AEM Cold Air Intake Review
05-04-20, 12:11 PM
#16
Pole Position
I am not sure how an open flap would make you lose low end power.
Question:
Why was there a secondary air intake flap in the first place?
Isn't that part of limiting intake for the Variable Valve Timing System?
If the air intake is disrupted by removing the flap, doesn't that affect the way the engine works?
I remember after fitting my Takeda system, the mechanic forgot to close the secondary flap before installing the filter element, and that causes the flap to remain stuck open as it was hitting the filter element head. That made the car sound great at the low end, but I definitely lost low-end power.
Why was there a secondary air intake flap in the first place?
Isn't that part of limiting intake for the Variable Valve Timing System?
If the air intake is disrupted by removing the flap, doesn't that affect the way the engine works?
I remember after fitting my Takeda system, the mechanic forgot to close the secondary flap before installing the filter element, and that causes the flap to remain stuck open as it was hitting the filter element head. That made the car sound great at the low end, but I definitely lost low-end power.
05-05-20, 03:37 PM
#18
Tech Info Resource
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The intake flap has nothing to do with VVT. It is primarily for noise abatement, but IS F owners have found modifying it to stay open all the time does reduce performance at the drag strip. It's better the way it comes from the factory.
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designo (05-05-20)
05-06-20, 02:16 PM
#22
Tech Info Resource
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05-06-20, 02:58 PM
#23
It could be that the tune is set up to maximize the low end torque the engine makes in the lower rpms and by increasing airflow without adjusting the tune, you may actually lose power?
Steve
Steve
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designo (05-06-20)
05-06-20, 03:22 PM
#24
Tech Info Resource
iTrader: (2)
It's really not clear why you lose power with the flap stuck open. It might be interesting to datalog intake temperature with the flap open and the flap closed. I have a suspicion with the flap open all the time there's more hot air getting into the engine just because the flap is not in a place where you would expect to find cold air, but the scoop that's always open is fairly likely to have cold air compared to the engine compartment ambient temperature. I also suspect it's a power loss that's brief, not sustained, which is why it definitely shows up on a dyno or a drag race, but I really doubt leaving the flap open would be a problem if the car is moving at any speed over 15 mph.
Given that all the aftermarket intakes do not do anything like this, whatever the difference is, it can't be dramatic.
Given that all the aftermarket intakes do not do anything like this, whatever the difference is, it can't be dramatic.
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designo (05-06-20)
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designo (05-06-20)
05-06-20, 07:01 PM
#26
Pole Position
good point, seems like folks from RR racing are right, temperature is a factor in the working on flap. We had the same setup in the ISF too?. I mean its the same design since 2008 when ISF came out which carried over in RCF/GSF possibly LC too. Lexus engineers won't notice to route the colder air to the Flap too so the internal motor temperature do not make you lose few HP.
It's really not clear why you lose power with the flap stuck open. It might be interesting to datalog intake temperature with the flap open and the flap closed. I have a suspicion with the flap open all the time there's more hot air getting into the engine just because the flap is not in a place where you would expect to find cold air, but the scoop that's always open is fairly likely to have cold air compared to the engine compartment ambient temperature. I also suspect it's a power loss that's brief, not sustained, which is why it definitely shows up on a dyno or a drag race, but I really doubt leaving the flap open would be a problem if the car is moving at any speed over 15 mph.
Given that all the aftermarket intakes do not do anything like this, whatever the difference is, it can't be dramatic.
Given that all the aftermarket intakes do not do anything like this, whatever the difference is, it can't be dramatic.
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designo (05-06-20)
05-07-20, 12:02 AM
#27
It's really not clear why you lose power with the flap stuck open. It might be interesting to datalog intake temperature with the flap open and the flap closed. I have a suspicion with the flap open all the time there's more hot air getting into the engine just because the flap is not in a place where you would expect to find cold air, but the scoop that's always open is fairly likely to have cold air compared to the engine compartment ambient temperature. I also suspect it's a power loss that's brief, not sustained, which is why it definitely shows up on a dyno or a drag race, but I really doubt leaving the flap open would be a problem if the car is moving at any speed over 15 mph.
Given that all the aftermarket intakes do not do anything like this, whatever the difference is, it can't be dramatic.
Given that all the aftermarket intakes do not do anything like this, whatever the difference is, it can't be dramatic.
I live in a very hot country, so yes it makes total sense that at low speed and traffic, heat soak is tremendous and affected my engine performance with flap open.
05-07-20, 09:03 AM
#28
I originally wasn't going to mess with an Intake kit. I was only going to opt for the K&N DropIn OEM filter. After reading this thread....I am going to go with.....
the Takeda Retain Stage 2 Cold Air Intake System
Any Negatives on this choice?
thankyou in advance
the Takeda Retain Stage 2 Cold Air Intake System
Any Negatives on this choice?
thankyou in advance
05-07-20, 11:53 AM
#29
Pole Position
I drank the kool-aid too and ordered the RR heat shield; I think eventually I will pair it with the takeda intake .
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RC51TOFUMA (05-07-20)
05-07-20, 01:06 PM
#30
Intermediate
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