Its a re-map Jim, but not as you know it (One man's E89 N20 Dyno Tuning)

[MACK]

Hi,

Finally managed to get to PTorque to have mine remapped on Thursday and to cut to a long story short I'm very happy with the results!

I've posted the printout below, like an idiot I spilt a bit of water on it on the way home! :headbang: :rofl:

Will at PTorque told me that on the "before" run on the factory mapping the car ran 190BHP, to which I said "so not really up that much on standard". Will's response was "actual the decat is definitely having an effect". He went on to explain that this engine in this state of tune would normally produce 178-180BHP on his rollers so there's clearly a bit of an increase. Then when he told me the torque had been bumped up to 234 lbft (317Nm) from 199lbft as standard, I could clearly see the value of the decat pipe in isolation. I would also imagine the fresh coils and plugs I fitted, as well as always running it on 99 octane fuel are also playing a role. I remember when I fitted the coils and plugs the car did feel slightly perkier and definitely a bit smoother. Checking back on this thread my " before results" are pretty much on a par with what Pete's (Pbondar) car achieved once the Performance Centre had reloaded a standard factory map back on to it which is also decatted.

Moving on to the after, The car achieved 282bhp and 303 lbft with more available. Will explained that my engine was good for another 15bhp and an extra 30lbft, which if I wanted I could have, but it would be entirely at my risk. He's heard/read the same things a lot of us on here have about these engines letting go if pushed too hard. He told me that they haven't personally had any issues but he's heard stories from others about piston rings being the weak spot and cracking. He did say that in reality I would probably be absolutely fine at the higher outputs for a quick blast and it's probably sustained track abuse that actually causes issue. But he didn't want to take the risk and to be honest nor did I. Don't get me wrong more is always nice but I do like to sleep at night.

On the way back from Wolverhampton on busy M6, M56 and M60 (as well as way too many speed cameras!) I didn't really get to test it but I took it out yesterday evening and on quiet roads the car is a completely different animal. Above 3k revs its ballistic, in 3rd gear you run out of space on most roads before you run out of revs and if you're not careful you'll run out of license very easily too! :rofl: Honestly the car is more than quick enough for road use, obviously as above, more is always nice but anymore and you wouldn't be able to stretch the engine in anything other than 1st and 2nd gear which would frustrate the hell out of me.

The exhaust note has changed too, the decat alone had changed things, but now with the map there's a much deeper growl to proceedings which is amplified by the exhaust valve bypass switch I have on mine. With the valve open even at low revs/speeds it really does sound like it means business now for a I4. However you definitely want the valve closed for startup and the first few minutes after as it amplifies the air pump which sounds pants and your neighbours will seriously detest you! :rofl: Yes it's never going to sound as good as a normally aspirated 6 or 8 cylinder, but in its own way it sounds mean, a lot better than it did from the factory. It won't be to everyone's taste with the valve permanently open, but that said with the exhaust valve closed its still reasonable sedate for a sports car.

All in all I'm very happy with the results and well worth the trip to a proper mapper rather than the "man in a van" variety. I learn't a bit while I was there about how these generic mappers operate and also how BMW themselves purposely handicap this particular engine from the factory to fit their product lineups.

 

[mr wilks]

Looking at the sheer number of 4pot E89s on the market & the prices they can be bought for in the next few years i can see a good few forum members following the above route of decat - remap on them .
They offer a good all round package once tuned when you factor in the relatively low running costs with ved + mpg .
Not ruled out the idea totally myself :wink:

 

[Anonymous]

Mack very interesting..if not surprising..

When I went back to the Performance Centre about a larger flow turbo that’s available for N20s their view was without forged pistons and stronger rods I had got as far as was reasonable..

At the risk of antagonising the 35i guys what I can’t work out, as you say, is on the roads I use, the re-map with the de-cat compresses the time and space to the point where I think actually this is enough power for me..and that’s with all the handling tweaks..

Another 100bhp sounds good but not sure what/where/how it could be used...

Is your N20 fitted with pneumatic or electronic waste gate control?

 

[Smartbear]

Looking at the sheer number of 4pot E89s on the market & the prices they can be bought for in the next few years i can see a good few forum members following the above route of decat - remap on them .
They offer a good all round package once tuned when you factor in the relatively low running costs with ved + mpg .
Not ruled out the idea totally myself :wink:

Personally i think the n20 with a map steps into the shoes of the 30i as the sweet spot of the range really well. It’s a good compromise all things considered
Rob

 

[JamieZ4C]

At the risk of antagonising the 35i guys what I can’t work out, as you say, is on the roads I use, the re-map with the de-cat compresses the time and space to the point where I think actually this is enough power for me..and that’s with all the handling tweaks..

