Final word on intakes

[1979scotte]

I prefer 1zz turbo to 2zz.
Not a fan really or k20.
I like torque.
Low down dirty torque.

Still hoping to win the lottery one day. If that would happen, one thing would be a 1ZZ engine rebuild and TRD compressor fitted (bulkhead modded ofcourse).

I wouldn't fit a TRD compressor if you bought me one. If you win the lottery I'd be thinking a bit bigger than that. Eaton TVS or whipple. Or rotrex but I think they work better on larger displacement imho.

A Rotrex would be great too, but I lóve the stealth non-look of the TRD and not aiming high ;-)  Would spend some too on going lighter still :-)  Found another 30 kilos or so money cán buy.

I love my Rotrex but I've 3l to fill in the bottom end. Not sure it works so well on smaller engines. Although if you rev the nuts off it I suppose it doesn't matter.

[Petrus]

Although if you rev the nuts off it I suppose it doesn't matter.

Ah, but did we not start with apreciating the low end grunt?!  ;-)

Just dreamin´ though; sofar no lottery ticket win. Not literally; as a matter of speaking I have nooooo complaining.

Right, now for the problem of today; rivited wood rim or leather wrap??

[shnazzle]

On topic please gents. 
Intakes. Not engines or compressors

[Beachbum957]

We have been running Caps MAF mod on 2 MR2s with stock airboxes (the one spacer even came from Cap).  It works as advertised, but only if you follow the directions exactly.  All experiments have shown a loss of power or poor running with any intake deviation (such as any air box mod, different height spacer, wrong injectors, etc). 

A friend did a before and after test on a dyno, and the mod added 5 hp. The only other mod in both tests was a Zero Exhaust header. Not bad for the cost of a set of injectors.  We have cheap clone headers and in normal driving, we get about 1-2 MPG improvement and better throttle response.

As a comparison, the same person added Crower stage 1 cams and a ported and flow benched head.  It didn't work well with the MAF mod and with the MAF spacer out and original injectors back in, they got almost exactly the same results as the stock engine with the mod.

As suggested, most CAI systems add noise and either do nothing or actually hurt power.  Unless you want to spend big bucks, most easy mods (like a header and / or MAF mod) will only give a couple HP at best

[Petrus]

Here a photo of the rear mudguard duct and how the fresh air flows (or not).

[shnazzle]

Just noticed that last picture;
I never noticed that actually if you remove that side-panel, you can create a pretty nifty enclosed intake from side vent all the way to the stock airbox. 
So now it goes from side vent, into engine bay behind battery, into the duct in the side-panel, around the  back and into the back of the airbox. That little part where it goes into the engine bay could be cut out which surely would increase the efficiency. At the cost of giving your filter more work to do, as it is more likely to pick up gunk from the side vent as it no longer has a chance to deposit the dust/dirt into the engine bay before going into the intake.

The only issue is cooling. By enclosing it and routing it all int othe airbox, you lose all of the airflow from the side vent into the engine bay. Diffuser and flat floor could help with that to "suck" hot air out of the back. That's a lot of change though.



On another note; A bit more logging since going back to stock airbox with my opened up exhaust (Zero manifold and custom 200cell cat);

"Load" is now always a steady max of 100. Where it used to be higher than 100, somehow suggesting that manifold pressure was "boosted" somehow on my stock car, which is almost impossible given the intake tract. This also tells me that the ECU is very happy with what the MAF is sensing and it knows exactly how much load is on the engine as all the formulas make sense. Which means it knows exactly how much to fuel.

What I have noticed is that my MAF readings can max out as high as 120g/s. Significantly higher than what I saw with my Hurricane intake and even more significantly higher than stock (usually just around 95ish).
This suggests that the opening up of the exhaust has a significant effect on the car's ability to pump air. 
This is further supported by fuel trims being up by as much as 10%. So all in all, the car is pumping a significant amount more air over stock, and hence having to add more fuel, and hence more bang and power. So if you want to add performance on stock, definitely start with the exhaust system.

Intake temperatures, while definitely a bit higher than on my Hurricane, are well within reason and I would say that if I found a way to cool them towards ambient, I might gain about 2-4hp on a very hot day. ... Not worth it.
So once again I can unequivocally say that even without a dyno, my car is definitely putting out more power on the stock intake and improved exhaust than the stock car.
Next is to clean all logs and put a "performance" panel filter in and see what it does, other than let more crap into the engine.

