Wargoul............without discussion you cannot continue to shoot everyones threads down, your comments continue to be abraisive and wont be tollerated, the staff will have a private discussion with you in the back room

Sorry gents continue on

 

right on! about time that whargoul a$$ is taken care of. sick of listening to his useless .02 cent posts.

on with the build!!!

well i got to get a bit more into this thing this weekend and let me tell you... i ended up finding out much more about this than i have seen posted anywhere so far... so hope this helps yall out!!!

i will start this by recommending to all that you completely pass on the drilling and tapping of the intake plate. there is no need for this and i only did it as i was following what little outline i had from my hunt for a write up. everything on this wastegate operates much smoother when it is all plumbed into the exhaust side only... this means both metered and un-metered pressure hoses should come straight off the exhaust side as that side of the engine tends to see more pressure across the board always (and you cant have boost without exhaust pressure so 99.99% of the time, the exhaust back pressure will be higher than the boost pressure). where this all ties in and helps is here:

when you have it set up the way all others suggest with metered boost pressure coming through the regulator and into the top of the wastegate (herein referred to as WG from this point forward),you have pressure spikes and drops... so say you have the regulator set to 20psi (ease of explanation numbers- not actual), and that 20 psi helps keep that WG closed above the max set psi possible according to the springs that you have installed inside... (i installed the small and large blue springs so my base pressure where the wastegate was to open without any positive pressure is set at 26psi).

when you have your exaust brake on, it turns the vanes and builds massive amounts of back-pressure to help slow you down... but while it creates this massive back-pressure, you are getting almost zero boost pressure, so you do not have the psi coming from the boost side to maintain keeping the WG closed above 26 psi. any pressure built above 26 or so PSI while the EB is on will be bled off through the WG, which then doesnt allow it to help slow the vehicle. this posed a problem for me as i always drive with the EB on and 26psi wasnt cutting it.

so i ran both metered and unmetered pressure through the exhaust side. unmetered goes straight to the bottom threaded port on the wastegate, metered goes to the top as normal. now when you build that over 40psi when letting off the throttle, you have the ability to tune just how much pressure is bled off of the EB. i have mine to bleed off at 36psi as of now. so at 36psi of either drive pressure (ie: while smashing on the throttle to merge onto the freeways at 80 (gotta love sothern cali)). or when letting off the throttle and it builds pressure through the VGT turbo, all excess pressures are bled off allowing the engine to sit at its comfortable drive pressure point.

sorry for the book... i couldnt think of an easier and less wordy way to describe it.

here you can see the unmetered going into bottom port but top port still metered off of boost....



and here i have placed a tee off the unmetered line and ran a line metering the exhaust then back into the top of the WG



CHEERS!!!

NICK

 

this is a good job i will tell what i found with a make shift drive pressure gauge after i blew a head gasket on my 6.7. i found the boost and drive matching lb for lb at 24 the best i could guess. the exhaust brake was showing 60 lb on the drive pressure when braking hard. when towing 32 lb of boost showed around 60 lb of drive pressure. this is how i came up with safe numbers of boost while towing. i try to keep 32 or below. keep in mind this was done with a copper tubing kit and cheap gauge hanging on the mirror for about a week. it should be close. i got 75k plus on a new gasket and my mighty diesel bolts.

 

well thanks for the kind words!!! i saw spikes in drive pressures reach the high 40's and started laughing... i couldnt believe that we have such massive drive pressures, yet an asshat can make an ignorant comment such as VGT turbos dont need wastegates.... on the contrary it is remarkable that they didnt come with them from the factory in an attempt to rid the vehicle of these high pressures even in a stock form. this engine whether deleted or not sees drive pressures that far exceed "safe" for its design.

 

they are a small turbo. 1 to1 is very low. i kinda like the vgt turbo but there is no question it is pushing the head past the limits if you let it. keep up the good work. ideally you want to pop the waste gate just above the exhaust brake pressures.

 

Nice

 

completely incorrect... sorry bud but if you follow this little write up you will see that this is more for a STOCK / STOCK-ISH application. why would i go blow a few grand on a new turbo when i can spend 200 and a few hours in fabrication to build something that will relive the excessive pressure off the STOCK turbo? hmmm... makes no sense. again... yes a vgt turbo does need a wastegate as we have proven with well over 60PSI of EBP when the STOCK exhaust brake is on....

 

damn whargoul you get a new id? you sound just like him! or is that your brother?

 

Oh no that's our good friend whargoul. Only she would be so ignorant as to not understand that yes you do you use back pressure for the exhaust brake to function,however 60 psi on a head without any studs on it is no good. Some back pressure is a good thing not a ton of it dumbass. Maybe instead of jumping on a forum and trying to act like you know it all, you might actually want to go learn something first. Or even a been better idea, do it like all of us old school guys and actually pick up a darn tool and start working.

 

well i was finally able to get into my shop and customize my new toy a bit more. got rid of the entire cross bar with the cut and welded 45* angles and tossed some tube in my bender... was able to get the back section nice and bent in a smooth progressive slope, and mounted a good ol' gnarly looking spike on the front for the front mount / ***** and giggles. i will post pictures up as soon as possible and you guys can comment on my hack fab! hahaha.