himself

Since my wife won't let me have Motons, I am going to do some "maintenance" on the stock parts by putting on stiffer springs and revalving the stock Bilsteins. But, I can't seem to find info on spring lengths. [FWIW, Bilstein only charges $65 per for this service, and for $35 more you can get them back in 3 days.]

Does anyone have a resource, web link, or just the right info for springs? Are the fronts/rears different lengths?

Basically, I'm looking at
120 mm main [f]
160 mm main [r]
with 60 mm tenders for both.

Thanks!

-td

MTB

td,
here you go.
http://eibach.com/eibach/img/ers-2010-catalog.pdf
http://www.hrsprings.com/applications/60mm_id_springs

Here are what Lex from moton recommended on spring lengths. These are for moton CS, should give you good reference:

F=4 to 5"
R=5 to 6"

Tender = 150lbs, when spring compressed, length is no more than 1.75"

If you stay with 60mm spring, you will need monoball mount & spring hat for the rear.

Michael

mooty

just lie to the wife.

Crazy Canuck

Motons are for safety.

deleonl1

"Motonance"

Just tell her you found a used setup on Rennlist for cheap.

SH || NC

Works for me. *Makes quote marks is air* 'Safe-teee'

va122

i use 4"/6" f/r per lex, but I have no memory, so I can't tell you what the stocks are. I couldn't wait to get them off the car.

KOAN

Might be best to state the entire spring # for more accurate comments, if anybody knows what will work.

911SLOW

What you need the stock springs lengths?

Mike K.

With the revalved Bilsteins we use 2.25" ID X 8" front and rear with no tender springs. Actually 9" is better in the back if I remember correctly. You will need new hats and perches ( although these can be machined to fit 2.25" springs). Also you will have to change to monoball shock mounts in the back as the original ones flex too much with stiffer shocks.
Pay the extra $35 for the speedy service or it can take a while.

mooty

the 2.5 ID springs gives more wheel clearance. i also have no tenders on the race car.
but for street car will that be ok, with no tender?

outline

not on bilsteins but im running 100mm x60mmID front springs and 140mm x 60mmID rears rated at 140N/mm and 160N/mm respectively.
ive got 60mmID linear tenders on each too, rated at 60N/mm (about 350lbs) i think. i'll check length later this week if you like. these are almost fully compressed under static load (about 10mm left before block height) but not quite. it gives a nudge of compliance on bumpy tracks (and the road) but anything serious just squishes them right onto the hard springs and all is well in the world. with the tight tolerance needed for this i had to calculate based on car weight so my tender info might not work for you. i suspect you will end up on block height with my lengths. they are pretty cheap though so you can always just work it out roughly if you dont know your exact figures and then adjust to suit.
ive a pile of linear tenders here that i just change out to if i need a bit of extra compliance, or only need it for negative travel (ie to prevent wheel lift)

911SLOW

Interesting
What ride height you have?
How is the droop with unloaded wheel?
Cups had front 100mm main with 75mm tender and rear 130mm main with 60mm tender but were running very low. On close to stock -20mm suspension wont have a lot of negative travel unless the tenders are super soft not 60n/mm.

outline

its exactly from my old 6cup that i stole the idea and just adjusted it slightly for this car and application.
from memory i think the 60N/mm linear tenders are about 95mm (60mm compression and 35mm block height) but i also have 70,50 and 40N/mm that i alternate in there depending on what i want to happen.
i think they range from about 90mm to 115mm length but have the same block height give or take. usually there is a 50N/mm on the front but with me not planning on tracking anytime soon ive got 60N/mm on both. this gives an extra couple of mm on the front for crappy roads.

im running 105mm front, 126mm rear ride height with -3.5 and -2.5 camber, on 255 and 315 tires for the most part and it seems to translate across road use and track evenings etc ok. any lower just gives a ton of headaches on regular driving that arent offset since i dont track the car heavily.
if i take the car to do a full weekend of track running and im not just using my 7cup i run penskes from my ex 6cup and use regular 6cup height/spring/geo.
ive got JIC cross that i use on the car normally which negates the need to be super accurate with main spring length since the spring platform is ride height independent to an extent (i guess it can cover about a 40mm variation in spring length). the tender calcs needed to be accurate though or else id have too little or too much movement available before working on the main spring rates.
with 140mm main spring and the 60N/mm tender compressing to 45mm height the lowest i could run on the front was 110mm. by changing to 100mm front i now obviously have the exact same spring response but can drop down much lower in ride height.

droop and negative travel is fine. based on the tender compression there is 50mm of negative movement available before a wheel would have to start lifting.
60N/mm seems to work fine to allow bumps to be absorbed and traction to remain intact. super soft tenders are fine if you want to give yourself droop and prevent spring displacement but using a firmer tender can work just the same but also allow you to have a different initial response if you calculate it properly.
theres no way i could run 140N/mm and 160N/mm on the road without this and not just have the car falling apart.

911SLOW

Nice, I was about to go the same route but since I didn't have them in the first place I either should have bought 3-4 setups of mains and tenders from the softer 996 cup versions cause on the 7 they went really hi with them in N/mm 260 F & R to play with or go for the cargraphic HR progressive springs that are awsome in anything but a very bumpy track. With 255/35/18 & 315/30/18 running F 102mm height and R 117mm height I had enough travel up and on release. Only problem was when I installed the airlift front and lost droop as the locking nut was bottemed out and spring pushed down so I modded the colars and regained back 15mm of droop.