[Tallest]

Hi!

I've been reading on these forums that it's possible to tune your 325i into a 330i.

My questions are:
1) Is this true first of all (i mean is there anyone who actually done it and can report back)?
2) Does this work for the 2.5l 325i 218hp engine (Europe)?
3) What parts are needed except manifold? Does it need a new software from 330i or something else?
4) What's the average cost them - 1000-1500 USD?

I have a 325i because finding a nice used 330i where I live is almost impossible (noone bought them new). Naturally, if there is a legit way to improve power (not through some chiptuning only) then I'm interested. Currently I only plan to buy PE Exhaust just for the sound but if this conversion is possible - why not consider it.

Looking forward to your answers.

[darkrom]

Read the threads. Its the most covered mod I can think of. Yes its real, no it doesn't work on the 2.5 to the best of my knowledge. You need a tune or some BMW ecu tune.

[e90pilot]

You've been here since '07 with 4000+ posts. Where have you been? Lol!

[accel]

It is covered - yes and no. List of things you need to buy and even some sorts of DIY guides on manifold swaps are here and there.

But when it comes to final result analysis - it is very poor and inconsistent.

My conclusion is - yes one can install just the manifold on US 325i - and this thing alone brings some gains, but it also has some "hiccups", such as hp\torque dips during acceleration. Actual gains _from_just_this_mod_ are not measured, because whoever had this done also had other things installed on their cars.

Then, there are tunes after the manifold swap itself... And again there's no consistent analysis of the outcome. All this makes me feel uncomfortable with pursuing this mod.

At this point I feel like I would be better with just throttle response remap. It does not give you any real gains, but it makes the car more agile. I do have the "Sport" button in my wife's Mini Cooper S which mostly does just this - throttle remap. And it does make difference in how the car responses. I know it does not increase any power, but there are things I can do in "Sport" mode which are a struggle to achieve in non-Sport.

[mike-y]

Originally Posted by accel

Then, there are tunes after the manifold swap itself... And again there's no consistent analysis of the outcome. All this makes me feel uncomfortable with pursuing this mod.

you obviously haven't been reading enough. manifold + AA tune on a US spec 325i most definitely produces very good gains. There have been a few dynos posted (mine included) that verify this.

[jc5988]

Originally Posted by accel

It is covered - yes and no. List of things you need to buy and even some sorts of DIY guides on manifold swaps are here and there.

But when it comes to final result analysis - it is very poor and inconsistent.

My conclusion is - yes one can install just the manifold on US 325i - and this thing alone brings some gains, but it also has some "hiccups", such as hp\torque dips during acceleration. Actual gains _from_just_this_mod_ are not measured, because whoever had this done also had other things installed on their cars.

Then, there are tunes after the manifold swap itself... And again there's no consistent analysis of the outcome. All this makes me feel uncomfortable with pursuing this mod.

At this point I feel like I would be better with just throttle response remap. It does not give you any real gains, but it makes the car more agile. I do have the "Sport" button in my wife's Mini Cooper S which mostly does just this - throttle remap. And it does make difference in how the car responses. I know it does not increase any power, but there are things I can do in "Sport" mode which are a struggle to achieve in non-Sport.

I think euro 325i already came with 3 stage intake...

[onephattai]

Do some research before you ask questions buddy. :read thethread:

[Tallest]

Originally Posted by onephattai

Do some research before you ask questions buddy. :read thethread:

Overreact much?


Thanks to those who answered whether this actually works on a EURO 2.5 car. I noted that I have a euro engine, and as far as I can tell in a month that i've owned a 325i (i had diesel 320d for 4 years before) - there is very little when it comes to engine modification of euro 325i.

threads here mostly deal with the US spec car. No thread I can find actually says what's the difference between euro 325i and US 325i if any.

Most euro 325i as I can tell are focused on ECU remap, which give about 15hp extra. I understand that opinion is divided between owners on the remap as some think only Dinan will do, other think anything that give extra HP is better and use. Good friend of mine swears by remaps but for turbo cars only and says it's pointless to chip NA engines like in 325i (he owns a chiptuning business).

