Is the cap maf mod worth it

[Jared]

Hi all new to the mr2 world and I'm loving this car.
I would interested to know if it can be bettered or did Toyota get it right from the off.
I know about the pre cat problem but mine is a 2006 so less of an issue but a new header us on my list, also do new exhausts like the Malian give any performance gains also is the cap maf mod worth the effort.
Thank you

[Beachbum957]

The MAF mod works, but only with the stock intake system and basically stock engine. The spacer must be the correct dimensions and yellow 2zz injectors are needed. It will work with the stock exhaust manifold and headers like the TRD, TRD clones, and Zero exhaust. I am not sure if anyone has tried it with 4 into 1 headers. The effect is mostly to add a bit more midrange power.  A friend dynoed his MR2 with Zero header and picked up 5 hp and more torque across the whole RPM range.

[Petrus]

Toyota got it impressively right.
We have to keep in mind though that they had to operate within legal constrictions. Also they designed for using regular petrol.
It is with the slightly less strict periodic inspections that we get some operating room to improve things a bit.

As observed the MAF mod works.
Do keep in mind that it ´tricks´ the cpu and as such the mod is sensitive to other changes.
You can copy the TRD intake mod as well with it though. The intake elbow on the filter box  has a restriction to reduce intake noise. Opening this up seems not to affect what the MAF mod does.
As far as the filter element goes, it does need sóme ´restriction´.  I have tried several filter elements and the K&N type (again as per TRD) is as open as it likes. It does not work well with the even better flowing foam filters like p.e. TwinAir.
 
On the exhaust side the 2 - 1 flexi connector of the cat pipe has a serious restriction again to reduce noise.  Other exhaust mods have little to no effect on the flow unless this one is improved.

If you improve the breathing, you increase the mean effective pressure.
The MAF mod in effect advances the ignition.
Bóth make the petrol quality/ octane rating more critical. CAP mentions this about his MAF mod and a higher BMEP is self explanatory. Now combine the ignition advance with higher BMEP and better fuel becomes even more critical.
So there is literally a price to pay    but it sure noticeably adds area under the 1ZZ-FE output graphs.

[Ardent]

I can not say if there is any increase in bhp or torque or not have not done maf mod, but in line with @Petrus comments regarding the restrictions in cat.
Remove them from the equation, and whatever you have, you get sooner.
That is very noticeable.

[Gibla]

Maf mod(inc the 2zz injectors) along with a complete Zero exhaust(exhaust manifold,sports cat + backbox)done on mine .....a very noticeable increase in performance! by how much? dunno! The only negative is a bit of 'stuttering' when on no-load (usually on downhill road section), but this immediately disappears when the loud pedal is re-engaged.

Maf mod is a very effective performance boost.

[Beachbum957]

The "stuttering" is probably a fuel cut at about 3,000 RPM with throttle off, and coasting. That causes a slight hesitation when reapplying light throttle.  It seems not every car with the mod has the effect or it can be a bit random and just a little annoying. 

[Petrus]

The "stuttering" is probably a fuel cut at about 3,000 RPM with throttle off, and coasting. That causes a slight hesitation when reapplying light throttle.  It seems not every car with the mod has the effect or it can be a bit random and just a little annoying. 

On mine it is júst about non existent and I would rate it a total non issue.

[Bugster_MR2]

I am running the MAF mod. Noticeable difference. Cheapest reliable performance mod IMHO. Then I added a Zero race cat, which made it a lot less "choked". Very happy with these two small mods. (I also have a catless header which was on the car before the MAF mod.)

[Petrus]

I am running the MAF mod. Noticeable difference. Cheapest reliable performance mod IMHO. Then I added a Zero race cat, which made it a lot less "choked". Very happy with these two small mods. (I also have a catless header which was on the car before the MAF mod.)

So now perfect it with a TRD (bell mouth) or Markiii (straight) type inlet replacing the elbow on the filter housing.

[Jared]

ok that all sounds good but I'm new to the MR2 so not sure what things like "bell mouth" are but I don't mind doing the maf spacer but only if its worth it. did not really want to change the injectors as on my last car (Porsche) I had real problems with injector swap and after a lot of money spent it made no difference so will think on that but the manifold is on the list of things to sort.
Cheers guys.     

[Petrus]

ok that all sounds good but I'm new to the MR2 so not sure what things like "bell mouth" are

Not MR2 specific at all:

Here it is on mine (the blue thing on the intake left top)




There is an entire thread dedicated to the intake of the ZZW30 btw.

