7875 + 5.9 + E85 + Megasquirt
- Thread starter subcom
- Start date
-
Tried to do mock up today with the new turbo. AR housing is too big and hits inner fender. Surgery required. Either on the sheet metal or redo a chunk of the hot side. I’m gonna drink and think on it.
Yes, the turbo housing hits. 4” downpipe on this new one. Gonna be fun! Yes, hot side is “divided” to the flange but was less important on the previous turbo because it was an open T4. The new one is a divided T4 and I’d like to keep it fully divided.
Butchery started. It’s never a simple bolt in replacement is it? Gonna have to do something with my coils and I need to clock the turbo a little more to get the 4” downpipe to run more parallel with the valve cover.
Turbosmblk
Well-Known Member
I have my coils mounted to the “belly” of the block on each side where the truck motor mounts would bolt on. Works great for me and gives plenty of room for the downpipe at the valve cover. Only thing is now it’s a pain to pull the valve cover without unbolting the downpipe.
Any issues with heat down there? Mine are mounted in the same spot and I’m about to install a heat shield between them and the manifolds. The coils start to misfire on longer drives.
I’ve thought about that but I have the block hugger header and the hot side pipe that travels in that same area.
I can’t say I recommend it. I did it for looks alone, and they’ve been a pain. I’ll likely end up mounting them on the valve covers like yours.
My downpipe is much further over, and allows acceptable access to the plugs. Having it that far over was also helpful for downpipe routing. A couple pie cuts could get yours a little further from the valve cover.
Fyi, the turbine housing on your new turbo is the same footprint as the bigger Vs racing turbos in case you might ever upgrade. So a S480 80/88 t4 1.25 will bolt up to your new up and down pipe. The compressor housing is a bit bigger though so you could clearance for that now as well to future proof. It seems like the 5.3ls guys are spooling those almost as fast as a 78/75 as long as they utilize the twin scroll.
Here’s a pic of the gen 3 78/75 compressor housing I’m running vs the housing you have now. It’s also the same size as a s480 so you can see the size difference.
Fyi, the turbine housing on your new turbo is the same footprint as the bigger Vs racing turbos in case you might ever upgrade. So a S480 80/88 t4 1.25 will bolt up to your new up and down pipe. The compressor housing is a bit bigger though so you could clearance for that now as well to future proof. It seems like the 5.3ls guys are spooling those almost as fast as a 78/75 as long as they utilize the twin scroll.
Here’s a pic of the gen 3 78/75 compressor housing I’m running vs the housing you have now. It’s also the same size as a s480 so you can see the size difference.
Last edited:
That’s the idea. I have the room since I went to coilover suspension and got rid of the torsion bars. Probably not 4” to the back bumper. Just something like header length for now to the torsion bar crossmember.
That cover is nice. They want $200 for it though. What’s the gain using it?
Awesome!! I forgot you went to coilovers. Even more excited to see your back pressure numbers now!
He told me it was worth a little more power, but I honestly only upgraded for the sound. The gen 2.5 was inaudible on my car, and I do love turbo noises
They also make a t51r cover, but it robs some power.
Turbosmblk
Well-Known Member
So far no. And I’ve driven roughly 2hrs non stop with stop and go traffic.
Nice. Ain't send cut send great? I have a Bambu carbon and that ***** awesome.
Got the new turbo tacked in place where I want it. Now the fun part begins connecting the foot bone to the ankle bone to the knee bone.
These Early A bodies don’t have the luxury of extra under hood space like you guys.
Matts440
Well-Known Member
Hey had to cut out part of my inner fenders lol Are you going to dump your waste gate to atmosphere now or plumb it back into the exhaust like before?These Early A bodies don’t have the luxury of extra under hood space like you guys.
I might try both just to see how back pressure responds. Got a new WG to add to the mix also. Thinking about controlling boost with dome pressure at some point in the future.
Matts440
Well-Known Member
45mm? Wow going CO2 pressure for boost control nice
50mm. Yeah I like the idea of being able to control boost from the lightest spring pressure to infinity.
Made progress in finishing the hot side. Mocking up the downpipe now. I think I’m going to have to bend it a bit with pie cuts to move it away from the plug wires.
-
