[Johnny D]

Originally Posted by TheAxiom

I do, so let mw ask you - Besides a dyno, when will you be at 100% load and have no airflow?

I do, so let mw ask you - Besides a dyno, when will you be driving around with your hood open?

[Taskmaster]

I know, you've never been to a dyno and you don't know how they work, so it's understandable why you would think that such a suggestion makes sense. The whole reason the hood is open on a dyno is to promote airflow that you wouldn't otherwise have with a stationary car. Doing a dyno in the way you and others have suggested doesn't make any sense - but your welcome to so your own dynos I'd you aren't happy with the way I do mine.

[Dylanize]

Originally Posted by TheAxiom

Why would I dyno with the hood closed?

I think it would be more accurate for the open/exposed filters, because when you are driving most the air is being pulled from inside the engine bay. Definitely put some air flow towards the grills/bumper, but I think it would be interesting to see any difference between hood open/hood closed.

Just my input and yes, I do not know anything about dynoing.

[mike-y]

Originally Posted by TheAxiom

I know, you've never been to a dyno and you don't know how they work, so it's understandable why you would think that such a suggestion makes sense. The whole reason the hood is open on a dyno is to promote airflow that you wouldn't otherwise have with a stationary car. Doing a dyno in the way you and others have suggested doesn't make any sense - but your welcome to so your own dynos I'd you aren't happy with the way I do mine.

Any reputable dyno shop will have a HUGE industrial fan sitting in front of the car blowing air into the front bumper area, so the point about airflow is moot. They leave the hood open because they connect the rpm lead to a coil or spark plug wire. and they have the wires coming out of the engine bay connecting to their equipment. They can still close the hood, but not all the way, just resting on the latch, and do an accurate test.

dynoing an E90 that has an open element filter with the hood open is not going to as accurate with the hood closed because of the way the belly pan seals off the bottom of the car. When you are driving, the only fresh air coming into the engine compartment is through the kidney grills and radiator opening. Any air that passes through the radiator is also heated up.

Opening the hood is bypassing all of that, and you won't get true results.

[Taskmaster]

Originally Posted by mike-y

Any reputable dyno shop will have a HUGE industrial fan sitting in front of the car blowing air into the front bumper area, so the point about airflow is moot. They leave the hood open because they connect the rpm lead to a coil or spark plug wire. and they have the wires coming out of the engine bay connecting to their equipment. They can still close the hood, but not all the way, just resting on the latch, and do an accurate test.

dynoing an E90 that has an open element filter with the hood open is not going to as accurate with the hood closed because of the way the belly pan seals off the bottom of the car. When you are driving, the only fresh air coming into the engine compartment is through the kidney grills and radiator opening. Any air that passes through the radiator is also heated up.

Opening the hood is bypassing all of that, and you won't get true results.

Except the giant fan in front of the car doesn't even get close to replicating the wind speeds of the car at say - 80MPH. For the record, Jeremy from OE tuning also suggested that I dyno with my hood open for this test, and you'd be hard pressed to find anyone who disagreed.

[SDemetris]

Damn. dyno both ways.. problem solved... no need to keep debating which is more realistic. or get a DAq system and time some like 3rd/4th gear pulls from like 2k rpm to redline if you really want it to be realistic. a tenth of a second should show up there if there is any difference in power. and all you need is a vent gage that you can keep in your car afterwards anyways so its no money lost.

[mike-y]

Originally Posted by TheAxiom

Except the giant fan in front of the car doesn't even get close to replicating the wind speeds of the car at say - 80MPH. For the record, Jeremy from OE tuning also suggested that I dyno with my hood open for this test, and you'd be hard pressed to find anyone who disagreed.

Then they have a crappy fan. our shop had a huge industrial fan with sheet metal ducting aimed right at the front of the car. it was so powerful that we had to take the wheels off the back of it because it kept blowing itself backwards, lol.

also, most acceleration tests are done from a standing start, which is 0 mph, so you aren't getting any significant amount of airflow until toward the end of your run anyway. that's why it's more realistic with the hood closed imo.


