How much backpressure was there? Did you measure it? Just curious. How did you measure the backpressure?

 

Did not measure it. The motor didn't sound good and didn't make the power it should have.

 

That could have been a bunch of things. You blamed it on backpressure? Honestly the backpressure on that motor should be less than a single setup on a typical 302. Think about it, you're pushing 250ci of exhaust through each T4 turbine. On a single setup like mine for example, I'm pushing 306ci of exhaust through a similar T4 turbine. There are other variables in play here too like boost pressure and a couple other things, but you get the idea.

 

We changed the turbine housings, whala.......The problem was solv-ed.

Why take the time to measure backpressure, consult an engineer and maybe pray to the lord for advice when the problem was obvious.

You weren't there, please let this thread die. Thank you.

 

Only if you lower your car about 2" :tu:

 

...and do a burnout in the parking lot.

 

REQUEST: Let's see an 8-71 blower hanging out of the hood! And maybe some trunk-mounted aerodynamic enhancements.

Mark

 

...and a 70 year old man with huge boobs!

 

I know what your thinking about

 

I'm new to the turbo world, I'm learning. If we take a v8 engine between 5.0l and 6.0l. We put him a twin gt45. We don't put wastegate, bov, or intercooler, run on e85 only. Large turbos shouldn't have positive pressure before 4000 rpm, but how high could they go up do you think at 6000rpm? It's a simple mechanical question ... Thank you.
What can happen? engine break? broken turbo?

 

Good chance of destroying the engine. Why not put the correct parts on it from the start like a wastegate and BOV

 

that's what I'm going to do, it's just to understand how it works ...

 

The wastegate gets mounted to the hotside and regulates the boost level. It has to be mounted a certain way to properly regulate boost. If the gate isn’t large enough you may not be able to set the boost as low as you need .Do a search on wastegate placement on here. As for the BOV it gets mounted on the intake pipe before the TB/carb and it opens when you close the throttle to relieve boost pressure.

 

First, they would most likely go positive before 4000rpm. Then, with no WG, they would probably go over 30psi depending on which "GT45"s you have.

 

You can use a large turbine housing to control boost but it will come on very late (especially when the header is cold) so you miss out on all the mid range that turbos are great for. That is why you need a wastegate. Alternatives are:
1. Exhaust restriction. A smaller exhaust will limit top end boost but still make early boost.
2. Intake restriction - same.
3. Controlled intake restriction. Add another butterfly between the compressor and the engine and control it with a diaphragm - same as a wastegate. (But opposite - wide open normally and closing off to limit boost)