Funny.

 

I dyno'd 350/350 with stock intake, stock LICP, and 100 octane at 26psi (spike).

The car ran an 11.97@116 the same week.

Most dyno passes are made with the hood open and fan crammed right in front of the intake. I'd like to see a dyno of an open air filter with the hood closed after the car has been flogged for 30 minutes straight.

 

Do the intake if engines are a big air pump why wouldn't you want more air. Just run one that uses the stock diverter valve to reduce noise. Let your engine breathe!!

 

i think im going to push my luck with the stock intake box. and going to look around for an inlet pipe

 

I tried the samco intake pipe and it made no difference at all. I don't think the lumpy stock intake pipe is any kind of restriction with the stock turbo. It is significantly larger than the turbo intake itself. The filter and MAF are probably the two biggest restrictions.

 

The biggest restriction is the stock snorkel. The entire engine has to breathe through that tiny opening. The OP can keep his stock airbox and pipe and get the benefit of an open element filter if he simply cuts the side of the stock airbox away from the engine. This will more than double the area for air to enter the box as well as keeping the hot air in the engine bay out.

 

But at speed that snorkle is a high pressure intake .... basically ramming cool fresh air into the filter. If you cut a hole in the box its quite possible the high pressure will bleed off into the engine bay.

Most of these conditions cannot be recreated on the dyno so supporting numbers are hard to come by. However if nearly stock 9s are running mid 11s on the stock unaltered box then why mess with a good thing.

 

That's hardly the case. Go and take a good look at how it is designed.

Your turbo at high boost pressures is spinning the compressor wheel at 120,000+ RPM. That compressor needs to suck in a lot of air. The more restriction is has, the more vacuum in the intake pipe and lower efficiency the compressor has and harder the turbo has to work.

It's the small area of the snorkel that is the issue. The snorkel is definitely good as a mini cold air intake, but it's just way too small by itself in area to feed that amount of mass airflow without causing excessive pressure drop. The poor turbo is trying to suck through that tiny straw.

It's been proven several times that the stock airbox is the restriction, a bigger restriction that the filter and/or maf. I even did tests myself when switching to a bolt on open element filter that showed this.

 

I was just looking at this a few nights ago while I was working on my custom cardboard cold air box. :-) As l2r said, the snorkel too small, and not only that but the weather strip on the hood sits directly in front of the intake snorkel opening. Air has to go between the break in the weather strip off to the side of the hood and then find its way back over to the snorkel.

 

So I assume you have done a few pulls with both setups. You used the AmsOil on the stock intake tube right? What mod did you do to the airbox lid. I have the right side of the airbox lid cover cut on mine and I am wondering if I should go to open air too. But I am woried about the hot air.

 

I had been running with a cutout in the side of the stock airbox lid for quite some time, probably 1-1.5 years. Switched to the Amsoil cone filter (with stock MAF pipe), and saw maybe 1/2 psi more boost at 7000 rpm, but no apparent increase in power. Post IC air temps definitely went up with the cone filter, at least 10 deg F despite having an ETS 3.5" FMIC. I've fabricated a cardboard cold air box that I'll be trying once I get my new fuel rail and rebuilt throttle body installed, hopefully next week. I'll be doing some pulls both with and without the cold air box.

 

PFFF... i would like to see you make 350 on pump gas with that sir.. 100 octane, thats not available at 99% of gas stations, hence why ppl go to intakes and cams, etc...

I could make 1000hp with solid fuel from the space shuttle..

 

I will find the exact pulls from the last time I did this, but I am not exaggerating the difference in the amount of power. If you log baro you will see the average kpa drop from ambient to final with the lid. With this off its 2-3kpa versus 9-10 with the factory setup and even a K&N in it. This equates into 12whp on a 338whp car the last time I tested it back to back. All I had done is pull the lid off no other changes.

 

what about ARC box intakes? i had scott from TTP tell me a couple years ago that it was holding me back from making good power. i was told that a cone intake was my best bet. im just wondering if he was full of **** or just trying to make a buck

 

Please keep us posted on your findings. I am thinking about getting a Perrin kit but the hot air part is holding me up. If I can get a custom airbox or shield I will try with an AmsOil. I am not sure if the stock intake tube is a real restriction on the stock frame turbo. I am now stuck around 350awhp on 93 on a Dynojet.

I saw a 5 hp peak difference between my dyno runs with mod airbox lid and works filter vs no filter and no lid on a dynojet. Same tune but a little leaner and a little more boost with no filter and no lid IAT were significantly higher with the lid off even with the hood open. This was on a real dynojet not a simulator.

Did you compare the logs with VDR with the stock airbox and with the AmsOil open air element?