Modifying Triumph Spit MK111 rear suspension.
Discussion
Hi guys,
Quick questions, amongst my projects I have a Spitfire I’m screwing back together, it’s a very long story but I’m just sorting the rear end and can’t help and think a little modification would improving the road holding / ride.. I don’t want to get carried away with complete wishbone kit but are there any small changes I can make at this stage of the project (its all so accessible). It will be fitted with new shocks, bearings and rubbers.
Thinking about a anti roll bar … something I can pull from another car always helps the budget…
Cheers
Matt
Quick questions, amongst my projects I have a Spitfire I’m screwing back together, it’s a very long story but I’m just sorting the rear end and can’t help and think a little modification would improving the road holding / ride.. I don’t want to get carried away with complete wishbone kit but are there any small changes I can make at this stage of the project (its all so accessible). It will be fitted with new shocks, bearings and rubbers.
Thinking about a anti roll bar … something I can pull from another car always helps the budget…
Cheers
Matt
1) Simplest option is to swap the rear spring/front anti-rollbar to for those from a pre-1973 Spitfire Mk IV.
The original spring is rigidly fixed to the diff. which can lead to the rear wheel tucking-under and spinning the car - but only really if you drive like a tool and lift-off mid corner. The Mk IV had a revised design where only the bottom leaf is rigidly fixed, the rest free to slide over one-another. You want a pre-1973 one because from this point to the end of 1500 production the cars had a wider rear track and so a slightly longer spring. The rollbar is needed to keep everything balanced
You can do it a lot cheaper using eBay but for a kit for all the parts brand new -> £250 (http://www.canleyclassics.com/?xhtml=xhtml/product/swingspring.html&xsl=product.xsl)
2) I'd probably say replacing the rubber bushes with Polybush/Superflex is next on the list as they will either be old and nackered or modern replacements that just don't last that well -> £120 for a full-car kit (e.g. http://www.canleyclassics.com/?xhtml=xhtml/product...
3) Next on the list would be some adjustable shocks, at which point the usual suspects crop up and you pays yer money, you takes yer choice. Koni, Gaz, Spax and Avos are all available -> ~£150 (e.g. http://www.rimmerbros.co.uk/Item--i-GRID005747).
4) The final low-budget step is a spring lowering block to give you a little more negative camber by default. 1/2", 3/4" and 1" are available though I found 1" to be too much -> ~£70 including longer diff. studs (e.g. http://www.canleyclassics.com/?xhtml=xhtml/product...
5) Beyond that you're in to silly-money land, converting to a Rotoflex rear-end but with CV joints in place of rubber rings -> £1000 if you go all-out for new, light-weight alloy parts
- http://www.canleyclassics.com/?xhtml=xhtml/product...
- http://www.canleyclassics.com/?xhtml=xhtml/product...
- http://www.canleyclassics.com/?xhtml=xhtml/product...
Shiny but expensive.
The original spring is rigidly fixed to the diff. which can lead to the rear wheel tucking-under and spinning the car - but only really if you drive like a tool and lift-off mid corner. The Mk IV had a revised design where only the bottom leaf is rigidly fixed, the rest free to slide over one-another. You want a pre-1973 one because from this point to the end of 1500 production the cars had a wider rear track and so a slightly longer spring. The rollbar is needed to keep everything balanced
You can do it a lot cheaper using eBay but for a kit for all the parts brand new -> £250 (http://www.canleyclassics.com/?xhtml=xhtml/product/swingspring.html&xsl=product.xsl)
2) I'd probably say replacing the rubber bushes with Polybush/Superflex is next on the list as they will either be old and nackered or modern replacements that just don't last that well -> £120 for a full-car kit (e.g. http://www.canleyclassics.com/?xhtml=xhtml/product...
3) Next on the list would be some adjustable shocks, at which point the usual suspects crop up and you pays yer money, you takes yer choice. Koni, Gaz, Spax and Avos are all available -> ~£150 (e.g. http://www.rimmerbros.co.uk/Item--i-GRID005747).
4) The final low-budget step is a spring lowering block to give you a little more negative camber by default. 1/2", 3/4" and 1" are available though I found 1" to be too much -> ~£70 including longer diff. studs (e.g. http://www.canleyclassics.com/?xhtml=xhtml/product...
5) Beyond that you're in to silly-money land, converting to a Rotoflex rear-end but with CV joints in place of rubber rings -> £1000 if you go all-out for new, light-weight alloy parts
- http://www.canleyclassics.com/?xhtml=xhtml/product...
- http://www.canleyclassics.com/?xhtml=xhtml/product...
- http://www.canleyclassics.com/?xhtml=xhtml/product...
Shiny but expensive.
You could hunt out a Rotoflex setup from a GT6 Mk2 or early GT6 Mk3, it goes on fairly simply although there is a pickup on either side ahead of the rear wheels that needs adding in. I had a hybrid Spit Mk3/GT6 Mk2/2500 years ago that had this arrangement and it handled well (the engine being 1ft further back in the chassis also helped 
)
RJ
)RJ
I think you'll find that all the swing springs (Mk4 and 1500) are the same length and it is just the drive shafts that differ...
If you do go down this route make sure that you get hold of the spring complete with the pivot box and all associated bits or you'll struggle to make it fit - a look at a Rimmers catalogue (free and well worth having) or a parts book will show all you need to know. You can get all manner of uprated springs, shocks etc. but to be perfectly honest the standard set up in good nick works pretty well.
If you do go down this route make sure that you get hold of the spring complete with the pivot box and all associated bits or you'll struggle to make it fit - a look at a Rimmers catalogue (free and well worth having) or a parts book will show all you need to know. You can get all manner of uprated springs, shocks etc. but to be perfectly honest the standard set up in good nick works pretty well.
goodwoodweirdo said:
Thinking about a anti roll bar
An anti roll bar transfers weight onto the outside wheel, basically it makes the car slide more.Front anti roll bar gives understeer, you really really don't want to put an anti roll bar on the back of a swing axle car, it'll make the tail swing around even more!
A Z bar or camber compensator might be ok, but generally softer springs and decambering was what VW did to make the Beetle a bit more predictable.
garethj said:
A Z bar or camber compensator might be ok, but generally softer springs and decambering was what VW did to make the Beetle a bit more predictable.
Camber compensators were available back in the day but these days even if you can find one I'd guess the swap to the swing spring set-up will probably be cheaper.All Mk IV and 1500 rear springs are the same. Which means the long shaft cars sit lower than short shaft.
Be careful if you buy a new spring that it doesn't make the car sit too high, but overall swing spring is by far the easiest way to improve the handling.
Did you know? - the swing spring was designed for the original Herald in 1959 - I suspect it wasn't used as it increased the cost of the car.
Be careful if you buy a new spring that it doesn't make the car sit too high, but overall swing spring is by far the easiest way to improve the handling.
Did you know? - the swing spring was designed for the original Herald in 1959 - I suspect it wasn't used as it increased the cost of the car.
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