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J60 Vs N62 Mafs In Blow Through Config

2.5T_/<ouki

By 2.5T_/<ouki,
in Engines & Forced Induction

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2.5T_/<ouki Contributor

2.5T_/<ouki

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Curious to know if anyone has experience with both of these mafs in a blow through configuration. Currently i switched to blow through on my RB25 running a J60 (stock) MAFS; I got some dyno time and my MAFS was maxing out @ 5v by 6500RPM so im in need of something that will be able to hold up throughout the whole RPM spectrum. I'm trying to find out if a N62 MAF would be a good choice for this as i already have my hands on one.

Thanks.

2.5T_/<ouki Contributor

2.5T_/<ouki

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Just look at the Nistune documentation. The power ratings of all the AFMs are listed there. FWIW, the easiest option for upgrading the RB25 unit is the Z32. I'm not sure that there are any useful ones between those two anyway.

I did see those, however this is in a blow through configuration which puts more stress on the AFM's as they become pressurized. Just curious to know if anyone had this on their blow through setup with successful results. Everyone told me the J60 was fine in blow through setup, however the dyno proved otherwise. I'm maxed out on my fueling as the AFM has reached it's 5v already before i even red line or finish the RPM range.

GTSBoy Grand Master

GTSBoy

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That's why you just need to look at the relative power ratings and choose one that has enough headroom over where you are peaking out now.

FWIW, I would never install one of these in blow through, as I do not think the plastic housing and the penetration seals etc were designed to have a lot of pressure inside. And that's before I even start to wonder about the wisdom of hitting the thing with a gutful of hot air (which can happen even after an intercooler if you manage to heat soak it).

2.5T_/<ouki Contributor

2.5T_/<ouki

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I've had no problems so far and i have a few pals that have run them 6yrs+ without any problems, however i do see what you're concerned about and it being pressurized. I am currently only at 13psi and I don't plan on upping it anymore.

2.5T_/<ouki Contributor

2.5T_/<ouki

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i had a z32 in blow through! make sure you have someone that can tune them in that config tho otherwise it opens up a whole world of issues

Yes, my tuner is able to tune for that MAF in that config. Did you run into any problems while in blow through? I'm running a pretty much stock setup, however my J60 was maxing out in blow through around 6500RPM's. It was already getting it's maxed 5v.

Frosty Grand Master

Frosty

Posted
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Yes, my tuner is able to tune for that MAF in that config. Did you run into any problems while in blow through? I'm running a pretty much stock setup, however my J60 was maxing out in blow through around 6500RPM's. It was already getting it's maxed 5v.

alot of trouble in blow through specially with controlling the fuel map! randomly would fill the cylinders full of fuel no matter what RPM/throttle. even on idle

this wasnt in stock form tho we are talking high mount and full built motor, boost was varied between 13psi and 30psi with no change to the way it acted

2.5T_/<ouki Contributor

2.5T_/<ouki

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alot of trouble in blow through specially with controlling the fuel map! randomly would fill the cylinders full of fuel no matter what RPM/throttle. even on idle

this wasnt in stock form tho we are talking high mount and full built motor, boost was varied between 13psi and 30psi with no change to the way it acted

Oh for sure i gotcha. So you didn't have any troubles with maxing out the maf? This is really my only concern.

2.5T_/<ouki Contributor

2.5T_/<ouki

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nah no issues on that side of things...

what is your reason for running in blow through config?

It all started when i made a custom turbo inlet pipe. I was tired of using the stock silicone accordion looking one. Once i made this new turbo inlet, i got reversion really bad and the car would just suddenly shut off as if the maf was freaking out causing the engine to stall. I read that blow through was a good option as it allowed for your BoV to be non recirculated and also that if your intercooler couplers popped off, you could still drive it home and fix it rather than being stranded.

I went blow through with the J60 stock MAF and have not had any more stalls or reversion so all is well ! I recently went to the dyno to get tuned (NIStune) and it made a lousy 230hp as my VVT solenoid was not working and my MAF was being maxed. I plan on keeping blow through, just wanted to make sure the new maf i replace it with is not going to max out like this one is.

