Printable Version | Subscribe | Add to Favourites
New Topic New Poll New Reply
Author: Subject: traction question
stretch

posted on 29/9/09 at 07:42 AM Reply With Quote
traction question

i build my car about 4 years ago and still love it,

the question is tho, i'm busy doing a complete overall on the car, basically take everything apart and putting it back together. (so engine might have a bit more power as well ), on the rear suspension i had to put in shorter shocks as the old ones very a bit long and were bottoming out. so i put in shorter shock and had to cut off one turn of the coils, but it still went in with a bit of preload.

on a test drive last night, the back felt very loose. 2nd gear putting your foot down at 3500rpm u cant feel there is a bit of spin on the wheels.

how much wheelspin is 'ok'? or normal under heavy acceleration?



View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member This User Has MSN Messenger
smart51

posted on 29/9/09 at 07:47 AM Reply With Quote
Cutting springs is a bad idea. The stiffness of a spring is increased if you cut turns off it. If it had 8 turns before and it now has 7 then you only have 8/7 of the lbs/inch you had before.

edit: I had got this the wrong way round before!

[Edited on 29-9-2009 by smart51]






View User's Profile View All Posts By User U2U Member
stretch

posted on 29/9/09 at 07:52 AM Reply With Quote
thats fair, but me and a buddy about 200kg between us - jumping could just get it to bottom out on 7/8 of the spring with about 2" travel.
View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member This User Has MSN Messenger
Phil.J

posted on 29/9/09 at 07:56 AM Reply With Quote
If you cut coil springs the poundage rate rate goes up not down!
This will be why you now have less traction having stiffened the rear up.

View User's Profile E-Mail User View All Posts By User U2U Member
andylancaster3000

posted on 29/9/09 at 08:01 AM Reply With Quote
Cutting a spring and removing any active coils will actually make it stiffer...
View User's Profile View All Posts By User U2U Member
stretch

posted on 29/9/09 at 08:01 AM Reply With Quote
quote:
Originally posted by Phil.J
If you cut coil springs the poundage rate rate goes up not down!
This will be why you now have less traction having stiffened the rear up.


makes sense, its what i had in mind as well - it does feel stiffer than before now. i was thinking if i got softer coils i wouldn't have to cut them and they 'should' have the right amount of preload to give the same ride hight. does that make sense?

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member This User Has MSN Messenger
andyharding

posted on 29/9/09 at 08:18 AM Reply With Quote
Will it not result in MOT failure too - like a broken spring





Are you a Mac user or a retard?

View User's Profile View All Posts By User U2U Member
stretch

posted on 29/9/09 at 08:24 AM Reply With Quote
quote:
Originally posted by andyharding
Will it not result in MOT failure too - like a broken spring


there's no MOT in South-Africa

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member This User Has MSN Messenger
procomp

posted on 29/9/09 at 01:04 PM Reply With Quote
Hi

For your aplication and the weights involved you want 160Lb springs of the correct length. What you have there look to be to firm.

Also the damper as pictured ( which i assume is in a non loaded state ) will not have enough travel once it is loaded. You need more travel on the dampers IE longer. Ideally 13" open length minimum.

Cheers Matt






View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
stretch

posted on 29/9/09 at 01:13 PM Reply With Quote
quote:
Originally posted by procomp
Hi

For your aplication and the weights involved you want 160Lb springs of the correct length. What you have there look to be to firm.

Also the damper as pictured ( which i assume is in a non loaded state ) will not have enough travel once it is loaded. You need more travel on the dampers IE longer. Ideally 13" open length minimum.

Cheers Matt


this is on loaded state, its allows just over 10cm travel, as is loaded is about 4cm in and can go in another 6cm.

i replaced the longer ones i had because they were bottoming out

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member This User Has MSN Messenger
MikeRJ

posted on 29/9/09 at 04:39 PM Reply With Quote
quote:
Originally posted by stretch
i replaced the longer ones i had because they were bottoming out


Surely that was simply because your spring rate or pre-load was not correct, rather than the longer shock travel?

View User's Profile View All Posts By User U2U Member

New Topic New Poll New Reply


go to top






Website design and SEO by Studio Montage

All content 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [ 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.