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Post by tig488 »

im about to do this for my setup, but im running an enthalpy ecu, its really rich right now, you think ill need to send it back to get retuned for the blow thru, or can i tune it with the safc?
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Post by LA240 »

tig488 wrote:im about to do this for my setup, but im running an enthalpy ecu, its really rich right now, you think ill need to send it back to get retuned for the blow thru, or can i tune it with the safc?
WoW i just emailed scott 2 days ago with the exact same question, and he said to go for it. The safc should be enough IMO to correct the tune. I am running extremely rich with the tune right now, so maybe by going blow thru it will almost correct itself. At least thats what im hoping for.
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Post by rn240sx »

tig488 wrote:im about to do this for my setup, but im running an enthalpy ecu, its really rich right now, you think ill need to send it back to get retuned for the blow thru, or can i tune it with the safc?
Well, i was tunned at 11.5 with the suction maf and converted to blow thru and it leaned out to mid 13's..... Then had to semi tune it back to 11's on the afc on the street cause i didnt wana spend another couple hundred $$$ on the dyno to re-tune it....
Go blow-thru and keep an eye on that wideband when u go wot on 3rd or 4th gear... Then re-tune it if it goes lean... which is WILL..!!
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Post by jmhalder »

rn240sx wrote:Then had to semi tune it back to 11's on the afc
see, i would have just re-scaled my TP scales... 8) SAFC FTL!
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Post by tig488 »

mine runs @ or below 10AFR, last time i checked. so leaning my out 2 points wont be that bad, but ill be sure to watch it once its done.
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Post by rn240sx »

I can tell u this, running a jwt ecu, the a/f ratio's do NOT stay the same from 8 psi up to 25 psi... At 8 psi it would run 11 flat on the wideband and at 25 psi it would go pig rich and the wideband would go 10 flat and stay there...
It sux that the a/f ratio would be that different from 8 psi to 25 psi... but then again.. its not like im staying within 5 psi. Thats a HUGE different powerband there...
So right now i have it tunned for 14 psi cause thats the highest i take pump gas to anymore (dont trust the quality of pump gas anymore) UNLESS the temps drop below 60 deg F, then ill push pump gas to about 18 psi and thats it..!!
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Post by ka-torqy »

so let me get this right for a blow thro all you guys did is just take the maf and move it from the intake pipe of the turbo and move it to the intake pipe on the cold side and thats besides retune the ecu
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Post by rn240sx »

ka-torqy wrote:so let me get this right for a blow thro all you guys did is just take the maf and move it from the intake pipe of the turbo and move it to the intake pipe on the cold side and thats besides retune the ecu
yes..
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Post by frosti108 »

im running blow through on my single cam ka. z31 T3 pushing through a small fmic, then to the maxima maf at around the sheetmetal to the engine bay. seems decent so far, but then again its been sitting in another state since i put the car together :oops:


so what all did you guys have to retune when you went blow through? all im running is an AFC. base timings retarded 5 degrees. got 440cc RB injectors. also have a FPR sitting in the garage if i need but it will probly go to waste.
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Post by MTX450 »

I have some blow thru questions. How come it makes the car run lean? I thought the extra air would make it run rich?

Also, would it work on the hotpipe, and then the BOV still on the coldpipe? I'm thinking no, but it's worth an ask.
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Post by Dave-O »

MTX450 wrote:I have some blow thru questions. How come it makes the car run lean? I thought the extra air would make it run rich?

Also, would it work on the hotpipe, and then the BOV still on the coldpipe? I'm thinking no, but it's worth an ask.
A MAF sensor works on the principle of measuring air velocity at ambient pressure, and is calibrated for such. When you force air through the sensor it does still read air velocity, but it's assuming it's at ambient pressure, not the pressure your charge piping is - this is where the lean-run condition occurs, but it can be easily "tuned" around.

Another viable option would be to run a GM MAF and a MAF-Translator [http://www.maftpro.com/] - countless high-power engine builds have run on a MAF-T setup [it's a popular mod among the DSM crowd]. They're known to be very reliable and accurate with high-boost apps.

So long as your BOV is before the MAF, you should have no issues at all.

