Airflow straighteners.

Soldato
Joined
18 Oct 2002
Posts
18,306
Since changing to a setup with a large MAF with a cone filter bolted right on the front and going right into a 45 bend it has issues idling and low rpm misfires. I'm told that using a honeycomb straightener will help significantly with this. Something like this http://www.treadstoneperformance.com/product.phtml?p=68172

Anyone know where I could get hold of something like this in the UK? I gather there is also some connection with PC fans and these things so maybe Ocuk is a good place to ask?
 
Not really, no. It's nothing special, plenty of OE's have them fitted to their MAF's but apparently it's only easy to buy them abroad.
 
My old astra diesel had a similar thingy on its MAF sensor. Like this:
https://cdn.autodoc.de/thumb?id=678495&lng=en
The actual sensor would just plug in and out of it. Might be worth trying scrappies for one? I had a spare but don't know where its gone, could have a look if you want?

** Do Not Hotlink images **
 
My Scorpio has one as standard. If it's good enough for Cosworth to fit............
 
No idea where to buy them in the UK but the usage seems fairly sound to me.

Larger diameter MAF is going to mean lower air velocity, and more turbulence giving fluctuations in MAF readout.

Ultimately ditching the MAF and using Speed density with MAP based load would be the best solution but I'm guessing there's no cheap/easy way to do so on the SR?
 
No idea where to buy them in the UK but the usage seems fairly sound to me.

Larger diameter MAF is going to mean lower air velocity, and more turbulence giving fluctuations in MAF readout.

Ultimately ditching the MAF and using Speed density with MAP based load would be the best solution but I'm guessing there's no cheap/easy way to do so on the SR?

For sure there is an issue, if I look at the MAF trace at idle it's like a saw blade and it runs like a big cammed motor. Apparently it's hard to get a silky idle no matter what when you have 740 injectors though, already had to increase idle speed to 1000 and bump the mixture to 12:1 to get it as smooth as this.

Unfortunately getting rid of the MAF is a case of spending big on a posh ECU. I'm using Nistune now.
 
My original Mustang had such a thing, I removed it as it restricted air flow, lol. :D

The newer Mustangs do not have anything like this, my 911 did have one however.

I would guess they definitely work but manufacturers seem to use them at random, I guess as someone said above on higher horsepower applications they limit flow so do not use them.
 
I doubt cosworth had anything to do with the MAF tbf, they usually just produce the engine and you'll probably find its a ford part.

It uses a Ford maf but the non Cosworth Scorpios don't have the honeycomb. The whole inlet design was laid out by Cosworth.
 
For sure there is an issue, if I look at the MAF trace at idle it's like a saw blade and it runs like a big cammed motor. Apparently it's hard to get a silky idle no matter what when you have 740 injectors though, already had to increase idle speed to 1000 and bump the mixture to 12:1 to get it as smooth as this.

Unfortunately getting rid of the MAF is a case of spending big on a posh ECU. I'm using Nistune now.

Poor idle is probably down to the sawtooth MAF readings rather than the 740s, people get MX5s idling like stock or even better with 650s
 
Most OE MAF sensors have these fitted. They are designed to straighten the air for a more accurate reading.

I've not tested it myself, but I would say they would not be restrictive at all really, especially on a turbo'd engine. Yes, overall size dictates the max physical airflow and readings, but that bit of mesh won't affect anything.

Must MAF sensors are produced similar sizes, so I would pop down the scrappy and find another MAF the same size and swap the mesh over.
 
Clarkey, what size does it need to be? I have a 3 inch honeycomb maf straightener just like this...

http://www.ebay.co.uk/itm/3-0-OD-76...tener-Screen-0-25-6mm-open-cell-/251913146245

It would need to be mounted inside a pipe but might do the trick. I bought it to see if I could use it with my cars modified airbox (which has a bigger maf tube than standard) but theres not enough space, it'd be much too close to the maf, apparently you need a good 2 inches between the maf and the sensor else you can get turbulence that effects the readings).

You can have it for free if its of use, I've had free stuff sent to me before from forum members here, so happy to share the favour.
 
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