The Sourceautomotive DP is too. It was rubbing untill I tweaked it again.

I do not like the sound of my Diamond Eye on the Utility truck. Odd dronish noise at highway speed. I have the muffler as well but it's a staight through muffler. I don't see how it would be overly restrictive except some swirl differences.

 

I have the Diamond Eye system with out the muffler. Its not as loud as you would think unless you step on it!

I'm not too sure what or if I can make any adjustment on the DP on my truck, it may be something I'm just going to have to deal with for now.

 

JerseyJello, does the straight pipe 4" have a drone in the cab at Highway speeds?

 

I don't really think so, before I had the stock exhaust cut right under the cab, so now with the pipe all the way out behind the wheel is seems way different. It still sounds like a cummins just a little more tuned in with no muffler, but who needs a muffler anyway

I been driving my truck to work every day for about the last six weeks, I've had some issues with my other truck {gas} that was my daily driver so I geuss at this point I'm pretty use to the exhaust. I mean if you want to hear a song on the radio it has to be up at pretty decent volume but that doesn't bother me. So far I am very happy with my new exhaust!!!

 

I have some thin (.020) rubber sheeting I was going to use as a gasket. It will also add some space for travel.

As far as the DP location, I think having it shortened a bit would be the better option. Mine is swung over as close to the frame as you can get with room for the stupid clamp which I had to turn outboard to keep the nuts and plate away from the drive shaft boot.

 

OK, sense the star wheel didn't help, I tried something else. I made a spacer to go between the AFC top and the pump to give me more "smoke screw" adjustment. It helped a little with the smoke but no help with the lag. I got to get rid of the lag. The total thickness of my shim was .110" including the gasket.

 

i want to think i took .100" plus what i tried to grind off with the grinder. i wish i knew exactly how much it was to help others out.

 

I pulled the DP and the intake hose to check for anomalies. No visible restrictions or damage to the turbo. It spins freely like it always has. The only thing I can think of is a lose of drive pressure a low RPMs.

 

I think I spotted a trend.
From this and other forums I'm on I noticed that people not having a lag problem also have smaller turban housings. Either on their H1C or with another turbo. Maybe I'm on, oops, onto something?

 

Something else I picked up on was some people picking up a lag with advanced timing. In those cases though, the timing was very advanced and they had very large turbos.

 

Timing does indeed give you turbo lag.

 

Which turbo housing do you have? The 21 that came stock on my truck wasn't really an issue until I swapped to a manual tranny...at that point the thing wouldn't even spool until high in 3rd gear, and only to mid teens until 4th gear.

The 12 on my truck now spools like a ****...but I'm still confused why strictly opening up your exhaust caused you to lag...that doesn't really make any sense...that should put less backpressure on your turbo and allow it to spool quicker, honestly.

 

It originally had a 21, but it was replaced with a 16 years ago. It worked fantastic with the 3" exhaust. I'm thinking it has something to do with a decrease in drive pressure which is now apparent in low load conditions. Then add to that the problems I had with the timing spacer (see old thread). I'm thinking the two equal lag. I'm going to find some one with the dial gage to reset my timing to stock and try that.

 

i doubt that timing spacer is giving you turbo lag.. i doubt the 4" exhaust did either.... sounds weird to me

 

The timing spacer came back off after a week of power loss and hasn't been on sense June (my other anomaly). I never touched the timing but the PO may have.