Spitfire suspension woes

[PeaTear]

Earlier in the year I decided it was time to sort out the horrible handling of my spitfire.

I stripped the front shocks and found both shock absorbers were dead and with a nice bonus from work bought a full polybush kit, gaz adjustable shocks and without researching it first, lower 330lb springs. Which is where I realised my mistake that the lower springs don't work with the shocks.

Is there any solution to this or do I just need to get new standard length springs?

[DanMi]

If they are too low then you can buy spacers which either go between chassis and top mount plate or under the spring or is there another problem as you don't actually state the problem

https://www.moss-europe.co.uk/shop-by-model/triumph/spitfire/steering-suspension/front-suspension/road-spring-spacers.html

[PeaTear]

The problem is once the car is on the ground there is about 1inch of free piston between the mounting plate and bump stop. 

 

[DanMi]

does the car sit far too low? You could either put a spacer (tt4405/6 in above link not tt4404) between spring and upper or lower plate  that would give more travel and raise ride height, change the springs for standard or use the shocks with adjustable spring seats, this would be my preferred option if you want the higher spring rate and what I finally did after faffing with spacers for years.

 

or of course just go standard as Pete would say maybe they are a must have that you don't need

 

[PeaTear]

Yup far too low. The trolley jack was stuck under the car when i dropped it to the ground.

Like you i don't think i want to faff about with spacers so new standard springs will be going back on.

[Clive]

What is the fitted length of the springs? (car on the ground)

Very surprised that the shocks are nearly bottoming out! That is a real problem. And yes, you need a low level trolley jack for a spitfire that has been lowered. Or run the car up on some 2" thick timbers.

[Pete Lewis]

so just what were /where from ,,,,,the  330 springs   you can up the spring rate if thats whats wanted but should maintain  a pretty std  ride height 

330 and lowered is a nightmare  of conflict 

note club shop uprated  springs specifically state does not affect ride height 

Pete

 

[DanMi]

Moss ones do lower the suspension but they don't say how much by (just slightly lowered for uprated and lowered for fast road) . I would always recommend adjustable spring pans if fitting uprated spring so that you can get the ride height as you want it

[Clive]

26 minutes ago, Pete Lewis said:

so just what were /where from ,,,,,the  330 springs   you can up the spring rate if thats whats wanted but should maintain  a pretty std  ride height 

330 and lowered is a nightmare  of conflict 

note club shop uprated  springs specifically state does not affect ride height 

Pete

 

Pete, I disagree. 330lb and a sensible height makes the car great. Sounds like something isn't quite right here.

My spit is currently on 480lb springs and I have used spacers so the ride height is only lowered 1/2". It was 1" down, but found it suffered on poor roads, so a compromise has been sought. 

The old club springs were terrible, they had the same uncompressed length as std, but were 20% stronger, so ride height went up. Great for an offroad car. Glad somebody has sorted that cockup.

 

12 minutes ago, DanMi said:

Moss ones do lower the suspension but they don't say how much by (just slightly lowered for uprated and lowered for fast road) . I would always recommend adjustable spring pans if fitting uprated spring so that you can get the ride height as you want it

std mk1+2 spit 140lb 7.00", mk3  150lb 7.50". IV/1500 180lb 8.00"

moss springs tt4301 330lb 7.25". tt4302 330lb 6.875" tt4407 480lb 7.00"

All fitted lengths from the old TT catalogue. Of course, we don't know the source of the springs. But finding original spec springs for the early cars is tricky. But here the fitted length of the springs should tell all. If they are about 7", then the shocks are incorrectly sized for an early spitfire.

[PeaTear]

I don't know what the height of the springs compressed on the car is, i won't be back home now until Sunday night.  

Uncompressed on the bench there is about 3" of difference between the old springs and new

[Clive]

As the new springs are 2-3 times as strong, they will compress much less when fitted. But really you need the measurement.

A friend ended up buying the TT ones for his mk3 spit as all the std ones made the car sit too high. We think suppliers were selling late spitfire springs, so the TT gave about the correct height. 

Spacers do work perfectly well, and it means you can get the ride height you want rather than hoping the next springs are the correct strength/fitted length. It is a gamble...