I appreciate your responses.

Frosty Grand Master

Frosty

Posted
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It all started when i made a custom turbo inlet pipe. I was tired of using the stock silicone accordion looking one. Once i made this new turbo inlet, i got reversion really bad and the car would just suddenly shut off as if the maf was freaking out causing the engine to stall. I read that blow through was a good option as it allowed for your BoV to be non recirculated and also that if your intercooler couplers popped off, you could still drive it home and fix it rather than being stranded.

I went blow through with the J60 stock MAF and have not had any more stalls or reversion so all is well ! I recently went to the dyno to get tuned (NIStune) and it made a lousy 230hp as my VVT solenoid was not working and my MAF was being maxed. I plan on keeping blow through, just wanted to make sure the new maf i replace it with is not going to max out like this one is.

I appreciate your responses.

fair call tho the easiest option would of been a GFB dual circ bov that is bolt on :)

GTSBoy Grand Master

GTSBoy

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There's a couple of items to address there.

1) Blow through AFM and venting BOV. This is only valid if you locate the AFM after the BOV location. And seeing as the best place for the BOV is close to the TB, this is hard to do properly.

2) New turbo inlet & reversion. I have a nice steel inlet that was fabricated to replicate the original shape & BOV return etc and never suffered any reversion problems. This was with up to 14 psi on RB20 (and now with less boost on 25Neo, which probably doesn't compare). Whether these things cause reversion problems or not is all in the design and fabrication. It's worth fiddling with that rather than relocating the AFM IMO.

2.5T_/<ouki Contributor

2.5T_/<ouki

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fair call tho the easiest option would of been a GFB dual circ bov that is bolt on :)

My BoV was on the coldpipe side and that would have required a long 4' hose across my engine bay making it even uglier :P. Call me ricer, but i love the sound of a venting BoV. It's good to know the N62 wont max out.

Thanks

There's a couple of items to address there.

1) Blow through AFM and venting BOV. This is only valid if you locate the AFM after the BOV location. And seeing as the best place for the BOV is close to the TB, this is hard to do properly.

2) New turbo inlet & reversion. I have a nice steel inlet that was fabricated to replicate the original shape & BOV return etc and never suffered any reversion problems. This was with up to 14 psi on RB20 (and now with less boost on 25Neo, which probably doesn't compare). Whether these things cause reversion problems or not is all in the design and fabrication. It's worth fiddling with that rather than relocating the AFM IMO.

AFM is already relocated about 8" from the TB and my BoV is located now on the hotpipe. My Setup is exactly how i want it and everything is in the location i want it.

scotty nm35 Grand Master

scotty nm35

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Whether these things cause reversion problems or not is all in the design and fabrication. It's worth fiddling with that rather than relocating the AFM IMO.

^^ This.

Lol at deciding to run blow a though afm simply because the bov return was welded on the wrong angle. Put it back to stock and run one of my intakes before you get defected. :P

2.5T_/<ouki Contributor

2.5T_/<ouki

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Nothing was welded on wrong....there simply was no BOV recirc fitting on the inlet. I do not want to recirculate my BOV as that would mean a 4' hose would be running in my engine bay.

Pics of "your" inlet?

scotty nm35 Grand Master

scotty nm35

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The bov return hose can be quite small, and you could use heater hose if you wanted to keep it a low profile. Have you got a pic of your engine bay?

My intakes are setup for 32-34 gtst so it may need mods to fit. Notice the angle the bov return enters, it needs to face the compressor wheel.

post-63525-0-50983600-1361827966_thumb.jpg

2.5T_/<ouki Contributor

2.5T_/<ouki

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The bov return hose can be quite small, and you could use heater hose if you wanted to keep it a low profile. Have you got a pic of your engine bay?

My intakes are setup for 32-34 gtst so it may need mods to fit. Notice the angle the bov return enters, it needs to face the compressor wheel.

Looks nice!

Do you have a pic of it installed?

I've got an S14 with RB25 so the fitment will be different i assume. There is less space for me to work.

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