[Petrus]

Your analysis of the rear quarter space is spot on imo.
Imo removing the duct is as good as it gets without messing with the cooling.
Without the duct, making a bell mouth on the filter hornshould make the effective opening of that larger, but that is pretty much it and furthermore it is not the bottle neck on an n.a. engine; indeed the exhaust it is.

There is a lót of room for flow improvement there with the caveat that the OEM compromise between noise, emissions and flow can not be bettered. Any gains in flow will have a larger trade off.

Your logging of good metering and up to 10% extra fuel means that the output is 10% more too.
That is quite neat!
My set up probably flows a bit more but I´ll sign of on that  10% ;-)
Add the 15% lightness and we get 25% more fun :-)

[shnazzle]

Put the K&N filter in today after a good clean and re-oil. 
One thing to note, as I hypothesised above; the stock system is much better at keeping the air that comes into the filter as clean as possible due to the air gap behind the battery. 

The stock filter I took out was very clean. 

When I took the Hurricane element out after 6 months it was filthy. So, there's another benefit of stock.

[shnazzle]

First results are in after a week of driving with the K&N panel in and logging. 
The conclusion iiiiisss... 

Entirely inconclusive as the UK decided to bathe in the chill of plummeting temperatures, making it a bit of an apples/oranges comparison.

For what it's worth, yes MAF readings are consistently higher across the board. Comfortably peaking at 116-119g/s at full chat repeatedly.

[shnazzle]

I love this guy, he destroys so many myths with such elan.

Yup. Basically everything we've (well, I for one) have been saying for a while. They're rubbish unless you change the ecu calibration but the key is MAF calibration. Mess with flow, you mess with MAF, you mess with ecu, you mess with power. 


You CAN have a very well-designed aftermarket specifically designed for the MR2 on a dyno, aimed at purposely changing the MAF reading such that it advances timing and makes you feel a bit more "oomph" but it's all fakery in the end.

[shnazzle]

Yup. Basically everything we've (well, I for one) have been saying for a while. They're rubbish unless you change the ecu calibration but the key is MAF calibration. Mess with flow, you mess with MAF, you mess with ecu, you mess with power.

I binge-watched his video today and have to say most if not all the stuff he says is rock-solid, common sense advice. He seemed to have stepped on the balls of some British BMW fanboy though cause that guy launched a very undeserved primitive personal attack against Scotty. The last time I saw someone get that primitive, personal and uncivilized were two sellers at a food market in Eastern Europe.

I haven't found him talk rubbish about anything yet. Some people don't like him but I think that's mostly a personal thing as his voice can be a bit grating. 

All in all, can't knock what he's saying.
I think frustration is actually at the root of many of his videos. Crap he's had to deal with because people took their car to an idiot or because they've done something because Google said they should

[Joesson]

Yup. Basically everything we've (well, I for one) have been saying for a while. They're rubbish unless you change the ecu calibration but the key is MAF calibration. Mess with flow, you mess with MAF, you mess with ecu, you mess with power.

I binge-watched his video today and have to say most if not all the stuff he says is rock-solid, common sense advice. He seemed to have stepped on the balls of some British BMW fanboy though cause that guy launched a very undeserved primitive personal attack against Scotty. The last time I saw someone get that primitive, personal and uncivilized were two sellers at a food market in Eastern Europe.

I haven't found him talk rubbish about anything yet. Some people don't like him but I think that's mostly a personal thing as his voice can be a bit grating.

All in all, can't knock what he's saying.
I think frustration is actually at the root of many of his videos. Crap he's had to deal with because people took their car to an idiot or because they've done something because Google said they should

Usually I mute the sound and enable text so Mrs Joesson can read or watch TV without having to hear Scotty's dulcet  tones.

[Petrus]

Found an illustration of the intake tract assembled; oh and the inlet horn/rlbow is fitted in reverse....


You cannot view this attachment.

[Petrus]

Looking to change the 45mm effective entry aperture





for a 90mm one, increasing the entry surface fourfold:





Basically a TRD elbow with larger entry.

[shnazzle]

Just a small link back to my recent post on Caps MAF mod thread.

