GR Yaris GR Parts Cold Air Intake

[sixtentouge]

Posting some detailed pics because I don't see much info. Originally bought it just as a "whatever." Only cost ¥33,000 from GR Garage.

I didn't think there would be much difference because I've tested the car with completely blocked stock (black) pipe, and it didn't make any difference, blocked or open.

Cruising at a sustained 2,000ish RPM on a dead-flat road, 33°C and 80% humidity. 30 second capture after all temperatures have stabilized shows a 4°C temperature increase over ambient ("Ambient Temp For AC" sensor is the one in the grille and not in the sun for this test) to the airflow meter ("Intake Air Temperature" in the MAF sensor). The data I have for the black pipe never showed less than a 6°C rise, usually a little more.


6-second pull in third gear from 3,000rpm to 6,500rpm shows a 12°C temperature increase over ambient, where it pretty much plateaus. Same conditions for the black pipe hit 50°C.

Was there a difference? Yes. A marked difference in second gear from 5,000-7,000rpm. I thought I was done, just taking a few AIT captures for fun, but never expected any tangible difference. Will now have to hook up high-speed data logger and quantify this... But first guess is that the ECU is pulling a significant amount of ignition timing due to the IAT generated on a 33°C, high humidity day. Even 5°C cooler at the MAF sensor is likely putting back some timing. We'll see soon...



This car has some titanium heat shielding and ducting that keeps the radiator air away from the lower duct, and at full throttle, the MAF sensor IAT runs pretty close to ambient (and makes significantly more power). Everything was removed for this test, and it was just a back-to-back, black tube followed by red tube. 60-second swap.

 

[4FGR]

https://www.gr-yaris.co.uk/threads/grmn-intake-duct.13566/?post_id=202329#post-202329

 

[sixtentouge]

https://www.gr-yaris.co.uk/threads/grmn-intake-duct.13566/?post_id=202329#post-202329

Strangely...I did a search there and over here, actually looking all of the threads in "Engines and Performance" on this forum

 

[Michael Knight]

started figuring own IAT's, moved to another topic.

 

[Yohz78]

Hello,

Bit of a naive question but the goal of lowering IAT is to lowering heat soak and to prevent the ECU from pulling timing which would make for a power loss ?

Would that a allow to better maintain power on track ?

Thanks !
EDIT : Also, where can I buy it ?

 

[Michael Knight]

Hello,

Bit of a naive question but the goal of lowering IAT is to lowering heat soak and to prevent the ECU from pulling timing which would make for a power loss ?

Would that a allow to better maintain power on track ?

Thanks !
EDIT : Also, where can I buy it ?

its all relative. with my A2 the intake temps are at 50'C after one pull so in that regard GR is quite good performer.
Hot air is less dense so you cannot make that much power if intake air is hot. that's one of the reason we like cold days here - they're good for turbo cars.

 

[Yohz78]

its all relative. with my A2 the intake temps are at 50'C after one pull so in that regard GR is quite good performer.
Hot air is less dense so you cannot make that much power if intake air is hot. that's one of the reason we like cold days here - they're good for turbo cars.

Cold day are the best days for turbo car indeed. My last track day was with 25°C ambiant and it was too much for intake & oil temp.

I'll only do trackdays during spring and fall now even with upgraded cooling. Best air temp are probably 10 - 15°C so tyre can warm up easily but intake and oil temp are under control.

 

[sixtentouge]

Hello,

Bit of a naive question but the goal of lowering IAT is to lowering heat soak and to prevent the ECU from pulling timing which would make for a power loss ?

Would that a allow to better maintain power on track ?

Thanks !
EDIT : Also, where can I buy it ?

The temperature of the air entering the engine on a turbo car carries a large ignition timing correction factor. So while the decrease in IAT will have a power increase simply due to increased air density (increased mass flow), the major player on a turbocharged engine is the ignition timing. A simple 10°C decrease in IAT can be worth substantial HP. This is also why a more efficient intercooler is worth more power than simply cooler air.

Then there's boost. On a car like the GR Yaris with ECU-controlled boost, the target (aim) will change with IAT. It has a base target surface, with correction surfaces for things like coolant temperature, IAT, etc. As the temps increase, the engine management will apply correction to the target, resulting in lower boost.

 

[Yohz78]

If I had the choice, I would go for both intercooler and oil cooler. I definitely felt the heat soak on track (even if honestly it is not that bad compared to other turbo car I have had). However my country is a bit stupid with car mods, pretty much everything is illegal ...

I think even intercooler are, I'd need other french to confirm

 

[Yohz78]

To bounce back on this topic, was this gr part CAI efficient ?

If yes, is there a way to buy it in europe ?

Thanks !

 

[sixtentouge]

To bounce back on this topic, was this gr part CAI efficient ?

If yes, is there a way to buy it in europe ?

Thanks !

I haven't had the time to do any in-depth data gathering, but seat of the pants is a very noticeable difference in power above 5K rpm, where it normally feels like it falls off. It just pulls strong to redline. Several attempts with identical results. Only takes about 60" to swap out on the side of the road, so when I say "back to back" testing, it really is.

Best guess is that there's a more direct path to the airbox, unlike the black tube with a large opening behind a 90° upward bend, so any pressure is just dumped. So if the GR tube delivers more air from the bumper to the air box, less air is being drawn through the lower duct, and therefore a lower IAT.

This intake comes stock on the Gen 2 GRY, so I don't know why it couldn't be purchased through a regular Toyota dealer that sells the car.