View Poll Results: Is your SC400 faster without the MAF?
Yes
17
32.08%
No
5
9.43%
I think this is a stupid post
20
37.74%
Its impossible so I will not even accept it as a possibility
11
20.75%
Voters: 53. You may not vote on this poll
Unplugged MAF = More torque, gas, fun 92-94
09-21-10, 03:51 PM
#46
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the maf is simple, it's programmed based on the size of the pipe it's in, If you increase the inner diameter of the pipe while using the stock maf the car will lean out because more un metered air is allowed past. This also opens up the restriction in the air path that is the stock maf. this can also be done in reverse, by placing the sensor in a smaller pipe the car will run richer.
Also for 02's you can pull them out of the exhaust stream while still giving them signal by using sparkplug non foulers like a vw guys do..
for 8 bucks some one should try it
something to think about
Also for 02's you can pull them out of the exhaust stream while still giving them signal by using sparkplug non foulers like a vw guys do..
for 8 bucks some one should try it
something to think about
Last edited by BoostedSC3; 09-21-10 at 03:56 PM.
09-21-10, 05:13 PM
#47
the maf is simple, it's programmed based on the size of the pipe it's in, If you increase the inner diameter of the pipe while using the stock maf the car will lean out because more un metered air is allowed past. This also opens up the restriction in the air path that is the stock maf. this can also be done in reverse, by placing the sensor in a smaller pipe the car will run richer.
Also for 02's you can pull them out of the exhaust stream while still giving them signal by using sparkplug non foulers like a vw guys do..
for 8 bucks some one should try it
something to think about
Also for 02's you can pull them out of the exhaust stream while still giving them signal by using sparkplug non foulers like a vw guys do..
for 8 bucks some one should try it
something to think about
I bought the non foulers a long time ago, but never did anything with them haha..
09-21-10, 06:41 PM
#48
the maf is simple, it's programmed based on the size of the pipe it's in, If you increase the inner diameter of the pipe while using the stock maf the car will lean out because more un metered air is allowed past. This also opens up the restriction in the air path that is the stock maf. this can also be done in reverse, by placing the sensor in a smaller pipe the car will run richer.
Also for 02's you can pull them out of the exhaust stream while still giving them signal by using sparkplug non foulers like a vw guys do..
for 8 bucks some one should try it
something to think about
Also for 02's you can pull them out of the exhaust stream while still giving them signal by using sparkplug non foulers like a vw guys do..
for 8 bucks some one should try it
something to think about
Last edited by BartleDoo; 09-21-10 at 06:46 PM.
09-22-10, 03:51 PM
#49
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Location: Fl
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Might be worth trying for a near-free fix until standalone. We could do some wideband testing to see which size housing gives optimal a/f ranges and see if we can get the o2s to stop trimming back to what the ecu wants. The housing would have to have the same style as stock to induce the vortices for measurement, though, correct? That would be a problem.
you make a point i am unsure of, but it would be worth the 3 dollar piece of pipe with the sensor stuck in it to try, I don't have a stock maf here at the house, or a non swapped car for that matter, but if i did i'd try it.
09-23-10, 09:38 AM
#50
Why do you want to mess with the o2 sensor? it only corrects in closed loop to stoich, when you mash on the gas you are in open loop and the o2 sensor does not do anything, it looks up fueling directly off the signal for the maf sensor.
Non foulers are used to trick the rear o2 sensor so you can run cat-less without a CEL, I have never heard anyone using them on the main o2 sensor or even suggesting that before as it is very dangerous for your engine.
A larger maf sensor would do the trick, but unless the ls400 maf is larger than the sc400 maf (i thought they are the same size), I don't really see how you are going to find a larger karman vortex maf that will work with the stock ecu.
taking the KVF Maf sensor and putting it in a new pipe isn't going to work easily like you can do with a Hotwire Maf, KVF mafs are extremeley sensitive and the housing needs to have the right shape, the sensor located in the right spot, and you need that air comb thing on the front of the housing for the sensor to work right.
