I like your heat shield on the HVAC box, just might borrow that same idea. What sort of support do you have on the two primaries? Is it just supported via the piping and tied together with the speed sign bracket?
I've found the same short comings of the VE as well. Especially compared to driving my common rail Cummins. Seems a VE will pull hard up to 2,800 and then turn off, allowing your forehead to bonk the steering wheel if not careful. The low end torque is hard to beat for daily work.
Also, when you narrowed the rear axle, did you remove the axle tubes? I see they are seal welded to the differential.
Yup, the HVAC box was a hoot.
As found, the blower motor was dead-against the 3" hotpipe coming off the upper primary. So . . .
- I moved the blower motor a little deeper in its mounting flange, that gave me almost a half inch.
- I raided the kitchen (again) and got a little stainless bowl and dimpled its floor . . .
- A small section of 26ga sheet metal completes it. There's right at 1/4" space between the heat-shield and the HVAC box stuff .. .
The primaries are tied together by a 10ga(ish) aluminum alloy bracket . . . .
Using that same metal, I made a second bracket that attaches to the block side of the lower primary . . .
At the block, that lower primary bracket attaches to the oil-cooler cover-plate. I included a notch in the plate so as to afford access to the oil pressure regulator . . .
While not intended as a sho'nuf anchor-point, the cold pipe Wye-pipe ties the faces of the two primaries, with the face of the secondary. Certainly, it helps steady things.
The exhaust down-pipe ties the rears of the primaries together. The downpipe is secured at the transmission bellhousing (as per stock/OEM).
I figure the general triangular shape of the turbo assembly, coupled with the methods/materials used to tie it all together, allow a little wiggle room for thermal expansion/contraction, etc.
Yup, my torque is rolling off well before 2500 IIRC. That being said, it's had over 400hp to the ground after 4000. :evil
The axle was actually narrowed about 2.5" per side. This was to ensure the same footprint as the original axle. Had to move the spring perches inward about 5/16". The narrowing involved simply cutting out a plug of the axle tubes close to the brake flange. (I farmed out the axle housing/tube stuff so they could keep the heap straight).
Currently, I run some stupid simple, bolt-on ladder bars. They are good for nothing but going absolutely straight. They do **** for general suspension performance other than prevent axle-wrap. That being said, I've run them for perhaps eight or so years now and, considering how i use the truck, I've never had a noticeable issue with them. But then, I don't intentionally try to diagonally traverse ditches either.
Well, with a new axle come an opportunity to improve on the anti-wrap stuff. Running heavy leaf-springs on top of a stock/OEM 8" block complicates poop though.
I had the axle tubes welded to the diff house in the event the method I used to locate the axle presented substantial twisting loads to one side or the other, of the diff housing.
At the moment, I was considering something like that used on some of the cars . . .
Dunno just yet. Bolted the ladder bars back on for now.