[DanMi]

I would use adjustable spring pan shocks, at the end of the day by the time you have purchased the spacers, the extra cost over the standard just stiffness adjustable is not much, if anything, and you may end up buying a few different spacers to get it right so actually spend more!, plus they are infinitely adjustable. I would be tempted to do this even if fitting standard, as modern repro springs may not be exact.

 

Clive was it the springs at fault making the mk3 sit high or the shocks having the lower spring seats too high, modern repro stuff causes a lot of headaches

[PeaTear]

Unfortunately buying new shocks again will be a no go.

In hindsight I should have researched it more but hey ho.  ive replacement standard springs.  As long as the car doesn't bounce uncontrollably across the road when hitting bumps ill be happy

[DanMi]

don't hesitate to ask, the only reason I think the way I do is because I did buy uprated springs and shocks and had exactly the same issues, then bought various spacers, never was happy til I replace the shocks and adjusted to my liking

[Clive]

12 hours ago, DanMi said:

 

 

Clive was it the springs at fault making the mk3 sit high or the shocks having the lower spring seats too high, modern repro stuff causes a lot of headaches

Springs were simply too long when fitted. They appeared to be for a late spitfire, and sat about 1" higher, with a fitted length of a little over 8". But all teh sellers were saying "one spring fits all". 

Yes, the old black crappy shocks did have the seat pans too high. But his were correct.

Downside of adjustable seat pans is that they are not made by Koni. Until you use Koni, you won't understand.

[PeaTear]

I've lowered the car again and measured the compressed length of the springs. I'm not great with imperial but it looks like the new springs have a compressed length of about 7.5inches and what looks more like 1/2 of piston travel which to me does not seem like enough

I fitted the old springs back on and have a compressed length of about 8.5 inches with about 1 1/2 inch of piston travel. 

Going by the numbers Clive posted earlier im not even sure if the old springs are correct for a mkiv

[p7rider]

i remember fitting uprated moss springs to my 1500. they were nearly twice as low as advertised. Fitted a pair from the club shop and they lowered the car about an inch or maybe 3/4" . but that was years ago.

[Black Cat]

I’m in a similar position and in the closing stages of a complete rebuild of a 1500 Spitfire, having decided at an early stage to fit new front Spax TT3301 shocks and then at a later date decided to fit slightly larger tyres, Yokohama 175/70/R13 which are now fitted.

Now the car has most of its components fitted so the ride height is about where it’s going to be apart from a driver and passenger but the front now sits about 20mm above the edge of the wheel arch which with additional weight of the driver and passenger I’m thinking is far too low especially when turning or going over uneven ground. The rear sits about right, about 45mm above the edge of the rear wheel.

The springs I fitted were slightly lowered TT4301 and are supposed to have a spring rate of 330Ibs each with a fitted length of 7.25”, which is what I have without the driver and passenger. With the standard tyres fitted the car was sitting much higher, in fact it was much too high, so by fitting different tyres I thought it would improve the ride height but in reality it didn’t work.

Looking in the Moss catalogue the TT4301’s springs, which I have, have the longest fitted length of 7.25” and a spring weight of 330Ibs, they do have a spring with a 7” fitted length with a spring rate of 680Ibs but I’m thinking this may be too stiff and may not help the ride height which is what I’m looking for.

Now I do have a set of 1” spaces which can be fitted on the bottom of the springs, that is according to the Moss catalogue but unfortunately they won’t fit on the flange of the Spax shocks bottom so I have fitted them on the top and this has given me sufficient clearance.

The first photo is without the spacer and gives me a 20mm gap, second with the spacer fitted at the top of the spring and the third photo is with the spacer fitted and gives me a 45mm gap.

What is the problem of fitting the 1” spaces on the top of the springs if any?

 

[DanMi]

spacers can go on top absolutely no problem. Mine was like that for 30 years

[Black Cat]

Thanks DanMi, was looking for some assurance that this was OK.

[johny]

Out of interest, is there any sideways location for the spring on those spacers? Cant see from the photo if theyre stepped...

[PeaTear]

Same as black cat I fitted spring spacers, overall I'm pleased with the setup and how the car sits.  Just need to sort the alignment out and fiddle with the shock adjusters.

 

@johny there is a step on the spacer that locates in the internal diameter of the spring