Chassis Strengthening RA28?

[jeffro ra28]

Hi there.

Today i decided to start strengthening the chassis on the ra28.
I dont really know if what i have done so far is right or not but i didnt really care at the time i just wanted to get out the tools and welder and have a play!

The car will take a 1jz in the near future and i want the car to be cabaple of copping anything a 1jz can deliver it. The sky will be the limit with horespower etc. I want to build the car for drag/drift/street/track, basically giving everything a go.
Other planned mods are rn25 hilux diff (already have one), coilovers, roll cage, rack and pinion steering and all the other regulars.


So far i have done.......and plan to do another half way down the front chassis rail.






This is what i plan to do......




Or another perspective




Or should i just seem weld this mount around the edges to reinforce it?.........






My first questions are.

1: Is their anything wrong with the mods i have done so far? other then weld qaulity

2: Is the need there for reinforcing the trailing arm mounts as pictured?

3: Has anyone got any tips or photos of their own work on their chassis?

Kindest Regards
Jeff

[barned01]

I won't dob MWP in as he is probably staying quiet

[MWP]

Heh.

Yeah, i did something similar with my RA28... though i have no idea how much of a difference itll actually make. My engineer seemed to like my plans though.
In my mind, any extra strength is a good thing.

Photos of what i did:

Joined front & rear rails.


Fully stitch welded chassis.


Added extra bracing.

[jeffro ra28]

Indeed looks similar
Can anyone comment on the diff linkage strength etc with hard launches on slicks etc? anyone had any problems with mounts cracking?????

[TurboRA28]

I like the idea of joining the chassie rails together.. Must do this on mine soon.

You've done well with your welding I reckon.. How do you weld so neat upside down? I can do some nice welds but not upside down, I find it pools badly and looks like p00.

[jeffro ra28]

ehhh. im sorta self tought, but thanks! The trick is to avoid running a bead and just do numerous long spot type welds beside each other. Also helps prevent from burning through the thin sheet metal as it keeps the weld pool to a minimum and heat down aswell.

Sorta like what you can see in the top of the second photo.

As you can see i welded some 3mm thick 30x30 RHS to the inside of the sill panel. This was an attempt to reduce any twisting affects and to give the joining rails from the chassis a larger area to share any stress loads. The 30x30 rhs length extends right back as seen in the 3rd photo down. I think the sill panels cop a fair bit of stress as they are basically the only thing that join the front and rear chassis together.

[barned01]

hey MWP
when you joined the front and rear rails together, what was your process. did you actually cut the pan so that you could see the end of the front rail and the start of the rear rail and then welded the rhs to those ends.
or did you weld the rhs into the general spot where the front and rear rails end and start but not cut the pan in any way?

[jeffro ra28]

Barned, on the underside, the chassis ends flare out to come to a flange. So whether or not you cut out the floor pan to expose the chassis rails themselves it wouldntnt really matter as you have 10mm leway either side to position your RHS due to the flanged ends.
Just a thought thats all

[MWP]

Barned, on the underside, the chassis ends flare out to come to a flange. So whether or not you cut out the floor pan to expose the chassis rails themselves it wouldntnt really matter as you have 10mm leway either side to position your RHS due to the flanged ends.

Yup, this was my thought too.
So no, i just welded above and spot welded the factory rails around the area below.

[LeeRoy]

You would probably be able to see the spot welds from the inside anyways and then just work from there. Not to mention the swaging in the floor stops so you could just center it from there.

[MWP]

Yup, thats exactly how i did it.

[30psi 4agte]

A good gearbox x member can make a big difference esp when it is tied from chassis rail to rail and through the floor. ( it has in my car )

I welded 3mm plates to the floor on the inside of the cabin to give it some thickness /strength where the bolts bolt up through.



Cuzzo also has a similar x member on his car too..... worth a look in his rides thread for more ideas if ya havent seen it.

As for the rear trailing arm mounts ....... id first stitch weld them and then make up some wedges to reinforce the mount and give it some more surface area...
Like this ...

http://img385.imageshack.us/img385/9...rmmountrq4.jpg

[30psi 4agte]

double post

[MWP]

As for the rear trailing arm mounts ....... id first stitch weld them and then make up some wedges to reinforce the mount and give it some more surface area...
Like this ...

http://img385.imageshack.us/img385/9...rmmountrq4.jpg

I dont think that will help much...
If the mount is flexing, the floor pan close to it will be flexing with it too.

Jeff's idea would remove that problem and would probably be quicker to fab up.

[jeffro ra28]

thanks for the input 30psi. I do think that would be very time consuming aswell tho and as MWP said, wont offer a great deal extra support as it is just ajoining to the thin sheet metal floor pan. I like your GB cross memeber tho!