Blow through maf users check in

Advanced discussion of improving KA-T components
motorhead
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Post by motorhead »

sup guys, i am succesfully running blow through 89 240sx maf on my ka-t truck. used to be draw through and i hated the slight delay.

i have no tune 8psi on a t28, 11.5-12.0 afr at wot and a fmu for now. i switched to blow through, there is 3 inches of straight pipe before the turbo then a bend to go down to the fmic. it would run good but wouldnt idle.

i clocked the maf sensor until the truck idled good, had to raise the idle speed a little bit.

now it runs lean at idle, runs rich at part throttle (11.0) and runs 12.0 at full throttle.

guys, seriously try clocking your maf. think about it, the maf signal could be higher or lower depending upon the way the air hits the maf inside the pipe! :shock: i hope i help you guys out!
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Ikera
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Re: Blow through maf users check in

Post by Ikera »

got my blow thru setup working ran it for over a year now

1 - Are you running a FMIC?
- YES
2 - What boost levels do you usually see?
- 11PSI
3 - How long are your MAFs lasting?
- a year and still going, blew open once, sealed up and good to go
4 - How long have you run Blow through? (kind of the same question as 3..)
- Since September 2012
5 - What MAF are you running?
- N60
6 - Where on the cold pipe is your maf located, how far away from the TB? Is it on a strait peice of pipe?
- about 6" of straight pipe 2.75" > 2.75" - 3" coupler > N60 MAF > 3" - 2.75 coupler > 2" of straight pipe
- about 16-20" before TB

KA24ET, N60 MAF, SAFC II Tune, 11PSI
Air Regulator and idle air control removed and capped off

I had problmes with idle and, but that didn't bother me as much as I was worried about my ignition timing
eventually I removed all the crap from the manifold and only the throttle controls how much air is going in.
runs awesome!
At cold start I have to keep the RPMs up manually for about 2 - 3 mins until it's able to idle fine by itself ~700RPM and when it warms up it idles ~900RPM

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sorry I don't really have any good pics of the MAF location
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bmaddock
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Re: Blow through maf users check in

Post by bmaddock »

Another bump from the dead.
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1 - Are you running a FMIC? Yes
2 - What boost levels do you usually see? 10psi
3 - How long are your MAFs lasting? on my first one, maybe a month so far
4 - How long have you run Blow through? since May 2014
5 - What MAF are you running? N62 from J30 (same as Z32, not to confuse anyone)
6 - Where on the cold pipe is your maf located, how far away from the TB? Is it on a strait piece of pipe? Using an S13 SR Greddy intercooler kit, I cut some pipe just from where the stock battery location was and it sits there. 2.75"->3" coupler, MAF,3"->2.75" coupler.


So I'm relatively still new to KA-T and haven't been driving it much due to some other things going on in my life. It definitely has a lean condition. N62/550cc/T3T4/Enthalpy tune. I'm afraid I'll have to retune for it because I'm anywhere from 14-17 AFR at idle and 13.6 in boost. Spark plugs were nice and white when I pulled them out to ensure the wideband wasn't bad. I also suspected vacuum leak but I pull around -20 at idle and -23 when in gear and off throttle.

EDIT: Sent ECU to RS Enthalpy for adjustment of my tune, will report back with corrected AFR numbers. He agreed the lean in boost AFR I was seeing could largely be a result of running a draw-through tune in blow-through configuration.
Last edited by bmaddock on Mon Jul 28, 2014 7:21 am, edited 1 time in total.
adamky
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Re: Blow through maf users check in

Post by adamky »

Not sure if it was mentioned, but there is a seller on ebay that sells aluminum MAF housings now. If anyone wants one, I have one that I probably will never use. Bought it last year before realizing I wouldn't need it due to going AEM w/ MAP sensor.
Wiseco/Eagle, JWT S1 cams, BC valve springs, PT5857, ID1700 injectors, SR20DET ECU w/ Nismotronic, COP conversion with LS ignition coils, etc, etc...
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hersheskuirt
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Re: Blow through maf users check in

Post by hersheskuirt »

bmaddock wrote:Another bump from the dead.
Image

1 - Are you running a FMIC? Yes
2 - What boost levels do you usually see? 10psi
3 - How long are your MAFs lasting? on my first one, maybe a month so far
4 - How long have you run Blow through? since May 2014
5 - What MAF are you running? N62 from J30 (same as Z32, not to confuse anyone)
6 - Where on the cold pipe is your maf located, how far away from the TB? Is it on a strait piece of pipe? Using an S13 SR Greddy intercooler kit, I cut some pipe just from where the stock battery location was and it sits there. 2.75"->3" coupler, MAF,3"->2.75" coupler.


So I'm relatively still new to KA-T and haven't been driving it much due to some other things going on in my life. It definitely has a lean condition. N62/550cc/T3T4/Enthalpy tune. I'm afraid I'll have to retune for it because I'm anywhere from 14-17 AFR at idle and 13.6 in boost. Spark plugs were nice and white when I pulled them out to ensure the wideband wasn't bad. I also suspected vacuum leak but I pull around -20 at idle and -23 when in gear and off throttle.

EDIT: Sent ECU to RS Enthalpy for adjustment of my tune, will report back with corrected AFR numbers. He agreed the lean in boost AFR I was seeing could largely be a result of running a draw-through tune in blow-through configuration.

Did this help your afr after sending the ecu back to be adjusted.
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bmaddock
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Re: Blow through maf users check in

Post by bmaddock »

Yes but no. I'll see 13.2 every once in a while at full boost but I do have an exhaust leak pre-wideband I want to fix first before I report on this. Maybe it doesn't make sense but I would think a pre-wideband exhaust leak would leaner readings. Last resort I'll have to revise my tune once more with RS Enthalpy. I will update when I finally have a solution, just been busy with work among other things.
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sdaigle240
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Re: Blow through maf users check in

Post by sdaigle240 »

if youre flashing 13.2 from mid 11s youd know it. sound and feel.
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adamky
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Re: Blow through maf users check in

Post by adamky »

Stumbled across this and felt like bumping it up.

1 - Are you running a FMIC?
Does a bear crap in the woods?
2 - What boost levels do you usually see?
15-20PSI (...for now... :twisted: )
3 - How long are your MAFs lasting?
Aluminum MAF housing... nuff said
4 - How long have you run Blow through? (kind of the same question as 3..)\
~1300 miles...
5 - What MAF are you running?
N62 Z32TT
6 - Where on the cold pipe is your maf located, how far away from the TB? Is it on a strait peice of pipe?[/quote]
Pics > words BTW, the aluminum MAF housing has a honeycomb-style air straightener
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Wiseco/Eagle, JWT S1 cams, BC valve springs, PT5857, ID1700 injectors, SR20DET ECU w/ Nismotronic, COP conversion with LS ignition coils, etc, etc...
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DRFTPUNK
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Re: Blow through maf users check in

Post by DRFTPUNK »

FMIC
10lbs
N62

Mounted just under the battery tray location.

I got an aluminum housing from MAP performance. I highly suggest it. I'm pretty retarded with soldering and it was straightforward of a swap from the stock to their housing. And it seems very solid not worried about leaks at all.
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Re: Blow through maf users check in

Post by Darkzide »

Just finished the turbo install on my KA24E (90 240sx - stock ECU, stock injectors, stock aluminum housing MAF) Pull through was causing poor idle and would die when letting off the throttle even under no load. Going to relocate the MAF on the charge pipe about 8 inches past the turbo (before the intercooler) tonight. I would install it after the intercooler but space is VERY limited. I'll post results and A/F readings after some testing. Expecting 5-7psi of boost.
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