Air intake mods

[Bling]

You could try Driven in the sponsors section, he sells a couple of their bits so may be able to source more.

[nz_climber]

As long as we are talking about airfilters, what about R2C filters, they seem to be very popular in the states at the moment for circle track stuff and off road. And slowly coming into the road market with specifically designed and dyno tested intake systems. Higher flow and better filtration compared to K&N (and no oil needed)

http://www.r2cperformance.com/

[Kiwi-Corolla]

I'm still skeptical of the scientific merit / repeatability of their results though.

Two or three of the filters there look to be made from the exact same generic filter material, same cone design and construction method, with the 3A racing one having a different coloured plastic top on it. Likely that they all come out of the exact same factory in China somewhere... Yet the filtration results vary.

I'm not convinced that you wouldnt get 10 different results with 10 different tests with their methodology. Especially since they only tested each one once, rather than a few times to eliminate possible margin of error.

I'd say that blowing dust into an enclosed environment surrounding the filter over a period of time would likely be a more accurate way to measure filtration, than just pouring black stuff on the filter.

None of the above cone filters have comparable cross sectional area to a panel filter anyway, so would get clogged earlier and easier.

Hmm, very true. I just discovered that three of the pod filters in the test (the Tenzo, Simota and 3A Racing) are identical, except for the brand name that's printed on them.

Australian Auto Accessories is the registered trademark owner for 3A racing and, from what I can gather, their filters are made by Simota. Even on the 3A Racing website it says "The 3A Racing Power Stack has all the features & finish of the Simota Power Stack".

Interestingly, both the 3A Racing filter and the Simota Power Stack were featured in the test, yet the results were different. The part number for the Tenzo filter is WS002, which is the exact same number as the 3A Racing and Simota filters, so one can only assume that it's also made in the same factory to the same specifications. The Tenzo filter came out very poorly in comparison to the other two filters.

I've already got a Simota Power Stack filter on my car, so now that I know they're identical I don't think I'll bother going with a 3A Racing filter, despite what the test results say.

[RomanV]

An australian run air filter test shows that an australian made filter flows and filters the best.

A japanese run air filter test shows that a japanese filter flows and filters the best.

Call me skeptical but it seems a little convenient!

I'm also skeptical of the simota type filter flowing better than the likes of an apexi...

Apexi has totally sweet bellmouth design, simota one is really average by comparison.

Either way, its debatable whether the flow test was even a comparable CFM to what an engine actually inhales.

If the vaccum tests were run at 1000% of what an engine ever inhales, its irrelevant if there's 5% difference in the restriction at that point.

Likewise if there's a test run at 5% of what an engine inhales air at, you'd not be able to extrapolate the restriction figures to that point.

Either way, I reckon air filters are overrated as a restriction, I think they're seen as a massive restriction because its counterintuitive to have air flowing through something you cant see through. When 90 degree bends and other aspects of the intake are likely to be a larger percentage of the restriction.

By which I mean, read some autospeed articles on the topic, Julian Edgar takes a painfully logical approach to these things. Although I guess the lack of scientific methodology towards car modifications in most cases is pretty disturbing, not the fact that he takes a methodical approach.

[BZG Wagon]

I was having an interesting discussion with my mechanic around 'front mount' intercoolers.

The basic idea of a front mount being it gives better cooling, therefore more dense air and more power. However his opinion on most setups he sees through his workshop were:
* Piping tends not to have any heat shielding which could result in higher air temps going to the engine, if the piping is too close to the engine or manifold etc.
* Excessive piping length could lead to a decrease in pressure - i.e more lag and longer time for turbo spool.
* Extra weight - although not that significant an issue.

From driving a lot of cars day to day, he seemed to reckon a stock setup often felt better than something aftermarket.

[Tagged]

wow....didn't quite expect this thread to last this long. I still cant make up my mind as to whether I should get back to the factory setup or go for a proper duct for the pod.

BTW, the factory setup has its duct from the back of the LHS head light right?
Why do they put it there? its seems odd to me....wouldn't it be better if the opening didn't have anything in front of it to decrease the air flow???

