E92 325i vs 330i differences? (N53)

[gsl67]

So there's lots of discussion on this, but people seem to always disagree with each other. As I understand, the only difference is the 3 stage manifold, and some people claim that the 325i can be tuned up to the same power with said manifold and a map. I've seen someone claim that a map is all that's needed to take it up there also. Anyone aware of any other differences between the two? Or anyone tuned their 325i up to 330i power and can verify these claims?

[the_g_ster]

It can be done, but you for the price differential on vehicles it's not worth the hassle of finding the parts, bolting on, getting coded etc. There are plenty of good 330's out there, both of them will have risk of the fuel pump going, injectors, etc, they are not cheap to run.

[cgauk]

I spent a lot of time looking at this topic a while back. I couldn't find a definitive answer. Some say the only difference is the software (limiting throttle to 70%) and others say it's that and the intake manifold.

It does seem that ~35hp gain is possible from a remap alone.

[gsl67]

the_g_ster said:

It can be done, but you for the price differential on vehicles it's not worth the hassle of finding the parts, bolting on, getting coded etc. There are plenty of good 330's out there, both of them will have risk of the fuel pump going, injectors, etc, they are not cheap to run.

The only reason I'm considering it is because of the rarity of 330s, especially in manual. If I was to keep about £1000 spare for maintenance I think I should be OK with running costs, though not sure if I'm wrong in thinking that

[gsl67]

cgauk said:

I spent a lot of time looking at this topic a while back. I couldn't find a definitive answer. Some say the only difference is the software (limiting throttle to 70%) and others say it's that and the intake manifold.

It does seem that ~35hp gain is possible from a remap alone.

Yep, I've read the same. I'm just cautious of buying a car and not having it live up to those claims though.

[Court_S]

Certainly on the 125 coupe with that engine, people are just remapping them to get up to / past 330 power. P Torque is a name that crops up a fair amount.

Manuals are pretty rare, most seemed to opt for the auto with the 330.

[bmwmike]

It's the combination of a map (different DME afaik) and the 3 stage manifold. Not sure if the manifold can actually flow more air or not.

[cgauk]

bmwmike said:

It's the combination of a map (different DME afaik) and the 3 stage manifold. Not sure if the manifold can actually flow more air or not.

I seem to remember something about an extra plug on the 3-stage that updated software /remap is needed to control. Apparently some 325i came with the 3-stage as standard but without the ability to control it.

[Mr Tidy]

Court_S said:

Certainly on the 125 coupe with that engine, people are just remapping them to get up to / past 330 power. P Torque is a name that crops up a fair amount.

Manuals are pretty rare, most seemed to opt for the auto with the 330.

Sorry, but the 125i only ever had the 3.0 litre N52 engine - just in detuned form. As I understand it Evolve among others can map it to 130i power levels.

But the N53 is a totally different proposition.

After reading about the other potential issues that can afflict N53s I've stuck to N52s, and am on numbers 3 and 4 at present!

If anyone reading this is thinking about an N52 325i, just spend the extra to get a 330i in the first place! I learnt the hard way.

Edited by Mr Tidy on Tuesday 1st October 23:21

[Sir_Dave]

N53 325i Power upgrade options are as follows:

Remap (aftermarket) - 255bhp or so
Remap (aftermarket) + Inlet Manifold - 275bhp or so
330i OEM map + Inlet Manifold - 270bhp or so

325i's are pre-wired for the extra plug that the 330i manfold needs

Some useful info in these two threads:

https://www.e90post.com/forums/showthread.php?t=13...
https://www.e90post.com/forums/showthread.php?t=12...

For when the N53 starts going bad, this is useful: https://www.e90post.com/forums/showthread.php?t=15...

[Court_S]

Mr Tidy said:

Sorry, but the 125i only ever had the 3.0 litre N52 engine - just in detuned form. As I understand it Evolve among others can map it to 130i power levels.

But the N53 is a totally different proposition.

After reading about the other potential issues that can afflict N53s I've stuck to N52s, and am on numbers 3 and 4 at present!

If anyone reading this is thinking about an N52 325i, just spend the extra to get a 330i in the first place! I learnt the hard way.

Edited by Mr Tidy on Tuesday 1st October 23:21

That’ll explain why people on BabyBMW are getting 270+ with just a map.

[Mr Tidy]

Court_S said:

Mr Tidy said:

Sorry, but the 125i only ever had the 3.0 litre N52 engine - just in detuned form. As I understand it Evolve among others can map it to 130i power levels.

But the N53 is a totally different proposition.

After reading about the other potential issues that can afflict N53s I've stuck to N52s, and am on numbers 3 and 4 at present!

If anyone reading this is thinking about an N52 325i, just spend the extra to get a 330i in the first place! I learnt the hard way.

Edited by Mr Tidy on Tuesday 1st October 23:21

That’ll explain why people on BabyBMW are getting 270+ with just a map.

Probably, because the 125i had a "detuned" 3 litre N52 and BMW claimed 265 bhp for the 3.0 litre N52 in the 130i and the Z4 3.0Si so 270ish after a map on a 125i doesn't seem unreasonable.

Whereas the E9* 325i with the N52 was only a 2.5 litre, so mapping wouldn't make much difference!

And the reason I replaced my E91 325i with an E90330i.

[84Reasons]

Sir_Dave said:

N53 325i Power upgrade options are as follows:

Remap (aftermarket) + Inlet Manifold - 275bhp or so

325i's are pre-wired for the extra plug that the 330i manfold needs

Hello,

I'm interested in doing the above quoted - slapping a 330 inlet manifold onto my 325i N53 + remap.
When you have stated the above about the 325i being pre-wired, are you saying all you need to do is buy a 330i manifold and its a straight swap + plugging the extra plug in?