Ride Height (again)

PostPost by: vincereynard » Tue Apr 24, 2018 11:29 am

Toad is far too twitchy on long down hills. I have a set of adjustables supplied by my old mates Spyder but before I fit them I would like to check the front / rear and side to side ride height as I'm told having the rear to high also increases instability (and reduces castor I imagine.)

Before I consider cheating by filling the tank and put a couple of bags of sand in the boot, to see if it makes any difference, is there any general data / recommendations for wheel centre to wheel opening lip for a S130?

Cheers
vincereynard
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1240
Joined: 12 Jan 2015

PostPost by: JonB » Tue Apr 24, 2018 5:35 pm

The measurement is normally done from the front crossmember to the ground and I guess assumes you have 80 profile tyres. Another rough check is to see if your lower front wishbones are horizontal.

I have a measurement you can take between the shock absorber top and bottom that Wiggy gave me but it's at home. I'll post it later.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2396
Joined: 14 Nov 2017

PostPost by: JonB » Tue Apr 24, 2018 5:51 pm

Found it.

JonB wrote:Regarding getting the ride height correct, that is what the guy at Spider said but my car does not have the facility to adjust it. However, measuring it would perhaps help diagnosis (not tried it yet, but we're looking for 13.5" from the front lower shock absorber bolt to the bottom of the upper suspension mount plate, apparently).


That's on the Spyder chassis with standard suspension arms.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2396
Joined: 14 Nov 2017

PostPost by: Foxie » Tue Apr 24, 2018 11:33 pm

JonB wrote:Found it.

JonB wrote:Regarding getting the ride height correct, that is what the guy at Spider said but my car does not have the facility to adjust it. However, measuring it would perhaps help diagnosis (not tried it yet, but we're looking for 13.5" from the front lower shock absorber bolt to the bottom of the upper suspension mount plate, apparently).


That's on the Spyder chassis with standard suspension arms.


I have a Spyder +2 chassis with adjustable spring perches/ride height. I set the sills at 5.5" with driver load up. It works good.

I went over to Spyder to see the original Zetec prototype. As I remember, the Spyder Zetec needs quite bit more ride height because the Zetec exhaust runs under the starter and needs extra ground clearance.

The main reason I never went Zetec :o
68 Elan +2, 70 Elan +2s
User avatar
Foxie
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1630
Joined: 20 Sep 2003

PostPost by: vincereynard » Wed Apr 25, 2018 8:37 am

Jon
Spyder suggest 13.5 " from the damper pivot to the underneath of the front tower. (bottom of the upper suspension mount plate.) Is that correct.

Foxie
Toad has Spyder double wishbone rear suspenders. I'm not sure if they have adjustable spring platforms.
At the moment it was set up by Spyder so each corner is a different height. :?
Doesn't 5.5" at the cills leave the exhaust very close to ground?
vincereynard
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1240
Joined: 12 Jan 2015

PostPost by: JonB » Wed Apr 25, 2018 9:48 am

vincereynard wrote:Jon
Spyder suggest 13.5 " from the damper pivot to the underneath of the front tower. (bottom of the upper suspension mount plate.) Is that correct.


Yes, that's my understanding, but I have yet to measure it on my car. My lower arms are horizontal, pretty much, and so I attribute my low ride height to the 70 profile tyres I have (fitted by the PO, too new to discard!).

I do not believe I have 5.5" at the sills, by the way (if by that you mean the lower edge of the body between the wheels, where the strengthener bolts are). Happy to measure it though.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2396
Joined: 14 Nov 2017

PostPost by: Spyder fan » Fri Apr 27, 2018 3:20 pm

Foxie wrote:
I went over to Spyder to see the original Zetec prototype. As I remember, the Spyder Zetec needs quite bit more ride height because the Zetec exhaust runs under the starter and needs extra ground clearance.