Another 100bhp sounds good but not sure what/where/how it could be used...

Just read this thread with interest. I completely agree with your thoughts. It's not just an E89 thing. I love the idea of a Z4M but I can't use the power I have in my 3.0si as much as I'd like as it is.

I made a similar comment in a recent thread about 'cheap' 600bhp cars (priced far beyond what I could or would ever spend on a car :lol. I posed the question when would you use all that power? No one could give me a response that made me feel like I was missing out.

If you're going to track these cars, drag them, whatever, then that's fine - go get a car with 600bhp. But on our roads, can you really use much more than 300bhp? You can, but is it worth the extra cost and potentially losing your licence or, worse still, hurting something or someone?

I think a tuned N20 is the sweet spot of the E89 range and the N52 3.0 is the sweet spot of the E85/86 and I'd challenge anyone to convince me otherwise!

 

[ronk]

My choice in the three Zs I’ve owned has always been 3.0l/6cyl engines.
Economy wasn't a consideration as I don’t do a lot of miles in the Z4 each
year and the £330 ved doesn’t hurt too much either. 30mpg is reasonable I think.

What I particularly like is the ability of the car to bumble along and find myself doing that quite a lot.

My concern about remapping the 2.0l is the stress levels. 145bhp/litre is quite high and once you’ve got to that level then there’s no further room for any improvement. I would like to see a bit of history before I started wringing the max out of an engine.

If you ever went out to buy a used 2.0l car and you had the choice of a bog standard car or a remapped car, which would you choose?

When it comes to insurance renewal I can tick the unmodified box and don’t have to start appealing for leniency or explaining the modification.

Please don’t read this as a criticism of those who have gone down the 2.0 re map route -these comments are nothing more than my reasoning for my own choice of engine.

 

[Anonymous]

My choice in the three Zs I’ve owned has always been 3.0l/6cyl engines.
Economy wasn't a consideration as I don’t do a lot of miles in the Z4 each
year and the £330 ved doesn’t hurt too much either. 30mpg is reasonable I think.

What I particularly like is the ability of the car to bumble along and find myself doing that quite a lot.

My concern about remapping the 2.0l is the stress levels. 145bhp/litre is quite high and once you’ve got to that level then there’s no further room for any improvement. I would like to see a bit of history before I started wringing the max out of an engine.

Please don’t read this as a criticism of those who have gone down the 2.0 re map route -these comments are nothing more than my reasoning for my own choice of engine.

Ron, all valid points...but time marches on..the BSA side valve guys bemoaned the lack of torque from the new fangled overhead valve versions etc etc..

BHP per litre has steadily increased..what’s different now is a focus on emissions / fuel economy figures..the ironic consequence is a bunch of high torque / lower reving smaller engines.,

If you look at the torque curves of the re-map N20s (now mine has been fixed) you see a very flat and rich torque curve spanning over 4,000 rpm..

That’s what gives these cars a real feel of push..allied to 8 speed boxes you have 3-4 gears to use at any point all making good progress..

I have no doubt that a normally aspirated 6 cylinder 3 litre BMW engine will outlive an N20...but that’s probably well north of 150k miles..

In terms of stress ..if we were operating these engines as we do in aircraft..ie full power in a climb for 30 minutes then I’m sure a tweaked N20 would not last as long as a NA six..but..for most of us..we are using full power for 10-15 seconds max..

Of all the failures I’ve heard off they have all let go on a racing circuit after hours of being trashed..

What I’m surprised at and most others who have had a remap is the transformational nature of the effect on perceived dynamics..

If you look at the torque / bhp curves you see all the dips n flat spots in the OE curves removed and net torque up from day 300 nm over a 2000 rpm range to 390nm over 2500 range..

The large increases in areas under the torque and bhp curves relative to stock result in a lot more real world go..irrespective of gear or type of driving..

Not suggesting you trade your 35is in.. :rofl:

 

[Jollyjoiner]

You can never have too much POWER :evil: :rofl:
35i's rule :rofl:

 

[ronk]

Not suggesting you trade your 35is in.. :rofl:

The current car is coming up 4yrs old and had 12k on the clock now and I did get the itch to go for an M40i last September but Itch was scratched by the £26k depreciation figure.

