[SFD507]

Hey everyone,

I am new to the forum, and am very impressed with it. I will be getting a 2007-8 335xi sedan in the next few months and am already looking forward to tweaking it. What I'm hoping is that this forum will be able to help guide me in the right direction with these modifications.
The first thing I want to do is a turbo back exhaust, to be followed most likely by a chip, probably from active autowerke. Perhaps after that, the BOV kit to reduce the strain on the stock valves generated by the increased boost from the chip. Either way, what I'm currently looking into is turbo back exhaust systems. I was wondering if there was a 'go-to' turbo back exhaust system that is considered the benchmark for the 335i/xi, or if there were a few front runners in the turbo-back exhaust game. I seem to be able to find more cat-back or farther exhaust mods than turbo back. Is there a reason for this? Is it worth getting a turbo-back exhaust instead of something farther back? Thanks in advance for the time anyone takes to read or reply to this thread.


- SFD507

[scheherazade]

Autobahn Exotics makes a DP back exhaust that is very popular.
HKS DP back exhaust is somewhat of a star performer (by barely an hp or two), but expensive.

DPs vary.
Generally, all start with 3", and taper to 2.5".
It's up to you which flavor you prefer. They all perform too close to call.



If you want bang for the buck, this is your upgrade order :

1) Piggyback. "JB3 + BT" or "Procede" (You may want the BT regardless)
2) Intake. Dual cone is effective. Next I'd recommend the Stett or UR intakes for obvious reasons.
3) Diverter Valves. Forge is the most popular. You don't want valve float, as it amounts to a boost leak (which can destroy your shit).
4) Intercooler. N54 heat soaks fast. This will let you run more boost, longer.
5) Downpipes. Better spool times. For some people these were a big power mod, others dynod with nearly no change. Generally accepted as a good HP gains mod.
6) DP back exhaust. Gives a tiny bit of hp, but not much. You've already got twin 2.25" inch exhausts stock. It's pretty good to start with.


-scheherazade

[SFD507]

Scheherazade,

First of all, thanks for the great info! I did a little research on your suggestions and find myself a little confused about some things.


1)Why is the active autowerke chip $785 with +55 hp and 70 lb/ft of torque, but the JB3 is 80/80, and can be found for $300? Does the JB3 create power at the expensive of something else, like reliability? How much of a reliability concern in general is adding these chips to an otherwise stock system? Then there's the procede which looks a little better than the JB3 but is a lot more expensive. Sorry to be such a noob, just trying to make better sense of all these things.

3) Is valve float a concern with the active autowerke BOV? Why a diverter instead?

Thanks again
- SFD507

[scheherazade]

Valve float is because of high boost pushing the valve open when it's NOT supposed to be open.

This can happen with a BOV or a new DV set.

Your choice what flavor you prefer, just do yourself a favor and upgrade the stock DVs to something better.

If you want the nifty loud, "PSSSSSHHHHHH" sound, get a BOV.
If you want a quiet "sssshhhhhh" sound, get DVs.

A long time ago some people had some dynos that claimed that DVs performed better on the N54, but I have no idea what became of the story, or how reliable the info was. As far as I'm concerned, that was the 'rumor'. So just get what you prefer.






AA has some good history, and they can charge *some* amount for their name (and cool logo).

Generally, AA is not 'pushing' the car that much.
JB3 and Procede have map options that go above and beyond AA in terms of aggressiveness.
You don't need to run an aggressive map with JB3 or Procede, you simply have an easy option to do so.

JB3 grew out of a guy that picked the Procede creators brain, and simply made his own version that does something similar.

Generally, both 'tunes' are of good quality.

Procede is more 'techy' . It's more gadget-like. You have more nifty options to play around with, and some fancy software, and data logging, and blah blah. It's a fun and interactive tune.
It also has the ability to clear codes automatically, so that your computer won't store any manipulation info, so you look 'non molested' if you uninstall the tune and go to a dealer.

There is also a Bavarian Technic tool (BT) that lets you clear codes. With this tool you can clear codes caused by either tune.

JB3 is a 'down to business' tune. It's got little extra features besides 'make you go fast'. It does offer some decent map selection options. You can tap your gas petal to select which map you want to use.
If you get the JB3 tuning tool (a little display that shows you codes, and readouts. Not exactly the easiest [read: not idiot proof] to use, but it works) you can adjust some custom parameters too.

With Procede you assign 1 map to each button on a remote fob, and you press one of those 2 buttons to go between 2 maps. Which is obviously simpler than gas petal tapping, but you only choose between 2 maps instead of having all possible maps at your 'foot' to play with. (Note : Procede has *upcoming* features that would let you use buttons on your steering wheel to select with.)

Some people worry about stress and failure, but the only person who has posted about blown turbos on here had a boost leak.

So far, no public engine failure has happened with JB3 or Procede. (Someone correct me if I'm wrong, please, by all means. I'd love to know.). People have had these tunes in their cars for ~50k+ miles.

If you're looking for the 'better' tune, you won't find it.
Both the main popular tunes (JB3 and Procede) are to date well vetted, and both put down very similar numbers.

If you run race gas, and supporing bolt ons, BOTH tunes can get you to the ~450 whp range.

FYI. Soon both tunes will have meth kits available. Possible procede will have one a little sooner, but both are currently in the works. So you should be able to hit ~450 whp on 91 + meth with either one.

Going back to AA.
It's a good tune too. It's more docile out of the box, and you have to contact AA for a custom tune if you want it to be more aggressive. But AA WILL do it for you. If you really want an AA, go for it. You'll just have to deal with some customer service if you want the same 'glory dynos' as JB3 and Procede comes out with.

Also, if you plan on running 'near stock', then everyone has a conservative map available for you to play with.

