Wastegate Questions
 

I did some reading on the wastegate plugging stuff and it sounded like somethin i'd try. Went out to the truck, plugged it and man i tell you what she'll really spool up! But i noticed something... It worked pretty well till about 2400 rpms and it felt like it was trying too hard to swallow all the air i was forcing into it. Needless to say, i didn't want to blow a head gasket or anything, so i unplugged the gate and runnin it as is now. Anyone else have this issue? I think i'll get a boost elbow and see how she works.

Well anything over about 37psi is just heat expansion and got good air to feed power, so it sounds like you are just over spooling the turbo.

Thanks. that was my thoughts too. So if i stay within the 30-35 psi range, she'll be able to handle it?

All day long! just watch the EGT's.

Don't plug the wastegate unless you have a boost guage.

jh

Yeah....

Not to mention it was probably your drive pressure going very high that probably limited you at 2400 RPM.

Not only was the turbo over reving a whole bunch, but the extra drive pressure was likely putting some extra stretch on the head bolts as value added bonus. Sweetness! :cool:

Jim

What do you mean by drive pressure ? I don't mean to hijack this thread but i have the wastegate turnbuckled on my hy35, just curious if that will cause me to blow my head gasket one day ?

Drive pressure (or Turbine Inlet Pressure) is the pressure in the exhaust manifold driving the turbine. A 1:1 ratio of boost pressure and drive pressure is a good thing to shoot for, sometimes you can get even better.

Another note. Without a boost "fooler" on the MAP sensor the engine was de-fueling after you plugged the gate to maintain lower boost pressure. Your sig doesn't show any electronic upgrades..

One more semi-related question, When the wastgate is NOT turnbuckled on my truck you can hear the wastegate blow off the excess pressure when i let off the gas suddenly but where does all the excess pressure go when its turnbuckled shut?

I know a lot of guys with autos on here have the wastegate turnbuckled so i'm curious of the negative effects?

I agree with Lil Dog. My 01 has a manual valve on the wastegate and at about 25 -27 lbs of boost it starts to defuel. It just feels flat if you stay into it. I`m planning on puttin on an Edge drag comp soon. That should cure that problem.

Thanks for all the replys guys. Helped me out!

Since you don't list a box or injectors, you are most likely NOT over revving your turbo. You will get a code in the computer though for over boosting, and your computer will cut back on the fuel due to the over boosting. This may be what you are experiencing.

I only have a little HY35 and a VanAaken box and she'll just break 30psi of boost turnbuckled shut. Between that and swiss cheesing the air box same day, she does start to sound a little wicked near 30psi[guitar]

Cool. Yeah i don't have a box or injectors and yes it did give quite a whistle! What about these Boost Foolers i've been hearing about? Where do i get my hands on one and what does it do? Any bad side effects?? Thanks

The wastegate is built in to the turbine housing (internal wastegate) and bypasses the higher pressure, higher temperature exhaust gases around the turbine wheel and straight into the exhaust to deliver less energy to the turbine wheel, shaft, and compressor wheel. Thus, it controls turbine speed and boost.

A blow-off valve is commonly used in turbo gassers to relieve pressure spikes after the compressor when the throttle slams shut. It prevents compressor surge (or stall, not sure what the difference is), also known as "bark".

In these trucks, you're probably just hearing the turbo barking or air traveling backwards through the compressor and out the air filter. Either way, it's hard on the shaft and not recommended.