Spring rate for Vixen S2

[becbunsen]

Hello,

I'm restoring a Vixen TVR S2. I bought 6 AVO shock absorbers (ref 418) to replace the genuine but coil springs on these shock absorber must be shorter than the genuine. (14' free lenght for the genuine, i think 12' must be good for the AVO)
ID is 2,25' on the front, 2,75' on the rear with a cup but i can replace by 2,25.

12' free lenght and 2,25 ID is a standart size and i can find it easily (AVO, Burton, demon tweeks,...) but i don't know which rate i can take for fast road use.

On the john upman site, there is genuine rate but i don't know if these are the good rate and i probably want something a little harder
http://www.zen11896.zen.co.uk/vixen/par ... nsion.html

You can see difference beetween genuine and AVO with photos on my post on french TVR forum
http://www.tvrcarclub-france.net/forum/viewtopic.p...

Thank you for your answers and sorry for my poor english
Julien

[nwarner]

Phone Steve Reid at Classic TVR on 44 (0)1928 719267

I bought a set of 6 AVO's the same as yours from him and he also supplied the springs.

[heightswitch]

nwarner said:

Phone Steve Reid at Classic TVR on 44 (0)1928 719267

I bought a set of 6 AVO's the same as yours from him and he also supplied the springs.

Or in the interests of even handedness Adrian Venn.

If you are going 6 spring then technically you half the spring rate on the rear. The reality is though that 2 springs per side on the rear with half rate still feels stiffer than a single spring with twice the rate.

They tend to ride better with 1 spring / shock set up per side using the forward mounting point. Some will tell you that its better to split the load on the lower pivot rod.

I think about 185lb all round is a good rate for a road car. up to 200lb if you are a fatty.

N.

[daza]

Once you know what rating you want, give these guys a bell:-

http://www.dfaulknersprings.co.uk/

They used to be good on prices, and if you were unsure about the ride, they would always exchange.


I agree with Neil regarding the rating,, however I'm one of those who also has a six spring six shock setup,,, lol


Regards

Darren

Edited by daza on Thursday 11th December 13:05

[becbunsen]

Thank you for yours answers

Heightswitch, i'm agree with you for a 180Lbs/inch rate for the front but i'm asking if the rear shoud be less hard.

In fact, i was ready to buy 200 at front and 140 at rear but i made my choice only with web search...
Most of setting i saw have the front stiffer than the rear but i don't know if difference between front and rear (200,140) is not too much.

For 2 or 4 rear springs, it's real question: it's more difficult to find a good rate with 4 springs (it's also more difficult to find little rate springs) but i think the upright suffer less.
(On my car, i have 4 rear schock absorber but only 2 springs at the forward point. The 2 rear upright was broken near the pivot bar (pivot bar was twisted))

I will contact steve reid but i'm taking always your opinion.

Regards

Julien

[heightswitch]

becbunsen said:

Thank you for yours answers

Heightswitch, i'm agree with you for a 180Lbs/inch rate for the front but i'm asking if the rear shoud be less hard.

In fact, i was ready to buy 200 at front and 140 at rear but i made my choice only with web search...
Most of setting i saw have the front stiffer than the rear but i don't know if difference between front and rear (200,140) is not too much.

For 2 or 4 rear springs, it's real question: it's more difficult to find a good rate with 4 springs (it's also more difficult to find little rate springs) but i think the upright suffer less.
(On my car, i have 4 rear schock absorber but only 2 springs at the forward point. The 2 rear upright was broken near the pivot bar (pivot bar was twisted))

I will contact steve reid but i'm taking always your opinion.

Regards

Julien

Steve will give good and accurate advice probably along the lines of.........

185lb rate all round.

Twin spring and coil overs at rear. rates approx 90lb each rear and 185lb front

You can go harder but for a road car I wouldn't

When you want to look at bullet proof rear uprights e-mail me off line.

N.

[becbunsen]

Thank you Neil,

Edited by becbunsen on Monday 15th December 09:03

[tvrbuell]

I'm running 220 on the front and 170 on the back of my S3. I find it a good compromise between ride and stiffness.

[becbunsen]

Thank You TVRbuell.

It will help me to make my opinion.

[becbunsen]

Another question about spring for AVO shock absorbers:
Which lenght to use?

Max lenght on the Avo is 11'
If i take 12'free lenght spring. spring will be 1' precharged to fit. I wonder if the car will down enough only with his weight. (depending of spring rate: with high rate spring, car will probably stay too high)

I think it's better to fit 10' free lenght and adjust the lenght on the shock absorber. In this case, the rate can(must?) be a little more stiffer.

It's only my imagination and i'm looking for spécialist opinion

Thank's

Julien