Questions about the stock air intake box/setup........... - The Unofficial BMW M5 Messageboard (m5board.com)

FAST 5 · 13th May 2003, 08:45

Hey Guys, having taken a good look at the stock air intake system, I noticed that there are "two" intake type tubes (one larger and the other one smaller) located & attached on the left side of the left air filter box. The right side air filter box only has one intake type tube attached to the air box (large tube).
Does anyone know why the left side air box has two tubes attached and the right side air box has only one attached to the air fliter box?
The inner lining of the right side (when facing the car) front fender has a small circular cutout hole, which would accommodate the smaller of the two tubes attached to the air filter box, but there isn't anything there/attached, why????
Last, how is DINAN's Cold Air Intake system any better than the stock cold air intake setup? The only difference I see between the two systems is that DINAN has there air filter located at the very bottom of the fender, and BMW's air filter is located at "mid-point" of the intake system. Would this make a difference? Also, DINAN rearranged the placement of the air temp. sensor. Other than the air temp. sensor, would DINAN's setup perform better than the stock setup??? Or is the customer simply paying for DINAN's fancy presentation with its carbon fiber tubes, to replace stock plastic tubes??? Thanks for your input & replies.
Robert

Matte · 13th May 2003, 19:30

L´ll take a wild guess risking that u call me a moron

Could the third tube, work as an wasegate, for over floud air to the vanos system?

Regards
Matte

TriflowM5+M3 · 14th May 2003, 00:21

Robert,

i wondered the same thing when i changed out my stg 1 bulbs for the new ones. I noticed that the stock airboxes have those secondary air inlets and i found this weird. I dont know how to explain this or how the dinan works as both you and i know...i dont have Dinan on my baby

XrayMD · 14th May 2003, 07:39

Robert...Tony (TonyS555) might answer this question better, but I do know that Dinan has two upgrades to their CAI. The first was to relocate the temp. sensors away from the engine. I can tell you that I think this made a big difference. If the temp. sensor is so close to the engine, it will read erroneously high readings and I think it will retard the timing and rob you of power. Vadim or Dave Z. would probably be able to confirm or refute this.

Second, the latest upgrade replaces the fog light covers with a cover that is open next to the foglight and also includes two metal "chutes" for lack of a better word that sit behind these open foglight covers and channel air (ram effect). When I first saw the "chutes" they didn't make any sense because I was looking at them wrong. They have a closed side with holes and I held the piece wrong and couldn't see how this would get more air in because of the restriction caused by the holes, BUT, I now know that the holes go on the bottom and allow water/rain to drip out the bottom and prevent water from getting to the filters. These also SEEM to work although I think there is an increase in intake noise (this may be a good thing...more air getting in...I don't know).

In the next couple days, Tony & I will get together and I'll use my Auterra to measure the intake air temp and MAF sensor flow rate for his M5 with the Dinan CAI, and my M5 with the Active Autowerke CAI. Will run both cars exactly the same so outside air temp and engine temp should be the same (except I have Water Wetter in).

I'll post the results...it should be interesting to see what's going on with these CAI systems.

FAST 5 · 14th May 2003, 08:31

I have a question for either one of you,
can a person simply purchase the temp. sensor relocating kit from Dinan and either do the relocating by yourself or by your trusted auto technician ? Would they sell it to a person who doesn't have the Dinan CAI system and only wants the temp. sensor relocating kit?
Thanks.
Robert

TriflowM5+M3 · 14th May 2003, 17:11

Dmn you robert...i was going to ask that same question...although im still going to look into making my own insulation stuff

XrayMD · 15th May 2003, 04:27

That's a VERY good question. I'll try to find out as I'll be at my dealership tomorrow. I do know that Dinan's CAI is $1999 and they quote 7hrs. labor to install and the upgrade kit is $499 and 3 or 3.5 hrs. Altogether, installed we're looking at a bit over $3400!!!

The upgrade kit ($499) consists not only of the temp. sensor and mounting hardware, but the "socks" that cover the air filters and the "chutes" and new fog light covers that allow more air to get back to the filters and keep water out.

Note: there really isn't any ram air effect here as there is no direct connection to the intake tubes like there is with the AA system. I'm not saying that there is a significant ram effect with AA's system either...but I'll know soon when I compare Tony's car with mine and get direct MAF readings.

It would certainly be a lot cheaper for me if I could buy the Dinan upgrade and integrate that with my AA system, rather than buy the Dinan CAI. Also, this would leave me with more $$$ to put towards StopTechs, or the ACS DFC suspension, or the M Advanced Driving course!

TriflowM5+M3 · 15th May 2003, 16:31

Steve,

sucker...i already bought the DFC! Take That...whos on top now!

StupidGrin8UP · 15th May 2003, 21:33

Quote:

Originally posted by FAST 5
I have a question for either one of you,
can a person simply purchase the temp. sensor relocating kit from Dinan and either do the relocating by yourself or by your trusted auto technician ? Would they sell it to a person who doesn't have the Dinan CAI system and only wants the temp. sensor relocating kit?
Thanks.
Robert

Be a little careful there. I remember listening to Steve Dinan lecture about the engineering they had done on the intake system. He said that it looked like the BMW engineers had made allowances for the higher temp readings. One idea was that there was a delayed tweak factor that the engine management software did that would allow the mixture to stay right as the engine warmed up. The moral of the story is that when they changed the mass air flow meter and the temp sensor they had to reprogram the car to use the information right. If you just move the sensor you will likely mess up your performance because the BMW engineers have already allowed for the current sensor placement. Dinan was convinced that he had improved the design by getting a better ambient air temp reading and taking that into account in the engine management software.

This was a few months ago so I hope I'm remembering it right.

XrayMD · 16th May 2003, 15:22

Well, I think I can safely say that that's not exactly true. My friend has an '02 with Dinan CAI with the upgrades and has the Powerchip, not the Dinan engine software, and his beast is running EXTREMELY strong. As long as Powerchip knows you've got CAI, they take that into consideration. I have the AA CAI but I know that the programming for our two cars is exactly the same.

The real issue here is warranty. Let's say I have the AA CAI and I manage to get ahold of the Dinan upgrade whicj moves the air sensor, etc. Suppose something happens to my engine. BMW might say, "Hey, you're not covered because this temp sensor is not integrated with the rest of a Dinan CAI system", and you wouldn't be covered by Dinan's warranty either because of not having the rest of the Dinan CAI.