[Captain comic]

First of all I'm not looking to do Headers, DP or else, but I have an opportunity to do a tune with discount (basically for $299). I have n51 and Auto and xi - probably the worst combo that can possibly be lol (in terms of power). So given this starting point - is there any sense in doing BPC tune (or any other tune)? The thing is I know n51 has less compression and already has 3-stage intake so I doubt tune can miraculously unlock extra ponies out of nowhere lol
Snake oil or real gains and if there are gains - then can someone explain in layman terms where they come from? I was told tune alone WITHOUT any hardware mods can add around 10-16hp - kinda hard to believe, but I wouldn't mind listening to someones lecture on this

[Bluewater328iT]

If you want to feel more power, the best thing is to trade for a 335i. The N51 with the three stage is tuned very well. A chip, a cat back exhaust, and a different airbox will add very little power. You will probably notice it, but it is not a night and day difference. A supercharger or turbo would help, but not as much as a trade for a 335.

[W37V]

Originally Posted by Captain comic

First of all I'm not looking to do Headers, DP or else, but I have an opportunity to do a tune with discount (basically for $299). I have n51 and Auto and xi - probably the worst combo that can possibly be lol (in terms of power). So given this starting point - is there any sense in doing BPC tune (or any other tune)? The thing is I know n51 has less compression and already has 3-stage intake so I doubt tune can miraculously unlock extra ponies out of nowhere lol
Snake oil or real gains and if there are gains - then can someone explain in layman terms where they come from? I was told tune alone WITHOUT any hardware mods can add around 10-16hp - kinda hard to believe, but I wouldn't mind listening to someones lecture on this

Why don't you just try it? Do base dyno, get the tune, do another dyno and show the world if there are gains to be had or not. You could waste $300 on worse things.

[Captain comic]

Originally Posted by W37V

Why don't you just try it? Do base dyno, get the tune, do another dyno and show the world if there are gains to be had or not. You could waste $300 on worse things.

I don't think there is a dyno for x-drive anywhere where I live. Even if there was a x-drive capable dyno within 200 miles from me - that's another $200 for before/after runs

I was interested in a logic behind tune - how exactly it extracts more hp? I can see gains for n52 WITH 3-stage intake mod and tune taking advantage of it, but I think it's a snake oil for n51, but I may be wrong of course. While I agree one could spend $300 on worse things, I'm ready to try butt dyno IF someone explains to me first how n51 can benefit from tune, because simply put for now I see no logic behind hp gain in n51 without ANY hardware mods

Anyone?

[W37V]

Originally Posted by Captain comic

I don't think there is a dyno for x-drive anywhere where I live. Even if there was a x-drive capable dyno within 200 miles from me - that's another $200 for before/after runs

I was interested in a logic behind tune - how exactly it extracts more hp? I can see gains for n52 WITH 3-stage intake mod and tune taking advantage of it, but I think it's a snake oil for n51, but I may be wrong of course. While I agree one could spend $300 on worse things, I'm ready to try butt dyno IF someone explains to me first how n51 can benefit from tune, because simply put for now I see no logic behind hp gain in n51 without ANY hardware mods

Anyone?

Why didn't you post in NA subsection of forum? Ask Bob. Hass is doing his own tune and is changing bunch of perimeters to up the power. Also, no tuner will disclose exactly what parameters they change to get more power.

[AZDesertBMW]

Steve Dinan would say there is very little to be gained from a tune on an NA motor. You have to change hardware to really get anything out of tune. With an NA motor you can only get increased power by relieving bottle necks, restrictive intake and exhaust systems. If there aren't any major restrictions than you won't see much power.

[hassmaschine]

Steve Dinan is wrong.

The N51 is probably one of the easiest to get power out of - it already has the 3 stage, but is detuned to 328i power. Half a point less CR doesn't make that much difference.

[Captain comic]

Originally Posted by hassmaschine

Steve Dinan is wrong.

The N51 is probably one of the easiest to get power out of - it already has the 3 stage, but is detuned to 328i power. Half a point less CR doesn't make that much difference.

Hass, I'm a complete novice in all this, but isn't it due to lower compression that BMW decided to offset by 3 stage intake to make it to 328i level, rather than mystically detuning it? If it was simply detuned, like power was limited by software I can see easy gains from n51 applying tune (given that tune will unlock that software block), but I suspect it's not as simple isn't it? I mean fundamentally a lower compression engine is a product of different hardware (whatever makes it lower compression) rather than simple software detuning - am I wrong? So what I'm saying is that only after changing some hardware - like rings (or whatever affects compression) will make it more powerful with tune, no?

EDIT: oh, I just saw your remark about half a point of CR making no difference. So then a simple question - can a tune really add power to n51 without any hardware change? Should I go with BPC tune then?

[hassmaschine]

No. It is detuned - ignition, Vanos, valve lift, etc - other than the 330i, all N52s do not even open the valves all the way, have reduced torque limiters, and run 14.7:1 at WOT.

A tune will absolutely make a difference. Of course, the lower CR makes *some* difference, but not all that much.

[Captain comic]

Originally Posted by hassmaschine

No. It is detuned - ignition, Vanos, valve lift, etc - other than the 330i, all N52s do not even open the valves all the way, have reduced torque limiters, and run 14.7:1 at WOT.

A tune will absolutely make a difference. Of course, the lower CR makes *some* difference, but not all that much.

Ok, so you convinced me to give it a try Now one more question - should I do a tune for 93 or 91 fuel? How important is that or it won't matter for the tune and I can still use both interchangeably? Will MAF be a problem for a tune as I've heard it was a nightmare for ESS SC on n51

[W37V]

Originally Posted by Captain comic

Ok, so you convinced me to give it a try Now one more question - should I do a tune for 93 or 91 fuel? How important is that or it won't matter for the tune and I can still use both interchangeably?

