Springs 400 front 325 rear
Springs 400 front 325 rear
Author
Discussion

RedCabbage

Original Poster:

3,606 posts

263 months

Sunday 23rd March 2008
quotequote all
After a disappointing experience driving fully loaded up to Wales in the Chimaera, I am thinking about upping the spring rates on my Nitrons from 325/250 to 400/325.

I know there are many people running much higher rates but this car has to be a bit of an all rounder so it has to be good for road, track and road trips (LM, 'ring).

Pasco

6,652 posts

259 months

Sunday 23rd March 2008
quotequote all
My nitrons are fine with 450 front 375 rear but i have to say the valving was special by Track Car Solutions and Nitron direct yesa super ride quality though i must say smile

RedCabbage

Original Poster:

3,606 posts

263 months

Sunday 23rd March 2008
quotequote all
Nitron claim standard valving will cope with four rate increases (25lb each) so I should be well within that. Joolz will probably be doing the set up anyway so I'll speak to him as well.

Pasco

6,652 posts

259 months

Sunday 23rd March 2008
quotequote all
RedCabbage said:
Nitron claim standard valving will cope with four rate increases (25lb each) so I should be well within that. Joolz will probably be doing the set up anyway so I'll speak to him as well.
Have a chat to him about my set RC i have no doubt Joo will sort it to your satisfaction fella thumbup

2Munkys

1,228 posts

268 months

Sunday 23rd March 2008
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I'm running 400/325; not with anything as luverly as Nitrons though.

Tahiti450

712 posts

268 months

Sunday 23rd March 2008
quotequote all
Im running 375 F / 325 R with Protech's from Jools. I reset the damper adjustment range to give stiffer settings and the result is really excellent. Mine is mainly a road car but also do sprints and trackdays and actually I feel its a bit on the soft side now so I might consider a set of stiffer springs.

Pasco

6,652 posts

259 months

Monday 24th March 2008
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2Munkys said:
I'm running 400/325; not with anything as luverly as Nitrons though.
Poor Monkey Boy smile

Chimjunkie

2,879 posts

242 months

Monday 24th March 2008
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400/325 going on in a few weeks smile Just need PlasticMan to put a new front end on for me bounce

Uncle Fester

3,114 posts

239 months

Monday 24th March 2008
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I have 400/325 with Nitrons. I gave Nitrons the data and this is what they suggested. It can crash a bit over potholed surfaces but the handling is very good.
They were supplied and the car set up by Ab Shocks. I wouldn't want to go softer, but would like to try a bit harder.

Pasco

6,652 posts

259 months

Tuesday 25th March 2008
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Uncle Fester said:
I have 400/325 with Nitrons. I gave Nitrons the data and this is what they suggested. It can crash a bit over potholed surfaces but the handling is very good.
They were supplied and the car set up by Ab Shocks. I wouldn't want to go softer, but would like to try a bit harder.
I agree regarding the pot hole comment Fester and i have 450 front 375 rear which has transformed the car smile

Uncle Fester

3,114 posts

239 months

Tuesday 25th March 2008
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Everyone seems to go up by the same amount front and rear.

Has anyone tried increasing one end more than the other?

What was it like?

spend

12,581 posts

282 months

Tuesday 25th March 2008
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That is what they are doing Stupid! The ratio is raised in favour of the rear...

K4TRV

1,819 posts

283 months

Tuesday 25th March 2008
quotequote all
Can I ask those with up to 450 front and 375 rears, are you running standard profile tyres ??

Lots of Phers seem to be running 17 or 18 rims with 35/40 profile tyres.

If upping the spring rate and lowering the tyre profile, how do you keep your fillings in ??

Out of interest I have Poly bushes, Avos with 275/250 following Jools recommendation for general running. Soft and pilabile for touring with 6/8 clicks.

I also do Sprinting and Hill Climbs (plus a Track day or 2) and the flexibility offerred by 10/12 clicks on the Avos and standard 55 profile front & 50 rears means I'm never too far off the pace - there's never many other TVRs to compare !! I would think the Std Goodyear F1s are the achilles heel, not spring rates ??

Trev Mac

Uncle Fester

3,114 posts

239 months

Tuesday 25th March 2008
quotequote all
spend said:
That is what they are doing Stupid! The ratio is raised in favour of the rear...
readit

One end more than the other. Not +75 front and rear like me, or +125 front and rear like Pasco.

As in +75 front, +100 rear, or any similar combination.

Chimjunkie

2,879 posts

242 months

Tuesday 25th March 2008
quotequote all
Uncle Fester said:
spend said:
That is what they are doing Stupid! The ratio is raised in favour of the rear...
readit

One end more than the other. Not +75 front and rear like me, or +125 front and rear like Pasco.

As in +75 front, +100 rear, or any similar combination.
Think Spendy had some sense in his exclaimed remark... A +75 front and rear is a greater percentage increase to the rear compared to the front. This is an interesting point though because i have always felt the back to be too soft with respect to carrying stuff in the boot.


Tahiti450

712 posts

268 months

Wednesday 26th March 2008
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K4TRV said:
Can I ask those with up to 450 front and 375 rears, are you running standard profile tyres ??

Lots of Phers seem to be running 17 or 18 rims with 35/40 profile tyres.

If upping the spring rate and lowering the tyre profile, how do you keep your fillings in ??
Trev Mac
Well i'm not running rates that stiff, as i said above (375 / 325) but again as stated I would certainly consider going significantly stiffer. I am running 17 / 18 inch rims with 40 profiles and find the set up very comfortable for road use, but then I like the car to be fairly taught and I drive it hard. Obviously personal preference, perception is going to be a major factor and what one person thinks is comfortable / soft someone else will feel is rock hard.

As far as changing the RELATIVE stiffness between front and rear, all other things being equal this will determine the basic handling balance of the car.
Stiffening the front relative to the rear will favour understeer and stiffening the rear relative to the front will move the balance towards oversteer, due to greater load sharing between the tyres on the softer axle (i.e the softer end of the car will grip more than the stiffer end).
Of course increasing stiffness overall will tend to increase grip (on smooth surfaces anyway) partly by reducing roll and the associated loss of tyre contact patch - which any roll induced increase in negative camber can only offset so far.

steve-V8s

2,924 posts

279 months

Wednesday 26th March 2008
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One of the reasons I went up 75 at both ends is you only need to buy two springs, at least that is the case with Nitrons. Put the front springs on the rear and the new ones on the front.

Pasco

6,652 posts

259 months

Thursday 27th March 2008
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steve-V8s said:
One of the reasons I went up 75 at both ends is you only need to buy two springs, at least that is the case with Nitrons. Put the front springs on the rear and the new ones on the front.
This is a man with a Brain yes

spend

12,581 posts

282 months

Thursday 27th March 2008
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Pasco said:
steve-V8s said:
One of the reasons I went up 75 at both ends is you only need to buy two springs, at least that is the case with Nitrons. Put the front springs on the rear and the new ones on the front.
This is a man with a Brain yes
...but then you can't take advantage of longer springs on the rear confused

Dave

Chimjunkie

2,879 posts

242 months

Thursday 27th March 2008
quotequote all
spend said:
Pasco said:
steve-V8s said:
One of the reasons I went up 75 at both ends is you only need to buy two springs, at least that is the case with Nitrons. Put the front springs on the rear and the new ones on the front.
This is a man with a Brain yes
...but then you can't take advantage of longer springs on the rear confused

Dave
Std springs from Nitron are same length front and back. But I did wonder when i changed mine yesterday that the rear has room for at least another couple of inches of spring length if this were to be a benefit.