Originally Posted by Lotus99

Between strut bars (I assume you meant "bar" as as I've not heard of anyone putting in a rear strut bar) and RD Sport sway bars, I'd totally go for the sway bars. Totally transformed the car. Quite a few people here have installed them and can vouch for that.

wow, hadn't heard the news about AR Design. Surprised as they were known as the highest quality downpipes. any links to the news or discussions?

Originally Posted by bmwmonkey

There's 3 bars from Ultra racing that fit the wagon. 1 upper and lower int he front. And one in the rear. Evan posted the part numbers I think a while back. I have the same ones.

Not sure about the "official" AR Design news. I tried to purchase from Modbargains and that's the message they have on their website.

"AR Design has gone Bankrupt. AR product is not available however ModBargains and our Experts here can provide you with great alternative brands that we stand behind. Please give us a call at 714.582.3330 or send us an email Sales@ModBargains.com"

Unfortunately for people with the E61 535xi in the US there is no "alternative brand" for this part.

Originally Posted by rkundrat

I just took ownership of 2009 535i Touring (manual!) This is being added to our 2011 335d which we have a JBD box on. In comparison, the 535 is down about 200 foot pounds of torque on the diesel, so am looking for some recommendations on power upgrades with the underlying requirement the car be kept relatively quiet. I've done research but have some questions:

Tune
The options in running are: 1) Burger JB4, 2) Cobb, 3) BimmerBoost/MHD flash, 4) Burger JB4 + backend flash.
Since I don't have a PC or Android device, Cobb seems the easiest plug-and-play. JB4 is a little cheaper, has some cool features, but I don't think I'd use them (no E85 near me, I don't use valet, I don't race...) I think the only time I would change map is if I were to upgrade bolt-on components. Power wise JB4 + a backend flash seems to be the best route, but between not needing the features of the JB4, and not having a device to flash myself this option seems extraneous for the added benefits. That said, if there's a compelling argument, I can pick up a cheap laptop.

Intake/Filter
Options are: 1) Drop in filter, 2) dual-cone intake, 3) some dual-cone intake with the shroud (like the AFE.)
This car will be used for long trips, so I don't want a lot of WOOOOSH... I assume a drop in filter is the quietest option? Will that still yield a performance gain that a tune can take advantage of, or do I really need to remove the stock airbox? While doing this I would consider changing the charge pipe as well. Will I see a performance benefit from that? Intercooler will probably be done at some point...

Exhaust
NO drone... wife will kill me.... As I understand it, I'll see the biggest performance benefit from changing the downpipes. I would probably stick with something catted due to state emissions inspections and noise reduction. If just changing the downpipes, will there be a noticeable increase in cabin noise? Are there any other things I should consider downstream of that that will benefit performance, but not make the car noisy?

Non-performance
What are the other recommended upgrades, either in support of the above, or just for general drivability? I understand this engine suffers from carbon buildup like our 335d, so was considering adding the catch can. Are any of you additionally blocking off the EGR as they do on the diesels to prevent the buildup in the first place? My car just received a walnut blasting before delivery, so I'd like to maintain a level of clean if at all possible... Diverter valves, Rob Beck PCV valves, are these necessary upgrades when doing any of the above? Anything else I should consider.

Thanks all, looking forward to joining the e61 community!

Originally Posted by GTYellowJacket

No one has mentioned anything about suspension. I think the KW V3s with the M5 rear sway bar have been the best mod I have made to my wagon. I'd suggest some suspension work before any intake, charge pipe / DV, or exhaust changes!

Originally Posted by pocholin

Pardon my ignorance but what will the M5 rear swaybar do? Make it stiffer? Once you have coilovers all around, doesn't that improve body roll?

Thanks,

Originally Posted by pocholin

Thanks guys!

Originally Posted by pocholin

Thanks for the explanation. So to improve the understeer issue with our wagons have, I need to stiffen the front and M5 swaybar?
I hope you have fun on those twisty roads...I miss driving in Sierras and mountains!

Originally Posted by rice_rocket88

Correct! Often the rear sway bar is a great way to improve things. Some will definitely argue that it will change the balance in a bad way and you should do both. I have done combos on different cars over the years, but for me I have always liked just the rear sway bar the best since it suits my driving. I've been lazy myself and haven't found the M5 bar for that cheap, and have been lazy to do it Someone on the forums had one for sale that was a good deal, don't know if it's sold now though. It will bolt onto the XI so it's a great upgrade!