ebay turbo dyno video

[455_82malibu]

Try the gap at 0.026"

How much boost?
Intercooled?
Pump Gas?

5psi, air cooled intercooler, pump gas 91, when driving on the street youd never guess the flatline, it pulls fine, 1st and 2nd gear are awesome, but on the highway when I floor it at 3000 rpm, boost picks up and its at full boost at 4500, If I take it to 5000 Im only doing 85 mph, thats why i thought it was the trans converter

 

[455_82malibu]

only other isssue Ive had is trying to get more boost, no matter how much I cranked the set screw on the wastegate down it was not making anymore boost, I finally added a 2nd spring and then cranked that sucker all the way down to hold the 5psi...so maybe I have to much backpressure and its blowing the wastgate open?

 

[Robert1320]

That was the next question. Back Pressure.
Do you have a gauge or a tap in the hot to measure pressure?
If adding one isn't too bad unless the hot side is coated?

 

[455_82malibu]

I can add one but not sure where or what to look for?
the turbo has a 3.5" vband outlet, I used 3" pipe to a 3" glasspack, i thought 3" would be enough. maybe I caused my own problems!!!

 

[Robert1320]

Pre-turbine back pressure. Add a 5" - 6" 1/8 pipe nipple and then run a length of tubing to a gauge or map sensor and read the back pressure vs boost pressure. Anything over 2 bp to 1 boost sucks. This excessive pressure can blow the wastegate open. It could be telling you your out of turbo as well.

 

[455_82malibu]

Ill try that, I have an O2 sensor bung i can use for a pressure port. I just cant believe its out of turbo or too much pressure at that low of rpm. But all this is new to me so....
If my downpipe is too small or the glasspack is restrictive would that cause the same problem.

 

[Robert1320]

It may, I would suspect the turbine first.
What turbos and hotside specs?

 

[455_82malibu]

cheap ebay gt45 clone, was using it for mock up, but it feels so good on the street I figured it was worth using...


Compressor:

Size: Inlet = 4 3/16"

Inducer = 68.7MM

Exducer = 97.8 MM

Trim = 69,A/R = 0.66

Intake (ID / OD) = 2.25" / 3.25"

Turbine:

Outlet = 4"

Turbo flange = T4

Downpipe flange = 3.5" V-band

Inducer = 87.4 MM

Exducer = 77 MM

Trim = 92

A/R = 1.05

 

[Robert1320]

Those should be fine. Drop back to a and look at the converter. It can make or break a combo.

 

[455_82malibu]

Those should be fine. Drop back to a and look at the converter. It can make or break a combo.

10-4 thanks for the help.