GR Yaris Intercooler performance and lag
- Thread starter Onehp
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- #22
Nice gain on upper half of the rev range. This is probably entirely because of better flow and not lower charge temps as the stock IC was making requested boost and normal timing. Of course if you add a box, there will be more heat headroom as the OE charge temps were right at the limit (50C). More comments here.
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- Thread starter
- #23
Revisited the thread and I see there is no explanation why lower pressure drop over the IC renders power.
The ECU target a given boost at the inlet manifold, so that is the same. A lower pressure drop over the IC system means the boost at the turbo compressor is actually lower. So the turbo needs to work less hard/less rpm, meaning that the wastegate is actually more open. That gives less backpressure and thus more power.
There is another way too. If charge temps are lower, the ECU will actually target lower boost pressure. This then again makes that the turbo works less hard and gives gains in a similar fashion as above, although the raised boost at higher charge temps tries to compensate for that, there is probably a little gain. As charge temps spiral too high, the ecu will cut back on boost and reduce power even more.
Something like that.
The ECU target a given boost at the inlet manifold, so that is the same. A lower pressure drop over the IC system means the boost at the turbo compressor is actually lower. So the turbo needs to work less hard/less rpm, meaning that the wastegate is actually more open. That gives less backpressure and thus more power.
There is another way too. If charge temps are lower, the ECU will actually target lower boost pressure. This then again makes that the turbo works less hard and gives gains in a similar fashion as above, although the raised boost at higher charge temps tries to compensate for that, there is probably a little gain. As charge temps spiral too high, the ecu will cut back on boost and reduce power even more.
Something like that.
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What I've seen is that the ECU adds more timing advance, so here is the extra power coming from. I also notice the boost going up to 1.4Bar as normal, some times during a long pull in 5th gear it gets down, but the initial boost is 1.4
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- #25
Yes, generally colder charge air is beneficial for knock, although I actually haven't seen much changes in timing between 10=>50C charge temp, at most maybe 1,5 degree reduction... Maybe depends on other factors how sensistive it is...
Just some data to add to the conversation. Wasn't logging timing advance. Boost was consistently hitting 20psi. Stock intercooler seems to perform well at this temperature but summer might be a different story. Another thing to note is that IAT consistently sharply drops at >100km/h, so the stock IC will likely suffer at low speed tracks.
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warren_RS3
Dedicated member
- Apr 20, 2022
- 103
- 203
Interesting thread. Not something I'm thinking of doing to the Yaris at the moment, but it's often a neglected modification when people start looking for power boost and often overlook the implications of heat in the system because their first run dyno plot looks impressive on a winters morning!
A few guys who are looking at 1000hp stage 3 upgrades on A VAG forum are currently investigating these: https://fiinterchillers.com/
Anyone on here have any opinions on them or experience with using this kind of solution?
A few guys who are looking at 1000hp stage 3 upgrades on A VAG forum are currently investigating these: https://fiinterchillers.com/
Anyone on here have any opinions on them or experience with using this kind of solution?
- Thread starter
- #28
So I've had my Pumaspeed IC with involuntarily boost pipes for some while, and I can say that in my spool test, off throttle slowing down to 2k rpm in 6th then nailing it, the increase lag is very noticeable, takes about 50% more time to boost up the additional volume. However, the lower IC temp/lower pressure drop compensate the lag in mid/high revs, so in the end it feels more or less the same. But I missed my goal for less lag with an IC upgrade. However I do get some more top end power which was another goal.
If I did it again I should have gotten the smaller Scara73 with the OE boost pipes, but difference is too small for me to bother with the change now.
For big power, do88 is coming soon with a full height IC that looks really good from the development pics.
If I did it again I should have gotten the smaller Scara73 with the OE boost pipes, but difference is too small for me to bother with the change now.
For big power, do88 is coming soon with a full height IC that looks really good from the development pics.
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i'm a little confused,,,can you please clarify. the chart header gives 16C as ambient, yet the log does not show that at all. are you getting the data off the CANBUS and a factory ECU ? If so, can you help me. when i ve tried to do this i get ambient and intake temps as the same value (constantly) so ive obviously not correctly identified that part of the data string
Yes, in HSVs with the lsa. Kirk is a smart guy. I talked to him about changing the gry intercooler for one of his interchiller kit liquid cooled versions. I didn't go through with it but it was looking about the same price as some of these larger units with bigger piping. Maybe once someone down here does some ecu tuning I will go further.
