Obsoleteasian

iTrader: (5)

I am really curious if someone can prove the temperture difference after the turbo. Since it obviously does make sense that the air must past thru the turbo it is heated up very fast, which in turn the intercooler purpose comes into play. Now the question is, the air going into intake what is the tempertures. After the turbo. with shortram intake vs. stock intake vs. modifed version stock (monster intake).

MalibuJack

iTrader: (5)

Sometimes I think I should keep my technical answers short and sweet.. The short of it is with a turbo car, the benefits of drawing air from outside the car is negligable.. The air temp will still be high after the compressor.. Not only does the air soak up heat just from passing through the ductwork, but the turbo compresses the air, and GENERATES more heat.. Anyway, its always better to get FRESH air from outside, but my point was it makes little difference on a turbo car.. HENCE the INTERCOOLER. Put a thermocouple just before the throttle body, and measure the temp, I'll bet you will see very little difference regardless of where the air came from. I think this whole argument is academic anyway.. The stock Air Box can be a restriction, if you like the panel filter, go for it.. If you like the cone, go for it.. If it bothers you that much, take the cone, put it in a box, and use the duct-top from the stock air assembly so it sucks air from the fascia.

Turboniam

? If RMR's webpage is "so true" then it must not make any difference how cold/hot the air is when I run my car... so that means at 2pm during the middle of summer my car should run the same 1/4 and mph it does during the middle of winter running the car at 10pm at night???

Right?? No that is wrong!

The air temp is a HUGE factor going into the "filter/pre-turbo" ... even RMR should know that.

The FACT remains that there is a difference between HOT air vs COLD air because of the density of air molecules and you will make MORE POWER with cold air vs hot air.

If you guys are new to turbo cars, I understand, but I thought everyone knew this principle not from research/science, but from the butt dyno itself... drive your car during a hot afternoon and get on it... the car feels like it can't get out of its own way... then drive it on a cool morning... the car feels like it is running a 50 shot of nawz!

Turboniam

This is NOT necessary to know "after" the turbo because

1) no matter what temp the air going into the turbo, the turbo will only heat it up to X degrees.

2) with the turbo "heat" being a stable X degrees, you only need worry about the deviation of the "pre-turbo/air intake" temp. (leaving intercooler efficiency to another thread).

so... if you are driving your car on a 100 degree day.. the temp will be 100 + X = how hot the air is that the intercooler will have to deal with...

if you are driving on your car on a 50 degree day... the temp will be 50 + X = how hot the air is in that the intercooler will have to deal with.

Cold air is more dense which = more power, so 50 + X makes more power than 100 + X i.e. cold air > hot air.

Turboniam

1) no matter what temp the air going into the turbo, the turbo will only heat it up to X degrees.

2) with the turbo "heat" being a stable X degrees, you only need worry about the deviation of the "pre-turbo/air intake" temp. (leaving intercooler efficiency to another thread).

so... if you are driving your car on a 100 degree day.. the temp will be 100 + X = how hot the air is that the intercooler will have to deal with...

if you are driving on your car on a 50 degree day... the temp will be 50 + X = how hot the air is in that the intercooler will have to deal with.

Cold air is more dense which = more power, so 50 + X makes more power than 100 + X i.e. cold air > hot air.


Intake temps make a HUGE difference on turbo cars PERIOD.

You would see the exact same difference at the throttle body that you saw at the intake/pre-turbo... which means there IS a difference and the cooler the better.

This whole argument is scientific.

I agree that the stock air box "can/could be" a restriction, but the point is if it is between a panel K&N protected from the engine bay hot air vs an open element cone filter that SUCKS up all the hot engine air it can get, the K&N inside the stock air box would be better... however, the actual best answer I would assume is the Monster Sport Intake, but I guess we will have to wait for dyno numbers to see how much an improvement it is over the stock air box.

The bottom line is that I believe once you "new to turbo" guys drive this car around through 4 seasons, you will realize that there is no getting around the FACT that you want the coldest possible air being sucked up into the engine.

None of you guys disagree with larger intercoolers as upgrades... so why would you not realize that benefit of colder air to start with vs hot air???

nine4surfah

Thanks for the info!! I Appreciate the time you spent to enlighten us "new" turbo guys......Evolutionm.net is a great web page to inquire information......

thanks
-ran

Turboniam

Fireball

iTrader: (15)

If you guys are finished...

It's pretty easy to solve the debate if this air filter helps at all. David Buschur dynoed his Evo with the factory air box, and then took JUST that out and put the air filter on. He gained 4whp and 7ft/lbs of torque, just doing that. Dyno numbers are hard to disprove there.

So, in closing (no more arguments about cold air intake, this isn't one of them), it does help a little, and sounds way cool. Good spending of $80 if you ask me.

MalibuJack

iTrader: (5)

True.. I agree with the hot day and cold day arguments.. I just have to disagree with the under hood air vs fresh cool air on the same day at the same temp on this car that happens to get alot of airflow through the engine bay when moving. Like I said, I don't disagree with the theories behind all of the arguments because I've always been a subscriber to those theories. But I do think the lower restriction outweighs the difference in ambient air temp. I haven't seen a low restriction fresh air kit tested yet for this car, so until we see that compared to these items, its a moot point. And the temp at the throttle body is important because the cooler the air going to the cylinders, the denser the air.. so optimally, measuring the temp in that location is relevent since it measures the air density..

I just think that all things being equal (same day, same ambient air temp) the lower restriction outweighed the sacrifice of using under-hood air from that location.

Besides, I'm really one to talk, I bought the buscher air filter kit, and I already fabbed up an aluminum box that draws air from the outside.. so go ahead and flog me for being devils advocate..

MalibuJack

iTrader: (5)

Oh, and even though the filter was tested on the dyno, the gains may only exist on the dyno.. in the real world it could help more, or hurt more.. He could have run the dyno with the hood open so the air temp under the hood could have been close to the ambient temp in the dyno room.

MalibuJack

iTrader: (5)

Oh well, I'm done..

Turboniam

Thats EXACTLY what my response was going to be to the person that finally brought that up!

Going into this thread, I had already read about slight hp gains from going to a cone filter, but just as you stated, it is on a dyno and in the real world, or as I showed from my datalogs, 20 minutes after the dyno the filter could be majorly heat soaked and lose power over the stock unit from all the hot air being sucked in from the engine bay

Turboniam

I would really like to see the Monster Sport Intake or one similar to it dyno tested against the stock unit/ stock unit with panel K&N, and cone filter... but not only on a car that is cooled off and sitting with the hood open on the dyno, but one that has been driven for a half hour or so, leave the hood closed, leave the car running, strap it down on the dyno AND THEN see which system makes more hp... that would be closest to real world use.

ru4real

I agree, except that cars aren't strapped down in real world use, they move (rather quickly in the Evo's case). The dyno shop should have one or two large fans blowing air at the front of the car to simulate movement.

erikgj

iTrader: (2)

At leats on the evo VII the monster sport airbox required the Monster CF hood or some mods for the stock hood. I reaqlly do like that airbox also.

Erik