If you read that, it explains why an aftermarket intake is not good.
Take my Hurricane for example; consider it half a MAF mod. 
So, make the ECU read lower load,to advance timing... But without the extra fuel. So, basically you're making the car run lean. Which then gets trimmed out by the ECU via the o2 sensors. 
Pointless.

[Petrus]

Just a small link back to my recent post on Caps MAF mod thread.

If you read that, it explains why an aftermarket intake is not good.
Take my Hurricane for example; consider it half a MAF mod.
So, make the ECU read lower load,to advance timing... But without the extra fuel. So, basically you're making the car run lean. Which then gets trimmed out by the ECU via the o2 sensors.
Pointless.

Indeed.
Wíth the MAF mod however things change. Will come back to that.

The OEM air horn narrows down to a 45mm aperture, the Markiii elbow has no restriction, the TRD is all 70mm too ánd adds a bell mouth.
The TRD stub goes with a sports filter to make use of the less restricted entry.
Strangely enough the reported effect is marginal. I thus ´discarded´ them because the last few top end horses are not important to me anyway.

Derestricting the exhaust means that the inlet must flow more. Thus the OEM horn becomes more of a restriction but the effect of TRD/Markiii stub is marginal regardless so other limiting factors are involved.
As I am not focussed on top end power, this has not bothered me but thinking the MAF mod through with more time on my hand, my attention has focussed on the OEM elbow again as is literally the bottle neck at load regardless of the revs becaúse of the MAF mod:

Remember the idea of the MAF mod wasn't to increase airflow or fueling.

However: Párt of the MAF mod is taking out the gate with the twin bars. Been looking at this and it is definitely restricting the flow, reducing the duct and creating turbulence. 
From post #83 in the MAF mod thread:




This explaines why the TRD/Markii stubs have limited effect; there is anóther ristriction at the MAF sensor!  The vane at the MAF mod ís a definite restriction of the flow.
This makes the MAF mod very much part of the final words on the intake.
As  I have the MAF mod, that restriction is out thus the OEM horn is now the weak link.
So, out with the OEM one, in with a new.

With a straight inlet stub, the entry aperture becomes the critical part: Any turbulence will in effect restrict the passage way, hence the bell moutn on the TRD stub.
Because both the ready made Markii and TD stubs are thin on the ground and pricey, I can start with a clean sheet and go my own route with the brief of eliminating any bottle neck on entry.
Hence thinking to fit a funnel with a large bell mouth. The entry opening of the air box, where all the above are stuck ín, now becomes the minimum aperture.

[shnazzle]

Just a small link back to my recent post on Caps MAF mod thread.

If you read that, it explains why an aftermarket intake is not good.
Take my Hurricane for example; consider it half a MAF mod.
So, make the ECU read lower load,to advance timing... But without the extra fuel. So, basically you're making the car run lean. Which then gets trimmed out by the ECU via the o2 sensors.
Pointless.

Indeed.
Wíth the MAF mod however things change. Will come back to that.

The OEM air horn narrows down to a 45mm aperture, the Markiii elbow has no restriction, the TRD is all 70mm too ánd adds a bell mouth.
The TRD stub goes with a sports filter to make use of the less restricted entry.
Strangely enough the reported effect is marginal.

Derestricting the exhaust means that the inlet must flow more. Thus the OEM horn becomes more of a restriction but the effect of TRD/Markiii stub is marginal regardless so other limiting factors are involved.
As I am not focussed on top end power, this has not bothered me but thinking the MAF mod through with more time on my hand, my attention has focussed on the OEM elbow again as is literally the bottle neck at load regardless of the revs becaúse of the MAF mod:

Remember the idea of the MAF mod wasn't to increase airflow or fueling.

However: Párt of the MAF mod is taking out the gate with the twin bars. Been looking at this and it is definitely restricting the flow, reducing the duct and creating turbulence.
From post #83 in the MAF mod thread:



This explaines why the TRD/Markii stubs have limited effect; there is anóther ristriction at the MAF sensor!
Now I have the MAF mod, that restriction is out thus the OEM horn is now the weak link.
So, out with the OEM, in with a new.

With a straight inlet stub, the entry aperture becomes the critical part: Any turbulence will in effect restrict the passage way, hence the bell moutn on the TRD stub.
Because both the ready made Markii and TD stubs are thin on the ground and pricey, I can start with a clean sheet and go my own route with the brief of eliminating any bottle neck on entry.
Hence thinking to fit a funnel with a large bell mouth. The entry opening of the air box, where all the above are stuck ín, now becomes the minimum aperture.

