[j.boom'r]

Looking to see if anyone has any experience with a lagging first stage boost that results in intermittent limp mode and a Boost Pressure Control-Control Deviation code?

I have a 2011 335d that has the EGR, DPF, and SCR removed. I have had AARodriguez Hybrid Turbos installed, and have had my ECU flashed with AARodriguez Race 2.5 tune. All vacuum lines have been replaced and a new wastegate installed. Ever since I put the ECU back in, the car is MUCH less responsive than stock. However, when the second stage boost kicks in, the car moves great. I've had two separate shops look at the car and they quickly jump to the conclusion that it's a programming problem. I have been in contact with AARodriguez, but they have been of limited help without actually being able to physically work on the car (they are based out of GA). They don't think it's a programming problem, and they're certain that it's not a physical turbo malfunction.

Having moved from the East Coast to SoCal, I no longer have a garage to do any major work on my own. Ultimately, I am having a hard time finding a European performance mechanic, let alone a diesel performance mechanic, who can/will work on modified cars in SoCal (the car is not tagged in CA).

I would certainly appreciate any suggestions for a diesel mech in the Ventura County/LA area, or suggestions on troubleshooting the first stage boost.

Best,

-JB

[KlarTX]

Sounds like the hp turbo isn't kicking in. Do you see boost on it at lower rpms?

[335dlci]

Originally Posted by joe.breeden

Looking to see if anyone has any experience with a lagging first stage boost that results in intermittent limp mode and a Boost Pressure Control-Control Deviation code?

I have a 2011 335d that has the EGR, DPF, and SCR removed. I have had AARodriguez Hybrid Turbos installed, and have had my ECU flashed with AARodriguez Race 2.5 tune. All vacuum lines have been replaced and a new wastegate installed. Ever since I put the ECU back in, the car is MUCH less responsive than stock. However, when the second stage boost kicks in, the car moves great. I've had two separate shops look at the car and they quickly jump to the conclusion that it's a programming problem. I have been in contact with AARodriguez, but they have been of limited help without actually being able to physically work on the car (they are based out of GA). They don't think it's a programming problem, and they're certain that it's not a physical turbo malfunction.

Having moved from the East Coast to SoCal, I no longer have a garage to do any major work on my own. Ultimately, I am having a hard time finding a European performance mechanic, let alone a diesel performance mechanic, who can/will work on modified cars in SoCal (the car is not tagged in CA).

I would certainly appreciate any suggestions for a diesel mech in the Ventura County/LA area, or suggestions on troubleshooting the first stage boost.

Best,

-JB

I actually moved from Ventura.

[dmanb2b]

Check turbo actuator

[robnitro]

Also if it started happening with the vac hoses change you could have cracked a nipple. The ones going to the vacuum reservoir tend to get issues.

[RL18]

I'm with robnitro. Might have a leak somewhere... I've been fighting a vacuum leak for awhile, changed all the vacuum lines, upgraded fittings to steel ones, all acuators changed, boost solenoids changed, vacuum reservoir changed, and turbine bypass changed. Problem on my low-end/ mid rpm hesitation got better. Just recently changed the o rings in the vacuum pump no signs of leaks but I wanted to try it and it's felt really good so far. Replacing any of those things would be a good place to start. Vacuum system controls brakes, turbo, and engine mounts so a leak in any of those areas will have negative effect on the entire system.

[robnitro]

From what I've seen in threads in the past, hp turbo issues are usually due to a leak or bad pressure converter. I guess the hp turbo is more sensitive to vac issues because it's adjusted more frequently than the lp or the changeover.

[bmwdiesel]

strange noon of those mechanics advised u on the most common problem with your delayed boost. and that's either unplugged red hose, or some other vacuum hose (there are few) or one of the turbo actuators or egr actuator....I would start there and then move on other things...you can search the forum there is plenty of material about it.

[fsd350]

Check pressure converters/switchover valves and vacuum system. There is a great write-up from Yozh. If you have Ista-D you can run a test plan also.

[Kozlio]

Originally Posted by j.boom'r

Looking to see if anyone has any experience with a lagging first stage boost that results in intermittent limp mode and a Boost Pressure Control-Control Deviation code?

I have a 2011 335d that has the EGR, DPF, and SCR removed. I have had AARodriguez Hybrid Turbos installed, and have had my ECU flashed with AARodriguez Race 2.5 tune. All vacuum lines have been replaced and a new wastegate installed. Ever since I put the ECU back in, the car is MUCH less responsive than stock. However, when the second stage boost kicks in, the car moves great. I've had two separate shops look at the car and they quickly jump to the conclusion that it's a programming problem. I have been in contact with AARodriguez, but they have been of limited help without actually being able to physically work on the car (they are based out of GA). They don't think it's a programming problem, and they're certain that it's not a physical turbo malfunction.

