Looking For Dinan E53 X5 CAI: D760-0534

[bcredliner]

Per 2002 Dinan Catalog the cold air intake system added 13 bhp at 5,700 rpms and 12 lb/ft. of torque at 5,700 rpms. It doesn't go away so you either are accustomed to the gain or something else is happening. There is no adaption that will compromise the tune though the ECU is always adapting the transmission to driving style. You could be driving less aggressively than when you first installed the tune.

Dinan tunes are historically on the conservative side though they are designed to match to Dinan Mods. I suggest adding the Dinan transmission software rather than Dinan Stage 2 tune since you already have a tune. The transmission software makes a big difference and is well worth the cost. It changes the shift points so you benefit more from what you got out of the cold air addition, it speeds up the shifts and makes them firmer. All benefits are especially noticeably in either manual mode. If you are in the full manual mode where you have to shift the transmission it will stay in the gear you select until you shift.

More air means more air out. There will be benefit from lower back pressure mufflers and a better sound comes with them.

[Plattus1000]

BCredliner,
I'm more trying to add my thoughts on what you said for the original poster's sake rather than being argumentative I apologize if it reads otherwise.
QUOTE=bcredliner;1057129]Per 2002 Dinan Catalog the cold air intake system added 13 bhp at 5,700 rpms and 12 lb/ft. of torque at 5,700 rpms. The CAI alone will never deliver these numbers on its own. DINAN is bending the facts a tad. You need the other stuff to see any real world gains. MAF, throttle body, engine software modification, exhaust with performance cats etc.

Dinan tunes are historically on the conservative side though they are designed to match to Dinan Mods. I suggest adding the Dinan transmission software rather than Dinan Stage 2 tune since you already have a tune. The transmission software makes a big difference and is well worth the cost. Trans software is a huge improvement but you can get a similar update for much less $ if you look around. As for the engine software---For a better hp:cost ratio of around $200-250 you can get better tunes from a local guy on Craigslist I've found or even ebay. They'll usually give you a copy of your original file and can tweak it after the flash to customize it for your needs and conditions.

More air means more air out. There will be benefit from lower back pressure mufflers and a better sound comes with them.[/QUOTE]

Adding headers and performance cats then a free flow muffler will do a ton. Running stock pipes and a fancy muffler will sound good

I did the whole Dinan dance on my last e39 540i 320hp. I didn't go with a supercharger but I was faster and sounded better than other 540i's but not anywhere near keeping up with an M5 at 400hp.

I thought about doing a Dinan CAI on the wife's 4.6is but after looking at her air box, I decided it was about as good a design as it gets and I would in no way have improved upon it with a CAI. Some very good evidence has come out stating that warmer air allows the fuel to burn better after more fully vaporizing by mixing with the warm (hot) air and that cold air unless turbo or supercharged and forced into the plenum is/can be derogatory to performance on some vehicles. Dyno test after dyno test have me believing the new math. CAI's sound/look cool but do very little on these bimmers compared to stock intakes which are already pretty amazing on e53's.

Just my 2 cents.

[bcredliner]

Originally Posted by Plattus1000

Adding headers and performance cats will do a ton. Running stock pipes and a fancy muffler will sound good

I did the whole Dinan dance on my last e39 540i 320hp. I didn't go with a supercharger but I was faster and sounded better than other 540i's but not anywhere near keeping up with an M5 at 400hp.

I thought about doing a Dinan CAI on the wife's 4.6is but after looking at her air box, I decided it was about as good a design as it gets and I would in no way have improved upon it with a CAI. Some very good evidence has come out stating that warmer air allows the fuel to burn better after more fully vaporizing and mixing with the warm air and that cold air unless turbo or supercharged and forced into the plenum is derogatory to performance.

Just my 2 cents.

The airbox gains were Dinan numbers and for the airbox alone. I didn't make that up.

Headers and high flow cats will also help but a muffler with lower back pressure is not just for sound. All of the above will make a difference but it won't be a ton. Dinan exhaust, including larger pipes was only worth 5 bhp and 4 lb/ft. torque.

