Mazda: FD's compressor surge from the factory
12-15-10, 11:03 AM
#28
POWERHOUSE
iTrader: (1)
Join Date: Apr 2009
Location: BREA, CALIFORNIA
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
This is a good thread and dont mean to clutter However just want the rx owners to understand why the twins are a little eratic and get surges. Simple to understand put some twins on the table follow the air flow pattern and see how your air crashes even if you have a prespool in the secondary. done with my comments....peace
12-15-10, 05:21 PM
#29
REPU Garage
iTrader: (17)
Join Date: Jun 2007
Location: Northern Colorado
Posts: 623
Likes: 0
Received 0 Likes
on
0 Posts
My friend and I reviewed the diagnostic setup and to our naked eye on video playback it appeared as if the charge control and charge relief solenoids switch at the exact same time. This was a 2nd gear run, however, so everything is happening relatively quickly engine speed wise, and since we have no clue how long this potential surge condition can last, we could have easily missed it.
We're going to try it again in a higher gear and see if we can see it.
We're going to try it again in a higher gear and see if we can see it.
12-15-10, 07:21 PM
#30
^ are you logging from the factory diagnostic protocol? Because that has a very slow sample rate
It is interesting that two different SAE papers talk about this surge condition (on the 13B-REW and the 20B) but the workshop manual and service highlights say nothing about it. I am inclined to believe the SAE papers.
It is interesting that two different SAE papers talk about this surge condition (on the 13B-REW and the 20B) but the workshop manual and service highlights say nothing about it. I am inclined to believe the SAE papers.
12-15-10, 08:30 PM
#31
HERE is what they failed to tell everybody.
The SEQ. turbo is the best concept ever HOWEVER this design is horrible. To cut a long story short you got two turbos forcing air agaist each other.
The SEQ. turbo is the best concept ever HOWEVER this design is horrible. To cut a long story short you got two turbos forcing air agaist each other.
thats why you get all kind of spikes and motor blowouts.
THE FIX. $$ have a welding guru weld dividers one in between your lower Y-pipe and one mid exhaust manifold. TO seperate your air flow from both turbos into the same direction.
Last edited by dgeesaman; 12-15-10 at 08:33 PM.
12-15-10, 08:48 PM
#32
REPU Garage
iTrader: (17)
Join Date: Jun 2007
Location: Northern Colorado
Posts: 623
Likes: 0
Received 0 Likes
on
0 Posts
^ are you logging from the factory diagnostic protocol? Because that has a very slow sample rate
It is interesting that two different SAE papers talk about this surge condition (on the 13B-REW and the 20B) but the workshop manual and service highlights say nothing about it. I am inclined to believe the SAE papers.
It is interesting that two different SAE papers talk about this surge condition (on the 13B-REW and the 20B) but the workshop manual and service highlights say nothing about it. I am inclined to believe the SAE papers.
12-16-10, 08:37 PM
#37
Full Member
As someone earlier pointed out, it may be that the research was done after the first FDs (series 6) were released. It may be that Series 7 (96-99) or Series 8 (99+) models have this new control technique.
Either way, it's pretty simple to check using a portable oscilloscope or logic analyser. I'd do it myself except I only have access to mains powered o'scopes.
Either way, it's pretty simple to check using a portable oscilloscope or logic analyser. I'd do it myself except I only have access to mains powered o'scopes.
12-17-10, 10:30 AM
#38
The second paper:
It is conceivable, although not likely, that it only happens rarely or under very specific conditions, and we would only be able to find out if we understood how the ECU was programmed. But if you can't observe it during normal driving, for all intents and purposes the service manual is correct and for whatever reason there is a significant difference between all of Mazda's test engines and their production engines. That in itself would be a fascinating mystery.
