firewall trans tunnel modifying. How much is too much?

[Evocom]

After getting the gearbox out of my SR powered KE with the motor in place and not being successful in being able to get it back in I'm thinking of further modifying my firewall. It has already been cut and boxed in a bit but the issue is that the engine has to be jacked at the front to allow the starter motor bit on the bell housing to clear the body when you pull it off. The engine doesn't seem to want to give me the appropriate angle now i want to put the box back on due to there being no weight on the back to pull it down.

Ive decided to pull the engine out now and put them back in together but i'm thinking of re-doing the firewall/tunnel hole as it needs to be slightly wider on the drivers side and a couple of inches deeper.

My query is; If i was to cut the boxed section out and make it larger but also removable will this weaken the structural integrity of the car. Bearing in mind that it has a 6 point welded in cage that is stitched to the pillars etc.
and
If it is removable will CAMS have any issues if i have to get it scrutineered for a drinft event.
Roadworthiness is not a issue as its a track only car.

this is the current state of play thanks to the previous owner.

[slide86]

i would have thought it would have been much easier to get the box in and out if the cut out firewall section had been modified to the similar shape as the bellhousing.......would have been nice if the original fitter had thought of that.

ie instead of just going at a 90 degree join, have the firewall/floorpan contoured to a similar factory shape with sheet metal.

how will you make it removable? bolt in and out affair?

[FAST EDDIE]

for a drift event they wont say shit about firewall mods but,,,,, drift australia had this big thing before they sold out about not having any firewall mods which never eventuated.

structualy try it and see, as that has been severly changed from origional and had some track days you would be seeing any effects already if any so go for it. Only issue i have come across is in my 86 the tunnel iscracking either side of the gear shifter and that only has slight tunnel mods.

[Evocom]

It was done ok originally but it just needs a tiny bit more taken out and it would work so much easier. It only really snags in the one spot. It doesn't help that i'm doing it without a hoist so i have very little room underneath to get it to work for me. Also i dont think it would have ever come out on its own if it hadn't been modded like it has.

I am thinking about cutting the bit out that is there and where the edge of the cut is weld some folded up tabs that go all the way round and make the cover so it slips over the top or something along those lines with nuts welded to the gbox side of the tabs so it can be bolted on from the inside and removed for easier access to the rear of the engine etc.

If anyone has seen anything along these lines done i'd love to hear it.

[--Redwork--]

Look at MOST of the higher end drag race guys. They have a removable tunnel thats only made of ally and is held in buy zeus clips..

I'd be making sure your cage runs a good brace from either side of the car behind the dash befor i went removing the hole tunnel though....

[Evocom]

Im not thinking of taking out the whole tunnel just a little more than is already gone. Am thinking of using 3mm maybe 4mm sheet steel. i've seen the clipped in setup but i was thinking if it was bolted it should have more structural integrity. The drag cars cages are a lot more comprehensive so i doubt they are worried about strenght.

[driftke70]

no such thing as too much

[FAST EDDIE]

ive taken my gbox out without the engine, undo engine xmember lift body up off the engine??? maybe try that first, you dont have to disconnect fark all

[Evocom]

I have thought about trying that but was worried about my alignment settings and i have to do a front main seal anyway so i figured it may as well come out. Did you totally undo the crossmember or just loosen the bolts a centimeter or so. I have a mate coming round to help pull the engine out this arvo but i might try that first. Anyone know if i just have to pull the harmonic balancer off to get the front main out? or does the timing cover have to come off and is it easier done out of the car?

[FAST EDDIE]

wont change alignment settings at all, ud probobly get away with just loosening them, the timing cover fits inbetween the alloy sump section and seals on the headgasket so hopefuly you dont have to take it off just screwdriver the bastard out