JET's 335Xi
 

Well, I am finally going to do the first mods on my 2011 335Xi sedan with the N55 engine. I am not going to be doing anything too crazy. I really like the ride and handling on it already, so just adding some more power. My goal is an 11 sec daily driver that behaves like stock.

https://fbcdn-sphotos-d-a.akamaihd.n...53866194_n.jpg

Stock power is ~280whp/320wtq on a dynojet
Stock 1/4 is ~13.6@102

The first thing I am doing is adding a JB4 piggyback tuner with flexfuel wires (it can autotune to ethanol content!) This mod has been shown to bump the power to 370whp/435wtq on the same dyno as above when running E40 (fuel pump isn't big enough to run pure E85).

https://lh4.googleusercontent.com/--.../n55+graph.JPG

This is a direct injection engine so there is no fuel going over the valves and oil tends to coke up on the intake side of the head some. This is much better in the N55 than the N54, but is still an issue. So I am also getting a specially designed billet oil catch can.

http://www.burgertuning.com/images/o..._CATCH_CAN.jpg

The stock charge pipe (upper intercooler pipe) is plastic and tends to blow apart at higher boost levels so I will be getting one of those pretty soon too. The turbo will be basically maxed out. There is development on 5 different turbo options from 3 companies going on right now. The first hybrid is out and maxed out at 480whp so far. I am waiting to see what happens with the others, the smallest one that is just a compressor wheel is set to do on the dyno any time.

I figured most of you guys aren't in to the 335 scene at all so you might find it interesting. I want to get this thing on the dyno sometime to do a baseline and moded run to see where I am at.

Re: JET's 335Xi
 

I like these cars. Do you expect mid 12's out of the current tune, and then high 11s with the turbos upgrade? Do these have an ethanol sensor stock, or is that something you need to add? How well does direct injection work with real e85?

I'm generally unfamiliar with direct injection, is that a mechanical or electric pump?

Re: JET's 335Xi
 

Yeah, hoping for mid to low 12's with just the tune (not bad for $475!) It is a single turbo on the N55 and I think the $2500 option is going to be good for 450whp and will be what I go with. Bigger FMIC is the only other thing I will need along with a low pressure fuel pump.

Direct injection in these is electronic for the feeder pump and 3 stage piston on the high pressure (3000psi). The low pressure pump is the one that runs out first and most people just throw an inline 255 helper pump in there.

I also forgot to mention is has the Valvetronic 3 in it, which has full control of valve lift. The throttle body in the car is only a safety device and is wide open all the time for better fuel efficiency. Intake amounts are controlled by valve lift.

Re: JET's 335Xi
 

Sounds like a cool project. Definitly a lot of new stuff to learn. Do the direct injection injectors have any problems with the high fuel pressures like some of the diesels do?

Re: JET's 335Xi
 

Wow, didnt know these cars were that modable. Those are some hefty numbers I'm excited to see them and see this thing at the track!

Re: JET's 335Xi
 

Excited to see this. Might be a good frum roll machine.

Re: JET's 335Xi
 

Wow, that is impressive. Another way I've seen to keep the valves and injectors clean on a direct injection engine is to suck a can of cleaner directly into the intake manifold. I did it on my 2.0 turbo 2009 VW Tiguan and it made a huge difference. They're also known for deposits on the valves and injectors from DI. That mod alone was worth about 19 butt dyno whp. :D

Re: JET's 335Xi
 

Super excited to finally see progress on this thing! It's gonna be a rip, we'll have to see how this minimalist bimmer build stacks up against a minimalist Evo in the spring. :D

Re: JET's 335Xi
 

Can you custom tune the JB4 unit?

Re: JET's 335Xi
 

Nope, no custom tunes on it but it has 7 different maps and 2 or 3 of them will autotune themselves quite effectively. You can set boost targets of course. I am pretty pumped for it to get a little more boost too!

Re: JET's 335Xi
 

That's pretty neat. I like it.

Re: JET's 335Xi
 

Very cool car, great bang for the buck mods too. I rode in a friends lightly modded 335 and I was very impressed, lots of torque down low in the RPM band.

Re: JET's 335Xi
 

Cool. I like seeing other platforms and whats done to them

Re: JET's 335Xi
 

Looks like a cool project!

Any more pics of it?

Re: JET's 335Xi
 

Thanks for the support guys! Here are a couple more pics, there are a few visual mods I want to do also. Delete the stupid amber fender reflectors and put a small trunk lip on at the minimum. And eventually a CF rear diffuser, but they are $600.

https://lh6.googleusercontent.com/-U...429_175951.jpg

https://lh4.googleusercontent.com/-N...429_175936.jpg

https://lh4.googleusercontent.com/-7...429_180015.jpg

Re: JET's 335Xi
 

Very cool! Glad to see you finally modding this thing a bit, will be cool to see it out and about on the new setup. Basic mods puts these thing as fast as a pump gas stock-turbo evo on the street, maybe moreso with the flexfuel stuff, didn't know it could do that! Very very cool!

Re: JET's 335Xi
 

Nice potential, should be a fun car.

BTW, what are the best forum's/sources of info for these cars? My buddy just bought a '11 335d and I think those have potential as well.

Re: JET's 335Xi
 

Hey Jet,
The car looks great, is this a auto or manual? Interested to see with e85 and stock turbos what it makes.