I have a 4.6 with all Dinan engine mods less supercharger. The Dinan airbox was a noticeable improvement when coupled with all the other mods, exhaust and the associated tune. The airbox has a larger low restriction air filter and a larger pipe to the intake. When coupled with the larger MAF and throttle body so the diameters are consistent to the intake it maximizes the airbox benefits but the airbox numbers I posted were just for the cold air system.

Cooler air is denser which means there is more oxygen per same volume of warmer air. A cool day with a fair amount of humidity will result in more power than a hot dry day. The reason for intercoolers with turbos is to cool the air to increase power with the same amount of boost.

Would love to read evidence to the contrary. Can you post it?

[Plattus1000]

I'll go look now... (looking)
Agreed, the info comes from Dinan. The airbox alone won't do much, also agreed. A good muffler will reduce back pressure but some back pressure or resistance is a good thing or you would see cars run 5" pipe from the heads more often. I run free-flow cat-back dual exhaust on my wagon and it feels faster but I also have a 3:18 rear end so comparing my last 540i to this 540it is n/a.
Cold air being denser hence a higher amount of oxygen per measure of volume, agreed but it being the case doesn't help fuel combust in a mist form more than a vaporous state. It lessens the overall mixture and surface area of the fuel, takes longer to burn and doesn't burn fully as it would as a vapor. (still looking)

[Plattus1000]

Here's the tip of this debate iceberg http://www.m5board.com/vbulletin/e60...no-review.html loss of power after install. It's a "support upgrade" to support all the other stuff that you need to make it functional as designed. I had one, loved it but other than a cool sound and people touching it to see if it was really carbon fiber dinan stuff, it only helped because I had the other parts. (still digging)

[Plattus1000]

A Dinan rep-"JUST ADDING A CAI WILL NOT MAKE A DIFFERENCE UNLESS DONE IN COMBINATION WITH OTHER DINAN MODS." We have a CAI from the BMW factory...

In order to make use of more airflow, the throttle body would certainly have to be larger to accommodate the increased volume of air and the software would have to be updated to reflect the change. Again, here we agree.

Dinan’s website claims that their CAI system adds 12 hp and 11 lb-ft of torque. They also claim a gain of 10 hp and 10 ft.-lbs. of torque for their software. However, they caveat the CAI claims by stating that “a Stage 2 version of Dinan's Engine Software is available for optimum performance from the High Flow Cold Air Intake System as well.” I'm not a lawyer: it isn’t clear if Dinan’s claiming a combined gain or a cumulative gain for the two systems.

If you just want colder air for your ride...move farther North! If you want cool Dinan street cred, add the other parts.

[Plattus1000]

AFE Intake Dyno and Review! - BMW M5 Forum and M6 Forums

[Plattus1000]

Cold air intake, myth busters

Even better, this first post in the thread speaks volumes.http://www.bimmerforums.com/forum/sh...&highlight=CAI

[Plattus1000]

At idle sitting parked, you might actually get colder/denser air but you would need a bunch of it to significantly increase the density some 30° difference to notice. Once you're rolling, how much colder do you think the CAIntake air is verses the air from the stock air inlet?

[Plattus1000]

Any dyno-proven intake mods? 540i m62 E39 - Bimmerfest - BMW Forums

It helps (cai) on some cars as a stand-alone but here, unless you're prepared to go down an expensive rabbit hole, just do the exhaust, engine/transmission flash and save up for a supercharger or headers, performance cats, free-flow exhaust and a good muffler. Then, save the last mod to be the CAI and you'll definitely feel a increase of 12hp.

This was my old 540i e39
And I thought about doing the same thing to my wagon: adding the bigger plennum and everything. I've gone over hundreds of posts about cai's on e39 and e53's and find no evidence that it does anything on its own but look and sound cool. UNLESS you do other stuff too, then it all works to give you more hp. A software flash to your engine computer and trans will do more for you as stand-alone mods than anything on the intake side. Headers next, but an s/c is the only thing that'll make your eyes water with joy after the install.

I'm just trying to save you some money on superfluous stuf. if however you have a pile of it and will never go s/c and stay naturally aspirated, go dinian intake, maf, t/b, manifolds, coil upgrades, software flashes, headers, cats, exhaust and muffler.

You can always go s/c later and be glad you built a foundation for it to breathe.