I'm glad I've stumbled upon this thread, I've been considering a blow-thru SOHC buildup, great info here. :wink:
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Post by siliva_K's »

hey guys idk if you still following this thread or not but ill give it a shot

i'm thinking of going blow-thru i have enthalpy ecu tuned for 550cc and z32 maf

my question is ...has anyone switched to blow thru with simliar setup like mine? and since i heard the enthalpy run rich on the regular ..did the car lean out or it kinda fixed it self to better by going blow thru?

info will help alot..thanks alot in advance
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Post by sdaigle240 »

stop skimming!!!!!!!1 lol. rn240 posted up his ish went lean after the switch, right on the first page. iirc he is also running a 550/z32 program
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Post by bmoses »

OK, please forgive my un-knowing here, but I always thought the MAF should go before the turbo, at ambient air pressure. Is there something to be gained by putting the MAF on the pressurized cold side?

By "blow through" does that mean the black plastic MAFs vs the the aluminum body MAFs?
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Post by 480sx »

Honestly, there SHOULD be no switch in AFR's or anything. The people who have problems with blow through are usually people who dont set it up right. Scott from Enthalpy was explaining it to me. Technically, to achieve the laminar flow of air needed to have a MAF read correctly you need 9 inchs of strait pipe on either side of your MAF. Now, to me that seems excessive and people get away with less.

I was also thinking of using honey combed aluminum at either end of the strait section of the coldpipe to straiten flow, i think this would help tremendously on any blow through setup.
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Post by sdaigle240 »

bmoses wrote:OK, please forgive my un-knowing here, but I always thought the MAF should go before the turbo, at ambient air pressure. Is there something to be gained by putting the MAF on the pressurized cold side?

By "blow through" does that mean the black plastic MAFs vs the the aluminum body MAFs?
it helps for drivability issues caused by atmospheric BOV's and limited intake space (like jgs mani). so the stock setup is "draw through" b/c ur pullin air through it, so then blow through is where the maf is on the cold pipe and its presurized, so air is being forced through it instead of being pulled through. as for "whats to be gained" do a lil research as ive never ran it, so theres no popint in me adding "what ive read"
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Post by zenkiBruce »

frosti108 wrote:im running blow through on my single cam ka. z31 T3 pushing through a small fmic, then to the maxima maf at around the sheetmetal to the engine bay. seems decent so far, but then again its been sitting in another state since i put the car together :oops:


so what all did you guys have to retune when you went blow through? all im running is an AFC. base timings retarded 5 degrees. got 440cc RB injectors. also have a FPR sitting in the garage if i need but it will probly go to waste.
I guess it doesnt count if you have a blow through and no air is being blown through it.. LOL :D

But you should check the SAFC guide. Im sure there's something in there thats close. You might have to do a little math though.
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Post by bmoses »

sdaigle240 wrote: it helps for drivability issues caused by atmospheric BOV's and limited intake space (like jgs mani). so the stock setup is "draw through" b/c ur pullin air through it, so then blow through is where the maf is on the cold pipe and its presurized, so air is being forced through it instead of being pulled through. as for "whats to be gained" do a lil research as ive never ran it, so theres no popint in me adding "what ive read"
Ah, ok that helps. I was just not understanding the jargon pull through vs blow through, but now I do. Thanks for the info, and thanks for not flaming me. :)

So a blow through setup allows you to get away with not running recirculation on a MAF setup? That would make sense to me because the air is being metered after the BOV so it doesn't know if the BOV is partially open at idle or not. In effect the system isn't losing air, whereas in a pull through system and having a BOV to atmosphere you're going to lose metered air and not idle at all and have some poor partial throttle driveability. I know this from popping off recirc tubes when I had a FWD DET.

Cool, I'll tuck this little piece of info away. Thanks all! :)

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Post by gtrpryde »

For those who run a blowthru Z32 maf, you realize your maf is plastic? How tight can you clamp down?

Mine immediately leaked from the sensor housing, and since i've switched back to suck thru, I haven't had any problems
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Post by esahuque »

gtrpryde wrote:For those who run a blowthru Z32 maf, you realize your maf is plastic? How tight can you clamp down?

Mine immediately leaked from the sensor housing, and since i've switched back to suck thru, I haven't had any problems
If anybody is having any problems with the square top popping off with a blow through set up, just use window weld its the best way to seal up the maf with out it ever popping of again!

my vac line came off of my W/G and i over boosted to about 30 psi and my maf that has been sealed up with window weld held together just fine. Cant say the same for my pistons though.
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Post by Kfred »

esahuque wrote: If anybody is having any problems with the square top popping off with a blow through set up, just use window weld its the best way to seal up the maf with out it ever popping of again!

my vac line came off of my W/G and i over boosted to about 30 psi and my maf that has been sealed up with window weld held together just fine. Cant say the same for my pistons though.
My square circuit cover popped off with 20psi, so i got some plastic weld epoxy and secured her down tightly. No leaks or problems since.
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Post by esahuque »

