1981 - 1985 S3/Turbo Esprit Suspension Upgrade

[silverfrost]

As someone who has looked into this, you need minimum to have the car on one of those roll over things.

As I am doing a full restoration it is easier to just change the chassis as I had a spare s4   chassis.

If you look at the extra plates that need to welded on and aligned.

Best of luck to whoever does all that welding on their back. Its thick metal so would not be like just welding a thin steel metal repair panel on a moggy minor !

The suspension is better on post 85 models for a reason as its well designed, due to evolution and good build quality, don't mess with the esprit chassis unless its stripped bare.   Weld in place and you run the risk of poor handling due to poor measurements, and not to mention the fire risk, anybody who knows about welding fairly thick plate steel will know the current and wire speed is cranked up causing lots of excess heat and sparks ! 

If your serious about doing this I would personally advice removing the body and convert but while at the point you may as well just fit a later chassis !

I will post some pics at some point of the difference between present 85 and post 85, lotus did not fit all that extra plate for no reason lol !

 

Just my 2 pence worth 

[pyropolymer]

will a SE/S4 chassis bolt right up to a S1-S2-S3 body?  that would be the preferred way but much more work?  

Im not sure if "saggitarius" ever finished his car but seems to you just need a lower A arm, upright, new pickup point and a reinforce triangulation beam.

http://www.thelotusforums.com/forums/topic/28055-ls4-engine-into-esprit-s2/?page=4

 

 

[V8-ESPRITS3]

I have also looked into doing this on my own esprit, its not an easy task! I have been trying to source some second hand (cheap) lower arms to fit and see how it looks, I already have the uprights. I believe the top arms are the same? would be nice to have a front end off a scrap chassis to play with and to use as a jig.

[silverfrost]

14 hours ago, V8-ESPRITS3 said:

I have also looked into doing this on my own esprit, its not an easy task! I have been trying to source some second hand (cheap) lower arms to fit and see how it looks, I already have the uprights. I believe the top arms are the same? would be nice to have a front end off a scrap chassis to play with and to use as a jig.

Top arms are indeed the same 

[Andyww]

Would it be possible to maybe fabricate some bolt-on mountings for the lower link rather than welding?

The loading on the front arm of the link isnt going to be huge. No more so than the existing load which is fed through the anti-roll bar.

Perhaps something could bolt onto the existing anti-roll bar mounting locations?

[andydclements]

To bolt on, you'd need access to the inside of the front T-piece, which is (to all intents and purposes) sealed, and you'd need the section to which you plan to bolt to be suitably strong, which I doubt it would be (unless reinforced), so possible but I suspect you'd need full access (body off) to weld bits in order to make it possible to bolt on the other bits.

Pre-85 ARB mounts to the front of a fairly strong part of the subframe. The 85MY ARB mounts a long way forward of that, so the load on it when the suspension moves would mean you need a decent triangulation to the subframe, namely at the top of the subframe and that's where access is problematic.

[silverfrost]

Did anyone ever hear back about the Canley uprights that had been re made to suit lotus cars ?   Seems a long while since emails had been sent....   anyone get any feedback ?

[molemot]

I was in contact with a chap in the USA who was supposedly doing this in concert with Canley. As far as I know, it all fell through...I ended up selling the Canley trunnion free kit to a chap on another forum...they fit the Triumph GT6. So I reckon we've had it.

[silverfrost]

Its a shame,   I looked into these things on the web as well as having a read back through this thread.   Online i found some folks chatting about these canley ones and the folks moaned more about the ball joint not having a rubber more than anyhing,  but one thing the conversation did say was spyder the company had desighned some lotus uprights to replace the trunnions,  and folks where saying these are much better and stronger in design.  However this was from a dead post pulled of an internet search.  I tried looking for spyder upright conversion on the interwebs but hit a brick wall ?     

So there may be a better out there but for the life of me i cant find anything on it,  did hope the canley things would get sorted but from what you have just said its dead in the water sadly.  

Still cant see why someone has not just made bottom arms that the modern 85 onwards ball joint fits into but using the old bottom arm design, then new uprights to use the old size wheel bearings/calliper mounts etc. 

Lotusbits sell brand new excel hubs for next to nothing,  i am sure these could be machined down or converted to accept the older bearings etc.  

I may look into this myself at some point as i have both front suspension set ups and will have a good look at the differences and options regarding mods maybe. 

[Lotus Guy]

So Hilly, The wheel rotors and bearing fit exactly as the originals? You've verified that the GT6 uprights are interchangable exactly?

Sam

[V8-ESPRITS3]

I brought the Canley GT6 uprights and new spindles and fitted them to my S3. I used my hubs which fitted direct to the spindles and used the S3 brake discs. You do need to weld the bottom mount to the lower arm as it will pivot.

It is not perfect but it is all that is available and better than the trunnion.

Edited January 15, 2020 by V8-ESPRITS3

[naasaa]

Difficult to see at the picture. 
But is there enough meet in the ball jount so that it would be posible to drill through and insert a locking pin, instead of welding?

[andydclements]

There are a few close-ups (blurry due to photobucket method) at the start of the thread, I'd have thought it looks like there's not enough metal in the ball-joint to drill and put a substantial pin through.

[drdoom]

John Zender, of California, has worked through adaptation of an SE chassis to his S2 in a comprehensive effort. Link to his firm attached, he might be forthcoming with advice.

https://www.fusiontechnology.com/

Cheers

[910Esprit]

Would there any negative effect on the geometery by moving the upright pivot point a couple of inches?  (Trunnions originally pivot on the outer bolt of the lower arm)

[andydclements]

5 minutes ago, 910Esprit said:

...  (Trunnions originally pivot on the outer bolt of the lower arm)

They rotated on the bolts, but only to accommodate the change in the angle between the lower arm and the upright, as they were fixed relative to the upright (by virtue of the threaded section of the upright).

 

I know that doesn't answer the question, but just clarifies on the later point you make.

[910Esprit]

Agreed  - The vertical axis looks pretty much unchanged, but the horizontal axis has moved significantly - No idea if this makes any difference!

[drdoom]

Effect to geometry is determined by the plane in which relocation is performed. Outward re-positioning of the lower arm outer pivot will change the camber and its curve, kingpin inclination ( therefore steering offset, where the axis of steering meets pavement relative to tyre contact patch ) and bump-steer curve. An adjustment of toe obviously required as well. It's not something to pursue without some analysis, my back-yard engineer's thoughts offered free of charge.🙂 

[naasaa]

On 15/01/2020 at 18:24, V8-ESPRITS3 said:

I brought the Canley GT6 uprights and new spindles and fitted them to my S3. I used my hubs which fitted direct to the spindles and used the S3 brake discs. You do need to weld the bottom mount to the lower arm as it will pivot.

It is not perfect but it is all that is available and better than the trunnion.

How did you set the right angel for the ball joint in relation to the lower arm?