New shocks and springs recommendation please - going for Protech

Moderators: scimjim, Roger Pennington, philhoward, Lukeyboy46, erikscimitardemon

lambo911
RSSOC Member
Posts: 152
Joined: Wed Jun 10, 2015 7:15 pm
Location: St Albans

New shocks and springs recommendation please - going for Protech

Post by lambo911 » Tue Mar 24, 2020 7:46 am

Hi All,

Now I'm going to be at home quote a bit I have my 78 SE6a in the garage and I am going to overhaul the suspension and clean up the underside.

I am going to fit a new set of shocks and springs all round and I would like to lower the car slightly, especially the front.

I saw an earlier thread about issues people had had with shocks and bushes wearing out prematurely but the thread never came to a clear conclusion on the best shocks to use.

Can anyone recommend a set of shocks with adjustable ride height and also what springs to use please?

Thanks
Richard
Last edited by lambo911 on Thu Mar 26, 2020 2:33 pm, edited 1 time in total.


Richard

1978 Scimitar SE6a MOD PS
1977 Scimitar SE6a MOD no PS
1986 Mercedes 190 2.3-16 Cosworth
1966 Jaguar s-type 3.8 MOD

Drury
RSSOC Member
Posts: 17
Joined: Fri Aug 16, 2019 7:11 pm

New shocks and springs recommendation please

Post by Drury » Tue Mar 24, 2020 9:39 am

My 6a is on AVOs.



User avatar
Dennis Nicholas
RSSOC Member
Posts: 767
Joined: Wed Jun 20, 2007 1:22 pm
Location: Devon

New shocks and springs recommendation please

Post by Dennis Nicholas » Tue Mar 24, 2020 11:53 pm

I was first person to work with PROTECH to get a set designed for my 6a (Rod Avon of AVO fame was their consultant) They supplied them with bushes fabricated from metalastic (Jaguar) ones which were internally bushed to fit the1/2 inch bolts and more importantly they were the correct 1 1/8 inch width to allow the Reliant spacers to be fitted INSIDE the brackets. (Some damper suppliers only recognise the bush width as 1 1/4 inch (the original 5 width before the Reliant modification).....look back through forum for extensive explanation.

I used 250 lbin front X 13.5 inch but on severe bumps the rubber built in bump stops were contacted so would have changed to 14 inch but car sold meanwhile as GTC became available at good price. There were 2 of 20mm = 1 3/4inch bump stops on front so maybe with just 1 it would not have bumped? The rears were 225 lbin X 12 inch with only 1 20mm rubber bump stop. Both were 2 1/4 inch interior diameter springs. Eye to eye fully open - front 390mm (15 3/8 inch) rear 451mm (17 3/4 inch).
Front spring seat was screwed up 3 1/8 inch to give 13 1/16 inches eye to eye under full load and standard setting of lower wishbones parallel to ground, so with 14 inch spring instead of 13.5 still plenty of room to adjust car lower (remember to reset castor and camber if you lower). Full load on front compressed spring by 4.83 inch and rear 3 inches
Rear was finally set at 16 1/4 inch eye to eye making chassis parallel to ground. (height to underside of chassis was 6 1/4 inch (195 x 70 x 14 tyres). There was 2 3/4 inches of thread at bottom to further lower car. The spring fully loaded was 9 inches seat to seat.
I have original (rough) drawings with some of my notes scribbled on if required, though I think I put them up on the forum
Adjustable spring seats and single damping valve adjuster control (as opposed to double - 1 for compressing up and 1 for release down)
Beautifully made with rounded ball ends in alloy.

This was all done back in mid/late 2007

Dennis


Dennis Nicholas(RSSOC)
1980 GTC Trafalgar Blue, 2010 basic Skoda Yeti (petrol), Austin 7s, Rileys.

User avatar
adamwilkes
RSSOC Member
Posts: 534
Joined: Thu Dec 26, 2019 9:01 am
Location: Poole, Dorset
Contact:

New shocks and springs recommendation please

Post by adamwilkes » Wed Mar 25, 2020 7:46 am

Are non-adjustable coil-overs still available? I think I read that they are not, so I bought Spax adjustables (untested as car still on axle stands :W ) They fit without washer spacers on my 5a.