Kfred wrote:
esahuque wrote: If anybody is having any problems with the square top popping off with a blow through set up, just use window weld its the best way to seal up the maf with out it ever popping of again!

my vac line came off of my W/G and i over boosted to about 30 psi and my maf that has been sealed up with window weld held together just fine. Cant say the same for my pistons though.
My square circuit cover popped off with 20psi, so i got some plastic weld epoxy and secured her down tightly. No leaks or problems since.
I tried that first myself and it stopped the square from popping off but when i did a boost leak test it still leaked air out of it. I took it apart and used window weld and it doesn't leak air anymore at all.
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Post by crazys14 »

Kfred wrote:
esahuque wrote: If anybody is having any problems with the square top popping off with a blow through set up, just use window weld its the best way to seal up the maf with out it ever popping of again!

my vac line came off of my W/G and i over boosted to about 30 psi and my maf that has been sealed up with window weld held together just fine. Cant say the same for my pistons though.
My square circuit cover popped off with 20psi, so i got some plastic weld epoxy and secured her down tightly. No leaks or problems since.
This is the first thing that will happen, the maf was never designed for boost and will leak all over the place and then pop off. then you will be driving along after a few months and your afrs will start to richen until they go wayyy rich that is from oil residue that gets past the oil seals on compressor...

if you dont catch this intime you can kiss the maf goodbye. I ran blowthru for over a year and replaced a maf after 6 months then i said screw it and went back to draw thru

only recommendation i can give you is get a can of that maf cleaner and spray your maf every few weeks it does buildup oil residue on the hotwire.
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Post by Kfred »

I have my mafs sealed up nicely with epoxy and it helds 30psi in my bench test with no leaks. I have absolutely no oil residue in my intercooler piping and by none i mean none. Inside the compressor outlet on the turbo i just sold looks like the day i bought it.

I've been running blowthrough mafs for over a year and the only problem i ever had was the one incident where the circuit cover blew off. A $5 tube of epoxy fixed that right up.

If your logic is the mafs wasn't designed to see positive pressure, so don't do it. Then don't turbo your ka because it wasn't designed to see positive pressure either. :wink:
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Post by esahuque »

Kfred wrote: If your logic is the mafs wasn't designed to see positive pressure, so don't do it. Then don't turbo your ka because it wasn't designed to see positive pressure either. :wink:
lol couldn't have said it better myself.
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Post by gtrpryde »

haha, I agree with everything yall have said, I just can't imagine a plastic housing with no bead to hold the clamp working for too long.

But if it works it works right?

If it were a gm maf or cobra maf (metal) I would be running that ish all day long.

Truth is though, I was running blow-thru until my tuner talked me out of the same reasons I just told you, plus my maf was leaking bad lol. If I get a Tial bov for cheap I might go back to this route, with said window weld. What color is the stuff anyways? Black poly?
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Post by esahuque »

gtrpryde wrote: with said window weld. What color is the stuff anyways? Black poly?
yeah its black, its that stuff thats used to seal around your windshield before they put the molding on. also its a cheap mod that people use to make oem motor mounts stiffer
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Post by all shal perrish »

bumping this bad boy back up. .
some of you may know that i am goign turbo within like 2 months, and anyway..
i had one quick question that searching was not able to answer.

i know that z32 maffs are sensitive to turbulance, and they are also 3 inch diamiter.
so my question is, i have 2.5 inch intercooler piping, if i get a 3 inch to 2.5 inch reducer to atatch the maff, will that cause enought turbulance to be an issue?
it looked like kfred was using the above mentione method. just wondering.
and i know thta it is recomneded that z32 mafs have at least 9 inches of straight before them, k fred, how many inches of straight do you have before your maff?
looks to be far less then 9 inches.

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Post by esahuque »

all shal perrish wrote:bumping this bad boy back up. .
some of you may know that i am goign turbo within like 2 months, and anyway..
i had one quick question that searching was not able to answer.

i know that z32 maffs are sensitive to turbulance, and they are also 3 inch diamiter.
so my question is, i have 2.5 inch intercooler piping, if i get a 3 inch to 2.5 inch reducer to atatch the maff, will that cause enought turbulance to be an issue?
it looked like kfred was using the above mentione method. just wondering.
and i know thta it is recomneded that z32 mafs have at least 9 inches of straight before them, k fred, how many inches of straight do you have before your maff?
looks to be far less then 9 inches.

thanks
adam
Thats how i run mine with no issues, 2.5 in 2.5 out, I think you need 8 or 9 inches of straight pipe and you should be good
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