Superman09

iTrader: (65)

Wondering what ideal pipe sizings would be for the following set-up.... Looking to:

1.) Run manifolds/headers into a single 3" or 3.5" pipe. This will run back over the axel and branch out into (2) 2" or 2.5" pipes running to the hot side of each turbo. Which sizes would you use and roughly how much power would each good suitable for?

2.) Charge piping.... Run 1.75", 2" or 2.25" piping from each turbo into a single 2.5", 2.75" or 3" pipe running over the axel and back up to the engine bay. Which sizes would you use and roughly how much power would it be suitable for?

OBVIOUSLY space IS an issue, so I would like to use the smallest diameter piping on each piece without getting stupid. Would like something that is suitable of making some power.... for kicks we will say 750 rwhp the piping needs to be suitable for. Thanks!


-Jon

Superman09

iTrader: (65)

bump for some help!

98Z28CobraKiller

iTrader: (17)

I'd say that all you need is 2.5" turbo to IC and IC to TB with a step at or near the TB to whatever size TB you are running. Hot side should be no bigger than 2.5" (merging into a single 3.5" at most if single turbo). DP as large as possible.

Superman09

iTrader: (65)

It will be twins.... a single pipe branching into 2 hot pipes (1 for each turbo obviously) after the axel. So you think 2 2.5" pipes per turbo (hot side) merging into a single 3.5" would be sufficient? What about 2 2.5" pipes merging into a single 3" not enough? Thanks!

cjmatt

iTrader: (4)

why not 1 turbo?

Superman09

iTrader: (65)

Well I put my college calculus to work and did some basic geometry

If I need 2.5" hot side pipes per turbo, then each hot side pipe will have an area of 19.63 in^2
So 2 of those are 39.27 in^2

So to keep it similar area, I will need a single 3.5" pipe as that would be 38.48 in^2, very similar.

So a single 3.5" pipe over the axel branching off into 2 2.5" pipes for each turbo hot side sounds like the ticket.


Cold side....

I could run 2 1.75" coming off each turbo flowing seeing 9.62 in^2 each so 2 would be 19.24 in^2. This would need a single 2.5" pipe as that is 19.63 in^2, Very similar.

If I wanted to bump it up to each side using 2" cold side pipes. each side would have 12.57 in^2 totaling 25.13 in^2, which would be equivalent to a single 2.75" pipe being slightly smaller at 23.76 in^2 or a single 3" being slightly larger at 28.27"


What do you guys suggest on the cold side piping. Will 2 1.75" piping merging into a single 2.5" pipe be enough or should I really think about 2 2" pipes merging into a single 3" pipe?

Downpipes will be 3" off each turbo.

cjmatt

iTrader: (4)

you only need a 3" exhaust pipe because you forgot to use you college thermodynamics...alot of the heat will be taken out of the exhaust by the time it goes thru the turbine, which will make it denser, allowing for a smaller sized pipe

Superman09

iTrader: (65)

so you're saying a Single 3" branching off into the 2 2.5" pipes for each turbo is sufficient?

Superman09

iTrader: (65)

I might but ironically I think fitting a large single would be more difficult than 2 smaller twins, only reason

98Z28CobraKiller

iTrader: (17)

Ok, if you have 2 turbos, each turbo should get 1 2.5" hot pipe to it's T flange. You don't merge hot pipes on twins. That defeats the entire ease of packaging advantage of twins.

Superman09

iTrader: (65)

hmmm, I think we might be on a different page, but maybe I'm wrong.

What would happen would be.... headers would Y into a single 3" pipe. This single 3" pipe would run out to the back of the car and over the axel. After it goes over the axel, it would Y out into 2 2.5" pipes, each going to a turbo.

98Z28CobraKiller

iTrader: (17)

Ok, so we are talking rearmount. First, I wouldn't do a rearmount. Lots of headaches ahead for you. If I were to be forced to do it, and I had to merge the pipes, then I would think that you would want it to step down towards the turbos. You don't want 2 2.5" pipes chocking down to 3" and then opening back up to2 2.5" pipes. That would hurt velocity. I'm not getting out the calculator but something like 2 2,5" into a single 3.5" and then into 2 2.25's and then into the turbo's t flange. You will end up with a major plumbing clusterfuck going down this road though, IMO.

BlwnLs1GTO

iTrader: (12)

A single TC78 might be the ticket if space is an issue. It's real compact and capable of your goals. I'd imagine you'd get more out of 1 turbo vs. branching off into twins anyways. You'll save a few bucks too.
Good luck either way. Sorry I don't have the input you're looking for .

Superman09

iTrader: (65)

It is going on a Corvette. I have space on each side where mufflers mount..... Easier to fit 2 smaller twins because of this. I might be able to fit a mildly sized single on one side....