The safc is the easiest thing to fix all your problems really, RedPhoenix got it right already.
Non foulers are used to trick the rear o2 sensor so you can run cat-less without a CEL, I have never heard anyone using them on the main o2 sensor or even suggesting that before as it is very dangerous for your engine.
A larger maf sensor would do the trick, but unless the ls400 maf is larger than the sc400 maf (i thought they are the same size), I don't really see how you are going to find a larger karman vortex maf that will work with the stock ecu.
taking the KVF Maf sensor and putting it in a new pipe isn't going to work easily like you can do with a Hotwire Maf, KVF mafs are extremeley sensitive and the housing needs to have the right shape, the sensor located in the right spot, and you need that air comb thing on the front of the housing for the sensor to work right.
The safc is the easiest thing to fix all your problems really, RedPhoenix got it right already.
Last edited by Ali SC3; 09-23-10 at 09:46 AM.
09-23-10, 10:33 AM
#51
It's really just getting a larger vortex screen that would be a problem. The problem Matt is referring to is when cruising the ecu wont let A/F be adjusted with the SAFC to above stoich for better economy. It sends it right back to stoich.
09-23-10, 11:41 AM
#52
ok, I hear what you are saying now. if the stock ecu runs the same stoich for both cruise and partial accel and you lean it out to 16 or so for cruise, you could be at that same lean afr in partial accell now, which is not so bueno. hey if it works it works the 1uz can take alot of abuse but I wouldn't do it.
you could always run the safc and disconnect the o2 sensor. I did that for quite a while on my sc3.
you could always run the safc and disconnect the o2 sensor. I did that for quite a while on my sc3.
09-23-10, 12:55 PM
#54
What I was trying to achieve was only up to 12% throttle 3k rpm or less in 5th, about 75-80mph to have it around 15.5 to 16. soon as you roll on the throttle to accelerate, it should go above that 12% throttle mark and afrs should richen up.... but cannot be done on the safc. However I will take the added power with the same fuel economy I have now until its standalone time.
09-23-10, 02:32 PM
#55
What I was trying to achieve was only up to 12% throttle 3k rpm or less in 5th, about 75-80mph to have it around 15.5 to 16. soon as you roll on the throttle to accelerate, it should go above that 12% throttle mark and afrs should richen up.... but cannot be done on the safc. However I will take the added power with the same fuel economy I have now until its standalone time.
I had it kinda doing this on my sc3 with no o2 sensor and the safc trimmed in low tps areas and maxed out at WOT (na-t), not consisten at all and I would be idling stupid lean.. its frustrating thinking about it even.. but it did work.
With my standalone I run 16-16.5 in cruise, 14.7 - 14.0 in vacuum, and in boost it transitions from 14.0 to around 12, every time.
to be honest trimming your AFR in cruise will only yield you a little more fuel economy than runnin stoich, the reason being is that the difference in fuel percentage between 14.7 and 16.0 at cruise loads is very little.
one WOT run at an AFR of 9 where the load is very high, (remember more fuel is required at higher loads to mainain the same AFR) would completely negate any savings from running lean in stoich.
Unless going standalone, the best bet is to trim back the WOT fuel to something alot more realistic around 13-14's.
09-23-10, 09:29 PM
#57
Yea, I'm gonna get my list of parts together this week and order all of the standalone parts I need. Went to the strip tonight for my first time ever and ran a 14.84 best after three runs. I could have still gotten it lower as I was dropping almost a tenth of a second every run, but the track closed. My trap speed was limited to 93.5 ish because my trap was around 63-6400 rpm in 3rd and the power drop-off is teeeerrrible in the upper rpms. I know people with standalone are pulling well past the stock redline without power drop. So, I should be considerably faster after I get rid of the ****tly stock ecu.
10-05-10, 06:24 AM
#59
Intermediate
Mine is a ī92 and didnīt work better without the MAF. My car have a BFI and gutted cats. If I revved up can make some misfires and in a quick acceleration test, bogged when shifting to 2nd.