[Teeeg28]

Recently I figured out I had an N51 instead of an N52. When I thought I had an N52 I was planning to do a 3 stage swap and a tune, but now I am doing a PI and tune on top of my PE. So basically what I have to ask is when you get a stage 2 tune on an n51 ( which has a 3 stage ) does the tune provided even more hp? I would think this because 1. it has a 3 stage and 2. with the N51 the factory "de-tuned" the car basically because of the 3 stage so when you get the tune it ( at least this is what I think ) unleashes the car to its full power.

I could be totally wrong in my assumptions thats why Im asking you guys
So if anyone has any information please fill me in, Thanks!

[jc5988]

Originally Posted by Teeeg28

Recently I figured out I had an N51 instead of an N52. When I thought I had an N52 I was planning to do a 3 stage swap and a tune, but now I am doing a PI and tune on top of my PE. So basically what I have to ask is when you get a stage 2 tune on an n51 ( which has a 3 stage ) does the tune provided even more hp? I would think this because 1. it has a 3 stage and 2. with the N51 the factory "de-tuned" the car basically because of the 3 stage so when you get the tune it ( at least this is what I think ) unleashes the car to its full power.

I could be totally wrong in my assumptions thats why Im asking you guys
So if anyone has any information please fill me in, Thanks!

yes, biggest difference is low end TQ 2300-2800rpm, which is freeway crusing speed in 6th gear.

N51 was tuned down to follow the tq curve of N52 328i, which is flat, so u wont feel when DISA is kicking on and dealer wont have to explain why N51 feels different then N52.

with tune, u will feel engine kicks on around 3300 and 4500 rpm, its feel almost like mini turbo boost or vtec.

[Teeeg28]

Originally Posted by jc5988

yes, biggest difference is low end TQ 2300-2800rpm, which is freeway crusing speed in 6th gear.

N51 was tuned down to follow the tq curve of N52 328i, which is flat, so u wont feel when DISA is kicking on and dealer wont have to explain why N51 feels different then N52.

with tune, u will feel engine kicks on around 3300 and 4500 rpm, its feel almost like mini turbo boost or vtec.

is it any faster then a n52 with a tune? so like a n51 tune vs. a n52 tune are the same performance?

[Xpander]

I doubt, but secretly hope, it is any faster than n52.
N51s have a smaller compression ratio of 10:0 and also a more restrictive exhaust.

There is also a secondary air injection system that pumps ambient air into the cats to slow their heating up. I think it is for SULEV requirements. I would love to know if this thing decreases or improves performance of the N51. Seems like unnecessary weight that's only used for emissions.

Teeg are u planning to dyno before and after?

[jc5988]

Originally Posted by Xpander

I doubt, but secretly hope, it is any faster ....

Teeg are u planning to dyno before and after?

agree, n51 wont make as much power as 330i N52, but 0.7 compression should be just 3-5hp/tq.

N52 came with secondary air injection as well, i think the other difference is with both main and secondary cat, it appears to be denser/havier according to online part catalog.

Originally Posted by Teeeg28

is it any faster then a n52 with a tune? so like a n51 tune vs. a n52 tune are the same performance?

N51 with DISA enabled should be on par with 330i N52 255hp if you had intake and exhaust swapped out , but not as much as 328 N52 with 3stage and tune. you should be worry about that, its only few hp, not day and nite difference.


here is the dyno chart for you guys to reference.
car is with early beta version of ESS N51 tune and PI.

ESS tune dyno'd first and stock tune second at same time, so probably not much time for DME to adapt back to stock setting. I feel car probably can do about 220hp with PE and current revision of the tune, but yet to find time to confirm.

[Wrngway]

I have an N51 with the AA stage 2 tune, PE, and modded stock air intake.

I don't have any dyno charts to show you, but I'd highly recommend the AA tune. My butt-dyno says it makes power. DS and manual mode on my auto are lots of fun.

The throttle delay from a stop is practically gone. Acceleration is increased. Throttle response is increased. You will definitely notice the difference once the car has adjusted over several hundred miles.

Two thumbs up for AA.

[50shadesofhockenheim]

I thought e90 328i was N52? How do you know you have an N51?

[Teeeg28]

Originally Posted by E90 LCI

I thought e90 328i was N52? How do you know you have an N51?

Open hood and look to see if it says sulev under there. Or just simple look to see if you have a DISA actuator motor on the manifold

[Teeeg28]

And I want to get dyno before and after but it looks like I won't be able to get one scheduled before the tune but I will get one done after

[Xpander]

Originally Posted by jc5988

agree, n51 wont make as much power as 330i N52, but 0.7 compression should be just 3-5hp/tq.

N52 came with secondary air injection as well, i think the other difference is with both main and secondary cat, it appears to be denser/havier according to online part catalog.


N51 with DISA enabled should be on par with 330i N52 255hp if you had intake and exhaust swapped out , but not as much as 328 N52 with 3stage and tune. you should be worry about that, its only few hp, not day and nite difference.


here is the dyno chart for you guys to reference.
car is with early beta version of ESS N51 tune and PI.

ESS tune dyno'd first and stock tune second at same time, so probably not much time for DME to adapt back to stock setting. I feel car probably can do about 220hp with PE and current revision of the tune, but yet to find time to confirm.
Attachment 796456

Thanks for sharing.
That's a substantial increase in torque in the lower RPMs.
Can't wait to see AA dyno on an N51

[manutdas11]

[e90coast]

Originally Posted by jc5988

agree, n51 wont make as much power as 330i N52, but 0.7 compression should be just 3-5hp/tq.

