Ram intake to compensate BOV atmo mode
- Thread starter vtakk
- Start date
it got me thinking.. it wont work by definition.
since we would still loose some amount result would be less than calculated.
we take x amount of air. calculate amount of fuel - f(x); then throw (x-n), n >0;
since f(x1)>=f(x2) when x1>=x2 we will get f(x)>=f(x-n);
amount of fuel injected has been calculated based on x amount of air BUT (x-n) has been used...
can smbd show A/F ratio log for Turbosmart BOV with 50/50 setup? how richer comparing to stock it runs?
since we would still loose some amount result would be less than calculated.
we take x amount of air. calculate amount of fuel - f(x); then throw (x-n), n >0;
since f(x1)>=f(x2) when x1>=x2 we will get f(x)>=f(x-n);
amount of fuel injected has been calculated based on x amount of air BUT (x-n) has been used...
can smbd show A/F ratio log for Turbosmart BOV with 50/50 setup? how richer comparing to stock it runs?
I think what he was saying is that all intake air, ram or otherwise, is still metered by the MAFS. Even if the ram air setup did net a positive difference in mass air flow through the intake, the ECU is calculating fuel delivery based on the increased airflow.
right right. it is not like putting extra it's just (absolute) putting more...
but does not matter since MAF still cals based on what it gets..
I'd really like to put a/f graphs on top of each other for stock and full atmo along with 50/50
Yes, and on top of that, it is a closed loop system using the wideband O2 sensor for feedback.
The ECU is smarter than it looks.
Thinking about fabricating your own ram air because no company makes one . . . Autoexe makes a ram air "type" intake but it still has a cone filter not to mention its like 800 bucks lol.
I think it would be easier to just move the MAF sensor if you must run VTA. My question is . . . is VTA really THAT great ??
I think it would be easier to just move the MAF sensor if you must run VTA. My question is . . . is VTA really THAT great ??
VTA on a MAF engine will make an already pig rich situation worse on this engine. The MAF thinks that metered air is going into the engine through the intake valves to be burned with the fuel has told the injectors to spray based on that MAF reading.
Changing the form of intake or making it a ram air does nothing to compensate for the metered air that got farted to atmosphere rather than going where it belongs, IMHO.
Changing the form of intake or making it a ram air does nothing to compensate for the metered air that got farted to atmosphere rather than going where it belongs, IMHO.
mazdaspeed32007
Member
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- Mazdaspeed3
your right. the engine waits for the BOV's recirc to enter the engine adjusting the fuel to the BOV's release. doing a VTA without tuning out the extra air from the BOV, 50/50 or 100%, is making a pig rich engine worse. there are tunes somewhere in this forum via ATR that adjust for VTA. as for your ram air i also agree that its like any other intake until you get above a certain mph...and by then i dont think your making much of a difference anyway. whether the calculations are there or not, sometimes they only work in very select situations.
Ok not stock anymore but I don't think that matters anyway. I'm running SRI, PG Turbo Inlet, Turbosmart dual port bov (50/50) on a 2009 MS3 and here are the results. I'm still learning to use the DH and I think I can record my runs but for now I have a pic at idle: Knk Ret = 0.0, ActAFR = 14.81, LTFTB1 -5.5%. I still got to find out how to monitor how much boost I am holding.
I did a couple part throttle runs and WOT in third gear. I glued my eyes to the DH and this is what I saw:
Knk Ret - 0.0 the whole time
ActAFR - as low as 11.XX to 10.XX
LTFTB1 - no higher than 8 %
During those runs I did not get any backfire, problem or what so ever. Car ran smoothe the whole time.
So, am I good?
I did a couple part throttle runs and WOT in third gear. I glued my eyes to the DH and this is what I saw:
Knk Ret - 0.0 the whole time
ActAFR - as low as 11.XX to 10.XX
LTFTB1 - no higher than 8 %
During those runs I did not get any backfire, problem or what so ever. Car ran smoothe the whole time.
So, am I good?
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Always makes me laugh when people have there BOV set to VTA that aren't running a tuned setup.
Their response is "I like the way it sounds".
Idiots.
My respons is " I like how well it holds boost". I understand that if i am running vta I might run into problems but 50/50 is treating me just fine. And my DH shows me not to be concerned.
So you don't mind that the boost you are holding is getting partially farted out of your BOV into the air after it was metered, after the ECU calculated how much fuel to add to that air that never got into the engine, after the injectors fire too much fuel into the combustion chamber, and after the ECU then detunes the engine over time to try to adjust for something it knows is not right?
Just wondering. Would it not be better to hold boost AND get all of that boosted air to actually end up in the combustion chamber where it belongs?
Nope. None of that concern me. I know I should listen to you because you do know alot. But like I said my car is running just fine. Better than when it had the stock bov, so how is 50/50 making it worse. If I was racing where I would go WOT and all, then yes i'll switch to reci just to be safe.
You do know that these engines run pig rich to begin with? There are reports of fuel dilution of the oil due to this. That's with full recirc. Adding even more unburned fuel would further wash down the cylinder walls, getting past the rings and ending up in the oil. Gasoline is not a very good lubricant.
But, if it sounds sweet, have fun! You only live once. You can always rebuild the engine when she loses compression or pops.
Edit: Sorry, that comment by me was too harsh. Apologies. I just want folks to think that actions sometimes have unintended consequences.
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