Ramjet31

Does anybody have recommendations for '07 550i performance upgrades such as Dinan in Southern California?
Thanks

acuteperformance

You won't find many fans of Dinan on this forum. Here is a list of recommendations you'll get and I sell them all.

RPi Induction Kit (BMC Filter + Air Scoop) 7-10 whp | http://acuteperformance.com/ram-air-...5-series-p-165

RPi GT Exhaust Axle Back (Click Link for Dynos) | http://acuteperformance.com/exhaust-...5-series-p-155

No CAI that I know of have given proven gains so I would pass on that. You can do an ECU tune but for the price not really worth it since your car is NA.

Michael
Acute Performance

zen68

I understand you want to sell RPI and I respect that but this is not an accurate statement.

To the OP, please do a search under "Part Accessories and Mods", you'll find more answers to your question.

Last but not least

acuteperformance

I should reiterate as what I posted was a bit misleading. Pros and cons from what I know about Dinan and the information I've read across many BMW forums.

Pros
* Dinan will cover the rest of your OEM warranty, but keep in mind BMW NA will NOT.
* Name. Dinan does carry some brand recognition.

Cons
* Expensive power to cost ratio. Better options out there that will give you more for your money.

Here's a link to Dinan 550i http://www.dinancars.com/store/home.php?cat=430

Even before I had my own business, I would NEVER recommend Dinan. I just couldn't justify a good reason to purchase them over other products.

Michael
Acute Performance

Ramjet31

Ramjet31

Thanks for the info and help!
I'll continue to search this forum....

v_therussian

There's a DIY on converting the stock intake box into a dual intake box. I think that was done on a 545, so may not be possible on the 550 - though I couldn't think of a reason it isn't. In any case, this is a "bootleg" mod - a DIY way of doing what Dinan does. Then you throw a second RPI scoop to make sure the air is going in better. All in all, people swear by this mod and best part - if you are a DIY'er, its probably the cheapest one you could do. Does require permanent modifications to the airbox and cutting a second hole behind the kidney grilles.

Search member brabusw209amg's threads - he posted the DIY, if I'm not mistaken.

sdg1871

I have thought long and hard about whether to do performance mods on my 550. The reality is that even if you do all of the bolt on mods and an ECU reflash, you will gain no more than about 40 bhp. That an decent, but really, incremental gain and is not going to dramatically transform your 550 into an M5 killer. By contrast, bolt on mods and an ECU reflash can result in power gains of over 100 bhp with the N54 engine in the E60 535. If you really want to transform your 550 into a monster, you gotta do real expensive stuff with the engine such as a supercharger. But for that kind of bank, you'd be better off with a 1 or 2 year old M5. And, of course, slapping on a SC will blow up your BMW warranty -- not something I'd want to do in a car that costs a king's ransome to repair.

There are some well regarded bolt on performance mods for the 550 such as the RPI exhaust and RPI ram air induction kit (RPI scoop paired with BMC air filter). And tuners claim horsepower gains of up to slightly over 20 bhp for an ECU reflash. Dinan makes an intake for which it claims a modest power gain but costs $1K (ouch!). Dinan also makes a high flow throttle body that is costly andfor which it claims an incremental power gain. I recall that members have attempted to do the dual duct mod on the 550 but could not get it to fit.

If I was going to do one bolt on performance mod to the 550 it would be the RPI exhaust. The sound alone is worth every penny. It makes the 550 sounds like a killer -- so very aggressive and menacing. And the RPI ram air induction kit is very inexpensive and does give you a modest power gain.

The key with doing bolt on performance mods with the 550 is to have realistic expectations about the power gains -- they are incremental.

1600

Just remember that the cost/performance ratio for the 550i is very limited. A full Dinan setup gives you about 30hp max max.
The cost for that rather modest increase is fairly steep. Fortunately, the 550i is pretty peppy on its own so the few basics that RPI offers make better sense, at least to this 550i driver.

Ramjet31

Thanks for all your comments and advice!
I'll keep you posted on my decision.....