Open filter vs PCM timing
#1
Open filter vs PCM timing
Here is some info I think ya'll who run open air filters and the stock ford tune will find interesting. Now, I can't speak for stock ford tunes other than what was programmed for my 2006 4.0L. But I'd suspect that other rangers are not much different than what I'm seeing on mine.
The stock ford tune for my truck starts to remove timing at only 80F!
As you'll see in the chart below the curve starts to fall rapidly once the intake air sensor sees 80F. The amount of timing that's actually pulled is not easily known because the engines timing is modified by other factors like, load, rpm, ECT, knock sensor, ect...
Point being, if you run the stock ford tune and have an open air filter; Chances are that your causing the PCM to remove power at even fairly cold temps! As you can see on my web page the air temps from the engine room are SIGNIFICANTLY HIGHER than the outside ambient temps. For example, take even a 50F degree day. At 50F ambient if you were driving around town in a 30mph zone, came to a stop at a light, then wanted to go WOT when the light turned green? You'd most likely be giving up 5-10HP just because of the engine room heat effecting the sensors readings.
So.. IMO if a guy is going to run a stock tune and a open air filter. You really ought to consider boxing in the filter. Or maybe going back to the stock airbox. Or... make sure your tuner has adjusted this for you. (you can't do this with the x-cal)
btw, I have my tune set to start to pull timing at 110F and I've created a true "CAI" (cold air intake) And even with my cai my intake temps will creep up over 100F in a certian 40mph zone I travel for work.
Just something to consider....
The stock ford tune for my truck starts to remove timing at only 80F!
As you'll see in the chart below the curve starts to fall rapidly once the intake air sensor sees 80F. The amount of timing that's actually pulled is not easily known because the engines timing is modified by other factors like, load, rpm, ECT, knock sensor, ect...
Point being, if you run the stock ford tune and have an open air filter; Chances are that your causing the PCM to remove power at even fairly cold temps! As you can see on my web page the air temps from the engine room are SIGNIFICANTLY HIGHER than the outside ambient temps. For example, take even a 50F degree day. At 50F ambient if you were driving around town in a 30mph zone, came to a stop at a light, then wanted to go WOT when the light turned green? You'd most likely be giving up 5-10HP just because of the engine room heat effecting the sensors readings.
So.. IMO if a guy is going to run a stock tune and a open air filter. You really ought to consider boxing in the filter. Or maybe going back to the stock airbox. Or... make sure your tuner has adjusted this for you. (you can't do this with the x-cal)
btw, I have my tune set to start to pull timing at 110F and I've created a true "CAI" (cold air intake) And even with my cai my intake temps will creep up over 100F in a certian 40mph zone I travel for work.
Just something to consider....
#2
what about us guys who have vacuum advance timing on older trucks??
i adjust mine by hand depending on my application...
i retard it if i go on long trips to get better gas mileage and higher top end speed for highway travel
and if i stay in town i advance it for acceleration and better idling
i adjust mine by hand depending on my application...
i retard it if i go on long trips to get better gas mileage and higher top end speed for highway travel
and if i stay in town i advance it for acceleration and better idling
#3
I'd suspect that there is nothing to retard timing based on intake air temps. At least I've never seen anything back in the day.
Rich
Rich
#4
Rich, what are the units on the Y, and X axis? It obviously isn't degrees of advance, or temp in degrees.
Good point on using the stock airbox!
Good point on using the stock airbox!
Last edited by Takeda; 10-06-2008 at 08:44 AM.
#7
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I have a Volant. Fully enclosed like the factory except with a cone filter inside. It pulls air from the same place the factory box does, behind the headlight. Also from the side by the fender. That is interesting what is going on though.
#8
How does the volant sound?
#9
Would please explain a little more what we should do in this situation or what the issue is call me stupid but i dont follow exactly what you said means..
#10
hmm...i love my thunderbolt intake box w/ steel tube....total cost: about $110.
pulls air from behind the headlamp...i regularly see nice cool temps compaired to my old mac set up, or my k&n setup. I rarely see 80* intake temp, unless at idle at a stoplight. In the summer....that's another story. lol.
pulls air from behind the headlamp...i regularly see nice cool temps compaired to my old mac set up, or my k&n setup. I rarely see 80* intake temp, unless at idle at a stoplight. In the summer....that's another story. lol.
#11
If only you would mass produce these you could make some decent money on here im sure.. powder coat em black or charcoal and sell em through the forum im sure you could make a good 40 - 50 an intake. if not more...
