Alright MBC only limp mode problems, I set it to 16 runs great no cel however it will...
05-14-2005, 10:17 AM
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Alright MBC only limp mode problems, I set it to 16 runs great no cel however it will...
go into limp mode at the most odd times. I am just stage 1 right now on this car and wanted to just controll spikes. I also thought it was supposed to spool up quicker and not taper,But it does. Any help or idears i don't weant to remove it as when it works it works great.
05-14-2005, 10:28 AM
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So you have K03s? If you set the MBC above 1bar, it will automatically taper because K03s can't flow
that much above 5500 RPM or so. Here is a boost log from when I was on K03s with MBC only to further explain what I'm saying:
Boost was set to ~1.2 bar with the MBC. As you can see, the boost stayed above requested near redline, but still tapered.
<img src="http://pictureposter.audiworld.com/69223/block_115-mbc_only-57d.jpg">
As for you going limp, I can't explain that quite so easily. Are you running GIAC or some other K03 chip? If it is some other, it could be positive devation from spooling up too fast with the MBC only setup, making the chip think something is wrong. Do you have any DTCs? Check fault codes with VAG-Com and post any codes you've got. Also, re-check your MBC install. You may also want to check your car for leaks, visually and/or by pressure testing.
Boost was set to ~1.2 bar with the MBC. As you can see, the boost stayed above requested near redline, but still tapered.
<img src="http://pictureposter.audiworld.com/69223/block_115-mbc_only-57d.jpg">
As for you going limp, I can't explain that quite so easily. Are you running GIAC or some other K03 chip? If it is some other, it could be positive devation from spooling up too fast with the MBC only setup, making the chip think something is wrong. Do you have any DTCs? Check fault codes with VAG-Com and post any codes you've got. Also, re-check your MBC install. You may also want to check your car for leaks, visually and/or by pressure testing.
05-14-2005, 10:33 AM
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Are you sure that you're experiencing limp mode and not throttle cut?
When I was MBC only with X chip, I would occasionally experience throttle cut around 5500 RPM when the actual boost would positively deviaton from actual (as shown in the boost graph I posted). Maybe you could log what you are experiencing (block 003, block 115).
05-14-2005, 11:25 AM
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Well i'm am apr chipped. And mbc only, My install seems to be very clean (no leaks). ..
I know apr is weak sauce and GIAC would work better on this application, BUt this is all i got from my parts bin till i go stage 3 i just wanted to tinker abit. I really appreciate your help doc, I noticed you said that you were once mbc only on k03 what was your resoning and what twere the results.
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05-14-2005, 11:29 AM
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With APR, definitely go limp because of initial spool-up being quicker than ECU expects.
That's one problem running MBC only on APR stuff. Go MBC in parallel, safer on your turbos anyway because you'll taper more up top and keep the turbos more in their efficiency range.
I was MBC only just because someone had to try it. Piggie and I decided what the hell and did it on our cars a couple years ago. I did it for a while until I decided MBC in parallel was safer with more taper up top. I don't think anyone should go MBC only on K03s, but that's just IMO.
I was MBC only just because someone had to try it. Piggie and I decided what the hell and did it on our cars a couple years ago. I did it for a while until I decided MBC in parallel was safer with more taper up top. I don't think anyone should go MBC only on K03s, but that's just IMO.
05-14-2005, 12:57 PM
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well i am now just going to runn it in parallel. I have had to many problems, and with wanting just
wanting to eliminate spikes this wil be my best bet any tips on how to run it
05-14-2005, 01:06 PM
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Follow this diagram....
<img src="http://photos.e46fanatics.com/data/500/8821atwood_mbc_path-med.jpg">
You need additional 1/4" ID hosing and 2 T-fittings. You can secure the hosing on the MBC, N75, and Ts with zip ties.
Here are a couple pictures of my setup:
<img src="http://img.photobucket.com/albums/v654/DocSlow/MBCSetup1.jpg" alt="Image hosted by Photobucket.com">
<img src="http://img.photobucket.com/albums/v654/DocSlow/MBCSetup2.jpg" alt="Image hosted by Photobucket.com">
Before anyone says it, I have since trimmed the zip ties so there is no excess as shown in the picture ;-)
You need additional 1/4" ID hosing and 2 T-fittings. You can secure the hosing on the MBC, N75, and Ts with zip ties.
Here are a couple pictures of my setup:
<img src="http://img.photobucket.com/albums/v654/DocSlow/MBCSetup1.jpg" alt="Image hosted by Photobucket.com">
<img src="http://img.photobucket.com/albums/v654/DocSlow/MBCSetup2.jpg" alt="Image hosted by Photobucket.com">
Before anyone says it, I have since trimmed the zip ties so there is no excess as shown in the picture ;-)