edavis949

I recently purchased a 2008 535i sport/premium with 36,000 original miles - babied by a 60 something year old phd. Score!

I am coming from a 01' 530i sport/premium - which i loved - but I want to take advantage of the unlocked potential of this new turbo charged car.

I realize there are tuning options out there - but would like input in the selection of one. I do not plan on doing any other performance mods in the future and this is my daily driver and zero issues with codes and limp mode, etc. is very important to me.

What is the best performing most bullet proof tuning mod there is?

Dinan, Cobb ...

Thank you!

bmwmonkey

Mixing E85 into your fuel and using the Cobb AP tuner is the best bang for the buck.

skrelnik

Get the Cobb AP v2. You can score a used one between $450 - $550, just make sure it is unmarried. Do not put any E85 in your car, you are asking for trouble. Keep it simple. We have a 2010 535 and this Cobb on Stage 1 makes it drive like a completely different car. Gas mileage is also up about 25% more because the turbos are working. After that put some nice shoes on the baby.

Keep in mind that everyone has their own perception on this topic, so go with what represents you. Our car is a daily driver and we don't want any issues with this car.

rice_rocket88

Burger Tuning JB4 .. make your own judgement call. Bang for buck I'd say JB4 wins..

FunTT535i

Jb4 or Cobb are both great options. E85 makes the car feel wonderful! 30-40% anything more than that will require changing lpfp. I have the jb4, DCI and running 35% e85 and the thing is amazing.

bmwmonkey

Where do you get E85 in San Diego? The only place I know that has is in El Cajon.

FunTT535i

There's a 76 gas station that sells it off Kearny mesa.

3860 Kearny Mesa Rd
San Diego, CA 92111-3728

biz77

Besides a tune, an ethanol mix is the next biggest horsepower bang for the buck you can do in this car. I've been playing with E85 for 10 years on multiple Subarus and two N54s. Never had a problem and I've seen very very few reported issues from others using it in modern fuel injected cars designed to run at least some amount of ethanol blended fuel.

Booyaazaa

So before people start mixing E85 into their fuel make sure your tune supports it. OP-there three main options to choose.
JB4: very nice power bump, multiple maps (change on the fly), by its self can handle approx E30 fuel mix, most power without having to do a protune. Negatives are its a piggyback so needs to be plugged inline with dme and need backend flash to run higher ethanol mixes.
Cobb: nice power bump, very easy install, self/ProTuning capable since its a flash tune, more flexibility in modifying map characteristics (including up to running straight E85), real time data display(s), easy logging capabilities. Negatives are it is more expensive then JB4, no on the fly map change or gauge hijacking, OTS maps are still conservative.
Dinan: another flash tune, nice power, very stable, equivalent to the BMW PPK tunes. Negative are very expensive, Dinan shop can only do the work, still conservative and not near capabilities of the N54 motor, zero E85 support.

For the guys running a Cobb AP I hope you modified your fuel scalers to the Exx mix you are using. If not and you are running a OTS map you are running lean and it will not be a good thing for your engine. ATR is free so get it from Cobb and bump your fuel scalers up to the appropriate value.

Errowen

I think i can confirm this from recent experience - last month. Winter gas in Canada from some major suppliers seems to include more ethanol, particularly the 94 octane I usually use. First signs of trouble were slightly reduced power and significantly worse fuel economy, followed by engine light coming on. BMW Service tested the gas in my tank, determined it was 11% ethanol, and advised that the engine error codes were the result of unburned ethanol getting through to the catalytic converter, detonating there. Changing to Shell (no ethanol) brought back performance and fuel economy, even though octane rating was reduced to 91. My conclusion: make sure system tune is appropriate for ethanol.