[Dell'Orto]

Factory is not setup for optimal performance, its set up for cost, packaging, sound emission well ahead of performance

[BZG Wagon]

I understand placement has to do with high air pressure areas under the bonnet. I imagine there's probably a fair amount of air there and the added benefit of not sucking up anything unwanted like bugs which you'll see covered on your bonnet after a decent drive.

IMO: go for a freer flowing panel filter. I had one on my bz touring (black top 4age) and it made one hell of a difference. Didn't feel necessarily feel lots quicker, but it would pull better from lower revs.

[MAC_HATER]

there is a worrying trend im starting to see where people are fitting intercoolers to NA vehicles - pluming one end to the intake and then just bolting a K&N to the other end of the intercooler

apparently its done for that "hellaflush" look which aside from introducing a huge restriction on an NA engine - i thought "hellaflush" was running cut springs and lowering it so much you ruin your tyres every 5000km from camber wear - guess the description changes often :S

[gt4dude]

The problem with filter in engine bay is not only hot air, the air intake is tuned to be certain length/volume to fix torque dips otherwise you would get without.

First thing people do is chuck away resonators from the intake and mess with length of the pipes. This upsets whole acoustics of the inlet tract and where it was optimised to cure the drops in torque curve, now it will have massive holes.

People who put filters in engine bay and claim that in cold weather it actually better, all they feel is a massive dip in the torque curve which then ramps up back to normal as RPM rises, thus making them believe it pulls harder. Just like disabling TVIS on a 4AGE.

People cannot feel the difference between power outputs unless it is in order of magnitude higher. You can drop power by 50% in such way that torque curve will remain the same (while having lower peak) and people will not notice, but if you create dip on lower RPM (so it produces less torque on lower RPM) and bring it back up to normal on higher, and they will feel as if car pulls harder.

You can simulate the effect buy keeping 30% throttle until ~4500rpm and then flooring it - it will feel fast does it not? Although if you put same car next your one, and it will start off 100% throttle, while you do 30% until ~4500rpm, obviously the car with 100% throttle will be faster.

I don't buy that explanation at all about the resonators and the torque curve.

The resonators are there for one purpose only, and thats to reduce intake roar. intake roar is that jackhammering sound you get when you have an aluminum pipe on an NA in the high revs, you don't get it with the stock intake and resonators even if you just whack a pod filter on the end of the stock intake.

what your saying about that feels faster because of a torque dip, is not because of those resonators patching up holes but because for every free flowing mod that you do, you always sacrifice a bit of bottom end for top end.

the effectiveness of an intake system to increase power output in a car depends on how much the engine flows and how restrictive the bottom end of the air box is.

for example, all celicas 3s-fe, 3s-ge, 3s-gte share the same air box bottom end. the feed from the fender area is nowhere near the size of the 3-1/8" port on the 3s-gte air box lid, but it is alot closer to the size of the 2.25" intake port on the 3s-fe airbox lid.

so for the 3s-fe you wouldn't gain much, and infact you dont. i know you dont. for the 3s-ge you do gain a little. on the 3s-gte you gain a shitload, enough to make a couple extra psi at peak boost

placement of the main air intake also affects losses and gains too. as low as possible means higher air pressure and colder air both yeild more oxygen to burn.

[gt4dude]

The perfect setup is an aluminum intake the same size and shape as the factory intake, with an enlarged fulled sealed airbox (none of this deflector plate shit that actually just chokes the pod filter) in the same place as the factory air box which houses a K&N cone filter, then with the same diameter as the intake or larger, you have a feed coming into the box from the lowest part of the front bumper you can find (ie, replacing a fog light) with a bell mouth on the end.

the box can also house things like air temp bung and idler minifilter etc then the box should also be covered in heat reflect insulator

[Grrrrrrr!]

what your saying about that feels faster because of a torque dip, is not because of those resonators patching up holes but because for every free flowing mod that you do, you always sacrifice a bit of bottom end for top end.