#12
hmm...i love my thunderbolt intake box w/ steel tube....total cost: about $110.
pulls air from behind the headlamp...i regularly see nice cool temps compaired to my old mac set up, or my k&n setup. I rarely see 80* intake temp, unless at idle at a stoplight. In the summer....that's another story. lol.
pulls air from behind the headlamp...i regularly see nice cool temps compaired to my old mac set up, or my k&n setup. I rarely see 80* intake temp, unless at idle at a stoplight. In the summer....that's another story. lol.
#13
I took my silencer out and on a hot 90degree day my truck was a dog, i put the silencer back in and now it sucks cooler air from behind the headlight... no heat soak, way more response.
#15
this is interesting. I am running the stock airbox and see heat gains. If 80 degrees is the point of the timing change it will undoubtedly effect both stock and aftermarket intake systems, albeit aftermarket more.
You were playing around with it on past threads- like getting the tube and/or brackets off of the radiator. Have you found anything that can make a real world difference?
I am an avid racer and it seems almost impossible to rule this out at the track. It seems like heat sink would effect it while the truck is off, just as well as sitting there at idle, waiting for your turn to go.
You were playing around with it on past threads- like getting the tube and/or brackets off of the radiator. Have you found anything that can make a real world difference?
I am an avid racer and it seems almost impossible to rule this out at the track. It seems like heat sink would effect it while the truck is off, just as well as sitting there at idle, waiting for your turn to go.
#16
additional question:
Would shooting nitrous upstream of the maf sensor be worthwhile or would this cause its own set of problems? In a wet set up its probably unlikely as the two would get in the engine at different times.
Would shooting nitrous upstream of the maf sensor be worthwhile or would this cause its own set of problems? In a wet set up its probably unlikely as the two would get in the engine at different times.
#17
Don't worry mr. ayers.....in this cooler weather right now i'm having no issues. I expect to be wrapping the tube when spring hits. probably with header wrap, or that aluminum heat wrap stuff people put on windows, or ceramic coating to help in the tube heat department. It's a work in progress. It's the best set up as far as cooling incoming air and pedal power i've had on my truck(stock, k&N fipk, Mac, thunderbolt box w/ stock tube, thunderbolt box w/ steel tube).
I'm curious....can the Xcal2 NOT help his 80* issue with a tune from Doug or Fred?
I'm curious....can the Xcal2 NOT help his 80* issue with a tune from Doug or Fred?
#18
Y is timing and X is tempature.
Keep in mind this is not a simple deduction. This is only one parameter in a calculation that the PCM does to given actual timing.
Rich
#20
Two things I see.
1) The H-U-G-E thermocycle of the delicate little MAF wires/pieces would just scare me. Consider that they are going from say.. 115F to -100F below zero in about 1-2 seconds is something that those parts were never meant to do.
2) The nitrous plume will actually pull a little more air into the engine at the point that it's injected. If you spray downstream of the MAF then the MAF will accurately read this increased mass.
Rich
#21
Hot air going into the motor would *only* result in less mass entering the cylinder. Timing would remain the same.
Rich
#22
Dont remove the "silencer" it kills power. Think about this thread.. think about where your airbox is getting the air from when the silencer is removed.. from the engine bay... this equals hot air... equals pulled timing equals less power.
I took my silencer out and on a hot 90degree day my truck was a dog, i put the silencer back in and now it sucks cooler air from behind the headlight... no heat soak, way more response.
I took my silencer out and on a hot 90degree day my truck was a dog, i put the silencer back in and now it sucks cooler air from behind the headlight... no heat soak, way more response.
btw, My caddy northstar motor REALLY REALLY responded to this little "mod". I dropped 0.15 and picked up nearly 2mph in the 1/4 mile from that alone.
Rich
#23
There is one little thing I've done that has improved slow speed / traffic temps a little. And that was to slightly raise the lids leading edge. As soo as the truck moved there is a little air flowing over the top of the headlight which then floods (or disipates) heat in the top of the air box.
I went for some time with this just taped to the rad cowl. As I was playing with the ram air ducting I found that by having it not taped seemed to help temps drop more quickly than the ramp air ducting! As is.. I don't have the ram air ducting and just have the leading edge raised a little.
Oh and BTW, I've seen ZERO increase of debris in the air box because of this.
Rich
#24
Couple points..
1) This has to be changed in the tune that Doug or Fred would write for you. The x-cal by itself is not capable of changing this.
2) Keep in mind that this is only a *parameter* that the PCM uses in calculations to determine timing. I have no idea what the timing is actually reduced by? I do know however that I've personally measure a solid 10hp difference with and without a home made shield. I can only guess that this is one aspect cause the reduction in power at first WOT.
Rich
#25
Rich, I've seen your tuner "derived" HP plots, and they don't come close to the actual 4.0L crank dyno measurements from Ford for the 4.0Ls. So, I don't think your method is very accurate at all: