Larger MAF, fuel and timing mod
02-22-2008, 01:02 AM
#161
Use the EBs MAF correction features for the MAF correction instead of injector correction.
Set the hardware dial to the Q45 MAF and set the software to the A33/Z33 MAF. I don't remember exactly what those settings are. I'll have to look at mine to see.
After you do that, be sure to monitor the Input and Output MAF voltages and you'll see the difference.
Set the hardware dial to the Q45 MAF and set the software to the A33/Z33 MAF. I don't remember exactly what those settings are. I'll have to look at mine to see.
After you do that, be sure to monitor the Input and Output MAF voltages and you'll see the difference.
This thread is a little outdated but I have a question about this procedure. I have the 80mm MAF and short ram built but not installed. I was waiting for warmer weather and was thinking I would need a tune. If I put these settings in my EB will I still need a fine tune? Or will I be all set to drive as is?
02-22-2008, 11:34 AM
#162
but I have a question about this procedure. I have the 80mm MAF and short ram built but not installed. I was waiting for warmer weather and was thinking I would need a tune. If I put these settings in my EB will I still need a fine tune? Or will I be all set to drive as is?
It also depends on if you have your PCV line still connected or not. If not, you will need to add a little fuel for a smoother idle. I think as long as you have a WB monitoring AFR, you should be fine as you will be able to see what you need to do (add fuel, take away etc.)
02-22-2008, 11:38 AM
#163
Just think of the possibilities when the CobbTuning AccessPort comes out. I'll revisit this idea again if/when they release this new reflash equipment. Remember, CobbTuning seems to be the only maker supporting the VQ35 powered Maxima/Altimas. (Along with my retarded early G sedan ecu). Timing/fuel should be cake. Not sure if or how to handle the bigger maf tube dia though.
02-22-2008, 03:34 PM
#164
Just think of the possibilities when the CobbTuning AccessPort comes out. I'll revisit this idea again if/when they release this new reflash equipment. Remember, CobbTuning seems to be the only maker supporting the VQ35 powered Maxima/Altimas. (Along with my retarded early G sedan ecu). Timing/fuel should be cake. Not sure if or how to handle the bigger maf tube dia though.
@ retarded ECU statement.
02-22-2008, 11:35 PM
#165
well I was tuned at 12.2 AFR, I may change that later. But my MAF will be 80mm, not 82 so it may not be perfect. I might grab a filter and do a small test run to see how it feels. i don't have a WB yet but I may borrow one for the trial.
03-24-2008, 11:31 PM
#167
just finished making a 90mm MAF... this thing is freakin huge. probably way more than what is prescribed. (i had a spare MAF laying around collecting dust and was bored). most likely not gonna use it but redoing it to 3". is it necessary to change all intake piping to the same diameter as the enlarged MAF?
Last edited by MrDicks95SE; 03-25-2008 at 01:26 AM.
03-25-2008, 05:23 AM
#168
just finished making a 90mm MAF... this thing is freakin huge. probably way more than what is prescribed. (i had a spare MAF laying around collecting dust and was bored). most likely not gonna use it but redoing it to 3". is it necessary to change all intake piping to the same diameter as the enlarged MAF?
Not 100% sure of how much the pressure and velocity drops, but say you are using a76.2mm pipe then opening up to 90mm, the pressure and velocity will drop considerably when it enters the 90mm cavity. But if you go back to 76.2mm on the other side the pressure and velocity will jump back up to what it was before.
03-25-2008, 06:20 AM
#169
just finished making a 90mm MAF... this thing is freakin huge. probably way more than what is prescribed. (i had a spare MAF laying around collecting dust and was bored). most likely not gonna use it but redoing it to 3". is it necessary to change all intake piping to the same diameter as the enlarged MAF?
I still see the added benefits of the larger MAF housing even when some of my tubing is still 70mm ID.
03-25-2008, 08:27 AM
#170
Hey Rich ,
You thinking about get a PTB and bored it out ?
Having bigger tubing around the 90mm would it be more benefit then just having the sufficient of the smaller tubing?
You thinking about get a PTB and bored it out ?
Having bigger tubing around the 90mm would it be more benefit then just having the sufficient of the smaller tubing?
Last edited by blkAEmax82; 03-25-2008 at 08:35 AM.
03-25-2008, 10:41 AM
#171
Not 100% sure of how much the pressure and velocity drops, but say you are using a76.2mm pipe then opening up to 90mm, the pressure and velocity will drop considerably when it enters the 90mm cavity. But if you go back to 76.2mm on the other side the pressure and velocity will jump back up to what it was before.
03-25-2008, 04:53 PM
#173
What housing did you use? It had to have been the Q45 housing because neither the 5th gen nor 4th gen( in your case I'm assuming from your sig pic) will accommodate that ID.
I still see the added benefits of the larger MAF housing even when some of my tubing is still 70mm ID.
I still see the added benefits of the larger MAF housing even when some of my tubing is still 70mm ID.
would using 90mm ID MAF on stock piping and stock TB pose any problems? itd be setup as cone filter - 90mm MAF - 70mm midpipe - stock TB. obviously with the aid of a SAFCII.
