GR Yaris The New carbon Forge inlet duct :)

Finally did some logging. IAT barely goes up at all past 4k rpm, maybe 2 degrees, I was reading 20 to 22 C in 17C ambient. This compared to 14-18 degrees increase in IAT stock (5 degrees ambient) as soon as one went past 4k rpm, maybe someone with a stock car can chip in with data at higher ambients (15-20C).. This is for 3rd gear pulls to redline.

I've also understood that the stock intake flap is getting colder air at high (track) speeds, say 4th gear pulls. But I rarely venture there.

So I would say this intake duct is very effective in reducing IAT, I fully believe the Forge claim it reduces the IAT with 7 deg C on track and from my logging led to believe the gain can be even bigger on the street, driven hard in lower gears. I haven't experience a mushy throttle like I have done before at similar ambients (up to 20 deg C), however I've also added a HJS that skews this observation quite a lot. So it's practically void, but still logically speaking this must contribute to that feeling :)
 
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This is one of the engine mods I quite fancy as it makes logical sense to provide a cold air flow particularly under heavy load. However, I have one question. It’s a complex part to manufacture in carbon, but not in plastic, so I wonder why Toyota decided engine bay air feed was satisfactory rather than doing something similar given their resources?

I will consider a remap once I can be convinced someone has created something that retains all the factory safeguards, then an OPF back exhaust, but I’m tempted to leave it there on this car.
 
did drive today with just snorkel IAT was 4'C above ambient. Not that hot engine though (oil 90'C or less)
 
Matt said:
Noise suppression will play a bit part in it
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If they’d heard my passenger side curtain airbag rattle (before I fixed it) it would have been largely inaudible! But joking aside, it’s strange how they determine diff resonance is fine, but air noise is offensive!
 
That bit of cloth in the airbox is most probably there for noise reasons as now it's out I can hear the difference.
 
could that cloth in the airbox have any negative performance impact? airbox volume / flow?

I wouldnt remove it for a louder intake sound....but I def. will if it could improve performance.

imho its better to have a silent 400hp yaris than a loud one....as stock looking / sounding as possible. but the plus on sound should be minimal?
 
Michael Knight said:
did drive today with just snorkel IAT was 4'C above ambient. Not that hot engine though (oil 90'C or less)
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You mean without flap opening? Yeah then it's the same with the Forge one. Bit higher difference then in winter.
 
Tralien said:
could that cloth in the airbox have any negative performance impact? airbox volume / flow?

I wouldnt remove it for a louder intake sound....but I def. will if it could improve performance.

imho its better to have a silent 400hp yaris than a loud one....as stock looking / sounding as possible. but the plus on sound should be minimal?
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I don't particularly like the loud Yaris exhausts etc but I would like it to make some noise, it's part of the enjoyment for me. It's less enjoyable if there's no way to quieten it down obviously.
 
Tralien said:
could that cloth in the airbox have any negative performance impact? airbox volume / flow?

I wouldnt remove it for a louder intake sound....but I def. will if it could improve performance.

imho its better to have a silent 400hp yaris than a loud one....as stock looking / sounding as possible. but the plus on sound should be minimal?
Click to expand...
I think a bit of cloth in the airbox can only be a hindrance to airflow :)
 
So I’ve been thinking about this. People obsess about the underbonnet temps impacting air intake temps.

1) the mini snorkel is always taking in cold air
2) the high rpm vacuum flap can only open when car is under full load - eg at speed

so given the above this means the air in the bay that the high rpm vacuum flap pulls from must surely be getting some form of cold air that is passing through the grille/rads/ic? I’m not going to suggest it will be cold as you’ll get heat radiance from the engine etc., but it’s not a static pot of boiling hot air like when you are sat at the traffic lights on a hot day.

I’m torn between this and a panel filter or just bite bullet & go eventuri but I can’t settle on what seems like the most pragmatic option.
 
As reported above, I've been logging the completely stock intake, up to 3rd gear inlet temps rise 13-18°C (av 15°C?) as the flap open past 4000rpm. Maybe this is less pronounced in 4th gear (e.g. trackdays) but for me for backroad drives where speeds aren't very high but revs go abovr 4k rpm as often as possible, the Forge makes a very noticeable difference, as temps hardly go up (maybe 2°C) as flap opens with it. All the while keeping OEM filtering and the OE filter isn't restrictive at all.
 
I bought it and pending track use, the results are very noticeable as said above…and you keep the OEM filter and so on…which for me is good enough.

I would like to see how this combination of forge inlet duct and a less restrictive filter compares against full on aftermarket intake options from different manufactures…I wouldn’t be surprised if it’s better than some or most of them
 
For those who have done the install, can you please help by explaining how to remove the retaining clip from the wiring loom, circled in white in the image? I can't seem to get it and thus can't tuck it away under the bumper.
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