Blow through setups

Trip

Trip

New Member
Correct me if i am wrong here, but in theory air being metered by the MAF has a long journey to reach the engine. In this long "journey", some air will be lost due to possible leaks, the same air will change temerature, and arrive at engine with a delay.

I am cosidering the idea to go for a blow through setup, so the metered air by MAF is instantly ingested in the engine which deminishes the possiblity of a bad MAF reading due to tiny air leak in the intercooler plumbing, and reduces the delay, so the throttle should be sharper. This setup would need the MAF beefed up not to blow under pressure.

Anyone ever tried this setup and what are the pro's and cons.

 
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pulsarboby

Guest
yeah ive done it with my old car
you have basically answered your own question with the reasons why its better. its also allows engine to continue running if you blow a boost pipe somewhere other than onto main plenum.

downside is that due to the maf being constantly pressurised it may shorten the life of the unit.
and as you have rightly said you will need to strenghen the casing (especially the top of z32) or youll blow it to pieces if your running any kind of boost.

ive reverted back to standard location in our new car due to space issues and the fact that im also now running aquamist with water methanol injection, but never had a prob with the blowby system
 
Trip

Trip

New Member
Did you use a BOV, if so where was it placed ?

Blowing a boost pipe will probably get you home (for road cars) but i would imagine a BB turbo will run its balls out too with no vacuum feed to control the wastegate.
 
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pulsarboby

Guest
yes still used a bov placed in original position off of plenum

the actuator will still open the wastegate if you blow a boost pipe as the vacuum side would not be affected but obviously the turbo will overun as there will be no pressure in the system so its life expectancy would be very short if its a bb unit.
 
stevepudney

stevepudney

GTiROC CHAIRMAN
Staff member
pulsarboby said:
downside is that due to the maf being constantly pressurised it may shorten the life of the unit.
and as you have rightly said you will need to strenghen the casing (especially the top of z32) or youll blow it to pieces if your running any kind of boost.
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So if I made a batch of these would more people be interested in a blow through set up...
 

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stevepudney

stevepudney

GTiROC CHAIRMAN
Staff member
Trip said:
Interesting. How is the lid closed and secured in place ? Will you supply them without electronics and we stick ours in ?
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Not sure yet....but probably just supply

The ageing OEM Z32MAF as a unit seems to rely on the internal mastic type seals surrounding the sensor, plug and lid and even when new have been shown to leak, especially when being used under boost pressures it wasn't designed to withstand.
On these units the sensor would be sealed into position this will seal the MAF unit completely, the lid as on the OEM MAF would then held in place by the sealant filling the box. The OEM lid could be re-used or if your concerned about the look an alloy lid could be fabbed up and again sealed into position.
 
Trip

Trip

New Member
stevepudney said:
Not sure yet....but probably just supply

The ageing OEM Z32MAF as a unit seems to rely on the internal mastic type seals surrounding the sensor, plug and lid and even when new have been shown to leak, especially when being used under boost pressures it wasn't designed to withstand.
On these units the sensor would be sealed into position this will seal the unit completely, the lid as on the OEM MAF would then held in place by sealant. The OEM lid could be re-used or if your concerned about the look an alloy lid could be fabbed up and again sealed into position.
Click to expand...

I am not interested about looks.. As long as its seals and holds pressure, it should pass.

Are you planning to do some ?
 
Trip

Trip

New Member
stevepudney said:
Yes, thats the same guy in the states that made the ones in the pics above in 2006. Thats when i originally looked at making them, I did all the R & D but there was never enough interest to warrant making them.
Click to expand...

The one from US is a billet type, more bling to the eyes and probably $$$ more.
 
stevepudney

stevepudney

GTiROC CHAIRMAN
Staff member
Trip said:
I am not interested about looks.. As long as its seals and holds pressure, it should pass.

Are you planning to do some ?
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If I was going to do it, I would probably make them with a billet CNC'd box tigged to 3" ID ally tube c/w beaded ends.

But as i said before, back in 2006 - 2007 (when there was loads more interest and development going on) there was only a handful of people interested, never enough to warrant making them.

A one off will cost ya ;-)

Get enough people interested, say 8 - 10 and I'll make some.....
 
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pulsarboby

Guest
its the lid top which is the weak point as its sealed by a silicone type sealant which in itself isnt very strong.

i ran a blade around the lid sealant and removed the lid then cleaned it up and used epoxy resin to re-seal it.
you then could use fibreglass and tissue matting to reinforce it, if you go all the way round the afm casing with that then it will be very strong and will not leak.
mine ran at 1.6 bar but was tried at 1.8bar also and it held with no problems and cost no more than a fiver and half hours work
 
stevepudney

stevepudney

GTiROC CHAIRMAN
Staff member
just get the lid sealed down like bob says and then set the whole MAF in a length of 4" - 5" ID black heat shrink tubing, shrink it down and hey presto........a leak free strong MAF
 
Fusion Ed

Fusion Ed

Active Member
If I may say so the problem is with the physical sensor itself, its held in place with an O ring, and some silicone underneath the PCB etc. Its this that fails, and when it does so it pressurises the whole area under the lid. Sealing the lid alone may only hide this. I would imagine one way to perhaps cure this is to pot the whole sensor pcb/area in potting compound, or seal the sensor itself within the MAF housing in a way that it cannot then move.
 
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