Too Low
- Thread starter MGNut
- Start date
Peter Delaney
GT40s Supporter
Murray, I think you are right - the front could do with maybe 1/2" & the back with 1". It all depends on what coil-over shocks you have - mine are UK AVO's & are easily wound up or down by turning the lower spring plate with a C-spanner. If you can show a pic of the shocks, I'm sure that plenty of experts on the site will be able to give you the clues.
BTW, you will need to re-do your wheel alignment after such a major change in height - I was surprised at how much mine went out after a similar change.
Kind Regards,
Peter D.
BTW, you will need to re-do your wheel alignment after such a major change in height - I was surprised at how much mine went out after a similar change.
Kind Regards,
Peter D.
Peter thanks for the reply, I thought that would be the solution but would that not alter the spring settings too, make it harder?. The coil overs are Spax M73A front and rear, not a clue as to the spring strength/poundage? Obviously as you can see from the phots, the rear suspension units are not bolted in place properly yet, that may make a difference too!! Lots of things to do and think about yet. Any suggestions welcome.
Cheers
Murray
Cheers
Murray
Attachments
Howard Jones
Supporter
Use the adjustments on the shocks to set ride height at 5" at the front and 5.5" at the rear. Have a look at it after and post a picture. Make your measurment at the point on the chassis frame rails that is nearest to the pavement. Same point on both sides of car. Make sure you do this on level ground. This setting will get you close and as you learn more about your car you can fiddle with it.
Does anybody think that those shocks look short? Anyway give the above a try. While you are at it measure the lenght of the shocks fully extended and again fully closed. Center of top eye hole to bottom eye hole. You might need these measurements later and they are easy to do now. Also measure the lenght of the springs unloaded and off the shocks. Take pictures of both. You might need them later also.
Also it is helpful to keep a log book on chassis situps. This could be you first entry!
Does anybody think that those shocks look short? Anyway give the above a try. While you are at it measure the lenght of the shocks fully extended and again fully closed. Center of top eye hole to bottom eye hole. You might need these measurements later and they are easy to do now. Also measure the lenght of the springs unloaded and off the shocks. Take pictures of both. You might need them later also.
Also it is helpful to keep a log book on chassis situps. This could be you first entry!
Thanks for the suggestions chaps, I shall try to have a go at setting the ride height, measure shocks/springs etc as per your post Howard, may take a bit of time though, and start a log book too. Good idea that. Better go and do some real work now. Will post again when I get some results. Thanks again
Murray
Murray
Chris Duncan
Supporter
It also looks like a very low profile rear tire. Like a 35 series or something. That's ok as long as there was a corresponding increase in rim diameter.
You may want to look at the height of the tire compared with the tire height that the chassis was designed for, as that will affect your ride height.
You may want to look at the height of the tire compared with the tire height that the chassis was designed for, as that will affect your ride height.
Kalun_D,
hi mate, yes the tyres are low profile, front at 215-45-17's and the rear 245-40-17's. I hadn't thought about the tyres. I believe this car was originally going to be a track car so needs to be sorted for the road.
Thanks
Murray
hi mate, yes the tyres are low profile, front at 215-45-17's and the rear 245-40-17's. I hadn't thought about the tyres. I believe this car was originally going to be a track car so needs to be sorted for the road.
Thanks
Murray
Hi murray
what steering rack is fitted? I have used a mk2 escort rack with extensions, but to reduce the bump steer i have relocated the rack further back, from your front end picture it looks like your steering arms are angled forwards. mine ended up almost straight when viewed from above. worth checking now while its still movable!!
dave b
what steering rack is fitted? I have used a mk2 escort rack with extensions, but to reduce the bump steer i have relocated the rack further back, from your front end picture it looks like your steering arms are angled forwards. mine ended up almost straight when viewed from above. worth checking now while its still movable!!
dave b
OOh No, something else to think about!! I havn't a clue what rack is fitted. Since I have got it down here and into the carcoon, it's been pretty wet, I'm not taking the cover off if it's raining!! I have an old MG which needs me to finish a major overhaul yet before I can start on the 40 but I cannot resist trying to sort things out now! Her Indoors is a bit more logical than me, get one thing finished first say's she. Ah well, I can fiddle a bit!!
I shall see if there are any distinguishing marks to identify the rack, any hints? Come on the sunshine!!
Murray
I shall see if there are any distinguishing marks to identify the rack, any hints? Come on the sunshine!!
Murray
Chris Duncan
Supporter
""to reduce the bump steer i have relocated the rack further back""
Front to rear movement of the rack does not change bumpsteer.
Up and down movement of the rack or the outer tie rod end location on the upright are some of the things that affects bumpsteer.
Front to rear movement of the rack does affect ackerman. Sometimes, depending on upright steering arm angle, a little angle to the steering tie rods is necessary for proper ackerman.
Front to rear movement of the rack does not change bumpsteer.
Up and down movement of the rack or the outer tie rod end location on the upright are some of the things that affects bumpsteer.
Front to rear movement of the rack does affect ackerman. Sometimes, depending on upright steering arm angle, a little angle to the steering tie rods is necessary for proper ackerman.
Brett James-McCall
Moderator
Murray,
You'll probably find it may be either a Cortina or Escort rack. Can you measure the width where the bushes go, I'll be able to tell you from there.
Brett
You'll probably find it may be either a Cortina or Escort rack. Can you measure the width where the bushes go, I'll be able to tell you from there.
Brett
So the rack is ideally pretty central to the wheels,? is that right Kalun-D?
OK Brett, will do as soon as I can.
Thanks everybody,
Murray
OK Brett, will do as soon as I can.
Thanks everybody,
Murray
I think Kalum may be incorrect when he says that moving the rack backwards does not affect the amount of bump steer. On original GT40s and the C type KVA the front wishbone to chassis mounting points are not parallel in plan view. Therefore if the steering rack is moved rearward the effective rack length will shorten and vice versa .This will affect the amount of bump steer in exactly the same way as shortening or lengthening the Rack.
I notice that Kalum has a scratch built chassis for his KVA body so maybe his suspension mounting points are parallel, as in a Tornado or GTD chassis, in this case he would be correct.
Tom
I notice that Kalum has a scratch built chassis for his KVA body so maybe his suspension mounting points are parallel, as in a Tornado or GTD chassis, in this case he would be correct.
Tom