How are you getting your BPC tune so cheap ($300)? I want in!

[Captain comic]

Originally Posted by W37V

How are you getting your BPC tune so cheap ($300)? I want in!

Lol it's complicated, but it's work related, can't go into details, but it's not a group buy or something that someone can use, otherwise I would have gladly shared it with you guys as I'm sure a lot of people would love to do a group buy for lower price

[STR8-6IX]

all aspects need to be taken into consideration when deciding on this. to begin with, you got a 325i, automatic, xdrive.

if you do a tune, its not worth your time unless you upgrade to a 3 stage manifold while you're at it.

you have to find prices and tuning options and ask them what they do as far as fuel/ignition timing goes

these cars are tuned somewhat conservative from the factory, but some ECU tunes can be aggressive and it will be different from the factory tune.

your auto box may also run into problems if the power gains are huge

bottom line, if you're going for a tune, dont bother unless you are doing 3 stage manifold as well.

[hassmaschine]

Can you read? He clearly says he has an N51 - which already has the 3si.

the power gains aren't going to damage his transmission, lol. it's basically the same as the one used in the 330i.

your posts are painful to read..

[Fundguy1]

Originally Posted by Bluewater328iT

If you want to feel more power, the best thing is to trade for a 335i. The N51 with the three stage is tuned very well. A chip, a cat back exhaust, and a different airbox will add very little power. You will probably notice it, but it is not a night and day difference. A supercharger or turbo would help, but not as much as a trade for a 335.

This.

[avocet]

Originally Posted by Captain comic

is there any sense in doing BPC tune (or any other tune)?

I am not familiar with the BPC tune, but if it modifies your transmission settings then it will be worth it! lol

I drove an auto loaner and the transmission made me want to shoot myself! Ya ya the adaptations were probably all screwed up because 10 different idiots drove the thing in the past 6000kms...

To get to the point, getting a tune might not give you a huge hp gain, but it will make it feel better. As in better throttle response, faster revs, better power curve etc.

I have never dyno'd my car, but I think 10-15 hp with tune alone is realistic with a 328i n51/52. With a 330i I think the gains are harder to come by(due to higher tune out of the factory).

I have the AA tune btw, and love it.

[avocet]

Originally Posted by AZDesertBMW

Steve Donna would say there is very little to be gained from a tune on an NA motor. You have to change hardware to really get anything out of tune. With an NA motor you can only get increased power by relieving bottle necks, restrictive intake and exhaust systems. If there aren't any major restrictions than you won't see much power.

Keep in mind everything is relative. Getting 20-30hp out of an n52 with just a tune would be considered monumental. Getting 20-30hp out of the n54 would be considered cheap and easy. So relatively speaking, there is very little to be gained with tuning a N/A engine vs tuning a turbocharged engine.

[redline2001]

OP your post should really be moved to the NA section. While your there you will find that this question has been beaten to death.$300 is not gonna burn a whole in your pocket but dont expect much in gains

[Captain comic]

Originally Posted by redline2001

OP your post should really be moved to the NA section. While your there you will find that this question has been beaten to death.$300 is not gonna burn a whole in your pocket but dont expect much in gains

I agree, but I searched and to my surprise all talk was about n52 and literally NO ONE did a thorough thread on n51 That is why I created this thread and as you can see not a single person that has first hand experience with tune on n51 (except hass, but again he haven't done it with BPC). I think it's VERY strange for e90 forum to have this elephant in the room that no one talks about
I asked Bob from BPC about it and he replied vaguely about a lot of power left on table for n52 with bolt ons I mean I was clearly aiming at n51 and not n52 and wasn't asking about any bolt-ons. I also emailed BPC after that and got same general response. I feel like they know the real story, but for some reason don't tell it (maybe they are reluctant to tell the customer that n51 tune won't give much)
To be honest I don't know where else to go or whom to ask - I mean if BPC can't or won't tell specifics and if basically no one on e90post forum done BPC tune for n51 - there is only one method left to find out the truth: try and learn on your own mistakes method lol. If I get tune done, I'll definitely post a review on forum

[dancing__narwhal]

Originally Posted by Captain comic

I agree, but I searched and to my surprise all talk was about n52 and literally NO ONE did a thorough thread on n51 That is why I created this thread and as you can see not a single person that has first hand experience with tune on n51 (except hass, but again he haven't done it with BPC). I think it's VERY strange for e90 forum to have this elephant in the room that no one talks about
I asked Bob from BPC about it and he replied vaguely about a lot of power left on table for n52 with bolt ons I mean I was clearly aiming at n51 and not n52 and wasn't asking about any bolt-ons. I also emailed BPC after that and got same general response. I feel like they know the real story, but for some reason don't tell it (maybe they are reluctant to tell the customer that n51 tune won't give much)
To be honest I don't know where else to go or whom to ask - I mean if BPC can't or won't tell specifics and if basically no one on e90post forum done BPC tune for n51 - there is only one method left to find out the truth: try and learn on your own mistakes method lol. If I get tune done, I'll definitely post a review on forum

I know you have the N51 motor but I did just order the BPC tune for my N52 (stock). I will let you know what I think once the re-flash is done.

Eventually I plan to add the 3-stage IM as well but I'll start with just the tune.

[Captain comic]

Originally Posted by dgaultiere

I know you have the N51 motor but I did just order the BPC tune for my N52 (stock). I will let you know what I think once the re-flash is done.

Eventually I plan to add the 3-stage IM as well but I'll start with just the tune.

Please do tell!

[hassmaschine]

N51 already has a 3 stage!