Cab Mount Chop - Food for thought?

I dont drive 80mph lol. And I dont know anyone personally that does. But, even if I did I wouldnt get flaps.

 

It is perfectly fine and a positive thing to discuss the safety ramifications of modifications made to a Toyota Tacoma on a forum that is devoted to discussing things about a Toyota Tacoma. The cruel reality is, modifications often have safety ramifications. Modifications often compromised the safety of a vehicle. Discussing the safety aspects of vehicle modification is entirely legitimate.

 

I've been a Mechanical Engineer for nearly 30 years. I have a pretty fair understanding of the mechanics involved in what you are describing. You clearly didn't read what I wrote. The CMC is the least of your worry in a crash like that and energy transfers over large surface/volumetric areas like that tire/wheel going into the wheel well will have larger ramifications if the angle of impact drives the tire/wheel inward and upwards. Not back towards that corner and you still have a firewall between you that tire/wheel.

Also, the chop itself is minimal and if done right with decent steel plate, even mild CRS (Cold Rolled Steel) of at least 3/16" of an inch with a seam weld all around will provide more than sufficient buckling/sheer stress strength to prevent the tire/wheel from entering the cab.

In all honesty, you don't really know what the problem is. Also, no PE worth their salt would ever 'sign-off' on what you presented. It's foolish and silly to even suggest it.

 

Camburg's fix the problem, give a better upper ball joint, and add 20 hp. Why cut?

 

So don’t do it then

 

I opted for JBA's myself. Can't wait to get them on along with the Fox's.

 

Plus UCA's look great. Which is why most of this stuff gets bought anyway.

 

Not an untrue statement. In my case, looks weren't the reason, but functionality since I'm going 285/70/17's, I needed the extra caster that the stocks wouldn't have given me with a 2" suspension lift. So it made sense to do. I was looking at Camburg, Total Chaos, JBA and for the price, I thought the JBA's were going to be a better offering. Looks aside the ride will be better than stock.

 

There’s tons of options with wheel and tire sizes to not have to chop it... either pick one that works without cutting if it means anything to you... or chop away and no one gives a shit. Simple.

 

Thank you!!! You have summed everything up here very nicely! Could not have said it any better myself in a million years. Bravo!

Case closed.

 

I am no engineer, nor did I stay in a Motel 8 last night. I have been a body man and welder/ fabricator professionally for years. I can appreciate the arguments both ways in this discussion and see the valid points. Without somebody actually testing this there is no true way to answer this question. I have done quite a few CMC's for Tacoma owners and , first hand , I can see where the incursion argument can play out when the end of the CM is removed. However, removing this end piece and removing material from the face of the mount should not weaken the mount if plated back with the proper materials. Whenever I do one I do not use prefabbed plates I fab my own out of 3/16 plate which is considerably thicker than stock materials. By shortening the mount and plateing with heavier materials you are actually strengthening the mount not weakening it. A "stadard" chop for 33's still retains the full length of the mount and if plated properly with heavier materials should be stronger. As a welder we seem to have a tendency to "overbuild" stuff to ensure it's strength.

Stock cab mount:


Standard chop for 33's



Mount is still full length retaining your incursion resistence and beefed up with heavier plating

Chop for 34's or 35's typically any larger and a relocate is necessary

Here the end and face have been removed I actually removed the face all the way back to the frame not seen here. This allows me to tie the 3/16 plate directly into the frame. By boxing the mount with heavier plate and decreasing it's size it "should" actually be stronger. Yes you lose the length on the end and i have no desire to debate whether this effects the incursion issue or not. I can only look at this from a practical point of view for myself. The full chop is on my own truck. I will happily put my family in it and go where I need to.




This is an interesting thread. I am neither pro nor con to this debate. I am simply trying to give a layman's point of view to this as some of it seems to be over thought. Nice topic OP

 

Thank you for taking the time for this contribution to the discussion. Very interesting.

 

Cab mount 1 / tire and wheel 0

 

Yes Sir, as I sad I am no fancy engineer but I have been doing structural and sheet metal fabrication for quite a long time. I in no way claim to know much of anything but I put alot of thought into the work I do to ensure it's strength for durabillity, and safety. Whether folks agree with me or not is their perogitive.

 

So here is a question (without looking under my truck on a rainy day to see if this is possible):

Could the back-side of the cab-Mount be buttressed/gusseted to return any (real or imagined) loss of strength in the horizontal plane?

 

Let me go outside and look real quick

 

I have a secong gen I don't suppose there is much difference in this, but, yes there is room to add a gusset or a couple of gussets on the back side of the mount. TBH with it boxed and in a triangular shape I don't think it's necessary, however, if this were to give you more peace of mind then by all means yes

 

The most thought provoking discussion I’ve seen in the past few weeks was around energy transfer. Specifically energy transferred into the cab and frame from a sturdy slider during a T-bone collision.

I really wish someone actually did testing of these mods to answer the questions.

 

Thanks for looking. That’s gives another option to consider.

 

Maybe we need all of TW to donate towards a “test mule” for all the upgrades. I guess you’d need a few of them.