2.0 tuning
- Thread starter hairyfrog
- Start date
Twin Turbo
Active member
So what your saying replace the DMU and you make an 18i to an 28i?
So how come no one has reported of doing this? (As I am aware)
So how come no one has reported of doing this? (As I am aware)
Smartbear said:
I doubt that the power of the DME module has anything to do with it. It will purely be the code that runs in the module that differs.
It's not as simple as just replacing the DME with one coded for a 28i as BMW have put measures in place to prevent that. I'm sure there is a method to circumvent this but beyond the reach of most people.
The best bet is for someone to reverse engineer the DME code like people have done with the N54 in the 35i and 35is. The N20 engine seems like a perfect candidate for the likes of Martial at MHD. If the N20 becomes popular for tuners then I'm sure it will happen.
I don't see why people get so upset about getting a de-tuned engine. You guys should be happy, you have an engine which will probably never go wrong since it's only running at 70% of its rated output.
Also there is the possibility that someone puts to effort into cracking the N20 DME and you guys have yourself a hugely discounted 28i.
R.E92 said:
It's already possible to get the 18i remapped to a higher output than the standard 28i.
I think the difference between the dme's is in the processing power, the light weight version probably can't support such sophisticated mapping & falls a little short because of this? (Just guesswork on my behalf)
Rob
Smartbear said:
Processing power has nothing to do with it. The processing requirements of an engine do not increase as the power output increases. The DME is just telling the plugs when to spark and how long the injectors should stay open when spraying fuel, no additional calculation is needed for the higher power output of the 28i.
The only difference will be a set of registers within the software which dictate how much boost the car targets.
Smartbear said:
If the engine, turbo and inlet/exhaust are are indeed the same then they will make the same power at the same boost and ignition timing.
There are other variables such as fuel ratio and valve timing which also need to be the same but I'll go out on a limb and say the reason the tuners can get more power from the 28i than the 18i is that they are using piggyback devices which still rely on the stock DME mapping to control the majority of engine operation or they are flashing the ECU with only partial access to the tables required.
In older 3 series cars I have seen threads where people talk about BMW limiting the valve lift as a way of limiting power output of engines. I think it was in the E46 330i and 328i models.
Piggybacks like the JB4 are limited on most of the new platforms by anti-tuning measures implemented into the DME and not by the potential of the engine. The DME will have a hard cap on certain things like airflow and fuel. The airflow cap is circumvented by intercepting the MAP sensor value and altering it to never hit the limit. Things like fuel I've heard are not so easy.
These hard limits will be set in the DME and be different for each power output of the N20 engine. The limits in the 28i will be higher than the 18i.
SteveSmith
Active member
R.E92 said:
This makes sense.
I don't doubt the engines are the same, never understood how the tuned figures where different though!!
Twin Turbo
Active member
But this goes back to my previous point - if the DMU is the only difference - why hasn't anyone just swoped them over - I been looking in the USA forums for F Series cars - and the chatter is about piggy back systems or re-maps
Twin Turbo said:
The DME will arrive without any code. You have to program the module when it's in the car, that's what BMW charge for.
Even though the existing module in the car is identical to a new one you can't recode it the normal way as certain registers that relate to the cars spec can only be changed during the first hour of the modules powered on life.
With N54 cars you could change the VO of the whole car then purchase a new DME and code it as a 35is. That's not needed in the N54 since there is a method of applying 35is code into the 35i and circumventing the 1 hour rule. AFAIK there is no method like that for the N20.
With the N54 enough tables are available so that you don't need to bother. This doesn't seem to be the case for the N20
Twin Turbo
Active member
So why dont people go to breakers and get an 28i DMU and fit into there 18i? - if the internals and auxiliaries are the same?
R.E92 said:
Yep I'm definitely with you both so far on the register table piggy-module code, but what about re-jetting the carb's?
I usually insist on understanding what's going on with my cars but If I ever go e89 I think I will just buy an 18 and give it to a tuner and fit some bigger brakes :wink:Twin Turbo said:
The VO (Vehicle Order) of the car needs to be modified to be a 28i model before the module will work. The DME then also has the VIN number of the car programmed in. If the VIN in the DME doesn't match the VIN in the other modules (CAS and EWS) then the car won't start.
These are safeguards against theft (preventing someone just replacing your CAS module and driving the car away with a new key) but also get in the way of tuning.
These are just the steps I'm aware of. The N20 is newer tech and I pay no attention to it's progression so there could be additional safeguards in that engine. You also have the problem of this new rolling ECU encryption they started adding to mess with tuners. I'm aware of some companies using bootmode to circumvent that but again don't really follow those updates!
The OP wants more oomph!
After reading thro some very well thought out arguments to wring more out of a 2.0l 4cyl and the potential problems, I would say save your cash for a 3.0l six in the future.
A featherweight will never go the distance with a heavyweight - or is that an over simplistic analogy !
Maybe just be content with what you've got? There will be plenty out there that would be more than happy to own a car like yours
Just my rambling thoughts and not wishing to offend!
After reading thro some very well thought out arguments to wring more out of a 2.0l 4cyl and the potential problems, I would say save your cash for a 3.0l six in the future.
A featherweight will never go the distance with a heavyweight - or is that an over simplistic analogy !
Maybe just be content with what you've got? There will be plenty out there that would be more than happy to own a car like yours
Just my rambling thoughts and not wishing to offend!