[BudVlad]

You must have one of the last 2.5l engines. From 2007 European 325i got the 3l engines where you can get substantial gain by ECU remapping. Tuners in Germany can get 240 hp from 2.5l engine. It’s more involved to tune NA engine than turbo but saying that’s pointless to remap NA engine is nonsense.

[N0OS3]

they made this subject a sticky didn't they?

From the 100+ threads i've read about it, it's not a 100% completely converted mod... it still has some hiccups when it comes to the ECU tune. Even as it stands now, you can likely see 40+ horsepower from the mod for around $1,200 (USD) as brand new parts from TischerBMW. If you are able to get to a recycle center that has a 330 in their yard, you can research the look and location of the parts and probably save $700+ by getting the parts used. You still retain your OEM ECU for the tune, but you can swap for the 330i tune if it has the same options as your car (or else you get a lot of errors).

There's a picture DIY on this subject that also includes every part number you need for the conversion. I was looking forward to a Video DIY, but one hasn't been made or brought to my attention yet... would make for a popular video for sure.

[BudVlad]

100% conversion is possible without any hiccups, depends on the tune. ECU of N52B30 and N53B30 were successfully remapped by DS Motorsport. The cost is €1,800.
ECUs are identical but loading 330i software into 325i doesn’t work. I found out the hard way.

BTW: For 100% conversion you have to install bigger brakes, different rear muffler and different final drive.

[Tallest]

Well, that settles it. I'll try the tune (since it's reversable) before doing any parts conversion. At 230hp it may have enough power to keep me happy-ish - mostly I'm after some torque bump anyway for town driving (i.e. pedal down in 4th = slow).

[MaximusJ]

Its 100% possible if you got the same engine.

3 stage manifold, decent exhaust system and proper tune will definitely put you near 330 territory. I've done it, e90pilot and mike-y did it before me, and we can all vouch for it.

Best bang you could get on this car for the buck.

[MDeez]

The biggest difference between the 2 is that the 325 intake is internally restrictive in allowing air flow at higher RPM. It does make a difference

[3002 tii]

Originally Posted by research

Hi!

I've been reading on these forums that it's possible to tune your 325i into a 330i.

My questions are:
1) Is this true first of all (i mean is there anyone who actually done it and can report back)?
2) Does this work for the 2.5l 325i 218hp engine (Europe)?
3) What parts are needed except manifold? Does it need a new software from 330i or something else?
4) What's the average cost them - 1000-1500 USD?

I have a 325i because finding a nice used 330i where I live is almost impossible (noone bought them new). Naturally, if there is a legit way to improve power (not through some chiptuning only) then I'm interested. Currently I only plan to buy PE Exhaust just for the sound but if this conversion is possible - why not consider it.

Looking forward to your answers.

This post

Your name "Research"

ha ha

[Tallest]

I think the worry is that I'm not going to find the right and compatible ECU tune - getting parts is OK, but the tune is unknown. Noone as I know where I am makes any tunes for 325i - 330 conversion.

[BudVlad]

Your problem isn’t the ECU tune it’s the engine size. You can’t convert 2.5l engine to 3l engine by software. As far as I know the max you can get from 2.5l is 240 hp by ECU tune.

[Tallest]

Originally Posted by BudVlad

Your problem isn’t the ECU tune it’s the engine size. You can’t convert 2.5l engine to 3l engine by software. As far as I know the max you can get from 2.5l is 240 hp by ECU tune.

Yup - but is 240hp that bad? I think a jump from 218 to 240 just from the tune is a pretty good deal, isn't it? You get a bit more drivable torque etc for few hundred euros. I'm going to try that first in spring to see how it feels. Supposed to give a consumption decrease of 4-6% too though I'm not sure about that yet.

Company doing it is German Wetterauer which is pretty good quality and well known.