So I was talking a guy who owns a shop here locally and I think that my turbo may not be what I want. I'm looking for something that will make a little less boost and he was suggesting going with a pair of BW 66's. I really like the idea but I have a couple of questions.

What could I get for my turbo? (Precision 78/75)

Could I merge the cold pipes to use my same intercooler (SI/SO 3")

Can I use one scavenge pump for both turbos?

 

Why not just change the wastegate spring? Maybe I'm misunderstanding your post, but it kinda sounds like your shop wants to convert a $10-15 fix into a $7000 fix.

A little more info on your build and what you want out of it would help with the understanding part.

 

I don't have any turbo stuff on yet. The shop is saying that this turbo I have isn't really great for my setup and I'd probably be happier running two smaller turbos.

 

Boost makes power.
Not really sure what the program is? A little more info.

 

What engine?
Mods to the engine?
How much power do you want to make?
What are you going to use the truck for?

 

Motor is a 7.4l bbc, stock rotating assembly (7.8:1) aluminum heads, HR cam swap with a T56 trans. Turbo I currently have is a 78/75 on a T4 flange. I knew it was undersized but i couldn't pass up the deal I got on it.

 

Looking for 550-650 at the wheels and truck is gonna be DD/autoX

 

Ah -- in that case, you probably want it "undersized" so you have "instant" boost at low rpms. Twins probably do a better job of getting you into boost faster than a big single, but it seems like the last thing you'd want to run is a big single since you won't be spending much time at high rpms. My advice is to figure out where you're going to spending most of your time (in terms of rpm) based on your gearing and track layouts, and go from there. You don't need twins to have good boost at lower rpms, you just need to spec the turbo properly for your needs.

In my remote mount twin kit I ran 60-1's but it had good boost at 1500 rpm

 

Truck won't turn past 5250 rpms. Racing it will be between 2750-and redline.

 

You should be fine with a single like Turbo said. I think the shop is trying to squeeze a little more money out of ya.