1995 Ginetta G27 4.5 V8

Bought some steel to complete the front suspension stengthening and modifications - next on the list of purchases is an Escort MK2 quick rack followed by sorting out some 1/4" mild steel plate.

Shorter stand to buy a bit of extra room



Steel - plus alloy for the coolant tubes on the Strato's



My version of cars and blossom. - Our apple tree with the centre tub sitting on the bonnet!



Tomorrow is the day set aside for starting the suspension works.

The Ginetta series does have some good racing - shame about the WEC aspirations and the Manor team debacle putting pay to any sort of Le Mans showing.
I shall try and keep up the good work when I eventually get really started on it - As I got distracted by the work on the Strato's the day set aside for the work on the front suspension was given up to that and the Flowbench.

I will get on with this.

So the season has moved on - all the blossom has fallen off the tree and now its full of little apples !

I have been ordering a few parts here and there for the project and today decided that I would have play with polybushes - as it has also been a subject with differing opinions on other threads this is my take.

The Ginetta G27 uses a Triumph derived suspension system - now people may look over the parts on this car and chassis and say "no bloody Triumph ever left the factory with those bits on it" and they would be correct - the uprights are bespoke the lower ball joints Saab and the upper a rose joint the steering arms bits of old gate - but the rack was Spitfire and so to an extent is the geometry and many left the factor with Triumph wishbones and uprights.

The bolts that fix the wishbones to the chassis are 3/8 UNF and the bushes are Triumph as well. You could probably take all the front suspension off of this G27 and offer it up to a Spiftfire and in a fashion it would fit and work.

This car came with a very odd selection of bushes fitted - some Nylon top hat bushes with not sleeves and some black Powerflex bushes with the crush tubes chopped down! This car had a 330 BHP/ton power to weight ratio and a 364 ftlb/ton Torque to weight ratio !

The Nylon I had to chop the rim off to push them out.







Not good.

Last week I was looking at setting up the upper and lower wishbones into a jig for doing some welding in order to progress the mounting of the steering rack and the chassis fabrication for the upper wishbones and I found that the alloy spacers that I had used for the G21 wishbone fabrication bid not fit... Hmmmm I thought these wishbones use the same CDS tubing as I used on the G21 so why don't they fit. The reason being that I turned the tubes out to the correct 13/16 ID that is required to match the Triumphs and Ginetta just left the ID as stock. - Well you can with sufficient force ram a square peg into a round hole or a Triumph rubber bush into a Ginetta wishbone and it will do its job - sort of.

However when you decide to upgrade to performance polybushes on your Ginetta that uses Triumph bushes you are going to come unstuck. Firstly not only are the tubes on the wishbones the wrong ID but they are also wider than the Triumph so the crush tubes are too short.

Anyway I bought myself a cheap set of Floflex / Deflex Orange 80 Shore poly bushes so I could see if I could get them to work correctly. I saw no point buying a set of SuperpoloyPowerflax bushes as they will fit no better than cheap ones.

So I bought a couple of drill bits - one being a 13/16 to bore the tubes to the correct ID.

So the out come

This is what happens when you fit polybushes to undersize tubes - this could be undersize due to poor manufacture as in my case or corrosion etc. in many others - The difference was 19.8 and 20.6 - just .8mm diameter or .4mm on the radius. So what does that piddly little difference make when fitting.

You can see that they both fit - but you can see the deformation in the narrower tube





And the bore was difference was 10.2 verses 11.5 - bear in mid that a 12.7mm tube needs to go in there.





And when you press the sleeve in - if there is not enough room for the volume of the poly it tries - well you can see.




The tubes are also far to short for these bushes so if your typical owners fitted these they would tighten them to a point of bending the chassis brackets and pretty well clamp the suspension solid. And no doubt eventually snap a wishbone and shout all over a forum how utterly curse word polyflexpowerpapsuperflow bushes are and how they nearly killed him. No, the installer tried to kill the driver not the component.

So for me to get this correct I have needed to ream the bushes correct and will need to fabricate new crush tubes to provide the correct length to just compress the poly - I will have a stainless crush tube and the bracket will be of a size to allow fitting of stainless penny washers so that the Poly is sandwiched in stainless that will not rust up or corrode and the friction surfaces to the poly will remain consistent but I may look at cutting spirals into the poly for lube retention.

Right then lunch over.

Welcome aboard Phil hopefully there will be something for people to take away from these rambles and posts.

And let's face it, there is much enjoyment to be had squeezing as much engine and power as you can into a tiny little car just to see how bloody scary fast you can really make it go. Almost as much as seeing just how many shire plodders an old naturally aspirated RV8 can kick out.

Just been sitting here typing, having dinner and doing some trig calcs for the position of the lower wishbone brackets for sufficient Caster trail adjustment - like you do -

Whilst in G27 mode

All wishbones bored to the correct ID and the poly's fit nicely - Stainless tube 1/2" x 16SWG ordered - Trig done and need to have 15mm of forward adjust-ability built into the lower wishbones to provide 3-8 degrees of Caster trail. I do have some 1/2" x 16SWG mild so may make up a couple of temporary crush tubes for testing.



Tomorrow I will cut and drill the lower wishbone brackets and may even tack them on and then have a look at the engine as I need to get that buttoned up.

Lunch stop


Drilled - spent a lot of time measuring as I want the brackets all aligned, parallel etc. rather than the pick and mix approach that Ginetta took to angles.




All four brackets tacked on - Time for further measuring and contemplation.





Also noted that the original installation of the upper rose joint was far from perfect as can been seen from the contact witness marks.






Another cup of tea then back to more measuring cutting drilling etc.

last day of a couple of days holiday just relaxing and playing with cars and time for lunchbreak.

Delivery man has just dropped off some stainless I ordered over the weekend for the crush tubes enough to produce 24 tubes 8 per car so that's enough for both the G27 and the G15 plus a few spares.





Enough brackets for both sides have been cut and drilled.



And its starting to take shape.



With the easy part over with now its time to figure what angles and lengths the rectangular box needs to be cut at to make all this work.

As it happens - the damper mounts are being moved:-

A) Because there is no upper mount at the moment as I cut it off.
B) To reduce the angle of lean and give a greater rising rate effect.

The original mounting type is a pin - and if you lean a pin type...







I may also remake the lower wishbones with the lower pivot closer to the ball joint - that way I can run a slightly lower poundage spring for the same chassis spring rate which makes life easier for the damper. Damper mounts will be changed to spherical ends and alloy body types.

G33 - Nice enough cars but not a great fan of them really, just one step too far in the evolutionary cycle. Better not elaborate as some owners are very odd and take things far too seriously, and boy they really get upset when people suggest they are not real Ginetta's - G32 being the last Walklett design. Not bad looking apart from the rather odd angle the door fillet and the screen cut make and the asymmetric jowly cheeks in front of the front wheels. Once you notice the front its hard not think that the mould had a stroke when it found out it was producing yet another G4 derivative You will never be able to tell a G33 owner that less is more..... I should stop now -


Machined up the spacers for the poly bushes - The difference in sticktion between the polished stainless and the temp mild steel sleeves that I made is quite marked.