[Carolyn]

Genuine Denso injectors aren't cheap.

I'll make myself unpopular her by saying all that faffing about for 5bhp, just doesn't add up for me.

The MR2 is not a high powered car.  It was never meant to be.  The bog standard car has more than enough power for fun and spirited driving in he twisties, which is what a lightweight sports car is all about.

I built a supercharged version, but I ended up selling that and keeping my MR-S with factory horsepower.

I prefer the car in its as-designed essence and it saddens me sometimes when folk buy these cars and start modifying before they've really got to know the thing.

[J88TEO]

I did the MAF mod with 2ZZ injectors, Markii pipe and Zero header, sports CAT and TTE exhaust and yes there is notceable difference.

[Beachbum957]

The wider torque band with the mod was much nicer on many back roads as we don't need to shift as much as the engine pulls nicely from lower RPM.

But I agree, the MAF mod may not make sense if you must buy new injectors from Toyota, and buying off brand may not give good results.  We managed to get a set of used yellow injectors, and another set of remanufactured.  Both were OEM Denso and work fine.

[Jared]

Are so bell mouth is just a larger opening before air filter, right.
So this is the thing with the MAF mod, do you NEED different injectors.
Has someone tried without and what was the outcome as with 5% (not a lot) more air the injectors in the car should be able to flow 5% more fuel when needed.

[Petrus]

Are so bell mouth is just a larger opening before air filter, right.

No.
Best google.

So this is the thing with the MAF mod, do you NEED different injectors.
Has someone tried without and what was the outcome as with 5% (not a lot) more air the injectors in the car should be able to flow 5% more fuel when needed.

Yes you dó need the different injectors.
Yes the OEM ones can easily flow those 5% more.
That is not at all how the mod works though.
Again best read up on ´Cap Weir MAF mod.´  It is cool trick imo.

[Petrus]

I'll make myself unpopular her by saying all that faffing about for 5bhp, just doesn't add up for me.

Fair enough.

Same thing applies to pretty much all modifications as Toyota got it pretty much spot on from the box.

[Jared]

No.
Best google.

I did a quick search and it looks like the end of a trumpet that you put on the air intake pipe
I think I was not far off

[Jared]

Anyway I do really like the section on the forum that people have put what upgrades they have gone and what bhp they are getting.
Looks like exhaust makes one of the biggest gains plus it loses some weight off the factory one as well.

[Petrus]

Looks like exhaust makes one of the biggest gains plus it loses some weight off the factory one as well.

Mainly the mid pipe Jared.

Keep reading; you´ll figure out that this car is not about power as Carolyn pointed out.

[Gaz mr-s]

Alternatively, have a watch of this.  https://www.youtube.com/watch?v=BZkYGBB48jE&t=411s

[Jared]

Very interesting, nice power gains but have a look at this
https://youtu.be/sJ3L-E-ufYo?si=VfHyIByntmGpD9Pz

Interesting how push performance filter actually filter

[shnazzle]

Could also up the fuel pressure to achieve the extra bit But by how much...who knows... and you'd probably spend as much on kit as on a good set of 2nd hand injectors and cleaning

[Petrus]

Hów?

How good    and at what cost of pressure difference.
The perspective is that the pressure drop equals the power drop in a naturally aspirated engine: The ambient air pressure is what feeds the engine! ANY restriction, pressure drop because of muffling or filtering = power drop.

As to HÓW, there are several ways´filters´ filter; the main distinctions:
1. through holes
2. using centrifugal force (usually with oil bath or sticky liquid)
3. static electricity/attraction (K&N)

The first is simplest; the more filtering layers, the smaller the holes, the more particles are caught. Also the more drop in pressure thus power.

The second are, in open foam form!, the best compromise with top notch filtering and véry little resistance to the flow. They need cleaning often though and the liquid used will affect the MAF.

The latter, the K&N is best nót used with the conductivity (static attraction) enhancing fluid as this too wíll affect the MAF.

Rests the compromise the owner chooses. Pick your poison.

The TRD inlet mod. consisted of:
- delete of air duct through quarter panel
. bell mouthed inlet stub instead of the restricted one
- K&N type filter element

I tried several types.
The TwinAir was best but the MAF did not like the lack of resistance nor the sticky stuff.
Now using K&N (without liquid) and I think it an acceptable compromise for my use/mileage.

Two caveats:
- on the stock ZZW30 a better flowing filter has very little effect because of the restrictions in the inlet horn and the mid pipe,
- the MAF mod has nothing to do with it; that is about fooling the ECU to advance the ignition