Seeking information to size for right turbos.
Borg Warner has program, however it is not for race only applications

I am absolutely not an expert. But what are you building? What cubic inch? RPM and HP goals? What kind of racing? Looking for top performance or more of a value build?

I will say that the Borg program is clunky, but accurate. But often it is easier to ask others what has worked well. Also, a single in some cases can be more economical and package better than twins. Sometimes not.

588 mopar, b1 pg trans dragster now runs low 7 wish to be mid 6. Run with group of 7.50 and under cars

I suspect 2 of these would be about right.

https://turbo4less.com/product...mm-billet-t6-1-32ar/

588 is pretty big.

I came close to pulling the trigger on a turbo for the 500” motor in the wife’s dragster. I was wanting to max out at about 1800 hp with a big single. I had trouble finding a setup where I could stay on the compressor map unless maybe I had the wastegate pinned shut. In the end I stuck with a blower.

This message has been edited. Last edited by: BJs Wild Ride,

Yes that is a higher HP consideration, but.....starting with what you have, you won't need a huge amount of boost pressure to achieve your goals. Just a pair that are capable of moving a good amount of air.
If you have not already, post your question on Yellowbullet in the Turbocharged section. Good amount of knowledge there in higher HP applications.
Certainly you don't want to completely oversize, because it makes them sluggish to start producing boost. Although with that size engine you may be able to leave on very little boost if you can alredy 60' nicely, and pull harder on the rest of the run.

For me a decent point of reference for boosting with turbos is that 16 psi about doubles your power output.

Considerations also:
-What compression ratio are you at now?
-Do you have boost friendly pistons, and a bottom end rated for where you will be?
-Fuel system requirements are obviously a lot different
-Intercooled or using Methanol? i prefer leaving intercoolers off drag cars. But it will require more fuel than most people including myself predict when boost starts coming on.
-How are you managing fuel and boost? Boost control can be as simple as just using the wastegate springs. But boost controllers with co2 are pretty slick and can give you some flexibility you can't have just using springs.

While you have lots of cubes . The smaller the turbo the easier and quicker it is to get to boost on line. You can run bigger and just blow off extra boost with waste gate.

Lil brother runs a turbo VR-6. He went from smaller turbo to quite a bit bigger with better parts and has not run as fast as smaller turbo on junkyard engine.

Just like about everything else, cubic inches make everything work better. Even boost.

Bucky, you think a pair of gt45s would go 6.50s on a 588? I pointed him a little bigger because I thought he might overspeed something smaller with that big motor.

I just bought my first eBay gt45 for a little street car project and I’m blown away by the apparent fit and finish for the price

To the OP, if you haven’t PMd Bucky yet, I’d recommend it. His combo is pretty badass.

Fresh motor has right stuff for doing turbos Car 60s 1.01-1.04 so low end good. Mid range to top end not so great. I am green about turbo so am so happy with input you folks have given..