N52 came with secondary air injection as well, i think the other difference is with both main and secondary cat, it appears to be denser/havier according to online part catalog.

N51 with DISA enabled should be on par with 330i N52 255hp if you had intake and exhaust swapped out , but not as much as 328 N52 with 3stage and tune. you should be worry about that, its only few hp, not day and nite difference.


here is the dyno chart for you guys to reference.
car is with early beta version of ESS N51 tune and PI.

ESS tune dyno'd first and stock tune second at same time, so probably not much time for DME to adapt back to stock setting. I feel car probably can do about 220hp with PE and current revision of the tune, but yet to find time to confirm.
Attachment 796456

I have the n51 e90, what is this tune and how do i acquire it because it sounds like great fun. Currently i just replaced the stock air filter with an k&n one.

[Rival]

Originally Posted by Zoheb mateen

I have the n51 e90, what is this tune and how do i acquire it because it sounds like great fun. Currently i just replaced the stock air filter with an k&n one.

Active auto werks. theres a big thread in this section. email a rep or goto their site.

They have dealers all over

[Wrngway]

Originally Posted by jc5988

agree, n51 wont make as much power as 330i N52, but 0.7 compression should be just 3-5hp/tq.

N52 came with secondary air injection as well, i think the other difference is with both main and secondary cat, it appears to be denser/havier according to online part catalog.


N51 with DISA enabled should be on par with 330i N52 255hp if you had intake and exhaust swapped out , but not as much as 328 N52 with 3stage and tune. you should be worry about that, its only few hp, not day and nite difference.


here is the dyno chart for you guys to reference.
car is with early beta version of ESS N51 tune and PI.

ESS tune dyno'd first and stock tune second at same time, so probably not much time for DME to adapt back to stock setting. I feel car probably can do about 220hp with PE and current revision of the tune, but yet to find time to confirm.
Attachment 796456

Those are good numbers on just the stock tune. Stage 1/2/3 are just revisions of the Active Autowerke tune. You'll get the newest version if you purchase it.

I've been running the AA stage 2 on my N51 for a little more than a year now. I still love it. I don't have any second thoughts at all after all this time.

It does take a fair amount of time to adapt. It took mine a week or two before it settled in so dynoing right after installing any tune probably isn't doing it much justice.

[Rich_NYC]

i have 328 n51 also , im going to pull the trigger on the tune myself, quick question what is "pe" ? and also would deleting cats and or res help ?

[manutdas11]

Originally Posted by itscard0man

i have 328 n51 also , im going to pull the trigger on the tune myself, quick question what is "pe" ? and also would deleting cats and or res help ?

PE: BMW Performance Exhaust

[Love The Drive]

Originally Posted by itscard0man

i have 328 n51 also , im going to pull the trigger on the tune myself, quick question what is "pe" ? and also would deleting cats and or res help ?

The Performance Exhaust already deletes the resonator. It is replaced with a Y pipe.
If you do remove the second cats, don't forget that it takes time for the ECU to adapt to. The adaptation takes about 1-2 tanks of gas. There after you will feel some power gain in the mid to high rpm range. You do lose a little bit of low end torque.
I can't speak for this paired with the AA stage 2 tune, but I'm sure that the tune will bring back the power on the low end. Hopefully at LEAST back up to stock if not more.

[Mike.]

Originally Posted by itscard0man

i have 328 n51 also , im going to pull the trigger on the tune myself, quick question what is "pe" ? and also would deleting cats and or res help ?

go to e shift performance in NJ to get it done... its in house, and you can just chill out while they do it. Its pretty close to queens as well.

Pe is the BMW performace exhaust...deff do it sounds amazing look it up on youtube.

[walkmeister]

Hello my brothers! One here is under the impression that the Secondary Air Injection is there to cool down the catalytic converter, and I have to explain, that is not the purpose. Secondary Air Injection simply blows air into the exhaust gases immediately exiting the exhaust valve in an attempt to further burn any unburned gas that is exiting the combustion chamber.

It is a small amount of air, and if one thinks removing this will gain you horsepower, as many in the 1970's incorrectly surmised, you would be wrong today, too.

As you may notice with the Automatic transmission models, when the engine is cold the transmission shifts occur at a slightly higher rpm than when warm by design, and for one purpose: to heat the catalytic converter quicker, as it does not burn unburned fuel when it is cold! They need heat to do their work and to keep clean.

[Kgolf31]

Originally Posted by Love The Drive

The Performance Exhaust already deletes the resonator. It is replaced with a Y pipe.
If you do remove the second cats, don't forget that it takes time for the ECU to adapt to. The adaptation takes about 1-2 tanks of gas. There after you will feel some power gain in the mid to high rpm range. You do lose a little bit of low end torque.

Curious on the Dyno to prove this claim.

Hint, it's a trick question

- N51 Engine with AA Headers, AFE Stage 2 SI Intake, Custom 3" Exhaust merging right after the headers.

[b-man]

Originally Posted by Kgolf31

Curious on the Dyno to prove this claim.

Hint, it's a trick question

- N51 Engine with AA Headers, AFE Stage 2 SI Intake, Custom 3" Exhaust merging right after the headers.

No cats or resonator? If so, video please!

[Kgolf31]

Originally Posted by b-man

No cats or resonator? If so, video please!

Has a 100 cell secondary cat, Vibrant Bottle Resonator and a Borla XR-1 Muffler.

Go to 1:00 on this video for the best clip I have outside of car: