PDA

View Full Version : My CAI setup!



Brandon J
03-30-2008, 05:33 PM
I did this about 8 years ago and used diferent filters and sizes. I also had the metal bent so it covered the section by the MAF. Unfortunately, it wasn't worth it in the end because more dirt did get into the engine bay. Also, the heat shield did not stay cool. You will notice the shield get hot to the touch. Another note about shielding, it is a good idea to seal the top to the hood, so the shied has to butt up against the hood so prevent the hot gases that float to the top from getting into the shielded area. I noticed different power bands with shorter filter compared to a long type filter. I even had different set-ups where the filter bent downwards. Ultimately, the sacrifice of having this type of intake was not worht it as water and dirt got into the engine, the filter will rub somewhere if not tied well and create a hole, the extra dirt that gets into the engine from the filter is not good, careful with the old with some of the filters as that can affect the MAF, and the heatshield isn't really shielding heat. I difference to the touch of the filter is probably because air is getting to it from behind the light, but also because the engine is sucking in the hot air/ hot filter and cooling it off. To get a real cmparison with temperature is to take a reading of the stock filter in its housing and compare it.

healtoeit
03-30-2008, 08:35 PM
Well! I'm very happy with it! Works great and i can really feel the difference over the stock airbox w/ K&N filter. Sub 3k pull is a lot better and just keeps pulling the higher rpm you go. The best part about this thing is the sound when u get on it! So cool!

Feel free to comment, I would like some feedback, good or bad!

Cost: Filter: $57 (K&N)
Shielding: about $10, I used air ducting for air conditioning systems
I put shielding around the power steering pump because last time I was at the track the fluid was boiling over, I don't want to risk that getting in my engine! I put the temperature sensor under the intake, same temp just not filtered.

http://members.roadfly.com/Ohmess/Alex/CAI 1.JPG

http://members.roadfly.com/Ohmess/Alex/CAI 3.JPG

http://members.roadfly.com/Ohmess/Alex/CAI 4.JPG

http://members.roadfly.com/Ohmess/Alex/CAI 5.JPG

Dave M
03-30-2008, 10:00 PM
Do you believe the intake air temperature is lowered with this set-up? If i had to guess, I would say the intake air temp has increased as you've moved the feed from a relatively isoltaed area behind the headlights to well within the engine bay. If the shielding provided a true funnel for cool air from the grille (remove high beam and place filter further forward...........), it might get even faster ;).

Maybe the 'seat of the pants' performance increase is attributable to the filter (realistic??), or, to the cool sound it now makes.

Either way, looks like you had fun with it,

Dave

healtoeit
03-31-2008, 08:18 PM
Do you believe the intake air temperature is lowered with this set-up? If i had to guess, I would say the intake air temp has increased as you've moved the feed from a relatively isoltaed area behind the headlights to well within the engine bay.
The air flow from the radiator goes past the heat shielding, after driveing the car at operating temp for about 12 miles, I stopped and stuck my hand on the heat shielding and to the area infront of the filter, and the area on the other side of the heat shielding. The heatshield itself was warm, making me think im going to move the filter itself up a little bit. The air inside the shielding was outside air temp, mabey a little warmer. The air on the other side of the heat shield was HOT. Although it looks cheesy, I think it works



If the shielding provided a true funnel for cool air from the grille (remove high beam and place filter further forward...........), it might get even faster ;).

I dont know the exact power figures but, I can really tell when i step on it, the thing pulls a lot better then it previously did with the stock airbox! Taking the headlight out is actually my track set up lol!

Qube
04-01-2008, 12:52 AM
You'll get a better sounding low end, coupled with a proportionate loss of torque therein. You may not notice it because the sound makes your butt dyno all giddy :) I live with it that way.

Blitzkrieg Bob
04-01-2008, 01:36 AM
Don't ebay your stock air box just yet!


You'll be putting it back in after your MAF craps out

Ferret
04-01-2008, 06:42 AM
Dido

White flag?

Someone pass my flame retardant jacket?

Ohmess
04-01-2008, 08:24 AM
Don't ebay your stock air box just yet!


You'll be putting it back in after your MAF craps out

What is it about this setup that screws up the MAF?

healtoeit
04-01-2008, 09:50 AM
You'll get a better sounding low end, coupled with a proportionate loss of torque therein.
I've never heard of a loss of torque from a Air Intake! Can you explain more?!

healtoeit
04-01-2008, 09:51 AM
What is it about this setup that screws up the MAF?
Dido

healtoeit
04-01-2008, 10:23 AM
Thankx for the input!
What would you suggest? should I make my own Airbox that is open to the same area that the stock one was? I was thinking of making a Y shaped box with an opening toward the headlight. Would this be ideal?

Another thing, you stated that dirt gets into the filter. From where? Is it the area above the fog light/under the headlight? I was planning on putting something there to creat a shield from dirt if thats the case!

I like your idea of closing off the top. I didn't think that the gap I created b/t the current shield I have and the hood was too much, but if it seems to be I will close off the top.

To get a real cmparison with temperature is to take a reading of the stock filter in its housing and compare it.

Is their something to be said for the smoothness of the airflow? i.e. not having to swirl around inside the stock airbox? and instead being filtered and going strait into the engine?

e34_Jay
04-01-2008, 10:50 AM
Thats not even a CAI intake, its just a short ram intake. True cold air intakes will have the piping with them and usually will go down dowards the headlight to get further away from the engine.

Qube
04-01-2008, 11:23 AM
What is it about this setup that screws up the MAF?
- oil deposits forming on the MAF sensor, attracting dust, screwing up readings

I've never heard of a loss of torque from a Air Intake! Can you explain more?!
- the most obvious is idling at a light. When you take off, it will suck all the hot air radiated and sitting in the engine bay. The stock airbox ducts behind the headlights and sucks cooler air, whilst somewhat isolated from the engine bay. At speed, you may not ntoice this, as you have the cooler air coming in.

Good effort though. I still say the rubbermaid is still the best intake done for this car :)

Robin-535im
04-01-2008, 11:59 AM
Not trying to sound like an a$$ or anything :) , but E34's come stock with a cold air intake.

The air box is specifically engineered for the engine, presumably to maximize engine power across a wide range of conditions.

I had a setup like yours on the car when I bought it. Around 3-4k RPM it had the meanest howl and really sounded like a monster... but I did some tests with my butt dyno with swapping back in the original box.

The original box had noticeably more power, but not the roar, so I kept the original box. Stock box has a venturi nozzle that admits only outside air in the front that accelerates the air and, if I recall my fluids class, will slightly pressurize the air box at speed to increase air flow over an ambient pull from the engine vacuum.

Jon K
04-01-2008, 12:10 PM
I have a cold air intake, it works really well

AngryPopTart
04-01-2008, 04:38 PM
Do the MAF equipped cars have the same venturi as the AFM equipped cars?

healtoeit
04-01-2008, 06:17 PM
What is it about this setup that screws up the MAF?
- oil deposits forming on the MAF sensor, attracting dust, screwing up readings


Thank you!



I've never heard of a loss of torque from a Air Intake! Can you explain more?!
- the most obvious is idling at a light. When you take off, it will suck all the hot air radiated and sitting in the engine bay. The stock airbox ducts behind the headlights and sucks cooler air, whilst somewhat isolated from the engine bay. At speed, you may not ntoice this, as you have the cooler air coming in.

Good effort though. I still say the rubbermaid is still the best intake done for this car :)

I noticed the hot radiated air being sucked in after sitting at a stop light... What could I do to improve this?

healtoeit
04-01-2008, 06:21 PM
Not trying to sound like an a$$ or anything :) , but E34's come stock with a cold air intake.

Not at all man! I know the stock air box takes air from a cold location, but i was trying to maximize the air that could be sucked through the location that the stock air box was taking air from.

Thankx for the input!

healtoeit
04-01-2008, 06:21 PM
White flag?

Someone pass my flame retardant jacket?

?

healtoeit
04-01-2008, 06:22 PM
True cold air intakes will have the piping with them and usually will go down dowards the headlight to get further away from the engine.