Again, those veins were taken out not to remove restrictions. Cap's original thread shows the flow bench results and quite clearly shows that stock flows just as much CFM as a 200gbp filter with no veins. 

They were taken out to change the profile of air to create the necessary conditions for advancing timing.

[Call the midlife!]

Re the vanes and assumed restrictions, purely as a layman looking on, if the air has already got as far as the MAF and been metered then I can't see how the vanes can be a restriction?
The air can't do anything other than flow past them, once it's in, it's in. 
So yes, I can see that they could be seen as a restricted for the throttle body sucking air in but you're still always limited to the internal dimension of the stock MAF housing. 
Other than for pulling colder air from the outside of the car you could just pull the feed pipe off the airbox and still pull the same amount of air as you would through a 4ft trumpet.
It's been proven that a standard car, standard ECU will run with an aftermarket MAF without the vanes as countless people have done it.
Unfortunately very few have then gone on to produce any tested results other than reporting that it sounds great and "definitely goes faster"...
From what I've read Cap's mod works if run as Cap researched and devised it, anything else is experimental at best and as yet unproven.
As the great sages say, "leave it be, standard is the best" and I for one totally agree...

[Petrus]

Again, those veins were taken out not to remove restrictions. Cap's original thread shows the flow bench results and quite clearly shows that stock flows just as much CFM as a 200gbp filter with no veins.

They were taken out to change the profile of air to create the necessary conditions for advancing timing.

It is not whý they were taken out.

Re the vanes and assumed restrictions, purely as a layman looking on, if the air has already got as far as the MAF and been metered then I can't see how the vanes can be a restriction?
The air can't do anything other than flow past them, once it's in, it's in.
So yes, I can see that they could be seen as a restricted for the throttle body sucking air in but you're still always limited to the internal dimension of the stock MAF housing.

The vanes sit just in frónt of the MAF.
They create a calibrated flow/turbulence which the MAF thén measures.

The plastic is a restriction just in front of the MAF body and the through photo illustrates it reduces the aperture.
Take it out and that area will potentially flow more.
If it does not, then the restriction is elsewhere.

Again; Cap Weir did not take it out to get more flow; it was part of his trick to advance the ignition.  Nevertheless have a look at it: Whichever way you look at it, it is a restrictor plate.
If that makes it easier, disconnect it in you mind from the MAF mod.
Imagine you find this gate in the inlet elbow.




Do you think is impairs free flow? Would you fít it between the TRD/Markii stub and the air box? At the entry of the air box?
Instead it sits in the exit of the airbox. You need to take it out of the airbox cover!  Basically the same thing as at the entry.
It is not part op the MAF housing. The MAF measures what flows throúgh this plate.

The MAF mod moves up the MAF so the calibration is out of the window anyway, the goál being to trick the ECU in ´measuring´ a low load. The side effect is that the vane is out.
It  wás no doubt part of the MAF calibration but taking it out = taking out a restriction.

[shnazzle]

Again; Cap Weir did not take it out to get more flow; it was part of his trick to advance the ignition. 

That's what I said

Theoretically yes, you're right. It is a restriction.
But there's theory and then there's reality for a given situation.
Given situation being that the diameter of that pipe + MAF + veins is more than sufficient for the 1zz to flow all the air it CAN flow stock.
And to prove the point further, the TTE turbo can flow enough air through that filter housing for 5psi of boost (and the associated vacuum created in the intake tract at full throttle).
And to take it yet another step further, the 2zz which had a CFM far higher than the 1zz, has the same setup (albeit a few mm bigger I/D).

MAF mod removes it as part of the "tuning" to the MAF being raised and injectors. Not to increase total possible airflow.

[Petrus]

The twó main principles involved in the flow through an engine are:
1. pressure difference
2- inertia of gas mass

1. Without a difference in pressure, air stays put.
It only flows to equalise pressure.
Without lower pressure in the inlet, no air will go thataway.

An air intake in front of a moving car and an exhaust at the back will already see air flowing through open valves.
Adding a scoop will increase the pressure at that end,´charge´ the inlet, flow more air. This is why legally it is not permitted to add a scoop to the intake of a car not fitted with one as it changes the homologated flow.