I just bought a 08 335i auto rwd a month ago. So far I am loving this thing as a dd. Found a open source freeware flash software from bimmer boost using a Bavarian Technic cable. Sucessfully flashed a tune for cobb stage 1 AP to my car for basically free. Have you looked into this at all? I believe using tuner pro you can tune as well. The flash tune is such a difference on these cars it is crazy even on pump gas, but be sure to replace the plugs if they have anywhere near 30k miles on them or the car will experience misfires.

Re: JET's 335Xi
 

E90post is the best forum I have found and they do have a 335d section. Bimmerboost is pretty much garbage, I can't stand that forum (at least the N55 section).

Mine is an N55 instead of N54, so the chassis is the same, but the engine/turbo/ecu is different. You should really look at the OFT flash for yours. Very cheap and gives you control over most of the ECU. Your stock turbos are a little laggier than my single, but they have better top end. New plugs 4k miles ago. Mine is also a 6AT, tranny shows to be solid up to 500wtq once you hit 550 it definitely starts to shorten the life. There are some upgrades available. Have you flashed the tranny with the Alpina software yet? Do you have paddle shifters?

Re: JET's 335Xi
 

Good to know information, I thought the open source worked for the n55 as well, but I know very little so far on this newer bmw stuff. The transmission has not been flashed, what advantage would that give? The car is a a sport package with the paddle shifters. My plan currently is to change out the oem transmission fluid for redline d4 as the car is nearing 93k miles.

Re: JET's 335Xi
 

The flash makes the sport mode on yours MUCH more aggressive and shifts in manual mode will be twice as fast. Be very careful changing fluids, BMW's are much pickier than most and BMW can spec some weird stuff. Tranny should be fine though.

Re: JET's 335Xi
 

Cobb had told me that the Racetuner/Free version of their software for the N55 was supposed to be out at the end of January. The N54 cars have a lot of tuning options.

Re: JET's 335Xi
 

Yes, you definitely need specific BMW tranny fluid for their autos. My old M3 required stuff that was like $50/liter.

Re: JET's 335Xi
 

My JB4 tune is shipped and I have the charge pipe, flex fuel wires and oil catch can ordered! I hope to put most of it on next weekend. :)

Re: JET's 335Xi
 

Car looks good. I'm impressed with your gains, the nice thing about these is the dont look to flashy!

I'd be a happy man if they sold the 335XI in wagon form with a manual. :)

Re: JET's 335Xi
 

Rosey, if we ever get a chance, gladly will let you drive mine with the flash tune. Ordered an INPA cable so I can flash the transmission TCU, damn you Jet!

Re: JET's 335Xi
 

You should have said something, I would have let you use my cable! You can do some other sweet coding in the car too if you want to :D

Re: JET's 335Xi
 

That is why I bought one, so I can have the cable at my disposal any time, so far there are 3 co-workers with 335's that may want the transmission mod too and other coding done. Speaking of INPA cables did you buy from ebay or one-stop?

Shawn

Re: JET's 335Xi
 

I got one from Ebay that several said they had good success with. I think it was around $40.

Re: JET's 335Xi
 

I wish my car had your motor.

Re: JET's 335Xi
 

Drove an N54 last night, I am sold and will be selling my car here pending approval from the Boss Lady.

Amazing machines.

Re: JET's 335Xi
 

Do you have any plans for exhaust? I keep going back and forth... Need to find another local it to hear how loud it is while driving!

Re: JET's 335Xi
 

The best sounding exhaust is the PE exhaust and they have figured out how to emulate it with your stock exhaust. I will be doing it sometime this year. Basically you drop the catback and cut open the top of the mufflers then take out some of the packing and put header tape over the perforations in the exhaust then weld it up. Easy and is supposed to sound great, not to mention cheap!

Re: JET's 335Xi
 

Interesting! I will be very curious to hear your car after you do it!

Re: JET's 335Xi
 

FYI the Xdrive also has an extra set of cats over the rwd for some reason. I would put a DP on if I wasn't still in warranty. VRSF makes a nice 7" FMIC too and it is pretty cheap. The mods you need to do to these are minimal and they make a big difference. I love the handling, the only thing I plan on doing is an M3 rear sway bar and subframe bushings. That should correct almost all of the understeer from the sounds of it.

Re: JET's 335Xi
 

The stock exhaust isnt restrictive at all? No neck downs or strange transitions? Otherwise that would be cool if you can just mod the stock exhaust if it comes in a good free flow platform.

Re: JET's 335Xi
 

Nope, stock exhaust is changed just for sound purposes only. Dual 2.4" (with a few neck downs but not bad) the whole way. DP gains 10-20hp from ditching the cat. That is the only worthwhile exhaust mod really for performance until you hit 500whp. With a hybrid turbo it would probably be worthwhile to ditch the mid pipe and secondary cat.

Re: JET's 335Xi
 

Very nice! About time stock exhaust comes decent haha.

Re: JET's 335Xi
 

Lovin all the info! Now with Rosey having a 335xi, the more info you share the better. So I have not done the Alpina flash because I am having trouble finding the latest software data files for the diagnostics software to communicate with the car on Windows 8.1. I might just make a windows xp mv image and be done. When are you installing all the goodies?

Re: JET's 335Xi
 

Looks like Chris Carey from MAP just bought one too.