Its an interesting subject.
On my Megane RS 275 circuit car I went to Wagner IC because I was loosing power over the course of a 15 minute track session especially in summer. It was twice as large as the OEM. However I got lag in the lower rpm range and it really spoilt the enjoyment of the car on the road for me. There was a noticeable delay when getting on the gas in 1 and 2 gears from the lights and just general driving. The power was there and on the track I was always mostly WOT or on the brakes and rarely below 3500rpm so it wasn't noticeable there. It solved the power loss issue. But it bugged me every time I drove the car on the road....
For the GRY even though its again a circuit car I decided not to go for larger IC and instead worked with a rally team to design and build a 8 pintel style nossle sprayer that is mounted directly above the OEM IC and triggered by a small 433mhz wireless button on the back of the steering wheel. It feeds from a 10L tank in the boot. So far the testing we have done has shown it works very well. In summer I will put ice in the tank to keep the spray water around 8c which would improve its thermal cooling benefits by a large degree. Once the weather is warmer I will test it further and once Im convinced I will the automate the system using a smart controller so its triggered by boost. ext temp, IC charge temp etc. Essentially it will become set and forget although I will only need to use it on the track. Data so far shows it also has a positive effect when used to the coolant temps so I assume that some of the spray is making it over the lower coolant radiator. The good news is the car is still a pleasure on the road and relatively lag free as it is from factory.
On my Megane RS 275 circuit car I went to Wagner IC because I was loosing power over the course of a 15 minute track session especially in summer. It was twice as large as the OEM. However I got lag in the lower rpm range and it really spoilt the enjoyment of the car on the road for me. There was a noticeable delay when getting on the gas in 1 and 2 gears from the lights and just general driving. The power was there and on the track I was always mostly WOT or on the brakes and rarely below 3500rpm so it wasn't noticeable there. It solved the power loss issue. But it bugged me every time I drove the car on the road....
For the GRY even though its again a circuit car I decided not to go for larger IC and instead worked with a rally team to design and build a 8 pintel style nossle sprayer that is mounted directly above the OEM IC and triggered by a small 433mhz wireless button on the back of the steering wheel. It feeds from a 10L tank in the boot. So far the testing we have done has shown it works very well. In summer I will put ice in the tank to keep the spray water around 8c which would improve its thermal cooling benefits by a large degree. Once the weather is warmer I will test it further and once Im convinced I will the automate the system using a smart controller so its triggered by boost. ext temp, IC charge temp etc. Essentially it will become set and forget although I will only need to use it on the track. Data so far shows it also has a positive effect when used to the coolant temps so I assume that some of the spray is making it over the lower coolant radiator. The good news is the car is still a pleasure on the road and relatively lag free as it is from factory.
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- #33
Set and forget is very very nice. Just fill up water when filling up fuel?
Can you log and see what charge temps you are getting?
I avoided Wagner because their piping and end tanks are big and optimised for flow, cooling and thus power, but not lag...
Can recommend the HJS cat, keeping everything OEM+ it really improves response and is probably the reason I'm not overly annoyed at the added low rev lag of my IC.
When I fitted the oem sprayer i did a lot of logging. It was taking 20.c out of the intake temps on hot days bringing them back down to about 10 over ambient max. It's a neat solution but my 6l tank only lasts 4 minutes....
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Yep 16 was ambient. Only intake and charge temps are shown in the chart. Yes factory ecu through obdlink
if you used the factory set up, thats totally expected. it uses washer nozzles that squirt water , not misting sprays. i have created a controller that links operation to boost and temperature that gives a lot more control than a simple factory switch. use a lot less water that way
many thanks for replying, but still confused , if ambient is 16C, how do you explain temps like 30C as intake??. what are the PID codes you are reading?
- Thread starter
- #38
Airbox opens a flap at approx >4000rpm which at lower speeds sucks in hot engine bay air, giving a steep rise in IAT temps (MAF sensor) (seen rise of delta 18°C on a single 3rd gear pull stock at most)
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Michael Knight
Totally Hooked
Boosting turbo makes air hotter - assuming the temps here were after ic not iat before turbo?
The engine oil is over 120°C and the engine bay is completely heat soaked. At low speed the intake air temp increases. Don’t know what else I can really do to explain