Thats the effect I was going for but i need to get more tubing to complete the routing that you are speaking of.

healtoeit
04-01-2008, 06:27 PM
I difference to the touch of the filter is probably because air is getting to it from behind the light, but also because the engine is sucking in the hot air/ hot filter and cooling it off. To get a real cmparison with temperature is to take a reading of the stock filter in its housing and compare it.
Thank you for the input! How would you suggest I cut the hot air being sucked in? You seem to be going through the same steps I have!

healtoeit
04-01-2008, 06:28 PM
I have a cold air intake, it works really well

I think mine costs a little less.

Just Mabye ;)

AngryPopTart
04-02-2008, 03:44 PM
Not at all man! I know the stock air box takes air from a cold location, but i was trying to maximize the air that could be sucked through the location that the stock air box was taking air from.

Thankx for the input!

Here: http://www.bmwe34.net/e34main/upgrade/Air_filter.htm

tjar66
04-02-2008, 06:14 PM
I agree with the statement that the BMW airbox is about as good as any CIA and I agree that you will lose minimal HP and TQ by going with a free flowing intake. However if you can get the same amount of air to the engine quicker wouldn't a faster spooling engine be worth a couple HP and ftlbs?

healtoeit
04-02-2008, 06:15 PM
Here: http://www.bmwe34.net/e34main/upgrade/Air_filter.htm

Well! I had read that article before, but I do not remembeer the UUC comment being there! Thank you, as of now im futzing w/ the intake I put in the car to see if It will work, however I have a feeling the stock airbox is goin back in soon!

skr
04-02-2008, 06:22 PM
now that's some ugly shielding... and zip ties? what ever happened to a clean install?

healtoeit
04-02-2008, 06:29 PM
now that's some ugly shielding... and zip ties? what ever happened to a clean install?

Mowing the lawn (time crunch) and not having a rivet tool (to make brackets).

What is wrong w/ zip ties? they holds my throttle cable in place!

healtoeit
04-02-2008, 06:30 PM
However if you can get the same amount of air to the engine quicker wouldn't a faster spooling engine be worth a couple HP and ftlbs?
Can you explain more? Do you mean raising the red line (which I cant do)? or getting a lightweight flywheel? something like that? lol

Robin-535im
04-02-2008, 11:34 PM
I agree with the statement that the BMW airbox is about as good as any CIA and I agree that you will lose minimal HP and TQ by going with a free flowing intake. However if you can get the same amount of air to the engine quicker wouldn't a faster spooling engine be worth a couple HP and ftlbs?
Well... I wouldn't quite put it that way... the BMW airbox is better than any other system *I've* ever seen or heard about. You're right about the air flow but the point is that the stock box IS the fastest way to get the most air.

High performance naturally aspirated engines are a keystone of BMW, the fact that they can get 100 hp/L from 5 liter NA engines is evidence of that. They have engineers with air flow models and spend a lot of money designing and modeling and testing with that exact engine in that exact chassis to come up with an optimal solution. Smart guys with PhD's in fluid dynamics, who speak German and know all there is to know about temperature dependent, compressible, dynamic, turbulent fluid flow. Not just the air box, but the entire system from the front of the car through to the exhaust is tuned as a unit. If a straight tube had advantages they would surely use it (and in fact parts of the intake are straight tubes, where it makes sense.

The odds are very much against accidentally hitting on a solution that improves on the system that was purposely designed with such vast resources, from a company that is perhaps the world leader in doing exactly that. It would be like someone who never played tennis stepping on the court and beating Roger Federer (http://en.wikipedia.org/wiki/Roger_Federer). As a scientist I'll admit that theoretically it *could* happen... :)

The counter example of course is that BMW's design point is a mix of performance and luxury, and guys like you and me will toss out all the luxury for a little performance gain. We'll happily use only high-octane gas if it lets us bump the timing up a wee bit, and will happily machine out the head and add a more aggressive cam to trade longevity and smooth idle for a wee bit better air flow... BUT for air flow, max flow is still the optimal design point whatever the application. SO... there's no reason to think that anything us mere mortals will come up with would be better than what the world experts came up with. ;)