Possible air flow problem
04-22-2017 | 04:09 PM
#1
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Possible air flow problem
I just put the first drink of water in my 10 year old RX8 GT 6 speed auto at 33k miles.
My low water light jumped on when I was on rough road, so I put less than a pint of distilled water instead of fighting a whole gallon of Fl22.
I've taken it to approx 12 track days, but last 4 years, I put my attention on my BMW X1.
With the great help of 9krpm and SARX, I got the BHR ign and fuel pump mods on at 22k miles along with auto trans cooler.
Car runs great, but my question is: MY SCANGUAGE USED TO SAY 180 MAF, but now I can't seem to squeak out much over 155.
I realiZe that I live at higher altitude than where I track 3k ft vs 700ft, but I got 170 once last month, and now only 155.
It has new plugs and air filter.
Maybe the Vflad or something isn't opening right from a vacuum leak?
My low water light jumped on when I was on rough road, so I put less than a pint of distilled water instead of fighting a whole gallon of Fl22.
I've taken it to approx 12 track days, but last 4 years, I put my attention on my BMW X1.
With the great help of 9krpm and SARX, I got the BHR ign and fuel pump mods on at 22k miles along with auto trans cooler.
Car runs great, but my question is: MY SCANGUAGE USED TO SAY 180 MAF, but now I can't seem to squeak out much over 155.
I realiZe that I live at higher altitude than where I track 3k ft vs 700ft, but I got 170 once last month, and now only 155.
It has new plugs and air filter.
Maybe the Vflad or something isn't opening right from a vacuum leak?
04-23-2017 | 05:47 PM
#2
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From: Austin, TX
Something I would keep in mind is that air density is a factor of both altitude and temperature. Over where I am, with the temperature swinging back and forth 50 degrees, there is a huge difference in power due to the air density.
If you still think you have an issue then I would start searching for vac leaks as well as get a compression test done. I doubt the VFAD is your issue, but if you have doubts, you could always unplug it and cap the line. Takes about 35 seconds if you have the cap on hand. I would take a look at your SSV and VDI and verify that they are opening at the correct RPM before doing a leak check. If you pop the hood and have someone else sit in the drivers seat you should be able to see the solenoids open and close.
If you still think you have an issue then I would start searching for vac leaks as well as get a compression test done. I doubt the VFAD is your issue, but if you have doubts, you could always unplug it and cap the line. Takes about 35 seconds if you have the cap on hand. I would take a look at your SSV and VDI and verify that they are opening at the correct RPM before doing a leak check. If you pop the hood and have someone else sit in the drivers seat you should be able to see the solenoids open and close.
04-23-2017 | 08:55 PM
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Ok, thanks. You suggested most everything it could be.
I was probably seeing that 180 when I was tracking car at H2R, and out here on the high plains air is thinner.
It's auto so it never hits those rpms others get. I just got back from running to 7500 redline in 3rd gear, and got 167, and car runs great, so I guess I'm just freaking out over nothing.
I wonder if I should run 4oz/12 gal of Mobil 2 cycle instead of the 8 oz I've run for years, since I have auto and can't rev it like manuals. Some guys never run premix and get over 100k out of engine.
I was probably seeing that 180 when I was tracking car at H2R, and out here on the high plains air is thinner.
It's auto so it never hits those rpms others get. I just got back from running to 7500 redline in 3rd gear, and got 167, and car runs great, so I guess I'm just freaking out over nothing.
I wonder if I should run 4oz/12 gal of Mobil 2 cycle instead of the 8 oz I've run for years, since I have auto and can't rev it like manuals. Some guys never run premix and get over 100k out of engine.