lee101315

Long story short.

Removing the top of the airbox or installing a K+N cone filter lets the stock turbo spool about 300 rpm faster.

Intake temps may be slightly higher in traffic, but while driving you'll get cool, fresh air to the cone filter

TurboTommy

Yeah, this is what I was telling myself as well, many moons ago.
I was **** and decided to make sure.
I taped a temp probe to the cone filter (a good spot where I would feel the cone would suck from a good average temp location), closed the hood, and drove around.
70 degree weather
After warmed up, in slow traffic, indicated temperature was around 120- 130 degrees (and climbing if I was stopped)
Out on the highway, it never dropped below 90 degrees.
So much for cool fresh air when at speed.
I fixed that in a hurry.

V2Rocket

If anybody has the cone filter adapter and a filter they don't want after this thread I would love to take it off your hands...

TurboTommy

Read my last post.
I don't assume anything and don't like to buy into the hype of repeated misinformation.
I can only give you my testimonials from modding these cars for 15+ years and finding **** out for myself with many different configurations.
Get your turbo to breath properly and you'll feel the improvement right away; more than which can only be measured on a dyno.

Zuba951

Got it.., I was deleting my last post..lol
Thanks, I appreciate the info. What do you think about the square K&N in the airbox?
Brian

Ronin-951

I go along with the snorkel being fine to the 350 mark, and a general rule of thumb is that every 10 degrees of increased intake temp costs 1 hp. I would be REALLY surprised if my engine bay was running 90 degrees, even in the dead of winter, more like 190 with the IC adding to the mix. Sure. I could idle around and short shift, but that's not really the goal is it? kind of like worrying about Fuel Mileage in a SPORT CAR! As far as K&N replacement filters go, initially better air flow, but I can put three replacements in for the cost, so long term, I'd bet my restriction is less with el-cheapo's and a 5k turnaround.

toddk911

Yep and about every 15 degree drop in intake temps (measured at the intake) nets you 1 more psi of safety margin, as per Corkey Bell.

I have to slightly disagree on the winter temps. I don't have temps on a guage, but in 45 or colder with my MAF running right next to the fender hole after WOT full boost runs I pull over and the IC pipe from the IC to intake is the same temp feel to my hand as the outside sheet metal; cold. The manifold is luke warm. Yes, I can hold my hand flat on the intake manifold and not hot at all.

Not to mention the butt dyno feels it. And I spin tires, even on warmer pavement and warmed tires up through the top of 2nd and into 3rd.

JBrown

ok cool also i have an older LR MAF set up that i was going to install but i was thinking since i have it mine as well install it , i got it used on RN the MAF was sold in 2009 abd has the MAFterburner set up , are the newer MAF better then the older ones, is it worth spending 1k on a new MAF or keep the one i have, also since my car is dyno tuned will i need a new tune ? or can i just use the MAFter burner to tune if my A/Fs are off a little?

MarkRobinson

Keep in mind that our intercoolers are pretty damn efficient.

I had spent a few hundred on a cool PH "military grade" temperature gauge that would measure two temps + difference between them: neat.

During dyno testing back in '96 with my Powerhaus modded 2.5l, I was getting 325rwhp/335rwtq @ 1.1 bar with 247d temperatures into the intercooler & 99d out. In '99 I re-dyno'd again with further mods: 355/345 @ 1.2 bar, 268d into the intercooler & 99d out. Years apart, probably different months, temperature, humidity, etc, and even with hot non-snorkeled air and change in boost/charged air pre-IC temp, the outcome temp was exactly the same (same IC) at 99d.

I don't think the ducted intake cold-air works as much on Intercooled intake systems as much as cold air works on cooling the IC itself; yielding colder post-IC charged air temps. On NA cars, sure, the colder the better.

Mark

Ronin-951

Very interesting observations Mark, so that was Airbox vs Cone. Two more questions before I enter long term meditation, Was the hood open and outside cooling fans used during the dyno runs? And do you run the Aerotray?

doabarrelroll

This video sort of illustrates how ineffective these intakes are.

http://youtu.be/gCi2yo4UqPI

toddk911

Some time ago when CAI first started getting popular a car mag did back to back dyno tests on them. It showed colder air made more power than more hotter air.

I.E. 250cfm at 100 degrees made more hp than 300cfm at 150 degrees. Just a rough example.

TurboTommy

Mark, you're right; a very efficient IC goes a long way to nullify any compromised intake air temps.
To illustrate this we can take it to an unrealistic extreme and assume an almost 100% efficient IC. In that case it wouldn't matter one bit what the temperature of the air is which the turbo compressor sees. So, therefore an IC that's very efficient would have that tendency.
However, this is only in the context of the charge air temp in the intake manifold which the engine sees, which, of course is important because we all know that colder air is denser for more power.
But, there is this other little known turbo phenomenon: a turbocharger has to work harder to make boost from hot air as opposed to making that same boost from colder air. This would result in higher exhaust pressure to drive the turbocharger. It's not insignificant and this is where the real benefits are to making sure the compressor has access to cold air.

kevincnc

Tommy: Hey, I’ll tell you what. You can get a good look at a butcher’s *** by sticking your head up there. But, wouldn’t you rather to take his word for it?
Mr. Brady, Customer: What? I’m failing to make the connection here.
Tommy: No, I mean is, you can get a good look at a T-bone by sticking your head up a butcher’s ***… No, wait. It’s gotta be your bull.
Richard: Wow.

kevincnc

Disclaimer: No connection was intended between TurboTommy and Tommyboy..

It's the snorkel/airbox FLOW restriction that's the probelm. Get cold air to a cone filter through a MAF or even the AFM and you're better off. I don't see why this is so hard to understand.