No, i disagree strongly. Replacing a clogged shitty filter for example, it improves flow eveywhere, there does not have to be a bottom end loss for you to make a top end gain. There might well be no gains at lower revs from an intake mod, but only a really shitty design should cost you power anywhere in the rev range.

[gt4dude]

what your saying about that feels faster because of a torque dip, is not because of those resonators patching up holes but because for every free flowing mod that you do, you always sacrifice a bit of bottom end for top end.

No, i disagree strongly. Replacing a clogged shitty filter for example, it improves flow eveywhere, there does not have to be a bottom end loss for you to make a top end gain. There might well be no gains at lower revs from an intake mod, but only a really shitty design should cost you power anywhere in the rev range.

I'm going to be a smartass and point out that going from a small turbo to a large turbo usually sacrifices low end for top end, are you going to try and disprove that?

But really the point I'm making is that a factory restriction may very well be to help low end drivability along with keeping things quiet, removing the restriction will always take away that advantage if it is so designed to be there.

+ What you said really defies what is possible since you're basically saying you can lengthen the power band using the same consistent profile, if that were the case engines would rev to infinity

[sergei]

on the 3s-gte you gain a shitload, enough to make a couple extra psi at peak boost.

This statement does not make sense. You are confusing overboosting with flow.
CT20b are notorious for overboost if you change the parameters of the exhaust and to some effect inlet. If your wastegate was working properly you would not see any boost gains once it reaches set boost level. As the matter of fact you are just confirming that by modifying inlet you create peaks and lows hence overboost issue is getting more prominent.

placement of the main air intake also affects losses and gains too. as low as possible means higher air pressure and colder air both yeild more oxygen to burn.

Let me approach this statement pragmatically:
Could you please tell me difference between 0.5m of altitude in pressure?
I will save you the hassle: ~5Pa = 0.00005 Bar.

Same applies to temperature between 0.5m difference.

These claims are scientifically unproven.
Placing filter too low means you are turning your car into road vacuum, and placing huge risk of sucking too much water in (you don't need to submerge the filter in puddle either, all you need is to exceed few tens of ml of water intake).

[gt4dude]

on the 3s-gte you gain a shitload, enough to make a couple extra psi at peak boost.

This statement does not make sense. You are confusing overboosting with flow.
CT20b are notorious for overboost if you change the parameters of the exhaust and to some effect inlet. If your wastegate was working properly you would not see any boost gains once it reaches set boost level. As the matter of fact you are just confirming that by modifying inlet you create peaks and lows hence overboost issue is getting more prominent.

placement of the main air intake also affects losses and gains too. as low as possible means higher air pressure and colder air both yeild more oxygen to burn.

Let me approach this statement pragmatically:
Could you please tell me difference between 0.5m of altitude in pressure?
I will save you the hassle: ~5Pa = 0.00005 Bar.

Same applies to temperature between 0.5m difference.

These claims are scientifically unproven.
Placing filter too low means you are turning your car into road vacuum, and placing huge risk of sucking too much water in (you don't need to submerge the filter in puddle either, all you need is to exceed few tens of ml of water intake).

you still haven't disproven that the factory air box bottom end and resonator setup is highly restrictive and robbing of potential top end power.

all you've proven is what is already commonly established that the gen3 head flows far more than 2 little 18mm wastegate ports can relieve of pressure.

the point about placing the air filter as low as possible (obviously low as possible means without risking hydrolock that would just be stupid) was that the engine bay heat rises, the source of fresh cold air is usually through a grille area placed at the lowest part of most factory bumpers.

in the case of a turbo, if it's sucking through a highly restrictive system it has to work harder to produce the same boost in the top end thats why its better at keeping the boost down.

[Tagged]

seems that how a intake system works is a hell lot more complicated than what I originally thought........

[sergei]

on the 3s-gte you gain a shitload, enough to make a couple extra psi at peak boost.

This statement does not make sense. You are confusing overboosting with flow.
CT20b are notorious for overboost if you change the parameters of the exhaust and to some effect inlet. If your wastegate was working properly you would not see any boost gains once it reaches set boost level. As the matter of fact you are just confirming that by modifying inlet you create peaks and lows hence overboost issue is getting more prominent.

placement of the main air intake also affects losses and gains too. as low as possible means higher air pressure and colder air both yeild more oxygen to burn.

