76 TR6 with GM 3.6 LFX

[Kard150]

[Kard150]

[malbaby]

I see that you have done some strengthening of the mid/front chassis.
Have you considered further strengthening at the rear to minimise the flex and twist that occurs at the cruciform?

[BlownMGB-V8]

Also the differential mount points may need to be beefed up a bit.

Jim

[Kard150]

Thanks, both of those areas are what I'm working on next, right now I'm taking all the suspension off.

I'm trying to decide on the best way with the least amount of weight added.  The twisting is something I'm most concerned about
 Any suggestions besides the kits already offered?

One idea I've been kicking around is a support inside the cabin tying the frame outriggers too the pedestal


I know I might not be able to because of the seats or getting it to sit flat against the floor, but this is something i want to explore

[malbaby]

Kenny, IMHO...you will have problems with the rear chassis unless substantial strengthening is done....extra weight is unavoidable.

The flex and twist occurs at the weak sections where indicated.
I have completed various strengthening measures on my project car.
One being,,,,welded in 8mm x 65mm plates 900mm long to the insides of the middle chassis rails, centred at the cruciform area.
Your idea of welding in braces that encroaches into the cockpit is valid.
I achieved a similar outcome with chassis modifications.

[Kard150]

Malcom you mention "various strengthening measures", was this something you did all at once or an evolution of modifications?

Do you have any pictures available?

 I did reinforce the upper t shirt area at the back where it forms an "arch" by adding a strap inside.
 I've got to replace the lower T shirt which is when i will add a wider strap under and tie it together. I just dont believe that is enough.

 As for the weight i just meant i wanted to look for the best idea with the least penalty, Strength being the 1st priority but not go crazy.

 I'm open to all suggestions.

Kenny

[BlownMGB-V8]

I'd avoid encroaching on the cockpit, it will add complications, although if you do opt for a roll structure of any kind it becomes more reasonable.

Crossways round tube members of large diameter are often used to brace long frame members against twisting force. Perhaps that principle can be put to use.

Plating suspension attachment points is a sensible reinforcement method in the TR frame, at any and all relevant locations.

Jim

[malbaby]

My 4A factory chassis has an extra bridge forward of the main diff cross member.
My main intention was to fabricate a steel structure from the front of larger custom made cruciform plates to the rear diff support, linking the tops of all three bridges together.
I also welded in a pair of flat plates so as to both bolt a roll cage directly to the chassis through the body and to provide a platform for mounts for telescopic shock conversions.
Welding in plates to the insides of the centre chassis rails is the primary strengthening.
I am having problems attaching pics, as my files are probably too large.

[Kard150]

Giving some updates. Finally finished the frame mods, I plan on using a roll bar to beef up the frame.
Painted the frame and now putting it all back together.
I did add to the T shirt area to stiffen it up some. some of it might just be token support but it can't hurt.

One last mod to the body, at least I
hope it's the last.

[Kard150]

[BlownMGB-V8]

The places where we saw failures were the attachment points for the front control arms, and at the rear the differential attachment points. I've also seen the rear control arm attachment points rust away. You might want to beef those up a bit.

Jim

[Kard150]

I added the usual brackets, is there something besides this? I made pieces to box the whole thing in but didn't add them.

[BlownMGB-V8]

Looks pretty good to me but I'm no expert. The front control arm brackets were especially flimsy where they are bolted through the frame rails.

Jim

[Kard150]

Some new updated pics

[Kard150]

[mrmom9822443@gmail.com]

Glad to see you're making progress Kenny. Thanks for sharing with us. The 3.6 LFX looks like an excellent choice for swapping in a TR6. I have a TR 250 I'm thinking about doing the same swap. I was wondering if you have considered what type of ECU you will use.
Keep up the great work! Dan

[Kard150]

Thank You!
I would recommend a E39 (stock ECM) from Kiesler Automation, quick turn around and lots of parts. Thats also where i got the Exhaust down pipes from.  DO NOT order anything from Swap Specialties, I'll leave it at that.

Tracy Lewis Performance is the guy i plan on getting the car tuned by.
If you do decide to go this route let me know and I'll pass along all my mistakes so far. no reason for you to repeat them.

[mrmom9822443@gmail.com]

Thank you Kenny. Appreciate your passing that on.

[Kard150]

[Kard150]

Getting ready for the driveshaft and then exhaust

[Kard150]

[BlownMGB-V8]

Kenny, here's something else for you to check while it's exposed. Dan used solid mounts for his steering rack in his TR4A and recently had a problem with a catch in the steering. After replacing the joints in the column and a bunch of testing and swapping we finally traced it down to the tightening procedure for the rack. It seems he had taken a little extra trouble to remove any slack between the mounts and the rack body so it couldn't shift from side to side and the result somehow put the rack in a light bind and caused it to get tight at one spot. When we loosened the mounts up it went away. Then we found a tightening sequence that didn't make it tighten up. I think it was caused by prying the solid mounts against the rack flanges but that's something that should be easier to check now than later. We did the final tightening without any sideways prying and that worked fine. I think the clamps are enough to keep the rack from shifting sideways, which of course the OEM rubber mounts allowed to some degree.

Jim

[Kard150]

Thanks Jim, i know there is a little plastic button that as i understand is something to be careful with. I'll have to put the steering together enough to see.

[TR6-6SPD]

I'm using a quick rack with solid mounts on my TR6. It's very sensitive in regards to it's positioning. I use washers to space it and take it easy on torqueing, otherwise it will bind.
The rack itself us to be set up properly too.
It's a pain.