Edit, I don't mean to bust your balls on this, I'm just stating what I think will give the most accurate results and minimize the margin or error.

Just do the best you can with what you have available.

[BeachsideF30]

I think I'd like to nominate this as an early winner for thread of the month.

[SDemetris]

Originally Posted by BeachsideF30

I think I'd like to nominate this as an early winner for thread of the month.

So do we have a thread that only has thread of the months on it? If not I nominate you to start that

[Taskmaster]

Originally Posted by mike-y

Then they have a crappy fan. our shop had a huge industrial fan with sheet metal ducting aimed right at the front of the car. it was so powerful that we had to take the wheels off the back of it because it kept blowing itself backwards, lol.

also, most acceleration tests are done from a standing start, which is 0 mph, so you aren't getting any significant amount of airflow until toward the end of your run anyway. that's why it's more realistic with the hood closed imo.


Edit, I don't mean to bust your balls on this, I'm just stating what I think will give the most accurate results and minimize the margin or error.

Just do the best you can with what you have available.

I'd like to see which shop you know of that has a wind tunnel fan - it would be the only fan capable of replicating the proper wind speeds.

The car will be dynoed with the hood open on all runs.

[mike-y]

Originally Posted by TheAxiom

I'd like to see which shop you know of that has a wind tunnel fan - it would be the only fan capable of replicating the proper wind speeds.

proper wind speeds at a standing start are zero. but it sounds like you have already made up your mind, so I'll stop reading this thread now.

[Dylanize]

Originally Posted by mike-y

proper wind speeds at a standing start are zero. but it sounds like you have already made up your mind, so I'll stop reading this thread now.

It'll be funny when all the best gains come from the exposed filters.

[AlpineSwift]

I think Gavin from MMW came up with a frankenbox setup a while back after experimenting with a few different intakes. The idea was to keep the stock box sans the carbon filter and stupid noise cancelling canister on the intake pipe, drop a K&N filter in, cut a hole in the unfiltered lower section of the box to mate another outside air pipe drawing from the fog light area. It was a bonkers setup when he explained it and showed photos but it made sense in the amount of air being drawn in increased aside from just the stock kidneys.

It's gotta be buried among hundreds of N52 related posts by now but its certainly worth looking into if you feel like digging into the past a bit on here.

[benzo23]

A sealed box, EURO or Stock w/ no carbon and a performance filter, attached with a dinan style ram air setup from the bottom is essentially the best setup on these cars. My euro box with pipercross foam seems to be the most practical setup for me. Are there any performance or sound gains? Idk but it helps me sleep better at night. If the OP wants to go thru with the test then go for it. It will be interesting to see the results either way. If I still ran my stock box I would wait for AA to release there green panel filter for n52's.

[Taskmaster]

Originally Posted by mike-y

proper wind speeds at a standing start are zero. but it sounds like you have already made up your mind, so I'll stop reading this thread now.

And at 50mph? 70? 100? You're right though, I have already made up my mind.

If you want to do your test that way, knock yourself out.

[Dylanize]

Originally Posted by TheAxiom

I'd say long tube intakes are the best type, that's what we determined last time

I just need to figure out a way to make one.

Yeah, most likely would be the best, space is rather limited up front in the e9x's.

Closest thing I have seen is some one mounted a flexible pipe in the lower grill, next to the brake vent and routed it up to a modified stock air box with a cone filter inside.

Basically a much cheaper Dinan intake system.

EDIT: This is an M3's intake, but thats pretty much what the dinan is.

[Taskmaster]

I picked up an injen intake - it has begun.

[Mike.]

Originally Posted by TheAxiom

I picked up an injen intake - it has begun.

Have you tried it out yet?

[Taskmaster]

Just bought it, so not yet.

[Taskmaster]

Anyone habve an AFE intake to donate?

[Taskmaster]

Got a baseline done, and my injen intake is in, just waiting on the rest of the parts.

[andrey_gta]

good on you. I hope the closed variants dyno well, since they are the preffered/recommended set up over the last year