Author Topic: hmph can't get more than 10psi (Read 2834 times)

sethyboy85 · « **on:** May 21, 2005, 06:09:34 pm »

diverter valve blocked off and turned up so it doesn't release till higher psi, el-ghetto bleeder put on metal line running from compressor nipple to wastegate and no change in boost pressure....

84 1.6l TD

sethyboy85 · « **Reply #1 on:** May 21, 2005, 06:10:10 pm »

compressor blades are good and the turbo is also tight, to rule out that senario.

Patrick · « **Reply #2 on:** May 21, 2005, 07:21:06 pm »

Takes heat to make boost, takes fuel to make heat. Got a pyrometer?

sethyboy85 · « **Reply #3 on:** May 22, 2005, 05:35:06 pm »

im blowing alittle black smoke before boost and during boost
no pyrometer, $$ doesn't justify it. if my other cars don't have egt gauges the jetta will definately be the last to get one.. unless I could find a pyrometer for $60, otherwise I will just look at the smoke coming out the exhaust. :lol:

Patrick · « **Reply #4 on:** May 22, 2005, 05:50:37 pm »

I'd say there's a problem with the wastegate if you're blowing black under boost and still not getting good boost. If you had no wastegate at all, with moderate fueling the exhaust would be clear if the turbo put enough air in the cylinders for complete combustion

jtanguay · « **Reply #5 on:** May 22, 2005, 06:02:20 pm »

is your el ghetto bleeder working properly? any shaft play in the turbo? I'd say block the boost hose going to the wastegate and see if that gives you extra boost (but don't run it like this for too long.. obviously)

sethyboy85 · « **Reply #6 on:** May 22, 2005, 08:56:46 pm »

Quote from: "Patrick"

I'd say there's a problem with the wastegate if you're blowing black under boost and still not getting good boost. If you had no wastegate at all, with moderate fueling the exhaust would be clear if the turbo put enough air in the cylinders for complete combustion

oh, I have turned the fuel up alittle over factory.

No turbo shaft play, as I stated in 2nd post it is a good tight turbo and mind you have experiece with turbo's... possibly I have a leak somewhere, time to get the soapy water out and rev the motor up and see if we got bubbles!

dieselweasel · « **Reply #7 on:** May 23, 2005, 02:39:11 pm »

Maybe the wastegate's stuck open a bit. You should also check your injection timing, as overly advanced timing causes low boost. Check for leaks as well like you said. If you have an ATAAC, you should pressure test it.

The tiny little turbos on our cars won't make much boost anyway. The turbos on these engines weren't really designed to increase hp very much...more to provide more air for better combustion and lower emissions. I checked the boost pressure on my engine and it doesn't go over 10 lbs. Haven't checked, but I think it's highly likely that my wastegate is seized shut. Many engines have turbos with no wastegates at all. What I'm getting at is I don't think you're going to make much more than 10 lbs with the stock turbo.

sethyboy85 · « **Reply #8 on:** May 23, 2005, 06:04:59 pm »

well, I have an 84 which to my knowledge is larger than most of the turbo's as it does have some lag till about halfway through the gear's (although I could be wrong about this)

I have about the same spec turbo on my daytona and if I wanted too, that turbo will make 30psi with the wastegate line unplugged, so I see no reason I should not get the 12-15psi that I am looking for on the diesel... of course I am intercooling it and adding water injection but the water injection is more for MPG than power.