03-25-2008, 04:54 PM
#174
03-25-2008, 06:26 PM
#176
right. i still need to pick em up a WBo2 before i slap this beast of a MAF on. need to know what my AFR is with headers, tp, catback too. this SAFC does me no good right now.... just looking pretty on the dash.
03-14-2012, 11:30 AM
#177
NMexMax I finally got around to doing this last week. Im not using an 82mm device, but I am keeping the same ID of the intake tube track (3" ID, now a 3" MAF to match). Just off the bat, yes response feels better. I went to tune the car last weekend (I'll post up results from that dyno once they email me my runfiles. For some reason, they used STD cor instead of SAE like they usually use. Comparing my old printout from another STD cor dyno, peak #s are in the same area, but I gained ~10whp at redline. I put ~ because I dont want to put official #s until I have the runfiles and put it to SAE #s. The temp is the dyno was 101*F, so I know temp correction alone is gonna show more realistic #s from my setup).
Nismology drove my car before and after, and he agrees with my findings that it definatly holds power better up top, feels more linear overall. Its an EXCELLENT complement to the "worked" IM. So now I have an intake that is 3"ID from the filter to the IM's elbow (PF and 3.5 eTB are 75mm ID, so ~3"). I guess at one point, the stock MAF is indeed a restriction.
Nismology drove my car before and after, and he agrees with my findings that it definatly holds power better up top, feels more linear overall. Its an EXCELLENT complement to the "worked" IM. So now I have an intake that is 3"ID from the filter to the IM's elbow (PF and 3.5 eTB are 75mm ID, so ~3"). I guess at one point, the stock MAF is indeed a restriction.
I would like to build a BB MAF for my 4th gen, but before I got started I wanted to measure various diameters of intake parts already on the car.
My current setup is a DEK motor, PF TB, 4th gen accordion, stock 4th gen MAF and JWT pop charger with velocity stack. I took some measurements too see what size the parts currently are. Keeping in mind that the measurement I took of the PF TB is from the front, and as NmexMax has stated, it needs to be measured from the inside, where the diameter is actually 70 mm (2.75").
The opening of the filter is 6", with the opening of the velocity stack being 3". The ID/OD of the MAF is 2.8"/3.2". The ID/OD of the PFTB is 2.9/3.2". This means air flows from a 3.0" opening in the filter/stack to a 2.8" MAF then to a 2.9" TB.
If the MAF is 2.8", I would be surprised if going up to a 3" ID would really provide any noticeable gains. If I'm going to go to the trouble of making a custom BB MAF, I would think my time would be better spent making one with a 3.5" ID (which would mean I would need a pipe with an OD of something like 3.75, right?). Are the gains from going from a 2.8" ID MAF to a 3" ID MAF mostly attributed to having a full smooth 3" intake all the way to the TB, or is that 0.2" increase in diameter really that beneficial for overall flow? I'm working under the assumption that going from 3"->2.8"->2.9" isn't ideal for air flow. However, if you use the 70mm measurement for the PFTB, that is 2.75", so my air goes from 3"->2.8"->2.75", which seems ideal for creating a venturi effect. Am I missing something here?
In regards to which input/output or MAF scaling to use for a 4th gen MAF, this is what 95BLKMAX said:
"Also, I forgot to mention, the Im using the Q45 MAF sensor input on the SAFC (01)"
So this means 01 for input, and whatever the 4th gen's number is for output? Has anyone used different settings?
03-14-2012, 01:22 PM
#178
I had a noticable mid and top end gain with my 3" MAF. I'm just running a 3" filter to the MAF and straight to the 3.5 TB. I had to bump the fuel pressure up to 60 psi from 40 and scale my VAFC2 up a bunch at idle.
I would say for a 3.5" intake/MAF. It's been proven to provide more gain than a 3". I'm probably going to end up with one.
For the whole venturi effect thing, the 3"->2.8"->2.75" situation more ramping up velocitythan anything else. The venturi effect is more of a tight and fast transition thing. Regardless, I'm still not convinced you really need this effect in the intake track of a fuel injected engine.
I would say for a 3.5" intake/MAF. It's been proven to provide more gain than a 3". I'm probably going to end up with one.
For the whole venturi effect thing, the 3"->2.8"->2.75" situation more ramping up velocitythan anything else. The venturi effect is more of a tight and fast transition thing. Regardless, I'm still not convinced you really need this effect in the intake track of a fuel injected engine.
03-14-2012, 03:35 PM
#179
I had a noticable mid and top end gain with my 3" MAF. I'm just running a 3" filter to the MAF and straight to the 3.5 TB. I had to bump the fuel pressure up to 60 psi from 40 and scale my VAFC2 up a bunch at idle.
I would say for a 3.5" intake/MAF. It's been proven to provide more gain than a 3". I'm probably going to end up with one.
