Gernby

iTrader: (1)

It might be brave, but I would be more concerned about it having enough CCAs to crank the V6. It actually seemed more powerful than the OEM battery in my S2000 even though it weighed 24 lbs less. The S2000 battery already looks like something for a lawn tractor.

al503

First, the difference in power wasn't a power hump. It was more of a power dip/shortfall in the stock intake run. Second, comparing a DI v6 to a inline 4 vtec screama is probably not apples to oranges but it might be granny smiths to red delicious. Your point is well-taken however as they are both internal combustion chamber engines. Third, applying occam's razor, I would argue that the least complex answer is still the inability to keep the car from downshifting and the feathering of the throttle that causes the dip in the stock intake plot.

When Das does his dyno testing, he has stated that he won't test below 4x00 rpms where the engine can't kick down under any circumstances with the throttle floored. I believe they are looking at some means to keep the tranny from downshifting at lower rpms but that requires some electrical work that may or may not be done. I'm hoping that they hack it (as long as there is no chance of permanent issues arising from it) so we can all see if there is an actual, very prominent dip in the powerband with the stock intake, which I highly doubt.

I guess we should differentiate the heat soak as I see two distinct 'issues.'
1. Heat soak from the metal intake tube: as you concede that heat soak will not last for more than a few seconds, those few seconds could and can make a difference in the 13+ second 1/4 run. The insulation is a great idea. I think the best intake would be the stock intake box (or similar) and a straight pipe like JoeZ's that's either made out of a rubber/plastic type material or taking JoeZ's pipe and wrapping it with the insulation.
2. Heat soak from drawing in hot air from the engine bay instead cooler air from outside the car: I think someone from the testing mentioned something about having engine temp issues when they had the hood closed with the fujita. This is what I was referring to in this thread. As I stated before, it's just like being stopped at a light or staging area before the 1/4 mile. You're not moving so the intake is going to suck in the hot air from the engine and put it back in the engine, etc. Sure it'll cool down after you get going but if the needle is moving higher from it's usual position, it's probably going to take more than a few seconds to cool the entire block down.

lobuxracer

iTrader: (2)

There are about a dozen reasons why all this stuff about CAI is not well thought out. First, IAT is a poor indication of thermal soak because it's at the front of the tube, not at the throttlebody. You're not measuring the air temperature at the throttlebody because you need to know the air density, so the MAF is in a spot where the airflow is relatively undisturbed (or at least it should be).

Then we've got a fundamental law of physics to overcome. Any fluid moving from a high pressure region to a low pressure region is endothermic. So what happens when the air goes through a partly closed throttlebody? It gets colder. That's why those "idiot" factory engineers plumbed hot water to the throttlebody - to prevent it from icing up and sticking open or blocking from ice under certain conditions.

So the only time we can even come close to inferring the actual air temp arriving in the combustion chamber (which ALSO has a strong endothermic action going through the intake valve) is when the throttlebody is at WOT and there is no vacuum registering in the manifold.

Let's add to this the real reason the whole import CAI thing got started. A smart guy noticed the OEM tube was collapsing at WOT on a particular car. The material was too soft when the engine compartment reached operating temperature. When the tube started collapsing, it made a significant restriction. Being the bright guy he was, he made a metal tube and eliminated the problem.

This did not go unnoticed by the OEMs. They're using better materials these days. So, if the intake tube isn't collapsing and making a restriction, what does the CAI net you? Not much. A dent in the wallet. More noise that the OEMs can't afford if they expect to meet EPA noise requirements. It can also introduce problems because it has a resonant frequency. If the guy designing the thing actually addresses this issue, you might pick something up, but it won't be without a corresponding loss somewhere else. Hopefully that loss is outside normal operation.

I'm very skeptical of aftermarket intake claims. Maybe you can tell?

Gernby

iTrader: (1)

I'm surprised, and a little embarassed that I haven't really done much searching around under the hood on this car, but someone mentioned earlier in the thread that the stock intake has TWO resonators. I just checked it out, and sure enough, there is another one on the snorkel. I just removed the snorkel to see how much of a difference it made in sound, and found that it REALLY DOES! I don't know if it sounds like the Fujita or LMS, but I imagine it does. Since removing the snorkel makes it a hot air intake like the LMS and Fujita, I would REALLY like to see some dynos (like the one in this thread) done with the snorkel removed. I imagine it would come pretty close, and still provide a similar sound.

BTW, removing the snorkel is super simple. There is just one clip and one 10 mm bold at the top.

Gernby

iTrader: (1)

I went ahead and removed the 2nd resonator (with a dremel) and blocked the hole so that it would still be a "cold air intake" and hopefully deliver more sound. Removing the resonator didn't make as much of a different in sound as removing the entire snorkel, but I added both setups to my previous bumper cam intake video.

http://d.turboupload.com/d/882493/In...isons.wmv.html

Gernby

iTrader: (1)

I seriously doubt heat soak from a metal intake pipe would be an issue in any case other than stop and go traffic. On the track, the pipe will be at it's normal operatiing temperature within a second or two, and I can't see that making even a 10th of a second on the drag strip. In stop and go traffic, it would still be a second or two, which would be more irritating.

Anyway, here is the picture that I tried posting a few days ago, but couldn't due to issues with CL. This is the Thermotec insulation that I put on the CAI in my S2000 with no measurable results (via OBD-II).

Gernby

iTrader: (1)

I haven't researched where the IAT sensor is, but on my S2000, it was in the intake manifold. Any measurements I made on it were done under controlled circumstances. I would drive on the highway with the cruise set at 60 MPH for 15 minutes, stop in a parking lot, and start recording temps. I did this with my stock intake, CAI, CAI with thermotek insulation, and CAI with thermotek insulation and teflon intake manifold gasket. The biggest difference came from the manifold gasket. All of my temp measurements while driving were done at extended periods of WOT (60 - 140 MPH). The biggest difference there was from the CAI. My IAT there actually went a degree below ambient (obviously due to vacuum at the sensor).

lobuxracer

iTrader: (2)

Toyota always puts IAT right in front of the MAF. It's a packaging decision. The true IAT at the manifold is pretty much academic as long as you have a measuring point and its response is consistently predictable. If it gives you a clear picture, then what happens after that isn't a big deal. It always happens the same way, so the absolute numbers are academic.

Another "interesting" thing: MPG guys like to play with IAT to maximize thermal efficiency. They tend to like to heat the intake air to promote better fuel atomization. Just another interesting variable out there to consider.

al503

Don't know too much about the fuel atomization for MPG thing but raising the intake temp 10-11 degrees = 1psi less air that you can stuff into the cylinders.

Pittdawg

Can't we just test all these intakes on a manual 250 and be done with the auto tranny upshifiting/downshifting choice of gear drama, sheesh!

MeTrO

yah, but no one would accept those results as translating over to the 350, which is what more people are concerned with. I do think it's a good idea though.

Hip_hop77

the only way your gonna be happy is to try it out...
dont liesten to wat ppl say.. its too much of a personal opinion...
so try it and dont like it? than trade with someone.. or sell it..