Looking for ideas...

I have the JMTC ported header and e45hp turbo installed and am only seeing 4-6psi boost no matter what I do. No codes, the car runs great and will rev right up to redline no problem. On hard 3rd-4th gear pulls it spools right up to 4-6 psi, I see a solid 85% engine load, and it stays at 4-6psi until redline.

At this point we've done a pressurized boost leak test and got the system to hold 21psi for nearly 2 minutes. I'm seeing the usual negative 6-10 psi vacuum when idle or light cruising. I've pulled out the 3rd party diverter valves and put in a brand new OEM unit. Running same intake and intercooler setup as I've run for the past 2 years.

We even tried tightening up the waste-gate, no change. At this point I'll be swapping the waste-gate back from my old JCW turbo to rule out a complete part failure.

As for a tune, I have a DynoComp bench tune, so I can't completely rule that out and before pulling off the turbo to put stock JCW back on, I'll have dealer flash back to stock.

Looking for other ideas short of putting old turbo back on and reflashing ECU.

How would it behave if the second scroll of the twin-scroll design wasn't able to properly capture/harness the exhaust gases?

 

I feel for you, I know you and your brother have been putting in a lot of meticulous work. I hope Arric and JMTC can work with you to get this sorted ASAP.

 

while i dont have a turbo car, and am still learning, i am interested and want to help. forgive any ignorance i have on turbos, along with possible dumb questions ;P

how are you measuring boost? mechanical gauge or electronically through the stock ecu? (like using android torque app).

first thing i notice, is on a pull you only see 85% engine load? using torque, i see that when cruising; any gas and it goes up to 100%.

external or internal diverter valve? (assuming internal since you say diverter valve vs BOV)... what are all your spring rates set at for wastegate and diverter valves? i guess i mean, are they "calibrated" to each other correctly? (assuming they are since youve got this far).

what is the tune allowing for PSI wise in the system? can the ECU be dumping boost somewhere without you knowing / wanting it to?

 

yikes, hopefully it's not the turbo taz. did you ever perform a backpressure test that Arric recommends doing?

 

I'm using Kiwi OBDII adapter and DashCommand to read the boost. The 85% is normal for my driving scenario. It's what I was seeing with OEM turbo and stock tune. The diverter is the OEM electronic one. If it was malfunctioning it would throw a code.

As for back pressure, I have a 3"->2.5" catless downpipe that goes to a straight through 2.5" system to a VIP racing muffler. This system was actually a bit too free flowing with the JCW turbo.

 

Well we swapped the JCW turbo's waste gate on to the e45hp turbo and nothing...

Per DynoComp we then cleared codes, disconnected the battery for 10 mins....and doubled our boost! But it's still half of what we should see. But that suggests that the ECU not only remembers fuel trims, but boost limits??? That could explain why we saw the exact same boost levels as Limp Mode. Those were our high water marks previously.

So now we are going to try and make a major adjustment to the waste gate actuator to see if we can get it to hold more boost. Of course we will clear codes, disconnect battery... what a PITA.

Not sure why other's plugged and played their turbo and I'm having to do major adjustments...

 

Hey Taz,

Sorry to hear the trouble your having. Don't mean to ask a silly question and I may have missed the answer above but did you inspect the vacuum line to the waste gate to make sure it's not split or has any pin holes?

 

Interesting, I'm having a similar problem but without the major modification. My car is only hitting 10 psi. I had changed to a new tune and DV. I removed both changes and still only 10 psi. Vacuum lines are my next check and pressurizing the system. The odd thing is it hits 10 and rides right there. I love working on my car in the hotel parking lot.

 

Try disconnecting the battery for at least 10 minutes. I believe this is what cleared the stored boost value.

 

Vacuum line seemed fine and system is showing the usual vacuum range.

We made another change to the waste gate and saw 17psi at 100% load. I'm thinking the DynoComp tune has changed the timing/boost/load behavior to where adjustments have to be made at the waste gate to compensate. I never ran the car on stock tune with new turbo so just a crazy theory.

Will keep adjusting the waste gate and clearing ECU until I'm seeing 21psi. Will be interested to see how my data logs compare to yours Tigger2011.

 

Sounds like you need a new tune. Stop fighting the ECU and have it work with the parts.

 

Bah, I will bend the ECU to my will!

I went with the one tuner who has hands on experience with JMTC products. Yeah it's a 'bench tune' but I'll take it if it means tested product.
Only time will tell if Battle/DNA and Renntech will have to do something similar to get the most from the e45hp.
Unexplored waters here and "there be monsters".

 

I'll give that a try this afternoon. It would awesome if that's all that it needs.

 

If you want to try some extra voodoo, briefly hold the terminals together. Not sure if this has been proven as needed or not with Minis.

 

Well tried disconnecting the battery and no change. I disconnected the battery before I left for work this morning. I thought it was kind of odd that it kept my radio stations, climate settings but cleared the trip, time and date. If this doesn't work I'm heading home this weekend and I'll be able to pressurize the system and look over vacuum lines better. I for the heck of it I'll try the AP back in and see if that does anything different.

This stinks, I want to put my DP on and I've been really thinking about pulling the trigger on a turbo upgrade but this needs to straitened out first.

 

Previous route to solution was not working out so we decided to take as much back to stock as possible.

The car went to the dealer to have it flashed back to stock, we installed the stock diverter valve, and set the waste gate as close to OEM settings as possible.

Initial tests have us seeing 17psi at 75% load which is about what I'd expect for that given engine load. So still some work left, but the initial numbers and settings are making more sense and more inline with what others have seen.

 

I agree with this. ^^

 

Deleted post and moved to new topic.Thx for advice

 

Hi Steven, I'd suggest starting your own thread so you don't cloud up Taz's and folks don't get confused or off topic. GL!

 

Spent some more time with the stock tune and several maps (various stage 2 and 3 canned tunes) from other tuners. Regardless of the map it builds boost quickly from 2000rpm up to 4200 and holds a solid 14-16psi(17 once) until I shift gears or hit redline. For comparison the JCW turbo would have been topping out 18-21psi. These are 2nd-5th gear pulls.

So it doesn't seem to be an issue of building boost...but getting the car to continue to build boost at the upper RPM range.

 

Have you made any progress?

 

No magical fix to report. Redoing my oil catch can and intake tubes to rule out any possible boost leaks there. Need to get on a dyno for a more controlled testing environment.

Autocross season has started so I'm in a position to getting working 'good enough' and not mess with it too much for awhile.

 

I did the same thing as far as all of my hoses and vacuum lines. I also cleaned both map sensors and maf, not sure what helped but mine improved from 10 to 15 psi. It hits and solidly levels out. I'm going to try to see if I can seal up the map sensors a little better.