smokeshow

iTrader: (16)

Backpressure definitely robs power. I dyno tuned my truck last year and didn't know my quick spool valve was stuck closed, so it was only running through one scroll of the 1.10AR T6 housing. Started off making 595hp/615tq when I started at 10psi, and eventually tuned up to 16psi getting only another 30hp, but an additional 280tq. Kept tuning and tuning, took half a dozen pulls to figure it out lol. It did make 600hp at 3500rpms though

Atomic

iTrader: (42)

Results, finally:


RUN 1
RPM 5200 5500 5800 6000 6200
Compressor Pressure [psi] 10 10 10 10 10
Backpressure [psi] 18 18 18 20 22
Intake boost pressure [psi] 8 8 8 7.5 8

RUN 2
RPM 5200 5500 5800 6000 6200
Compressor Pressure [psi] 11 11.5 12 12 12
Backpressure [psi] 18 19 20 22 25
Intake boost pressure [psi] 9.5 8 8.5 8.5 8.5

RUN 3
RPM 5200 5500 5800 6000 6200
Compressor Pressure [psi] 0 13 13 13 14
Backpressure [psi] 0 19 22 25 27
Intake boost pressure [psi] 0 10.25 11 11 11

RUN 4
RPM 5200 5500 5800 6000 6200
Compressor Pressure [psi] 13 14 15 15 15
Backpressure [psi] 18 22 24 26 27
Intake boost pressure [psi] 12.75 13 13 13 13

RUN 5
RPM 5200 5500 5800 6000 6200
Compressor Pressure [psi] 0 16 16.5 17 17
Backpressure [psi] 0 25 27 30+ 30+
Intake boost pressure [psi] 16 15 15.5 15.5 15


Good news is my new intercooler is doing a great job: At most only a ~2-3psi loss.
Bad news is backpressure is close to or over twice compressor pressure most of the time, kind of what I figured.

My testing methodology was to video my gauges for compressor pressure and backpressure, and compare that to manifold boost pressure on my hpt log. It should be pretty close, but as with any gauge and judging it by eye there is room for slight error. I feel this is pretty accurate and useful though.


Also discovered tonight the flex coupler going to my wastegate from the crossover has a pinhole leak and makes a nasty sound.

smokeshow

iTrader: (16)

Wonder how mine is with the giant turbine... I assume you are running the sensor into one of the analog inputs on your cable?

Atomic

iTrader: (42)

...What sensor?

My testing methodology was to video my gauges for compressor pressure and backpressure, and compare that to manifold boost pressure on my hpt log. It should be pretty close, but as with any gauge and judging it by eye there is room for slight error. I feel this is pretty accurate and useful though.

Spoolin

iTrader: (8)

I think it would be neat to compare log manifold hot parts with tubular manifold hot parts.
Great info and sounds about right, being at 2:1 makes sense. Interested to see how going with a T6 will change that.

smokeshow

iTrader: (16)

Wasn't sure if you had converted it to analog and were monitoring with the scanner.

lglowe

iTrader: (3)

Looks like that turbo your running with the 81mm exducer should be a awesome size for a 6.0-370" motor I would think. You gonna step up to a t6 or a big 96mm wheel?

Spoolin

iTrader: (8)

i think he has a 402 ci motor.

lglowe

iTrader: (3)

I know. And he needs a bigger turbine than what he had now if he wants closer to a 1:1 ratio. That's why I said the one he has now should work even better with less cubes.

Spoolin

iTrader: (8)

Oh Gotcha!! Well in that case... Richard give me that turbo! I have too many people bitching at me to get a bigger turbo. Lol