For the whole venturi effect thing, the 3"->2.8"->2.75" situation more ramping up velocitythan anything else. The venturi effect is more of a tight and fast transition thing. Regardless, I'm still not convinced you really need this effect in the intake track of a fuel injected engine.
I would say for a 3.5" intake/MAF. It's been proven to provide more gain than a 3". I'm probably going to end up with one.
For the whole venturi effect thing, the 3"->2.8"->2.75" situation more ramping up velocitythan anything else. The venturi effect is more of a tight and fast transition thing. Regardless, I'm still not convinced you really need this effect in the intake track of a fuel injected engine.
Where has the 3.5" MAF been proven to do more than a 3"? I seem to remember NmexMax saying that he felt no difference between the two.
I do find it hard to believe that increasing the diameter of the MAF from 2.8" to 3.0" would give gains that you could feel through your butt, but I could be wrong. Feeling full 3.5" piping I could believe though....
03-14-2012, 03:40 PM
#180
METHINKS/IMO
That the gains won't be felt from upgrading the size of your maf but having more linear piping for higher velocity, that .1" could be harming your a bit in the higher end because of the uneven flow caused by the discrepancy in piping diameter.
Just my thoughts on it.
I'd say go 3" ID all the way to the TB.
That the gains won't be felt from upgrading the size of your maf but having more linear piping for higher velocity, that .1" could be harming your a bit in the higher end because of the uneven flow caused by the discrepancy in piping diameter.
Just my thoughts on it.
I'd say go 3" ID all the way to the TB.
03-14-2012, 06:31 PM
#181
3" ID, I assume? PVC or aluminum? Do you know the OD? So you're not even running a mid pipe? Were you running a midpipe before the BB MAF install? I've never heard of anyone not running a midpipe. Are you just venting your crankcase to the atmosphere? I would love to see pics if you have them.
Where has the 3.5" MAF been proven to do more than a 3"? I seem to remember NmexMax saying that he felt no difference between the two.
I do find it hard to believe that increasing the diameter of the MAF from 2.8" to 3.0" would give gains that you could feel through your butt, but I could be wrong. Feeling full 3.5" piping I could believe though....
Where has the 3.5" MAF been proven to do more than a 3"? I seem to remember NmexMax saying that he felt no difference between the two.
I do find it hard to believe that increasing the diameter of the MAF from 2.8" to 3.0" would give gains that you could feel through your butt, but I could be wrong. Feeling full 3.5" piping I could believe though....
http://forums.maxima.org/4th-generat...-bore-maf.html
My no midpipe setup is kinda ghetto and yep, the crankcase is venting to the atmosphere. This is the only pic I have of it installed:
The proven gains I was talking about were moreso the 3.5 crowd using the LRMAF and 3.5" tubing. Admittedly I was thinking the LRMAF was closer to 3.5" ID but it's 3.25". Even here I think a full 3.5" all the way to the TB is the way to go.
I could have sworn there was a dyno showing gains for this but couldn't find it. I did find this:
After my Dyno I did the SSIM and the 3.5" intake and LRMAF my PB after Dyno was 14.2 @ 97mph after SSIM and 3.5" intake and LRMAF all things being equal (no weight reduction) 14.1 @ 99mph but my best ET at this time 13.96 @ 100mph no back seat and pass seat.
I think the only option for reflash was TS but I think they wont be doing this anymore I heard some rumors that JWT may do the reflashes like they did but have to confirm this...
I think the only option for reflash was TS but I think they wont be doing this anymore I heard some rumors that JWT may do the reflashes like they did but have to confirm this...
03-15-2012, 06:13 AM
#182
METHINKS/IMO
That the gains won't be felt from upgrading the size of your maf but having more linear piping for higher velocity, that .1" could be harming your a bit in the higher end because of the uneven flow caused by the discrepancy in piping diameter.
Just my thoughts on it.
I'd say go 3" ID all the way to the TB.
That the gains won't be felt from upgrading the size of your maf but having more linear piping for higher velocity, that .1" could be harming your a bit in the higher end because of the uneven flow caused by the discrepancy in piping diameter.
Just my thoughts on it.
I'd say go 3" ID all the way to the TB.
I just feel like if I'm going to go to the trouble of making a custom MAF, that it might as well be 3.5". Does anyone think that going that big could actually be harmful?
Can anyone confirm SAFC settings when using a 4th gen BB MAF?
Does anyone know where to get 3.5" piping that has a nipple for the crankcase breather hose?
04-01-2012, 08:44 PM
#185
This is listed for Silicone hoses 2-3" but with a little work I can't see how it wouldn't fit larger.
http://www.siliconeintakes.com/produ...16c57535aaf74a
http://www.siliconeintakes.com/produ...16c57535aaf74a
04-01-2012, 11:53 PM
#186
Just drill and tap a hole for a 5/8" hose barb. http://www.autozone.com/autozone/acc...er=266061_0_0_
04-08-2012, 09:06 AM
#189
I like having the pcv. Its there for multiple reasons and the advantages of deleting it arent worth the trouble. I have something planed that will fix the issue for us all but i need to make it work for myself before i share.
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