Actually K&N's dyno runs seem to show the same type of curve and no I'm not putting my foot into it more for the sound, but like I said before Take it for what its worth. I just thought some people would like to see some real data.
Absolutely, I very much appreciate the data. Particularly since you have a usefull comparison given that you've dyno'ed before and after mods on the same dyno.
I'm just blown away by the performance of the intake in the midrange. I hadn't considered any power mods, but this is too good to pass on.
It is exceedingly unlikely that the exhuast you installed significantly altered EGTs. There really is no logical explanation at this point for why the cat back reduced fuel economy.
I think that it was cool to do back to back runs, but it doesn't change my outlook on changing out the air intake and replacing it with K&N, Airraid, etc. I am sure on any dyno you will show an increase no doubt, but I bet if you were to re-dyno in say 1 month, your gains will be all but gone. Without a programmer the truck is just gonna readjust for the added air flow and all you will have left is the intake noise. Which is not worth $300-$400 in my opinion.
Looking at the stock curve, it appears as if you didn't put your foot into it enough to get a WOT reading, at least that's what the A/F ratio curve says - the stock (green) A/F ratio stays at 14.7 (closed loop) longer. This may magnify the apparent gains you were seeing from the other curves in comparison.
__________________
2007 Tundra 5.7 4x2 RCSB slate metallic
2005 Corolla - all stock, cause it's the wifes
1986 Mustang GT - the stereo is under the hood
1990 Corolla - cause it was really cheap
I think that it was cool to do back to back runs, but it doesn't change my outlook on changing out the air intake and replacing it with K&N, Airraid, etc. I am sure on any dyno you will show an increase no doubt, but I bet if you were to re-dyno in say 1 month, your gains will be all but gone. Without a programmer the truck is just gonna readjust for the added air flow and all you will have left is the intake noise. Which is not worth $300-$400 in my opinion.
These mods were done over the course of a week. The intake mods as well as the exhaust mods were done at wide open throttle. Therefore nothing should change because the computer is in what I think is called open loop which doesn't use the O2 sensors only the mass air sensor. At that point we are just running according to what the computer is mapped to run at. So many CFM= so much fuel. Thats why we need programmers or adjustable mass air sensors to change this setting or fool the computer. That was a concern of mine as well with testing over a short time. Thanks for the idea.
__________________ 07 Black Crewmax 5.7 4X4 FE, BU, CK, DZ, AA, HM, MG, CF, SIRIUS, K&N CAI, SMITTYBILT SIDE STEPS, SMITTYBILT BULL BAR, TRUXXX 3" FRONT 1" REAR LEVELING KIT, BFG 305*65*18's, JBA DUALS, CHROME HANDLES...BLAH..BLAH..BLAH....
Looking at the stock curve, it appears as if you didn't put your foot into it enough to get a WOT reading, at least that's what the A/F ratio curve says - the stock (green) A/F ratio stays at 14.7 (closed loop) longer. This may magnify the apparent gains you were seeing from the other curves in comparison.
Thats completly on the dyno operator. Only they are allowed to run the dyno
__________________ 07 Black Crewmax 5.7 4X4 FE, BU, CK, DZ, AA, HM, MG, CF, SIRIUS, K&N CAI, SMITTYBILT SIDE STEPS, SMITTYBILT BULL BAR, TRUXXX 3" FRONT 1" REAR LEVELING KIT, BFG 305*65*18's, JBA DUALS, CHROME HANDLES...BLAH..BLAH..BLAH....
The newer vehicles actually do some fuel triming at WOT, so its not completely open-loop. The first I've read of this was the early 2000's Ford lightening.
Hard to say waht Toyota does with there computers??