I just could not contemplate a change at this point.

 

[lyricalgangsteruk]

[/quote]

The current car is coming up 4yrs old and had 12k on the clock now and I did get the itch to go for an M40i last September but Itch was scratched by the £26k depreciation figure.

I just could not contemplate a change at this point.
[/quote]


Hi there, I'm looking to get back into a z next year! Although I'm looking around now to get a feel for what i want, specs etc etc.

Yours looks perfect, and if you do considering selling sometime next year (even Autumn time!)- please bear me in mind.

I don't want to step on any other members toes though!

Regards,

John

 

[ronk]

I will remember that!
Who knows what the Springtime brings ?

 

[Anonymous]

Meanwhile back on topic..

Looking at MACK’s and Smartbear’s dyno runs its very interesting ..if you are a sad bunny..

You can see in all cases the original N20 torque curve with a small hole around 3,200 and then a gentle rise to a flattened peak at 3,500 and then a slow n steady decline to the red line..as a result the BHP curve rises with a flattening at 3,200 them hits a peak around 4,500-5,000 rpm then flattish to the redline..

What’s interesting is how the tuners have worked their craft..I wonder how much tailoring these guys can/do do..

I notice some tweaks peak later at the expense of more mid range ‘variations’ and less mid range torque others peak earlier but are ‘smoother’ having a broader range of peak hp..although maybe less peak power overall..

Is it the tuner, is the difference between pneumatic and later electronic waste gate control, or is it other factors..?

 

[Smartbear]

Meanwhile back on topic..

Looking at MACK’s and Smartbear’s dyno runs its very interesting ..if you are a sad bunny..

You can see in all cases the original N20 torque curve with a small hole around 3,200 and then a gentle rise to a flattened peak at 3,500 and then a slow n steady decline to the red line..as a result the BHP curve rises with a flattening at 3,200 them hits a peak around 4,500-5,000 rpm then flattish to the redline..

What’s interesting is how the tuners have worked their craft..I wonder how much tailoring these guys can/do do..

I notice some tweaks peak later at the expense of more mid range ‘variations’ and less mid range torque others peak earlier but are ‘smoother’ having a broader range of peak hp..although maybe less peak power overall..

Is it the tuner, is the difference between pneumatic and later electronic waste gate control, or is it other factors..?

I think the maps are different for the different types of actuators, which you would expect for the electronically operated version. I don’t think it necessarily gives more absolute power as such but possibly a degree more control.
That would only make a small difference in pick up after a gear change/throttle off situation rather than more peak power :?
Rob

 

[Busterboo]

You can never have too much POWER :evil: :rofl:
35i's rule :rofl:

Almost.

:wink:

 

[Anonymous]

Meanwhile back on topic..

Looking at MACK’s and Smartbear’s dyno runs its very interesting ..if you are a sad bunny..

You can see in all cases the original N20 torque curve with a small hole around 3,200 and then a gentle rise to a flattened peak at 3,500 and then a slow n steady decline to the red line..as a result the BHP curve rises with a flattening at 3,200 them hits a peak around 4,500-5,000 rpm then flattish to the redline..

What’s interesting is how the tuners have worked their craft..I wonder how much tailoring these guys can/do do..

I notice some tweaks peak later at the expense of more mid range ‘variations’ and less mid range torque others peak earlier but are ‘smoother’ having a broader range of peak hp..although maybe less peak power overall..

Is it the tuner, is the difference between pneumatic and later electronic waste gate control, or is it other factors..?

I think the maps are different for the different types of actuators, which you would expect for the electronically operated version. I don’t think it necessarily gives more absolute power as such but possibly a degree more control.
That would only make a small difference in pick up after a gear change/throttle off situation rather than more peak power :?
Rob

I’m not sure hence why I asked the question..interestingly one of the re-map ‘kits’ offered for home use offers about 20 bhp more for the electronic controlled waste gate..

https://www.protuningfreaks.com/collections/bootmod3-menu/products/bootmod3-n20-n26-bmw-220i-228i-320i-328i-420i-428i-520i-528i

 

[Smartbear]

Meanwhile back on topic..

Looking at MACK’s and Smartbear’s dyno runs its very interesting ..if you are a sad bunny..