This is irrespective of internal restrictions. Those restrictions only limit how múch ar flows between the two ends as they reduce the net pressure difference driving the flow.
Restrictions can be seen as resistors in an electrical current. Current flows to equalise a voltage difference. Each resistor will have a voltage difference at both ends but only if there ís a flow.
Same thing restructions in the air flow.
All restrictions/resistors added up result in a resting difference in pressure/voltage which ´drives´ the current of air/electricity.

ALLWAYS keep this in mind:
Pressure difference equals flow of air and vice versa.

2. the mass of the air flowing through a tube is again based on 1.; the inertia of the ´body´ of air is like a cork travelling through that tube; it will push slower air ahead and suck slower air behind it; again that pressure difference.
In guns this is a major pita as the projectile needs to first push out the air column sitting in front of it in the barrel and that is in effect an air shock absorber.

Now to our MR2.
If we would fit a scoop to the side vent, the engine WÍLL flow more air with the car moving forward.
The air scoop scoops up more air.
More air gets into the engine bay.
The pressure in the engine bay will rise, however little.
Thus the intake of the engine behind the battery will rise.
Thus the engine will breath in more air, however little.

Any restriction between the inlet and exhaust tip is like the electrical resistor.
There will be a pressure difference at either end of ány restriction.
Removing a small restriction will still see the total flow increase although only a little.
In turn, removing a larger restriction will see the pressure differce over other restrictions increase because of the increase in flow.
The comparison with a chain is very apt.

In the case of out MR2, Toyota has put a lót of effort to get maximium flow within the constraints of pollution and noise limits.
They have designed a chan with equal strength links.

If we owners to some extend ignore legal contraints, we can faff with the flow chain. If we take one restriction out, the flow increases but not all that much because the other restrictions will have an increase in pressure difference because of that.

All in all two main things to take into account when faffing with the flow of the engine:
1. removing ány restriction, however small relative to other restrictions will increase flow
2. any increase of flow will increase the pressure difference over every restriction

The latter applies to supercharging too ofcourse. In extreme cases the tubing on the suction side can collapse because of the difference with ambient air pressure.
If the intake of te turbo would be fitted with a bellmounth, than the flow into the engine bay becomes critical.
Although with an n.a. engine that is not much of a risk unless you make it breath through a plastic bag, it does illustrate the core principle; air only flows to equalise a pressure difference.

Looking at the OEM airbox, the engine will never flow more than can get into the duct through the quarter panel or with that removed into the space behind that panel.
On the other hand, adding a silly big scoop....


It´s both very simple and wonderfully complicated 

[Petrus]

And to prove the point further, the TTE turbo can flow enough air through that filter housing for 5psi of boost (and the associated vacuum created in the intake tract at full throttle).
And to take it yet another step further, the 2zz which had a CFM far higher than the 1zz, has the same setup (albeit a few mm bigger I/D).

Read my previous posts and you will understand that this is both a non-argument:

The turbo súcks as much as it needs t get at the limit set by the boost controlle. Restrictions in the inlet will see the boost reached later. It being reached is no proof of the inlet not being restrictive.

The few mms extra increase the aperture súrface with the square of the diameter which takes any ´proof´ out of the equasion.


As I wrote, your ECU adding up to 10% more fuel to the air means that the inlet flows up to 10% more, making any and each restriction in that tract more so.
The fact that it cán flow 10% more and in the case of a turbo 30%+ more, tells nóthing about how restrictive it or each restriction is. In only tells that there is enough súction to overcome the total of restrictions to pass that extra air.

Ergo, back to my OEM horn delete, the extra flow through MÝ engine has made the restriction of it more critical than it was before. The vane delete was just a spark igniting my mind, my chain of thought  :-o

[shnazzle]

I'm clearly not explaining what I mean correctly so, I give up  
Remove all restrictions at will  

It's weight savings in the end anyway so a win there

[Petrus]

Remove all restrictions at will

The calibrating vane already ís out.

It's weight savings in the end anyway so a win there

Nope.
The silicone rubber elbow weighs about the same as the TRD alu one, a bit less than the steel Markii, but more than the OEM plastic one. It is thinwalled, lighter plastic ánd has on average less diameter.

[Petrus]

Next; not exactly supercharging, just that more ín than OEM, ánd part of the intake