kittypancake
Well-Known Member
What are the pluses and minuses of each system?
Can you explain 1.8:1 pressure ratio for me?
Gale Banks did it for years. My buddy has a 440 out of an old motorhome with his setup on it. Due to the size of the turbo it is very limited on power. You would have to cut a hole in your hood too.
That was done for a reason. We did 440 motorhome systems as well. The single turbo setup was sized for about 7psi, which kept the 440 alive. We could have made more power, but in a vehicle like that you can hold the pedal on the floor for long periods of time. Even a 440 has it's limits.
That 440 with no intercooler & stock pistons / smog cam from 1978 would make 500 horsepower @ 7psi. Push a stock 440 to 500 hp on the road for half an hour and it sort of heats the oil up. The 727 is not real happy about it either. We would beat on them that hard on the Baker grade - 32 foot coach with 24 feet of trailer behind it.
B.
Pretty impressive for such a small turbo and a draw through setup.
Which setup does your friend have? Which turbocharger, Garrett TO4B or Rajay E series?
B.
He has the Rayjay setup. His also has the piece under the carb that bolts directly to the top of the intake. If I remember correctly the turbo mounts to the top of the passenger side exhaust manifold and a crossover from the driverside manny comes under the engine into the bottom of the passenger side manny. That was a mouth full lol.
So this setup produced those kind of numbers?
So he has the split box with the angled floor under the butterflies? Vacuum to the compressor inlet out the front, compressor discharge in the back under the secondary butterflies & into the intake?
That part was ok on a smallblock. It was very close to the secondary butterflies on a spread bore carb at WOT, so it was a bit restrictive.
Add a 1" spacer under the carb, and make sure you have a big carb. An 800 cfm TQ or a QJet from a big block.
You can probably get to 460+ hp with that wafer adapter. they were only about 2 inches high. Adding a spacer will help, along with a big carb. The good news is that one kept the stock linkage & cables.
We used a boxy manifold with a 3" nipple to couple the carb right to the end of the compressor inlet with a hose. That flows better, but means using a new throttle cable & kickdown cable.
That exhaust manifold was an off the shelf piece, we all used that part. The crossover under the pan can be wrapped for a little gain, but they burn out quicker when you do that. The shop motorhome had one made from stainless schedule 40 pipe & wrapped. I never had big enough balls to put a thermocouple under the wrap.
Do not run ported spark with that setup. You need to run manifold to the vac on the distributor. We usually set timing with the line disconnected at factory (smogger) numbers. Gave it plenty of advance at idle & dumped it all before boost came in.
What is the 440 in now?
B.
Thats the one! It is on a engine stand now.
When you get a chance, write down the numbers on the turbo tag. Should be riveted down on the side of the compressor discharge nipple.
It should have a couple of lines, the top line will have both numbers an letters like :
3 A1 EE _ _ _ B1
There may be dashes for blank spaces, or info in those underscored lines above.
The second line will be a number, usually six digits with a dash & two more digits like this:
600586-62
That will tell me a little more about the compressor.
I would be a liar if I said that 500 hp number was easy for that turbocharger. It took a special trim on the compressor wheel, and was basically all that unit had. It was out in the 55% part of the island near the choke line to get the job done. Back then we just did not have the turbocharger selection that is available today.
A lot of Gale's motorhome units were 4psi setups. The ran in Vail, CO like a stocker did at the beach. A huge improvement to be sure.
B
Yes, I was going to get a new 1/2" sending unit for the tank...run an electric pump with a regulator....tee off from the oil pressure gauge tap and run a braided line over to the top of the turbo. Big line out the bottom and run it to a block off plate where the old fuel pump was.Wow. Have not seen that exhaust manifold in about 30 years. That is almost a unicorn. Nice find.
Rotomaster still sells service parts for that turbocharger. As long as the wheels are not damaged, it can simply be rebuilt. Not really difficult - some carbs are harder to rebuild. Here is the kit:
http://www.rotomaster.us/index.php?p=products_details&product_id=308&cid=3#
That intake adaptor should be fine on a dual plane intake. Can you post a picture of the bottom side of it?
The exhaust dump can be as small as 2.5 inches if it needs to be. You will probably need to make some room for that manifold on the passenger side of the early A body. I look under the hood of my '65 Barracuda and know I will have a hard time getting the exhaust upgraded. Can probably hammer a little clearance for that manifold, and sneak a 2.5 inch pipe out past the torsion.
Can you post a pic of the actuator on the exhaust?
The turbocharger needs a good oil drain. I recommend removing the mechanical fuel pump, and using that port to return the oil. Make sure the return line has at least 1/2" inside diameter all the way from the turbo to the block. Install an electric fuel pump at the tank.
What carb do you plan to use?
B.
No problem running that draw through. I can support 1800 cfm easily enough, more if necessary.
Pretty common on things like an 8-71. In fact I have never seen a roots blower set up as anything but a draw through.
B.