The main reason I never went Zetec :o


After much head scratching I cured the Zetec exhaust manifold problem. On the prototype car the gearbox was an MT75 cable clutch gearbox that has the starter motor on the exhaust side which is opposite to the 4 speed gearbox. So the design of the exhaust manifold routed much lower and further forward actually passing under the ARB, the perfect sort of position to ground out and send sparks flying on any average bumpy road. Absolute murder on speed humps. The cure is to have a hydraulic clutch MT75 gearbox which puts the starter motor where it should be on the inlet side of the engine, luckily I had one of these boxes fitted, but Spyder still used the old design manifold. I bought a new manifold from Paul Dunnel that was based upon John Pelly?s design for his Zetec Elan, the result is a car that can run as low as the spring perches will allow and no grimaces when you go over the bumps, looks good as well!
6b6d9f42-0765-496a-a887-48d6bf1af43c.jpeg and
Kindest regards

Alan Thomas
User avatar
Spyder fan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2843
Joined: 11 Jun 2009

PostPost by: Spyder fan » Fri Apr 27, 2018 3:26 pm

vincereynard wrote:Jon
Spyder suggest 13.5 " from the damper pivot to the underneath of the front tower. (bottom of the upper suspension mount plate.) Is that correct.

Foxie
Toad has Spyder double wishbone rear suspenders. I'm not sure if they have adjustable spring platforms.
At the moment it was set up by Spyder so each corner is a different height. :?
Doesn't 5.5" at the cills leave the exhaust very close to ground?


Vince,
I?m pretty sure your car has adjustable coil overs on the rear, I seem to remember seeing it up on the ramps at Spyder, no reason why the fronts won?t be the same. The quality of the springs seems to be questionable these days, they do seem to settle unevenly. Ground clearance is meant to be around 4 inches, so 5 inches at the sills doesn?t sound too low.
Kindest regards

Alan Thomas
User avatar
Spyder fan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2843
Joined: 11 Jun 2009

PostPost by: JonB » Fri Apr 27, 2018 4:10 pm

Just to follow up on those measurements. I have:-
  • 13.5" at the front shock absorber (pivot bolt to tpo plate underside)
  • 5.5" between the floor and the bottom edge of the sill (on 70 profile tyres)
That last one surprised me somewhat and yes, my exhaust is very close to the ground but I think this is caused by the engine being slightly down on the exhaust side (which pushes the manifold down) - maybe due to mount rubber failing in the heat, I need to look into it; and the exhaust itself being a very poor fit.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2396
Joined: 14 Nov 2017

PostPost by: vincereynard » Fri Apr 27, 2018 4:54 pm

Spyder fan wrote:Vince,
I?m pretty sure your car has adjustable coil overs on the rear, I seem to remember seeing it up on the ramps at Spyder, no reason why the fronts won?t be the same. The quality of the springs seems to be questionable these days, they do seem to settle unevenly. Ground clearance is meant to be around 4 inches, so 5 inches at the sills doesn?t sound too low.


I think you are correct Alan. I checked by the simple procedure of groping about behind the wheel and it definitely feels like a castellated collar something. Hopefully enough adjustment to drop the rear a good bit.

JonB wrote:Just to follow up on those measurements. I have:-

13.5" at the front shock absorber (pivot bolt to tpo plate underside)
5.5" between the floor and the bottom edge of the sill (on 70 profile tyres)


I measured Toad. On the driver side the cill is 6.25", front and rear. Near side is just under 7".
This on 175/70 tyres which are 0.4" smaller radius than original. https://tiresize.com/comparison

So it is riding high, and leaning a bit. It should be tweakable. Then fit the adjustable A arms and orf we go!
vincereynard
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1240
Joined: 12 Jan 2015

PostPost by: gavk » Sat Apr 06, 2019 6:23 pm

Vince,

I battled with the intermittent "tippy toes" on my +2 for some time, it would come and go and every now and then there would be a loud "gong" or "bong" sound and it would fix itself!!

Happened once mid way through a track day at Bruntingthorpe and the difference in handling was unbelievable.

Had me perplexed for a while, I knew it was a suspension issue but couldn't figure it out, I got under the car at mot time and no issues were apparent.

Eventually I realised one of the adjustable rear shocks was wound up more than the other. Through usage the spring was also rotating on the perch and the spring sometimes got stuck in an extended position, the end of the spring digging into the perch rather than sliding across it. The car would feel on tippy toes when it was in this position, when the spring eventually released I would hear the bong sound and it would feel better again.

The fix for me was lowering both spring platforms to the bottom of their travel, now one shock is no longer taking the bulk of the load and I have had no issues or binding for a couple of years.

Gav
gavk
Second Gear
Second Gear
 
Posts: 113
Joined: 23 Apr 2014

Total Online:

Users browsing this forum: No registered users and 26 guests