Porsche's own Motorsport sheets that shows all the rates of their Turbo and "Cup" cars back when they ran competitively. Porsche lists the 25.5 mm bar as 31 N/mm which is 177 lbs/in. They also then give the variable rate coilover helper spring rates at 34-65 N/mm which is 194 lb/in - 371 lb/in. They then give the total Rate at the wheel(T-bar plus coilover) as 45.4 - 58.5. Back out the rate at the wheel due to torsion bar which they list as 31 and you have 14.4 - 27.5 at the wheel due to the coil over. So take your pick, 14.4 / 34 is approx 42% or 27.5/65 is 42%. X is right about them being inboard but his numbers are off. Actually they are correct I think in that the motion ratio is about 65%. But when calculating wheel rates from spring rates it is the motion ratio squared that is uses. So 0.65 ^2 is , guess what,... 42.25% which is the number that Porsche's own sheet claims as I outlined above. So your torsion bar is 177 at the wheel, and your helper spring rate is a 285 which is 119.7 lb/in at the wheel. So working backwards 177 plus 119.7 is 296.7 pounds per inch at the wheel. Divide this by .42 and that is you equivalent coilover, or 706 lb/in coilover (initially I had 661 lb/in which is attributable to my measurement error - I had 47% and Porsche lists it at 42%). So it may be a bit stiffer in the rear than I might run but with the ability to tune sway bars etc... you should be Fine. Your setup is actually much stiffer in the front than the Porsche cup setup which ran progressive front springs (200 - 371 lb/in) with the rear setup I described above which is not that far from what you have( yours is 296 at the wheel and theirs was 259 - 334 lbs/in at the wheel). Hope this make sense, but believe me, what is above is 100% correct. I can fax you the Porsche motorsport sheet if you think it will help. 
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