Let me approach this statement pragmatically:
Could you please tell me difference between 0.5m of altitude in pressure?
I will save you the hassle: ~5Pa = 0.00005 Bar.

Same applies to temperature between 0.5m difference.

These claims are scientifically unproven.
Placing filter too low means you are turning your car into road vacuum, and placing huge risk of sucking too much water in (you don't need to submerge the filter in puddle either, all you need is to exceed few tens of ml of water intake).

you still haven't disproven that the factory air box bottom end and resonator setup is highly restrictive and robbing of potential top end power.

all you've proven is what is already commonly established that the gen3 head flows far more than 2 little 18mm wastegate ports can relieve of pressure.

the point about placing the air filter as low as possible (obviously low as possible means without risking hydrolock that would just be stupid) was that the engine bay heat rises, the source of fresh cold air is usually through a grille area placed at the lowest part of most factory bumpers.

in the case of a turbo, if it's sucking through a highly restrictive system it has to work harder to produce the same boost in the top end thats why its better at keeping the boost down.

Prove that the stock system is highly restrictive. ie.: stick a manometer in the inlet path before turbo and see if you get any substantial vacuum.

On the topic of 2x 18mm wastegates, I had them enlarged to the maximum possible and the over-boost still happened. They are in bad place for them to work without restrictive exhaust system.

My point is following: If your engine is stock standard, and your ECU is stock standard, there is no point of either fitting "high" flow loud exhaust or aftermarket inlet system. For starters your ECU will not take advantage of it (it will need to be retuned) and any HP you gain in the top you will lose more on the bottom (unless you are overboosting but that is not good gain).
Toyota is not stupid, they still had to make a good performer.

I agree - once you are starting to fiddle with Turbo/Boost and engine management, you can ditch factory exhaust and intake system. I also I agree that the bottom part of ST205 intake system is not the best, but if it was overly restrictive it would have been changed by Toyota to a ST205 specific part when they tested the car.

For some reason a lot of people think they are smarter than engineers with millions of dollar worth of gear and budget. In some cases (ie American car manufacturers ) these engineers don't do a good job, but in case of euro and Japanese, where the competition is tight, every single HP matters as it can sway sales.

Speaking of horse power, I was driving a Hyundai Getz other day, which apparently makes same power as my Ist, but it was phenomenally slow, and had a lot narrower power band, I think Hyundai lied about the power output (that is how competitive market is).

[RomanV]

IMO the reason for having such a small entrance to the air filter box...

The entrance to the box is generally in a high pressure area ahead of the radiator panel, where it's mostly sealed off except for through the radiator and into the air intake.

So you can have a smaller cross sectional area inlet to minimise the amount of bugs/rocks/etc getting in, to maximise time period between filter swap.

While not being too disruptive to overall flow, because it's in a higher pressure area than in the engine bay. As well as being air that hasnt been heated by radiator etc.

People have this hard on for cold air intakes as though it's some sort of new invention. Pretty much every car ever does the exact same thing from factory.

[gt4dude]

A cold air intake system that provides even a little bit denser air throughout the entire operation of the engine should help to even out the factory conservative AFRs so the gains you would see would not only be from the extra flow but also from getting closer to stoich

on the topic of 3sgte there is a whole lot more to be had than 250hp out of the box, as with most modern 2L turbos

[sergei]

A cold air intake system that provides even a little bit denser air throughout the entire operation of the engine should help to even out the factory conservative AFRs so the gains you would see would not only be from the extra flow but also from getting closer to stoich

on the topic of 3sgte there is a whole lot more to be had than 250hp out of the box, as with most modern 2L turbos

If you exclude EVO and WRX, most modern turbo 2L engines produce around 220-230Hp.

Another thing you said that Gen3 head flows so well you get overboost. Not true at all: I had Gen1 engine overboosting a CT20b turbo, so the head design has nothing to do with overboosting.