Adam Wilkes
Scimitar GTE 5a 1973, kinda Highland Purple; after months of work, still a ruin!
I can't help myself - I have to ask questions and find out why. Why ? Dunno :shock:

lambo911
RSSOC Member
Posts: 152
Joined: Wed Jun 10, 2015 7:15 pm
Location: St Albans

New shocks and springs recommendation please

Post by lambo911 » Wed Mar 25, 2020 7:53 am

Dennis Nicholas wrote:
Tue Mar 24, 2020 11:53 pm
I was first person to work with PROTECH to get a set designed for my 6a (Rod Avon of AVO fame was their consultant) They supplied them with bushes fabricated from metalastic (Jaguar) ones which were internally bushed to fit the1/2 inch bolts and more importantly they were the correct 1 1/8 inch width to allow the Reliant spacers to be fitted INSIDE the brackets. (Some damper suppliers only recognise the bush width as 1 1/4 inch (the original 5 width before the Reliant modification).....look back through forum for extensive explanation.
Thanks Dennis, I have emailed Protech for a price with the 250lb 14 inch front and 225lb 12 inch rear springs


Richard

1978 Scimitar SE6a MOD PS
1977 Scimitar SE6a MOD no PS
1986 Mercedes 190 2.3-16 Cosworth
1966 Jaguar s-type 3.8 MOD

lambo911
RSSOC Member
Posts: 152
Joined: Wed Jun 10, 2015 7:15 pm
Location: St Albans

New shocks and springs recommendation please

Post by lambo911 » Thu Mar 26, 2020 2:05 pm

I've decided to go with the Protech ones.

Front 15” open 10” x 300lbs

Rear 17” open 12 x 250lbs

Slightly different to the spec Dennis mentioned but after speaking to them this was what they recommended.

They are a good price too, quite a bit less than the AVOs.


Richard

1978 Scimitar SE6a MOD PS
1977 Scimitar SE6a MOD no PS
1986 Mercedes 190 2.3-16 Cosworth
1966 Jaguar s-type 3.8 MOD

lambo911
RSSOC Member
Posts: 152
Joined: Wed Jun 10, 2015 7:15 pm
Location: St Albans

New shocks and springs recommendation please - going for Protech

Post by lambo911 » Thu Jul 02, 2020 12:06 pm

Hi All, thought I should give an update now they are fitted.

The shocks look great and seem to be well made. i had no problems fitting them and the springs could be put on without needing to compress them.

I did have an issue with the 300lb front spring, the coils closed up quite a bit and I struggled to get a decent ride height. Protech swapped them for 350lb which sorted the problem however the ride is quite hard.

I think a 12" 300lb front spring rather than 10" 350lb would work better so I might try that when I get around to it.

I didn't have any issues with the rear shock specification.

Here is a picture, they did come with top hats, which aren't in the pic
20200408_143727.jpg
20200408_143727.jpg (189.69 KiB) Viewed 735 times


Richard

1978 Scimitar SE6a MOD PS
1977 Scimitar SE6a MOD no PS
1986 Mercedes 190 2.3-16 Cosworth
1966 Jaguar s-type 3.8 MOD

User avatar
scimjim
RSSOC Member
Posts: 40503
Joined: Sun Oct 01, 2006 10:08 pm
Location: Gloucester

New shocks and springs recommendation please - going for Protech

Post by scimjim » Thu Jul 02, 2020 4:56 pm

There’s loads of threads on this already but in the one in the FAQ section (about the 5 series but equally applicable to 6/8 series), I said
scimjim wrote:
Mon Apr 30, 2012 10:14 pm
so something around 12/300 or 275 Front & 14/250 or 225 Rear would be a good starting point?


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), 1400 1600 1800 Zetec ST170 powered SS1 (G97), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre, TI SS1 (snotty), 1600 SS1 (C686CCR).
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

User avatar
Dennis Nicholas
RSSOC Member
Posts: 767
Joined: Wed Jun 20, 2007 1:22 pm
Location: Devon

New shocks and springs recommendation please - going for Protech

Post by Dennis Nicholas » Thu Jul 02, 2020 11:18 pm

As I said stick with 14 inch X 250 for front (13.5 found to be just a bit too short) Tried and tested on a GTE. Very surprised that Protech gave 10 inch to start with as I very quickly proved them to go coil bound with 250. 14 also allows plenty of height adjustment availability with the bottom spring seat.
My Protech were 15 3/8" (390mm) fully open eye centre to eye centre.
Car weight compressed 250 by about 2.4 inch. By definition a 250 spring will compress the same amount no matter what length it is i.e 250 lbs will compress the spring 1 inch whether it is a 10 inch, 13 3/8 inch or 14 inch.
Do not be confused by "pre-loading"......that is wrong terminology for "compressing the spring to get it on to the damper"...It is the weight of the car that accounts for the amount the spring compresses. If you have to compress the spring with say 50 pounds of pressure you DO NOT USE UP 50 pounds of the 250 rating.....once the full weight of the car is on the spring it will still compress the same amount as it would if the spring did not have to be "compressed to get it onto the damper"

Dennis


Dennis Nicholas(RSSOC)
1980 GTC Trafalgar Blue, 2010 basic Skoda Yeti (petrol), Austin 7s, Rileys.

