# Random/Mod Questions and List of Mods for 335d anywhere?



## rungolden1 (Dec 14, 2014)

Ok, so I recently bought a 335d and am pretty frustrated about the lack of information available on what modifications are possible as well as which can be done without voiding warranty. I also have some random questions. 

1) My Speedometer reads 5% low - can this be easily fixed?

2) My mpg's read 2 MPG lower than real life on my fill-ups...any easy way to fix that?

3) Is there a somewhat comprehensive list of popular performance mods for the 335D?

4) What performance mods can be done to the 335d without voiding a warranty??? Wagner Intercooler? Cyba Scoops? Anything else?

5) What intake air filters are people having the best luck with?

6) Is there a water/meth kit available for the 335d? The only thing I can find is the generic snow performance one for $550. 

7) What do you guys do about the TPMS malfunction warning when you switch tires?

8) Will a remap/tune void my aftermarket warranty? If I have a JBD, is it that much better and/or worth doing?

I've got more...just can't remember them at the moment! Any help would be much appreciated!


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## ChasR (Aug 29, 2012)

1. My speedometer read 3 mph high at 80 MPH (Indicates 83 at 80 actual, 3.75%). Reading low isn't typical on E90 BMWs. Does it have the stock tire sizes? Changing the rear tire size from 255/35 to 265/35 reduced the error to about 2 mph at 80.

2. You can enter a correction factor in the cars computer. I used data from my last 10 tankfuls and recorded the computer mpg to determine the factor. Default is 1000. My computer indicated around 2 mpg lower than actual and the computed correction factor was 913. Now, it's rarely perfect, but always within a couple of tenths. 

3. As far as suspension and body work, pretty much the same mods are available on the 335d as on the 335i.

4. I doubt you can do anything without risking voiding the warranty. You can probably get away with a JBD by removing it prior to servicing.

5. I'm going to stick with paper filters. There isn't much to gain going to a cloth permanent filter.

6. I think Burger has done a meth kit for the 335d for a few customers.

7. TPMS works when you switch tires. If you get new wheels and don't move the sensors, you'd best get BMW sensors for the new wheels.

8. ECU remap will void the warranty. Having had both an Evolve Tune and a JBD, I'd recommend the JBD. There's not much difference in performance between the two and when you get CBU, and they wipe the computer to get the injector codes to go away, you won't have to send the ECU out for reprograming, if you have the JBD.


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## Nadir Point (Dec 6, 2013)

7. Any competent Tire/Wheel dealer will pre-install compatible TPMS sensors in new wheels.

If not, find somebody better.


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## rungolden1 (Dec 14, 2014)

ChasR said:


> 1. My speedometer read 3 mph high at 80 MPH (Indicates 83 at 80 actual, 3.75%). Reading low isn't typical on E90 BMWs.  Does it have the stock tire sizes? Changing the rear tire size from 255/35 to 265/35 reduced the error to about 2 mph at 80.
> 
> 2. You can enter a correction factor in the cars computer. I used data from my last 10 tankfuls and recorded the computer mpg to determine the factor. Default is 1000. My computer indicated around 2 mpg lower than actual and the computed correction factor was 913. Now, it's rarely perfect, but always within a couple of tenths.
> 
> ...


1) To clarify, it reads 90 when I'm actually going 86, 60 when I'm actually going 57, etc.

2) I've seen some threads on doing the correction, but nothing that was spelled out real clearly. I'd love to do this!

3) I was more asking about performance mods like intake, intercooler, meth, etc.

4) Ok, good to know. I took my JBD off before taking it in for service last week.

5) Good to know. The guy I bought it from had a K&N installed. I'm thinking I'll go back to stock unless someone has better filters to recommend.

6) I wrote burger and they said they don't do sell meth kit for the 335d unfortunately. I really want to know where to get one of these!

7) I switched wheels, but didn't get new sensors put in. Are TPMS even worth having? I check my air regularly anyway! The malfunction warning is annoying.

8) Good call


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## thatwyteguy (Apr 22, 2015)

rungolden1 said:


> Ok, so I recently bought a 335d and am pretty frustrated about the lack of information available on what modifications are possible as well as which can be done without voiding warranty. I also have some random questions.
> 
> 1) My Speedometer reads 5% low - can this be easily fixed?
> 
> ...


As for the meth kit, AEM has the best in my opinion. It more focused for a car and not a truck plus it is also safer. It has a safety shutoff (which snow did not last i checked) and also has a spray modulation control.

Im picking one up pretty soon


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## Doug Huffman (Apr 25, 2015)

On information and belief, it is a DIN requirement that speedo reads high to prevent speeding citations, which in Germany are expensive.

Will OPie be so proactive about Carbon Build Up that 335d's are known for.


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## Nadir Point (Dec 6, 2013)

1. A modest tire upgrade to 235 section width fits well on the stock wheels and cuts the speedo error in half.


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