mitsuguy

iTrader: (2)

First off, this really affects most all Lexus' that I can think of at the moment, though the testing was done on my personal 01 IS300. I also contemplated putting this in the IS300 performance section, but thought it proper that everyone see it. (plus, I'm the mod here and I want more people in my forum!)

Anyways, the test:

Short Ram Air Intakes - what you should know...
Intake tested - purchased from Ebay, a simple 3" polished pipe with a 45 degree bend at the throttle body end - PCV port, Mass air flow, and Evap solenoid ports are all in place, though the PCV port required a slightly larger hose to accommodate the diameter. Air filter used was a generic 3" conical air filter

Car test info:
2001 IS300, 96k miles, automatic 5 spd
Emanage Ultimate
AEM UEGO Wideband
91 Octane Premium fuel
Torque Android App / OBD2 Bluetooth Module
Stock everything else, Emanage not changing any settings

Stock air box in place:
Air temp outside: 68 degrees
Intake Air Temp:
@ 60 mph - 70 degrees
@ 30 mph - 70 degrees
@ idle, parked, heat soaked - 85 degrees

Short Ram Intake installed with 3" Conical air filter
Air temp outside: 69 degrees
Intake Air Temp:
@ 60 mph - 90 degrees
@ 30 mph - 115 degrees
@ idle, parked, heat soaked - 180 degrees

A/F Ratio (still no changes with the Emanage)
12.2-13.0 w/ stock air box
13.5-14.2 w/ short ram intake

Fuel Trims (still no changes with the Emanage)
2-4% w/ stock air box in place
16-18% w/ short ram intake

Summarized:
Many people replace the "restrictive" air intake with a short ram intake as their very first mod. Given the extra noise from the engine and the claims from manufacturers, many believe it makes them some horsepower. What most don't realize is that it also ups the air intake temperature - see above, sitting in a drive thru in less than 70 degree weather, the air intake went up to 180 degrees. Even when moving at 30 mph, it was still well over 100 degrees. It wasn't until highway speeds were reached (and had been moving for a little bit) that intake temps made it to 90 degrees, still over 20 degrees above ambient temperature. The factory air box does a very good job at allowing cool air into the engine by ducting air from outside the engine compartment. There is a general rule that says that for every 10 degrees in intake air temp, you lose (hotter air) or gain (cooler air) 1 hp. If this is true, this means that at a stoplight, I have just lost 10 or so horsepower. That is assuming the ECU doesn't pull timing because of the high intake temps and lose even more horsepower.

So, you've heard the claims of adding 10-15 horsepower. I'm not sure I've ever seen that proven, but, if it did add horsepower, I imagine it was on a dyno with the hood open and a fan blowing on the engine, in which case, you would be getting cooler outside air to the short ram intake, something not easily doable with the factory setup. Ever see a car on the drag strip missing a headlight? This is why - they use some sort of intake where the filter sits in the open in the engine compartment and removing the headlight is the only easy way to get fresh cool air to the intake.

I also checked 0-60 times by use of the Torque Android App. I realize this is not super scientific, but, no matter how many runs any way I did it, I always ended up with between 7.0 and 7.5 as a 0-60 second time. Most were around 7.1-7.2 seconds. Heat soak affects things other than the air intake too, so some differences may be attributable to that... One last thing regarding fuel trims and the change in air fuel ratio - I believe this is because of the larger diameter of the intake pipe. The factory is smaller in diameter than the 3" pipe that I purchased. The ECU doesn't know there is a difference, so, it is adjusting part throttle by looking at the feedback from the O2 sensors. It ups the fuel trim percentage because it sees an issue that more air is getting in to the engine than it believes. I personally believe that this high of a long term fuel trim (LTFT) percentage will eventually set the check engine light, as there are error codes specifically for this, and I have worked on cars with fuel trim issues less than 18% that this is right now. Under full throttle, I am seeing much higher air to fuel ratios. Lean is Mean, or so we say, so, the leaner air fuel ratios may mean slightly more horsepower (but this is probably negated by the intake air temps). In my experience, these new air to fuel ratios are too lean for consistent use and could lead to detonation. I will richen them up and see if we get any more power, but I doubt it...

So, short ram air intake - not a great buy (but they are cheap as can be), but they sound cool, especially once VVT-I kicks in...

For the record, I only purchased it as I will be using it as my upper intercooler pipe when I go turbo... At that point, I will be trying to figure out a way to get cool air to the turbo, as this under the hood air filter just isn't the greatest for performance...