ALSO, unlike many turbo cars, the N54 does not get the most bang-for-the-buck from an exhaust mod.
DPs are pretty good, but I'd save the 'full CBE' for later, as it will not make a night-and-day difference.

-scheherazade

[dmurray14]

Originally Posted by SFD507

Scheherazade,

First of all, thanks for the great info! I did a little research on your suggestions and find myself a little confused about some things.


1)Why is the active autowerke chip $785 with +55 hp and 70 lb/ft of torque, but the JB3 is 80/80, and can be found for $300? Does the JB3 create power at the expensive of something else, like reliability? How much of a reliability concern in general is adding these chips to an otherwise stock system? Then there's the procede which looks a little better than the JB3 but is a lot more expensive. Sorry to be such a noob, just trying to make better sense of all these things.

The Procede and the JB3 are far and away the most popular tunes on this forum. You will find heated arguments as to which are better. It's a preference thing. In general, people seem to find the JB3 to be more raw and "kick in the ass" while the Procede is smoother and more refined. Unlike the AA (to my knowledge, at least) both the JB3 and the Procede are updated continuously, the JB3 by way of new chips, the Procede by way of USB port.

It's best to do some searching on here and figure out which you like more based on the info on them; if you ask which is better you're only going to get arguments!

Good luck!

[ar design]

We currently are the only manufacturer making 3" XI downpipes.... FWIW

[jpsimon]

My UR catless downpipes have been great!

[NM_BMW]

Originally Posted by ar design

We currently are the only manufacturer making 3" XI downpipes.... FWIW

+1 for AR DPs.

I bought an exhaust as one of my first mods although I'm happy with my exhaust tone, the power gains were minimal if nothing. The catless downpipes on the other hand gave some good gains. The tune should be your first pick if your going to start modding. My real power gains came from the DCI, Procede and the combination of catless downpipes and exhaust. None of it would of been possible without the tune though.

[BavarianBullet]

Originally Posted by SFD507

Hey everyone,

I am new to the forum, and am very impressed with it. I will be getting a 2007-8 335xi sedan in the next few months and am already looking forward to tweaking it. What I'm hoping is that this forum will be able to help guide me in the right direction with these modifications.
The first thing I want to do is a turbo back exhaust, to be followed most likely by a chip, probably from active autowerke. Perhaps after that, the BOV kit to reduce the strain on the stock valves generated by the increased boost from the chip. Either way, what I'm currently looking into is turbo back exhaust systems. I was wondering if there was a 'go-to' turbo back exhaust system that is considered the benchmark for the 335i/xi, or if there were a few front runners in the turbo-back exhaust game. I seem to be able to find more cat-back or farther exhaust mods than turbo back. Is there a reason for this? Is it worth getting a turbo-back exhaust instead of something farther back? Thanks in advance for the time anyone takes to read or reply to this thread.


- SFD507

Welcome in advance to the BMW 335 family!

Some points I'd make
1) the 335XI works great in the snow with all-seasons but it's about 220lbs heavier than the 335i and rides a little over 1/2" higher. It also doesn't have quite as good a suspension as the 335i, but there are parts for it to fix that.
2) The stock runflat summer tires are dangerous in the snow. Change them before winter (or ASAP if you don't want to "bubble" them).
3) Choose rims carefully. 18" or 19" wheels are very prone to damage in the northeast's excuse for roads. I managed to "bubble" (bulging sidewall) 3 of my 4 runflats in 3k miles when I first got my car. I have stock 162 Rims with Yokohama all-seasons now. They ride 10 times better (less bumps) and work great in the snow.
4) the automatic trans shifts like a race auto and is not like most slushboxes. The autos tend to be a little quicker than manuals and have better gearing. I'd get auto (I have 6MT)
5) The stock DVs seem to work fine up to around 15psi or so which is on the racier side of the available tunes. Beyond that it seems aftermarket DVs are needed. You may never need them or at least not right away.
6) There are flash tunes as well as piggyback computers available for the 335 and there's no shortage of evangelical rants for and against all of them from those that bought "the other tune".
Flashes are single map non-adjustable as yet and tend to run about the same $ as piggies unless you go Dinan. They are supposedly invisible to the dealership service dept and they make decent power though the piggyback controllers seem to have left them behind recently.
The piggies are cool and allow multiple maps and other fun stuff like code clearing, soon meth integration etc. The piggies also can be found as simpler devices like the resistor-based ones, to the JB3 (microcontroller) to the Procede V3 which is a modified haltech miniceptor http://haltech.com.au/index.php?opti...d=25&Itemid=22 which probably has the most features and is most sophisticated because of who makes the board (haltech).
JB3 comes in the $349 "pinout" version (for cheapskates like me) which means you'll need to take apart the stock wiring harness and pull 11pins and manipulate them a little to install it. There is a JB3 "PnP" version which is like the procede only in as much as both just plug right into the stock computer wiring harness (no pin pulling) and both of these are closer in price than the pinout jb3.
7) Catback exhausts all run over $1k it seems and don't yield much power by themselves. If you add a full turbo-back, then you can see a net of some 20+ WHP or so the conventional (dyno-backed) wisdom suggests.
8) The stock intercooler is ok but for max power aftermarket ones seems to make a reasonable increase in power if you boost high (or is summertime heat).
9) not that it matters that much but the 335 can knock down some crazy gas mileage for what it is. I managed 27.5mpg doing 80mph for 100 miles each way to the dragstrip. And that's with the 6% "ethanol penalty"!
10) Keep an eye out for group buys. Some of the recent ones have seen cheap downpipes ($300?) and intercoolers and items.

Good luck on the car search!

[E92TTKING]

What is a good pair of rims for my car which is a 09 335x drive?
Thanks,
Alex