found a crack in my chassis what are my options ??

[dub-disaster]

Hi,
    Just wanted to ask about welding the chassis up for more strength , baisicaly I've got my lump out n the bay needs paint here and there anyway so gonna repain both cassis legs and area around them. Whilst I'm at it I've got a mobile welder coming tommorw to take a look at strengthening the cassis for me as I know it's week.
   Ive looked at yoofs thread on this and it is very helpful I'll definantly having a bit of bar welded above the driveshaft area, but what else is nessecary on a road car to have stich welded wanna get it all done now but I don't wanna be going over the top as my car will see fast road an occasinal track/drag days. Do the chassis legs need stitch welding and the turrets need stitch welding aswell?? Just want this done for peace of kind realy .
    

[Puncharado]

This one?

http://www.polog40.co.uk/forum/index.php/topic,7.html

Seems pretty comprehensive info to me!

Also look at this one

http://www.polog40.co.uk/forum/index.php/topic,138.0.html

[dub-disaster]

Yea ok didn't see that second one some pretty brutal cracks there, hopfully i won't see any like that on mine once I've had this done

[hayesey]

mine is pretty much the same as yoofs, stitch weld all the chassis leg to inner wing joins, the top gearbox mount area and then add that bar between the bulkhead and chassis leg.  A subframe helps hold everything in place too.

Yoof does brutal 1/4 mile launches with LSD and MT slicks and we've both done several track days both with 200bhp and more and these mods have kept everything in tact for both of us.

[dub-disaster]

Thanks for that hayesey, when you say stich weld chassis leg to all the inner wing joints you mean like in yoofs thread like what he's done to his mk1 ?? I'm definanlty having a brace bar welded in there you two only have a brace bar on the passenger side? I suppose the stich welding stops the chassis leg from coming away from the inner wing , or does it serve another purpse aswell.I've got a stage 3 frame winging it's way to me soon hopfuly

[hayesey]

yeah stitch weld is basically - weld an inch, miss an inch, weld an inch, miss an inch etc...etc...  It strengthens yet still  allows some movement which is important to absorb stress instead of just transferring it somewhere else.

Bar on drivers side doesn't seem necessary but adding one wont do any harm.

[Yoof]

You can see the stiching here on my mk3:

[dub-disaster]

Cool thanks for that guys I'll get the chassis legs stiched on the inside and all around top gearbox mount and a brace bar both sides whilst I'm there, then throw a subframe at it and I'll be happy to throw it around a bit n be sure I ain't gonna brake anything. I've got a strut brace so I assume that the area around the top mounts doesn't need stich welding aswell ?

[hayesey]

yeah I do those too.

[dub-disaster]

For those brace bars did you guys use round bar or box and what size as I'm gna nab some from work if we've got some 

[hayesey]

I used box for mine as it's what I had knocking about in my garage, I think yoof's is round. 

[Yoof]

Just a short length of CDS 

[dub-disaster]

Thanks yoof I'll try and get some from work but if I can't get it from there where's likley to sell it, and what size should I be going for inch and a half maybe ?

[dub-disaster]

Ok got my chassis all welded up at the weekend quick question though do I need to re seal it with seam sealer or did you guys bit bother? Also the bloke who did it for me just stiched weleded the bar in that's ok isn't it or should it have been welded all the way around or does it not realy matter ? Thanks

[dub-disaster]

just about to paint my engine bay and whilst rubbing it down i found this carck in the passengerside chasis leg rite at the front what can i do ? if i get somone to put a weld in there will it not push it apart or will it pull it together ?? how can i stop this crack spreading and is it realy likley to spread it doesnt look like its in a stressed bit of the chassis although i dont know sweet fa about chassis strengths and stresses, ive got a subframe to fit and all the seams in the engine bay including the gearbox mount have now been stick welded any advise ?
    heres a few photos what do you guys rekon ??