I have been running without a boost elbow for some time and I installed the adjustable elbow today and there is no increase in boost pressure, 27-28 lbs and I am still getting over boost code. Also, if I get into it hard, as soon as I let off there is a poping noise, like a backfire in the area of the turbo. The poping noise just started last week and has only done it about 5 times and is intermittant.When I installed the boost elbow, I turned the screw down all the way, then back it out about 1-2 turns, still get the code and same boost numbers. Then cranked the screw down all the way, same results.Any ideas?

Well you need a boost fooler to over come the ECM over boost code. You'll never get any gain of boost with a module that hooks to the MAP sensor to fool the ECM from seeing true boost.As for the adjustable elbow it will change boost after you have a boost fooler installed. But a small 1/16 of a turn could change 5 PSI. I normally screw it in and go for a test drive and check the MAX boost and keep bringing down the boost pressure till its below 35 PSI (Stock HX35 turbos). Or you can figure you approximate HP amount and give 1 PSI of boost for 10 HP your creating. (Roughly speaking).

Thank you, that makes a lot of sense, I am still in the learning curve, on the backside and I really appreciate this site and all the effort that you have put into it.I'll get the boost fooler on the way and see what happens from there. Thank you again.

Remember a fooler and a elbow does not equate high boost Fuel and a tight air system equates high boost

I am not looking for alot more boost, I have a stock turbo and 60hp injectors and I only pull a 27' 5th wheel. I am just an old guy with an old truck havin my second childhood as my wife says.I suspect that from Mike's reply, I might be lookin and a Edge Comp. I saw his write up on his and that's probably the way I'll go. I have all the gauges and stuff and my system is tight so if I have the Edge that should do it, for now.

I am still a little curious about the popping sound and backfire. Did it do it before the boost elbow install?

The noise you're hearing is called "turbo bark". It occurs under relatively high boost loads and quickly letting off the go pedal............you get a little "bark".Turbo bark is not "good" for your turbo. I'd recommend a lighter right foot!!! Or easier let up on the go pedal under load. It's possible to break vanes off the turbo with "barking"!!!!

Thank you for the reply about the turbo bark, I will back out it for sure, I just checked the vanes and eveything is tight and nothing bent or broken of which I am very thankful.The information is greatly appreciated for sure.Thanks again.

I know 'barking' is a common issue with a gas-powered turbo vehicle, as they require a throttle plate (butterfly).On those, the barking occurs when you're making a lot of boost, then let off the throttle suddenly, thus slamming the 'door' closed. since the turbo is still spinning at supersonic speed, that remaining boost pressure is still present, but has nowhere to go. so, it back-feeds pressure to the turbo, and applies an "air-brake" load on the compressor wheel. This can, and has caused fins to break, as well as twisting turbine shafts in half. A bypass valve, or blow-off valve cures this, provided it is large enough to accommodate the boost levels and volumes of air.I didn't know the diesels could effectively get this, as well, provided there is no throttle plate nor a BPV/BOV.