__________________ 2008 Tundra CrewMax Limited 4x4 5.7, White w/ oak leather, Moonroof, NAV, Factory 20's, XM.
2006 Nissan Murano SE Black, Loaded, Black leather, 20" Dubs
2005 Corvette C6 (#581) Coupe 6 spd Black, Loaded, Black Leather, Navigation, XM, Onstar, HUD, F55 Magnetic ride, Z51 Brakes/calipers/sway-bars, Route 66 Exhaust, Intake, Custom Tune, 160 stat. Only 2 runs at the track...12.4s @116mph
I'm not being negative or anything, I think your gains are Great!
But I did noticed on the K&N site that the picture shows that its a "boxless design" that uses the hood to seal the top from hot engine heat, but if the hood is open on the dyno runs....then it is sucking cool air from All 360 degrees. Now with the hood closed (such as when driving) you are mostly getting air from the fender hole(I believe). With the stock filter box assembly it makes little diffference in cfm if the hood is up or down.
I wonder if that would explain the extraordinary power difference.
It would be interesting if someone does a closed hood run with the same cai
Anyway NICE gains
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2007 Tundra SR5 Crewmax 4x2
5.7L Slate Metalic, Graphite Fabric
Bucket seats w/floor-shift
Bedliner with deck-rail system
Last edited by Rocketsled; 10-17-2007 at 08:16 PM.
These mods were done over the course of a week. The intake mods as well as the exhaust mods were done at wide open throttle. Therefore nothing should change because the computer is in what I think is called open loop which doesn't use the O2 sensors only the mass air sensor. At that point we are just running according to what the computer is mapped to run at. So many CFM= so much fuel. Thats why we need programmers or adjustable mass air sensors to change this setting or fool the computer. That was a concern of mine as well with testing over a short time. Thanks for the idea.
I think on this PCM the "open loop" really is used more for start-up than wide open throttle on this engine. On my last dodge the PCM had a very tight INT and BLM value window. Once you moved to one end or the other of the scale it would default a 14% value and detune. Next time you cranked it up it would read and detune again until it got into a measurable window. If you made a change it couldn't compensate for it would trip into "limp" mode until you took it to the dealer to have the PCM reflashed. It sucked. This PCM is not going to be as simple to crack and adjust like those of chevy. I wish we had something like an LS1 type flash, but I think were going to be screwed for sometime.
I think on this PCM the "open loop" really is used more for start-up than wide open throttle on this engine. On my last dodge the PCM had a very tight INT and BLM value window. Once you moved to one end or the other of the scale it would default a 14% value and detune. Next time you cranked it up it would read and detune again until it got into a measurable window. If you made a change it couldn't compensate for it would trip into "limp" mode until you took it to the dealer to have the PCM reflashed. It sucked. This PCM is not going to be as simple to crack and adjust like those of chevy. I wish we had something like an LS1 type flash, but I think were going to be screwed for sometime.
I think the graph shows pretty clearly that the ECU makes a switch into open loop. It would appear that the run timing skewed the early portion of the graph.
Thats completly on the dyno operator. Only they are allowed to run the dyno
What dyno shop did you go to? Big shot up, in the Falls?
I used to live in the "Lakes".Moved six months ago to NC.Somedays (most)I miss it there.Guiseppe's pizza yum
What dyno shop did you go to? Big shot up, in the Falls?
I used to live in the "Lakes".Moved six months ago to NC.Somedays (most)I miss it there.Guiseppe's pizza yum
Hey former neighbor, just had Guiseppe's the other night. I took it to Akron Horsepower. Eric is a really good dude and seems to be the master when it comes to mustangs. They do some wild mods there(1800+ hp)
__________________ 07 Black Crewmax 5.7 4X4 FE, BU, CK, DZ, AA, HM, MG, CF, SIRIUS, K&N CAI, SMITTYBILT SIDE STEPS, SMITTYBILT BULL BAR, TRUXXX 3" FRONT 1" REAR LEVELING KIT, BFG 305*65*18's, JBA DUALS, CHROME HANDLES...BLAH..BLAH..BLAH....
Re: MODS+DYNO Results
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