User avatar
ScimiTom
RSSOC Member
Posts: 685
Joined: Fri Feb 04, 2011 10:07 pm
Location: Houston, Scotland

New shocks and springs recommendation please - going for Protech

Post by ScimiTom » Thu Jul 02, 2020 11:40 pm

Thanks for the update, Richard. It's handy as I'm about to order some too.

Dennis, would you suggest 14" x 250lbs for the rear as well then - or better with 12" x 250lbs (or even 225)? I'm thinking of a 5a, in my case.


Current: 'Boffin' (1971 SE5a)
Previous: 'Sunshine' (1980 SE6b)

gtcse8
RSSOC Member
Posts: 3082
Joined: Fri Apr 24, 2009 10:11 am
Location: Steeton, Yorkshire Dales

New shocks and springs recommendation please - going for Protech

Post by gtcse8 » Fri Jul 03, 2020 8:35 am

Tom Be very careful about fitting longer springs.
Reliant used longer springs at the rear as the shocker travel was longer too.
As they may have more coils wound on them to get the extra length they may go "Coil Bound" before they should, therefor losing suspension travel.


Mark Wilson. Garage sale everything must go. :cry:1 SE6b, 1 GTC Shell &1 SE6a shell & a Triumph Daytona. Also on YouTube :wink: lookup V8 Chevy https://youtu.be/lbpvDGAMY6g https://youtu.be/7xTrbr0ETSA https://youtu.be/K7HfYVd5Flo

lambo911
RSSOC Member
Posts: 152
Joined: Wed Jun 10, 2015 7:15 pm
Location: St Albans

New shocks and springs recommendation please - going for Protech

Post by lambo911 » Fri Jul 03, 2020 9:49 am

Be careful because I think spring poundage takes into account the number of coils.

So a 300 10" spring with say 10 coils may have a spring thickness of 10mm
and a 300 12" spring with 12 coils may have a spring thickness of 8mm

It is better to have as long a spring as you can for comfort but of course on an adjustable shock the length you can use can be limited. For the Protech shocks, I think 12 on the front would be the max with 14 on the back.

A 5a is only 75kg lighter than a 6a so I don't think there would be a big difference in the poundage used between the to models


Richard

1978 Scimitar SE6a MOD PS
1977 Scimitar SE6a MOD no PS
1986 Mercedes 190 2.3-16 Cosworth
1966 Jaguar s-type 3.8 MOD

User avatar
DARK STAR
RSSOC Member
Posts: 6728
Joined: Tue Aug 04, 2009 8:56 pm
Location: Antibes, France
Contact:

New shocks and springs recommendation please - going for Protech

Post by DARK STAR » Fri Jul 03, 2020 8:25 pm

Best ever technical article on springs and shocks by Terry Rickard in current Slice.
I have always used and recommended Spax, Tony Shakeshaft is very helpful (and knowledgable)


Chris Johnson
RSSOC 1979> Rhubarb SE6a V8 1979-1997 Dark Star Coupé 1989> Scimitar France 2010> Vert Soleil GTC 2014-2018
Scimitar France Website site Scimitar EUROPEEN
On the road I don't drive fast, but I don't slow down for corners
In competition I drive very fast, but not always on the track ...

PilotLight
Posts: 43
Joined: Sat May 16, 2020 7:45 pm
Location: Suffolk

New shocks and springs recommendation please - going for Protech

Post by PilotLight » Fri Jul 03, 2020 8:58 pm

Richard,
Can we get a photo of the new stance and ride hight please?
I'm trying to figure this out for my 6a too.

Thanks,
Andy



User avatar
Terry Rickard
RSSOC Member
Posts: 196
Joined: Mon Feb 26, 2007 8:58 pm
Location: Bristol

New shocks and springs recommendation please - going for Protech

Post by Terry Rickard » Fri Jul 03, 2020 9:25 pm

Thanks very much Chris (Dark Star) :)



Post Reply

Return to “Se6/6a/6b/GTC”