What springs do I need to upgrade ride?
Discussion
Just returned form the TVR Lakes and Scotland trip after grounding the rear of the car on whar seemed like every bump on the road.
I changed the shocks to AVO's last summer but didn't upgrade the springs.
The front springs seem fine, but it's not difficult to push the rear of the car down. It was like a boat compared to the other Cerbera's (they claimed not to have upgrade the springs).
I've taken the springs off the shocks - Eilbach 30/98 TVR D 0117.
Does any one know what spec these are?
What springs should I move to, for fast road with a firm ride?
Oh, the rear shocks appear to be too short - probably why she's grounding.
The AVO's when closed (no springs fitted) are 12 inches centre to centre on the bolt holes. Is this right?
Any help appreciated.
I changed the shocks to AVO's last summer but didn't upgrade the springs.
The front springs seem fine, but it's not difficult to push the rear of the car down. It was like a boat compared to the other Cerbera's (they claimed not to have upgrade the springs).
I've taken the springs off the shocks - Eilbach 30/98 TVR D 0117.
Does any one know what spec these are?
What springs should I move to, for fast road with a firm ride?
Oh, the rear shocks appear to be too short - probably why she's grounding.
The AVO's when closed (no springs fitted) are 12 inches centre to centre on the bolt holes. Is this right?
Any help appreciated.
Ring Derek at 'Absolutely shocks' I've just had a new Gaz Gold shock and spring kit fitted (And friggin good they are too!!) he'll tell you what length the shocks should be, and what springs to fit. because they used my car as a 'development guinea pig' with Euphoria Racing.
Oh B*****ks - Wst Ham have just scored !!
Oh B*****ks - Wst Ham have just scored !!
I'd also recommend speaking to Joolz (trackcar) -- www.track-car-solutions.co.uk
Well-known as the god of Cerbera suspension
Well-known as the god of Cerbera suspension
My cerb is a 4.5 but for what it's worth, I fitted Avo PH1063 on the rear. I also fitted stiffer 350 pound (stiffness not money) springs that are 2.25 I.D. by 10 inch. My car actually rides higher than yours looks to. I can clear road humps. I have done quite a bit more though to get my car to handle well. I live near Wilmslow in case you ever come over this way. If you can push your car's rear end down, you cannot be using much damping, assuming your shocks are adjustable with 22 positions for stiffness.
You may wish to consider 350Lb on the back and 400/425lb on the front.
The rear shocks should be 15 1/2" with uprated springs centre to centre and the fronts 14" centre to centre, both with the shocks at full open. I'm generally using a 10" spring on the back and 9" on the front these days.
I should say that these numbers were arrived after consulation with Andy at APM and Steve at Euphoria and the sizes of open lengths are reduced from the original fitment because of fitting stronger springs causing the cars to be too high.
The rear shocks should be 15 1/2" with uprated springs centre to centre and the fronts 14" centre to centre, both with the shocks at full open. I'm generally using a 10" spring on the back and 9" on the front these days.
I should say that these numbers were arrived after consulation with Andy at APM and Steve at Euphoria and the sizes of open lengths are reduced from the original fitment because of fitting stronger springs causing the cars to be too high.
oo interesting post Derek, it's actually in complete contrast to what i normally do which is to run as long a rear stroke as i can without running out of cv joint angularity. As i generally run 300/325 rears too you must have your cars set very low or run massive preload and very little droop on the rear .. normally a killer for rear brakes locking up under forward load transfer when the rear runs out of droop travel.
trackcar said:
oo interesting post Derek, it's actually in complete contrast to what i normally do which is to run as long a rear stroke as i can without running out of cv joint angularity. As i generally run 300/325 rears too you must have your cars set very low or run massive preload and very little droop on the rear .. normally a killer for rear brakes locking up under forward load transfer when the rear runs out of droop travel.
Sorry Joo, when I say shorter than the original fitment, its by 5mm only and thats because we run 350lb springs on the rear and with 10" springs on minimal preload, height is not an issue.
Differently valved dampers, different solution, thats all.
the gazman said:
oo interesting post Derek, it's actually in complete contrast to what i normally do which is to run as long a rear stroke as i can without running out of cv joint angularity. As i generally run 300/325 rears too you must have your cars set very low or run massive preload and very little droop on the rear .. normally a killer for rear brakes locking up under forward load transfer when the rear runs out of droop travel.
Sorry Joo, when I say shorter than the original fitment, its by 5mm only and thats because we run 350lb springs on the rear and with 10" springs on minimal preload, height is not an issue.
Differently valved dampers, different solution, thats all.
FIGHT FIGHT FIGHT FIGHT FIGHT FIGHT
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can never find the popcorn smiley when I need it.
Grrr .. wish people would stop turning every techie post into something it isn't, really annoys me. NOT being picky over what someone else is doing, just interested that we've gone completely diferent routes. I favour long travel rear with gradual unloading of the springs whilst derek seems to prefer shorter stroke (about 15mm at the wheel) and was intersted why ..
I've got Eibach springs on mine is there an easy way to tell what spring rate they are?
Also the Eibach website mentions they do springs with a 'progressivly firmer spring characteristic with increased compression' any ideas if this has been tried on Cerbies? I suspect this isn't for the std 2.25" spring tho' and I suspect my springs don't have this, as the coils seem to be evenly spaced.
