just wondered what people's thoughts wer and if it is really a must 2 strengthen chassis 2 stop cracking chassis legs. i have a front lower ged bar and 2 b fair my suspension is rock hard just wondered if strengthening is woth looking into or am i just being over worried??

i have hit a pothole a few times and its been a fucking nasty bang wen I've gone over it but nothing has changed no visible damage......+ going into my garage everynite its a steep very uneven drive would this cause problems??

the fact you've braced everything and got stiffer suspension is only going to put more stress into the chassis, so in theory you've made it worse and should defo get the chassis legs braced.

the fact you've braced everything and got stiffer suspension is only going to put more stress into the chassis, so in theory you've made it worse and should defo get the chassis legs braced.

ye thats what I'm saying i thougth it would make it worse just want 2 no if people think its an absolute must or weather bracing the chassis is going a little over the top. well thats 1 saying its a must

n e 1 else?

thanks 4 you are reply.

Edited 29 February, 200818 yr by mrgt

+ were exactly is the right place to put all these strengthening bars??

+ how many polo's on here are lowered?? a fair few so is it really that common??

Edited 29 February, 200818 yr by mrgt

mines lowered seems to be ok...never heard of people strenthening the chassis

mines lowered seems to be ok...never heard of people strenthening the chassis

yeh I've never heard of it either........not saying it shouldnt be dun just want people's opinions thanks 4 the reply m8

iv hit afew pot holes also apart from shit me up when I'm driving to college at the crack of dawn there is no damage

ye sme here 1 pot hole especially its very deep and wide I've hit it twice and it shits me up everytime but no damge or n e thing as far as i can tell

Anyone got a rough how to on this? I wanna do it on the G40

Anyone got a rough how to on this? I wanna do it on the G40

yeh like jake said n e 1?? + is it really needed??

Edited 29 February, 200818 yr by mrgt

if i had a g40 i would do it but... just not worth it with a 75bhp car lol

if i had a g40 i would do it but... just not worth it with a 75bhp car lol

It has nothing to do with the engine...it's a chassis issue.

This is probably in the wrong section too.

it's very much an engine issue. you have just as much torque as is trying to turn the wheels as is trying to turn the engine itself in the opposite direction (newtons 3rd law, fairly fundamental to physics), most of this force is onto the top gearbox mount and the bottom gearbox mount. If you look at the top gearbox mount it's just thin steel with a few spot welds holding to the chassis leg, so it's pretty important to beef those welds up. Then the next weak point is the area where the chassis leg meets the bulk head, how is best to sort that out is up for debate really short of spaceframing. A subframe should help as at least it spreads the load slightly. But stitch welding helps too.

Also, moved to more appropriate section.

What I was trying to say was regardless of whether you have a G40 or not chassis leg cracking could still present its self as an issue if you are running stiff suspension and other uprated components. Of course like you say it's a much bigger issue in a G40.

LregG seems to recommend welding in some tubular steel up front, he put some pics up in my build thread. yet to have a look at the car there.

Summat like this would be good

hmm, thats interesting. kinda similar to what yoof is trying to achieve with the piece of bar welded into his. When I put my rebuilt engine into my G I intend on doing something like that. Although I could do those on the outside, yoofs bracing (which is what I had planned) is on the inside of the engine bay, might do the outside ones like that and then inside when I've got the engine out next.

Benefit of the outer type is that you can pretty much hide the patch under loads of re-applied underbody seal.

it is an issue, my g destroyed the front gearbox mount, was just dangling on by a thin strip.

i did give it shit tho. hahaa

yeah but the same can happen on a 1L with the front gearbox mount. its not just higher powered cars that have issues

the stress cracks/breaks are due to the positioning of the gearbox mounts.

the gearbox movement under acceleration causes fatigue due to "working" the metal in the joint.

overcome in many ways really either weld up the joint, or add a gusset.

most simple of all which doesnt require removing gearboxs/engines is to make a front engine mount to stop the amount of movement under acceleration.

Youngprodigys

P.S. should really apply to G40's really as the load under acceleration is higher.

I braced my Mk1 Chassis legs on the inside- the only really effective place in my opinion. Nick, the plate on the back of the leg will do little to stop it actually coming apart- nor will bracing infront of the gearbox mount between the gap in the chassis leg, the forces are acting rearwards from that.

Stich Welding of Mk1 Chassis Leg- not done this on my mk3 as it's a road car, mk1 is intended for hard track use (plus andy might drive it )

If you're running really stupid spring rates then it's worth stich welding the rear up too, mine started to split slightly on the mk3 after running silly cup car springs, so have done this to the mk1:

Below you can see the stich welding on my mk3 (just the gearbox mount only)

And the rear leg brace:

Usually passenger side leg splits, which is no surprise when you actually look at the differances:

And the Mk1 bracing- more industrial than the mk3, but will have more power and harder suspension set-up:

And if you don't believe me here's how the professionals do it

Hope this helps,

Pete

Cheers for that Yoof, I was just hunting through your mk1 blog to find it