LiCelsior

iTrader: (32)

nice job Cody.

mitsuguy

iTrader: (2)

Thanks!!!!

02Legend

iTrader: (3)

Very informative information.

BDSL

For those engineers or mathematicians and understand bernoulli equation in fluid dynamics,
ram air intake doesn't really have any performance gain until you hit really high speed (i.e. +200mph). And even still, the gain is fairly minimal...relatively speaking comparing to other modifications.

mitsuguy

iTrader: (2)

While in general I agree, its been a while since I looked at the numbers... It is possible to have some decent power gains at less than 200 mph, I believe Ferrari, for instance, has a car out now that only achieves its maximum horsepower while it is under way... The biggest advantage in a ram air system is the loss in obstruction in the intake tract and abundant outside temp air...

GS4_Fiend

iTrader: (22)

That is the reason why I never buy aftermarket intakes. You will lose low end torque in additional, you don't get the cooler air from the OEM intake as it gets the air further out on the engine so theres less heat compared to sucking hot air from the engine compartment. Hot air has less molecules, therefore, less air. It would only make sense if you had turbo, but not for OEM setup.

Lexmex

It's tough to do a good intake on a NA (Naturally Aspirated) vehicle. I started doing intakes in Mexico City to deal with the high altitude and lack of power that I got (it was not racing related at that time, and that came later) and sea level has made it more difficult in some respects because too much air on a ram air system (true ram air coming from behind a hole in a bumper on my RX300) is not read right by an unadjusted ECM (Engine Control Module). Right now, I have a short ram and yes it will suck up that engine heat. When I get the time to do something more constructive, I am going to try to work on a design that will take in some cooler air while not screwing up the ECM causing P0171 lean errors, but it's a tremendous trial and error to do on your own.

That's why when someone asks me what intake they would recommend, I can give them a few names, but I tell them that better to tinker with the muffler or something else for performance first.

Most of my early experiences was a nice roar at 3000 RPM and not much else until I did some better work.

Another thing I find and I get this on CL from time to time with new members. Don't expect a certain mod to be the "the thing". Certain items I have recommend over the years for performance or maintenance I do because they can clear up a certain issue, but they won't be the 'warp drive' to everything.

Even if you want to do a turbo, supercharger, nitrous or even some of the custom intake and muffler work I have done, my best advice is maintenance over modification. Get your vehicle running right (especially in this economy) and learn what makes it tick. In Mexico and true of the world and maybe other parts of the universe (I am sure somewhere in the universe right now someone is asking a question some discussion forum about parameters for getting their warp drive in tune when they have little budget), that you have to build up a vehicle before you can do extreme modifications. I saw a lot of crappy turbo set ups in particular at my track that ended up in vehicle disaster (blown trannies, clutches, you name it) because they put in the turbo and didn't build up the platform to support it. You may impress the crowd a few times at the track, but you'll tick them off when had to stop the show to drag the car away because your flywheel cracked.

onihc

iTrader: (1)

do you remember IceMan intakes? do these qualify with your statement? i remember magazine tests showed a significant gain, but it was done with the hood opened.

mitsuguy

iTrader: (2)

Yes and no... reason I say yes, is that, you do get the cold air intake effect, which is good, and yes, because it should be less restriction than the stock intake system...

No, because its not nearly as efficient as a proper ram air design... Look at how the ram air system is designed in a Ram Air equipped Camaro or even how the stock intakes work on a C5 Z06 Corvette... the air literally travels straight with no restriction whatsoever to the mass air flow sensor which is only an inch or two in front of the throttle body... it is nearly as restriction free as possible, with the air filter being the only thing in the way and almost no turns...

rayon78

Great information man.

James12345

I agree. Many short airflow boxes do add increased engine temperature to the air intake. I have used a duel flow pipe kit to pull in fresh cool air with great success.

mr3gs300

what I always wonder was they say cold air makes the motor work better go faster what have you, so what if someone made an air conditioned box around the intake feeding it cold air constantly

mitsuguy

iTrader: (2)

Cold air, yes... and if you could make the air intake charge cooled all the time, sure... problem is that you would lose more power through driving the electrical or mechanical cooling than you would gain...

GS4_Fiend

iTrader: (22)

Cold air means the air is more densed in the result of more air molecules. Hot air is less dense so you will get less air. More air = more fuel. Less air = less fuel, lean running condition.