Topic

Thats a lot of good work

Have you considered the twist on the body between the front and back of the car by making both ends so rigid

Shock tower fracture/flex

The race version of the F (cup car) had stiffening bars to brace the shock mounts... and the actual mounts were beefed up too (standard item has 4x spot welds)

So for the front I seam welded the brackets to beef up the original 4 spot welds..

Then welded 6mm angle around the shock mount.. then cross braced (to mirror the Cup cars set up)





6mm welded to the sides of the rad housing



Cross bracing fitted to stiffen up under the bonnet (note too the 2 bars going through the bulk head into the cabin, they are welded to the larger cross brace under the dash)

The rear set up is again a copy of the Cup cars..

The brackets seam welded both sides.. gusset added to the middle (20mm box) then the two towers braced by one bar.. welded each end.. and welded to the body at the top where it meets the body




(ignore all the dust from doing body work)

Stiffening the car body shell is a similar process..

You can buy this brace that goes under the dash (already there on the TF)

Althought the F requires 2 brackets welding in to mount the brace.. this brace eliminates screen shake/flex







They also sell a cross brace that bolts to the F subframe (already fitted to the TF)

Mine is actually welded on to increase stiffness

Diesel Destroyer wrote: wrote:

The rear set up is again a copy of the Cup cars..

The brackets seam welded both sides.. gusset added to the middle (20mm box) then the two towers braced by one bar.. welded each end.. and welded to the body at the top where it meets the body

(ignore all the dust from doing body work)

There is a fundamental difference between your car and a cup car it is effectively a hard top car it has a solid roof due to the roll cage the same as the car in video

You have stiffened up ether end and as a road car it could make a difference but it still going to flex right in the wrong place being a convertible

The draw back of a soft top

I totally agree..

The only two options are.. weld in roll cage.. weld on a roof..

As I want neither... I have opted to improve what I can..

I am under no illusions that my car will still flex.. but will flex less than a stock MGF/TF

I have also beefed up the rear mounts.. the standard engine braces mount to the rear bulk head.. the bulk head is double skinned and pressed steel.. so fairly resistant to flex.. but now I hve braced them to the rear of the boot it will flex even less

Ive also ditched the stock anti roll bars.. as they are not up to the job I want them to do..

I have 2 pairs of custom ones made.. (80% stiffer)

I have apair.. and Andy Watson has a pair to fit..

Standard item is 19mm.. new ones are 23mm

Then in order to fit the new ARBs... I have beefed up the drop link mounts all round.. now all double shear..

Drop links have been replaced too.. rears were custom made.. fronts are rose joints..

All four spheres have been indidulaised too (various kits available)

Lowering pins fitted (Mike Satur)

One thing I havent opted for... which could be done.. Is subframe braces (2x bars run under the car to tie the two subframes together)

I dont want a roll cage.. but as Purple F rightly says.. a weld in cage will add loads of stiffness..

Hence why track MG Midgets have weld in cages..

The TF got all 3 braces fitted as standard to improve handling.. So any F driver who wants to drive their car hard on either road or track would do well to start there..



Torsion stiffness is important for the track... hence why so many 'performance' cars are space frames now..

Hi, I wanted more detailed information on the construction of the structure of stiffening of the body of mgf. for example, tubes of the structure are all of the same diameter?
As is often the metal that composes the tube?
What material are the tubes?
Of which are thick, where the plates are welded to tubes?
thanks
I have many questions yet, but proceed a little at a time

perry wrote: wrote:

I have many questions yet, but proceed a little at a time

Welcome aboard Perry.

Allan (Diesel destroyer) is more likely to answer your question quickly if you pm (personal message) him. That way he'll get an email. Having said that, there's a few members here that may well be able to give you appropriate answers to your initial questions.

I'm not one of them. I just didn't want you thinking that your first post was being ignored.

Our eldest granddaughter has just been fitted with a brace.
Has done nowt to stop her gob constantly moving.....

I feel a lot more comfortable when I wear a belt in conjunction with my braces; specially if out on the town for a few pints or real ale.

On a more serious note torsional stiffness is quite difficult to achieve on a convertible as its only the floor pan/tunnel and sill structures that keep the car from folding in half when both doors are open.

Some torsional stress analysis has been done on the link below from ultimatemg.com. The TF does very well in this category as it is factory braced in some areas.

It shows the the ZT at the top of the table which is an unfair comparison as having a roof connected by pillars and bonded front and rear screen make a mono-cock passenger cell which is obviously not possible on a convertible.

The TF is a strong contender.

Brian.

http://mgf.ultimatemg.com/group2/body/