Why do we trust dynos for intakes??
 

i'm thinking about replacing the OEM intake for mainly auditory reasons, but wouldn't mind a little extra throttle response and giddyup. i have been searching the threads and looking at dyno shootouts like the dsports one and i'm at a little bit of a loss:

1. The first way to dyno compare is to look at manufacturer dynos which is silly because there we can't make direct comparisons (i.e. no controls for the type of dyno, the car, the temp, etc. its not apples to apples)

2. the second way is a dyno shootout (like the dyno thread and the dsports shootout). in these shootouts the dyno runs are done in rapid succession after installs and the ECU has no time to recalibrate for the intake to run optimally for A/F ratio, etc. this is a big deal since many intakes "achieve" extra power pretty much from just moving the MAF sensor.

3. 99% of dynoing is not done in a wind tunnel and instead we have an open hood and a fan. that maybe works for testing headers and exhaust or turbos but the whole point of a good intake is to maximize airflow when the car is actually moving and the hood is down. when the hood is up for example we have no idea how the intake manages heat, and even with the hood down the fans aren't going to accurately reflect the air that goes in while driving. The gains observed from an intake dyno, unless extreme, are probably just as unreliable as the dreaded "butt dyno." The one exception i can think of is a true CAI like the perrin.

i guess that means reviews are important since its not like manufacturers and magazines are going to drag their cars and see if there is a discernible difference in acceleration. i guarantee the high end manufacturers and OEMs (TRD, HKS, Toms, etc.) are doing a lot of testing that is not dyno-based for these.

just thinking about these things as i shop intake options. i originally had an airaid intake on there from the previous owner and it sounded great, but the dynos showed that it lost a lot of power. now in this case i don't doubt that it lost power (though probably not the mentioned 16whp from the dynos here). the gospel here is to just use a drop-in filter and an intake tube, but i wouldn't be surprised if designs with a larger box for example are actually producing more power. After all Toyota themselves went with a much larger intake box on the TRD version (i.e. dramatically greater surface area for the filter and less piping to the intake manifold). Maybe there is something to that.

Now in my intake search I am mostly looking for quicker throttle response and a deeper, louder intake sound with the sound tube deleted. I'm starting to think that there are some intakes that may be worth the money as opposed to just going with the drop in filter. Thoughts?

The smart folks will datalog street runs to ensure the conditions on the dyno aren't too far off. It's really not that bad imo. The most practical way to select an intake is to look at the stock one and identify the restrictions. In some cases there are restrictions and sometimes they're pretty free flowing. It's important to keep the MAF reading properly too.

Based on my observations, high specific output NA engines tend to have pretty good intake and exhaust systems from the factory.

i get that . the whimpy filterbeing replaced with a drop in with larger surface area seems to help. i would think another weakness would be the sound tube. not that deleting it instantly helps without a corresponding redesign of the intake, but i would think the additional outlet for the tube lowers the velocity of air reaching the manifold or creates some type of drag (i'm not a scientist m8).

i agree that its hard to find extra power in a high compression N/A engine. I suspect the FA20 is basically the FB20 but with higher compression and Toyota's direct/port injection. The FB20 puts out like 150bhp, so Toyobaru has essentially already tuned this engine for ~50hp increase over stock. Any gains left are going to be small until you start talking forced induction.

I think that you are waaaaay overthinking this whole intake thing ......;)


humfrz

Gotta agree.
1. Accept that not all real-world conditions will me modeled on dyno.
2. Dyno with intake 1. Record.
3. Dyno with intake 2. Record

Compare 1 and 2 and make decision.
Not like there will be a 30 rwhp difference.

I do agree that it is useful to see what is different on a TRD part compared to stock!:D

The big thing is if you are going to do more mods the community seems to believe that any initial gains from an intake are flattened once you get a good header and exhaust any ways. But some intakes claim extra power, who knows if it is true.

I think the biggest difference after installing an intake or high flow filter was the noticeably better throttle response, cracking the throttle open more. I don't think that's really measurable by graph without some fancy monitoring equipment.

Uh... OEM pulls air from the same place as the Perrin (or GrimmSpeed or ...most...)

Also, there is no viable alternative, and it has been demonstrated a dyno is acceptably similar for most types of intakes. IAT is measurable, and varies based on a lot of things, and that's what changes the most when you start moving.

1. That's why people do baseline pulls. They're more useful than any manufacturer provided data would be.

2. Dyno doesn't tell the whole story, ever. For example, GrimmSpeed did a ton of work to make their setup not require MAF scaling, and logged a bunch of extra data.

3. See note about IAT. Measurable.

Dynos are a tool. They're often used without context to sell a product. But... What else is there?

All fair points, but assuming the rest of the car is stock it's a total waste of money and does nothing for sound or power.
Did mine and did jack all... with other mods (you mention the trd car) then probably, but on a stock car. Personally wouldn't bother only doing a CAI.

I love how the subject is dyno tuning for something as useless as an intake. Save your dyno tune budget (expensive) for something more meaningful like a header plus custom tune, or an fi kit.

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define "flattened"

for example a cat back exhaust on its own isn't going to add much if any power, but when you have headers installed the bottleneck is no longer in the initial cat. while you may get 0 whp from a cat back exhaust and 6-7 whp from a header, you might get something like 10-12 whp from a header and exhaust in tandem.

if your car is doing more on the back end with flow, it could probably also do more with intake flow.

I knew I'd be losing some power with my K&N intake but the sound makes up for it.

I honestly cannot say, but reading the intake threads made me think the only real problem with the intake is the manifold, which is actually too large for the engine. One member actually saw a power increase by adding material into the manifold to increase air velocity.

Now there are intakes that claim an extra 10 hp with a tune. They are also later additions, so maybe with extra time and research they figured out how to better the intake flow. The only way we'd know is to dyno an intake added to a car with a full everything else.