Having moved from the East Coast to SoCal, I no longer have a garage to do any major work on my own. Ultimately, I am having a hard time finding a European performance mechanic, let alone a diesel performance mechanic, who can/will work on modified cars in SoCal (the car is not tagged in CA).

I would certainly appreciate any suggestions for a diesel mech in the Ventura County/LA area, or suggestions on troubleshooting the first stage boost.

Best,

-JB

Out of curiosity, how much, for pure numbers game, does yr setup make? Before hybrids, the Stage 2.5 Race is +85 HP, +135 TQ however u have the added boost from an upgraded hp turbo.
Hope ur figuring out the potential vacuum problems.

[RL18]

J.boom'r what rpm do you feel the lag is? There's four stages to our turbo system... check out this (page 111-112): https://www.e90post.com/forums/attac...4877650#page78

This shows the stages of our turbo system. Really helped me to pin point the issue. My issue was in the second stage 1,500-3,250rpm. I got to the point where I knew literally everything was changed or brand new in the vacuum system, no leaks or anything and the only thing that I haven't touched was the adjustment on the turbine bypass. Mine (stock) had about 15/16 threads showing, I had read somewhere on here that 23 threads showing is the "sweet spot". Did that and my boost issues in that rpm seemed to get even better and I think I'm finally (hopefully) fixing my issue.

[Torqu3]

Originally Posted by RL18

J.boom'r what rpm do you feel the lag is? There's four stages to our turbo system... check out this (page 111-112): https://www.e90post.com/forums/attac...4877650#page78

This shows the stages of our turbo system. Really helped me to pin point the issue. My issue was in the second stage 1,500-3,250rpm. I got to the point where I knew literally everything was changed or brand new in the vacuum system, no leaks or anything and the only thing that I haven't touched was the adjustment on the turbine bypass. Mine (stock) had about 15/16 threads showing, I had read somewhere on here that 23 threads showing is the "sweet spot". Did that and my boost issues in that rpm seemed to get even better and I think I'm finally (hopefully) fixing my issue.

I have 16 threads showing and have read elsewhere that's the number to be at. I think going higher will just make the large turbo come online sooner in the RPM range, which probably isn't an issue depending on setup.

[RL18]

Originally Posted by Torqu3

I have 16 threads showing and have read elsewhere that's the number to be at. I think going higher will just make the large turbo come online sooner in the RPM range, which probably isn't an issue depending on setup.

Yes I understand that. In my application I needed the big turbo to kick in sooner. I was just using my issue as an example, not a fix for his issue.

[robnitro]

RL18, I'd think that's more of a tuner issue because those actuators can be adjusted by tuning. Back in the tdi vnt days people used to adjust the rod longer to reduce spikes on tunes that were using the stock vnt map. In the beginning of tuning 35d engines there was porting of the waste gate which later on was fixed by tuning... Why didn't you ask your tuner to adjust it instead of messing with the preload of actuators?

[RL18]

Originally Posted by robnitro

RL18, I'd think that's more of a tuner issue because those actuators can be adjusted by tuning. Back in the tdi vnt days people used to adjust the rod longer to reduce spikes on tunes that were using the stock vnt map. In the beginning of tuning 35d engines there was porting of the waste gate which later on was fixed by tuning... Why didn't you ask your tuner to adjust it instead of messing with the preload of actuators?

Nothing to do with the tune. The car had issues before the tune. I'm starting to address them now because they're more obvious with a tune

[j.boom'r]

Gents, many thanks for the responses.

I believe that the issue is with the first stage, HP turbo. The shops both did suggest vacuum problems, so all of my vacuum lines have been changed and the vacuum system has been put under test with no indication of a leak. The turbo actuator has also been changed. The last time I had the car in the shop (Funfzehn in Anaheim), they were in comms with AARodriguez and were working on adjusting the actuator and the thread protrusion. They made some small progress, but after two weeks of frequently putting my car on the sidelines to work on other vehicles, I had to bring the car home.

The lag occurs at low RPM; off the line. It isn't until the RPMs rise above ~3,000 that the LP turbo boosts and the car surges with power. However, if I linger between ~2,500 and 3,000 RPM, that is generally where the car will enter limp mode. If it does go into limp mode, I've found that once I can get the RPMs back around 3,000, the mode will clear.

I couldn't tell you the final numbers for the Stage 2.5 with the hybrids, as I have yet to realize the car's optimal performance with the upgrades. I don't believe my current setup will be much beyond the advertised Stage 2.5, because I still need to upgrade the inter-cooler and fuel pump to get the full potential out of the hybrids.

Also, I found Yohz's posts - thank you for the steer.