Vixen dampers 4 vs 6
Discussion
they tend to handle better with 2 front / 2 rear, that said their are disadvantages with the std set up if running only 2 rear.
on a Vixen with a crossflow 180- 200lb all round is a good fast road spring rate but with the very heavy triumph 6 up front the front spring rate will need to be heavier. I have no idea what the std tuscan V6 rates are at the front but would plump for that.
In theory the resistance of a damper to spring rate is negligible whether going for a 2 spring or 4 spring set up at the rear but if you do double up then you need to half the spring rate.
I have set Dads car up with 90lb springs x 4 at the rear because he is 8 stone wet through and 5 foot tall. Their is a long term benefit using 4 springs and dampers on the rear regarding the lower pivot rod and halving the loads on the rear upright / pivot rod. if the rod isn't already bent then it would be a good time to go for some EN16 replacements.
I would talk to Steve Reid or Adrian Venn who have more knowledge of all the derivatives of these cars and what combinations have worked well over the years on the different models. steve will have a better knowledge on the Thurner chassid cars.
You haven't said whether your car is an M chassis car or a Vixen chassid car. I think the vixen / 2500 came In both but I am not too sure
N.
N.
on a Vixen with a crossflow 180- 200lb all round is a good fast road spring rate but with the very heavy triumph 6 up front the front spring rate will need to be heavier. I have no idea what the std tuscan V6 rates are at the front but would plump for that.
In theory the resistance of a damper to spring rate is negligible whether going for a 2 spring or 4 spring set up at the rear but if you do double up then you need to half the spring rate.
I have set Dads car up with 90lb springs x 4 at the rear because he is 8 stone wet through and 5 foot tall. Their is a long term benefit using 4 springs and dampers on the rear regarding the lower pivot rod and halving the loads on the rear upright / pivot rod. if the rod isn't already bent then it would be a good time to go for some EN16 replacements.
I would talk to Steve Reid or Adrian Venn who have more knowledge of all the derivatives of these cars and what combinations have worked well over the years on the different models. steve will have a better knowledge on the Thurner chassid cars.
You haven't said whether your car is an M chassis car or a Vixen chassid car. I think the vixen / 2500 came In both but I am not too sure
N.
N.
Edited by heightswitch on Friday 12th August 17:40
vixenlotus said:
Hi all, I am trying to set up the suspension on my recently acquired 71 Vixen 2500. Currently the car has fairly new Spax G936 dampers on each corner of the car (4 total). I have been considering putting 6 Dampers/springs on the car and have some questions. If I buy two more of these Spax G936 Dampers for the rear of the car will the car be over damped ? The second question is if I do indeed run 6 dampers/ Springs, I will need much lighter springs in the rear. Lets say I want to run 180lbs on each corner that would mean that each rear spring would have to be 90lbs. I have no idea were I could find a 90lb 12inch long spring. I have looked and can not find any. The final question is should I even be looking at putting 6 dampers/springs on the car? Is 4 better than 6? In my head when I look at the rear suspension it seems that if I just use one on each side in the rear that would twist/torq the control arm/hub. Thoughts?
Welcome to the forumAdrian advised me to use 6 dampers for exactly the reason you pointed out, and I am using 6 springs too on a Vixen S1, although they are AVOs. I don't know whether the length is the same for Spax dampers, but I am sure either Adrian or Steve can easily provide you with exactly what you need
Very timely topic for me, thanks Guys!
I am about to make the damper purchasing plunge and any additional info would be helpful.
I have a Vixen S2 - looks like it came with 6 but was running 4 when purchase in a shabby, half assemble shape.
I am converting it to a Tuscan V8 (blasphemy I know!) so I would love to hear about what they would run for dampers and spring rates.
Thanks!
Jeff
I am about to make the damper purchasing plunge and any additional info would be helpful.
I have a Vixen S2 - looks like it came with 6 but was running 4 when purchase in a shabby, half assemble shape.
I am converting it to a Tuscan V8 (blasphemy I know!) so I would love to hear about what they would run for dampers and spring rates.
Thanks!
Jeff
My S3 has Spax adjustables, fitted by a previous owner back in the 80's. One of these weeps very slightly so will need replacing at some point. When I do, I would probably replace the springs at the same time but I would like to keep the currently spring rating as it feels just about spot on. I have always wondered what spring ratings I have but don't know if there is any way of finding out. Should the lb'age be stamped somewhere on the coil?
Moto
Moto
Moto said:
My S3 has Spax adjustables, fitted by a previous owner back in the 80's. One of these weeps very slightly so will need replacing at some point. When I do, I would probably replace the springs at the same time but I would like to keep the currently spring rating as it feels just about spot on. I have always wondered what spring ratings I have but don't know if there is any way of finding out. Should the lb'age be stamped somewhere on the coil?
Moto
The spring rate = (1406250 x d x d x d x d) / (N x D x D x D)Moto
d = wire diameter in inches
N = Number of active coils.
The flattened coils at the ends are not considered active.
D = Mean diameter of spring.
Half way between the inside & outside diameter.
I tried this on a few sprinmg when we set up the race car and its pretty accurate
vixenlotus said:
...I have also been told that when using 4 relatively light weight springs in the rear frictional forces come more into play and it is a good idea to use Torrington bearings on the spring platforms...
Strongly disagree. 1.) The resistance becomes part of the spring load, and can be viewed as part of the "system." Slightly lower spring rates will garner the same net result.
2.) That adds complexety, and another SIX points for attention and constant maintenance. These would be exposed to the elements, after all.
B.
vixenlotus said:
I would rather have the springs do the work rather than the friction from the spring platfroms. When springs compress they also tend to unwind. These bearings will allow them to do just that and they hardly add any complexity. Most of us are not using these cars as every day vehicles and consequently do not see high yearly miles put on them. A once a year (or every other year) cleaning is no big deal. However if you do not want to clean them, bearings of this nature are also available using delrin flat washers that require no maintenance at all or added “complexity”.
You seem to have become a bit of a suspension guru regards the rear end of the vixen. We've come a long way from just a few days ago when you needed to understand the rudiments of halving a spring rate when doubling up at the rear 
Before you waste £200 on some torrington bearings, which aren't really even fitted to any racing griffiths over here in the UK, why don't you consider where you could best spend your money, for example re-bushing the uprights, making up some solid spacers instead of your standard crush tubes, replacing your EN7 Pins for some EN16 etc etc ! Then when you are really sure you need the extra performance gain that some torrington bearings will give you you can upgrade them.
Stroll On!
N.
Six bearings were only £20 and at that price i think it is well worth it. If you do not want to use them no one is forcing you. I am Far from a guru, I am only passing on advice after doing extensive research. Your advice about rebushing the uprights and replacing the EN7 pins are sound ones and it is in this cars future.
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