It sounds like a good idea to me especially in view of the ground clearance and limited stroke available.
Matt
Also the Eibach website mentions they do springs with a 'progressivly firmer spring characteristic with increased compression' any ideas if this has been tried on Cerbies? I suspect this isn't for the std 2.25" spring tho' and I suspect my springs don't have this, as the coils seem to be evenly spaced.
It sounds like a good idea to me especially in view of the ground clearance and limited stroke available.
Matt
trackcar said:
Grrr .. wish people would stop turning every techie post into something it isn't, really annoys me. NOT being picky over what someone else is doing, just interested that we've gone completely diferent routes. I favour long travel rear with gradual unloading of the springs whilst derek seems to prefer shorter stroke (about 15mm at the wheel) and was intersted why ..
I'm sorry, I for one like to hear the to and fro, and am actually quite impressed by the way you guys try not to tread on each others toes.
If my lighthearted post was going to close down the discussion I heartily appologise. Please continue.
Reason I wanted my popcorn smiley is that when two shocks people or whatever ever experts start talking on a thread, thats when the rest of us realise where our gaps in knowledge are.
350matt said:
I've got Eibach springs on mine is there an easy way to tell what spring rate they are?
Also the Eibach website mentions they do springs with a 'progressivly firmer spring characteristic with increased compression' any ideas if this has been tried on Cerbies? I suspect this isn't for the std 2.25" spring tho' and I suspect my springs don't have this, as the coils seem to be evenly spaced.
It sounds like a good idea to me especially in view of the ground clearance and limited stroke available.
Matt
they're just single rate Matt, but TVR employ a looooong propgressive squidgy bump stop (spring assister) which effects pretty much the same function.
350matt said:
Can you get 2.25" progressive springs then?
Matt
Well technically the TVR springs are 60mm but you can get anything made up if you want .. i choose not to use progressive springs in 99% of what I do .. if I have to tune teh travel limit I do it on spring assisters (bump stop) as you can vary the length hence the point of operation easily .. to do it on the spring means having lots of springs made with the coil variation at different wire lengths which isn't practical.
The chims/griffs use a progressive eibach spring on the rear.
Correct me if I'm wrong here, but I was kind of thinking that the reason behind a progressive spring is to improve the ride, so the spring stiffness is comfy and soft for the first 10-15mm of wheel travel and get progressivly harder the more compressed the suspension, kind os having your cake and eating it fix? Or have I missed the point?
Also as I've got Nitrons fitted won't they be a std 2.25" spring?
Matt
Also as I've got Nitrons fitted won't they be a std 2.25" spring?
Matt
I run the GAZ set-up with 500 front 400 rear, although this is predominantly for racing I find that they allow a fair movement and a reasonable, ungrounding ride. I pump the tyres back up for the racing but drive to and from the events at 23/25 and find this set-up a great compromise. Set up was done by Gazman, Dave from Gaz and of course Andy of APM.
This is the third set-up I've had on the Cerb and is the best balance for my needs.
Jonny
This is the third set-up I've had on the Cerb and is the best balance for my needs.
Jonny
350matt said:
Correct me if I'm wrong here, but I was kind of thinking that the reason behind a progressive spring is to improve the ride, so the spring stiffness is comfy and soft for the first 10-15mm of wheel travel and get progressivly harder the more compressed the suspension, kind os having your cake and eating it fix? Or have I missed the point?
Also as I've got Nitrons fitted won't they be a std 2.25" spring?
Yes I think that is the main advantage of rising rate suspension - it gives you a good compromise between high total energy capacity (ability to absorb big bumps) and low natural frequency (ability to ride over small bumps without harshness). This means your car can be more comfortable for a given ride height, or lower for a given comfort. The disadvantage is that the suspension characteristics are not consistent as the body moves in bump, pitch and roll so optimising the spring/damper rates gets difficult. I would have thought that most people speccing aftermarket suspension would be better of going for a constant rate setup rated similar to the 'hard' part of the progressive spring as a starting point, just because it is so much easier to understand and change what is going on.
Guys thanks for such a interesting debate, but I must steer you back to my situation.
From what I understand, I need to purchase 350 lbs for the rear and 425 lbs for the front. This should give a firm ride for fast road (the roads on the Lakes tours were very bumpy at 70mph) - Yes / No?
It appears my rear stocks are too short when closed at 12" bolt hole to bolt hole.
What open lenght should the rear shocks be?
On visiting Demon Tweeks they had tender / helper springs. Are these any good?
Julian, do you supply springs to fit my AVO's?
johnbear said:
Guys thanks for such a interesting debate, but I must steer you back to my situation.
From what I understand, I need to purchase 350 lbs for the rear and 425 lbs for the front. This should give a firm ride for fast road (the roads on the Lakes tours were very bumpy at 70mph) - Yes / No?
It appears my rear stocks are too short when closed at 12" bolt hole to bolt hole.
What open lenght should the rear shocks be?
On visiting Demon Tweeks they had tender / helper springs. Are these any good?
Julian, do you supply springs to fit my AVO's?
On Avo's I'd run 400lb front and 325lb rear because of different valving and use 9" springs.
Springs should be around £20 plus carriage and Mr Brown's bit.
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