You can see in all cases the original N20 torque curve with a small hole around 3,200 and then a gentle rise to a flattened peak at 3,500 and then a slow n steady decline to the red line..as a result the BHP curve rises with a flattening at 3,200 them hits a peak around 4,500-5,000 rpm then flattish to the redline..

What’s interesting is how the tuners have worked their craft..I wonder how much tailoring these guys can/do do..

I notice some tweaks peak later at the expense of more mid range ‘variations’ and less mid range torque others peak earlier but are ‘smoother’ having a broader range of peak hp..although maybe less peak power overall..

Is it the tuner, is the difference between pneumatic and later electronic waste gate control, or is it other factors..?

I think the maps are different for the different types of actuators, which you would expect for the electronically operated version. I don’t think it necessarily gives more absolute power as such but possibly a degree more control.
That would only make a small difference in pick up after a gear change/throttle off situation rather than more peak power :?
Rob

I’m not sure hence why I asked the question..interestingly one of the re-map ‘kits’ offered for home use offers about 20 bhp more for the electronic controlled waste gate..

https://www.protuningfreaks.com/collections/bootmod3-menu/products/bootmod3-n20-n26-bmw-220i-228i-320i-328i-420i-428i-520i-528i

That’s surprising, not seen different results like that before? I’ve always assumed the maps are up to the safe mechanical limit and don’t see how that’s been extended by having a solonoid controlled waste gate over a pneumatic version? :?
Rob

 

[Jakg]

This isn't terribly helpful after the fact, but this is a great reason to be wary of places that use generic flash maps.

Doubly so when they quote lots of power outputs, but have no dyno proof, or even access to a dyno for that matter.

The last car I had remapped was done by someone who'd done loads of that model before. Standard power run, flashed a map he'd made before, and then 2 hours tweaking for the car.
Back again a couple of weeks later for some tiny tweaks to improve drivability.

Unfortunately those companies are very easy to get to, even better if a "dealer" can flash the car. As the proper places are always miles and miles from anywhere!

I've no direct experience of Celtic's remaps but I've been an Alfa owner for many years and followed the owners forum very closely. I can't say I've heard of many people who have had a positive experience of Celtic tuning. I personally wouldn't consider one of their remaps.

To be honest, most remappers - even those using generic maps - get great reviews because whether they've spent £100, or £500, the car "feels" faster.

Whether it actually is faster, or driveability is any better, is a whole different question.

 

[Anonymous]

This isn't terribly helpful after the fact, but this is a great reason to be wary of places that use generic flash maps.

Doubly so when they quote lots of power outputs, but have no dyno proof, or even access to a dyno for that matter.

The last car I had remapped was done by someone who'd done loads of that model before. Standard power run, flashed a map he'd made before, and then 2 hours tweaking for the car.
Back again a couple of weeks later for some tiny tweaks to improve drivability.

Unfortunately those companies are very easy to get to, even better if a "dealer" can flash the car. As the proper places are always miles and miles from anywhere!

I've no direct experience of Celtic's remaps but I've been an Alfa owner for many years and followed the owners forum very closely. I can't say I've heard of many people who have had a positive experience of Celtic tuning. I personally wouldn't consider one of their remaps.

To be honest, most remappers - even those using generic maps - get great reviews because whether they've spent £100, or £500, the car "feels" faster.

Whether it actually is faster, or driveability is any better, is a whole different question.

You raise valid points..since I was a ‘victim’ I’m having to agree with you..

As you say for most people the car will feel faster..no person that I know can, in normal road conditions, ascertain whether it’s x BHP or x+20 BHP increase..

I’m genuinely disappointed at Celtic a) for obviously getting it wrong in some way that they have not disclosed and b) being a ‘tier 1’ player for making this mistake on what is a very common engine..

Certainly I’ll be getting the next car on the dyno for a before n after set of runs ..

Reflecting on this..back in a dim n distant galaxy we used to mess around with main jets and needle positions when we used to tweak engines, as never two seemed to be the same..

So contrary to my original assertions I think even for a standard ‘upgrade’ it’s worth paying the extra money and time to get a set of dyno runs.. :driving:

 

[Smartbear]

Main jets & needle positions, the good old days! Those micro circlips must have beamed themselves into alternate dimensions as they never reappeared after pinging off :lol:
Rob

 

[ronk]

Main jets & needle positions, the good old days! Those micro circlips must have beamed themselves into alternate dimensions as they never reappeared after pinging off :lol:
Rob

What about the float valves on SU carbs that allowed Petrol to flood out?