M42/M44 ITB Kit Design

[MLM]

I wouldn't think so. His diameter is too large, and the collector is a short distance from the ports for it to be contributing to lower down torque. I would be inclined to think that it's responsible for the top end performance. Just going off the shape of his torque curve I would be guessing that the headers are operating ideally at 5000RPM, and that the 3500RPM represents one end of their tuned behaviour and that 6250RPM represents the other.

If you can give me the lengths and diameters MLM I can try and calculate it and see where they're supposed to perform 'academically speaking'.

If I had to take a guess, it would probably be something to do with the timing and/or a secondary resonant mode with his intake (he is using Euro ITBs I believe).

While I'm on the topic of anomalies, there are a few guesses for what causes the spike in my power:

• Related to the engine timing, due to the expectation for the DISA to open which no longer exists.
• It could be a secondary resonant mode - possibly a resonant mode with the pulse chamber or the pipe connected to the filter.
• It may be a 'timing test' that the engine runs to check fuel RON. It advances the spark until detonation then adjusts its timing that way.
• The stock map may just not be capable of handling the intake dynamics at that point for any or all of the reasons above.

Its pretty reassuring though with the results from Rama's kit. It really shows that it is well matched to the engine and that there is still a lot of headroom to play with.

Rama has actually started selling his own ECU with an adapter made for it so that no wire splicing needs to be done. Just plug and play swap into your car. I wouldn't mind doing that.

$1500~$2000 AUD for new headers
$1600 AUD for the ECU

Unfortunately there is going to be a very very long wait till I have the same mods as MLM  It will be awesome to see what can be squeezed out though!

Oh, but unless something changes, I will be getting one of his LTW flywheels!

To be honest I cannot remember the lengths though primaries are similar to the longest oem primary length and the secondary's longer than oem. 1.5 inch primaries - 2 inch secondary's. For a quick calc you could probably use 450mm primary and 550mm secondary's as a starting point.
You can probably find more here http://bimmersport.co.nz/topic/28044-itb-m42/page-1 Its a 4-2-1 design as the stock RHD manifold is compromised. USA LHD wont have this issue. For ~ $450NZD Im happy with the result.

The low end torque is real and usable. In daily use this makes for a very drivable car. You can hear the engine note change for the torque curve on this dyno run as the engine heads for 5000rpm  https://www.youtube.com/watch?v=o8SuUTX98qs . For a tired old M42 im quite happy with how it compares to the M44 plot. As we use the same chassis, drive line losses due to frictional losses and inertias will be virtually identical.

Would it be correct to say that MLM has the advantage down low due his exhaust manifold? Which is an excellent piece of kit. You have a oem exhaust manifold and I'm not sure what Ralph is using. Possibly super sprint.

All itbs
Ralph 45mm
Lambertious 42 mm
MLM ?

Nice comparison lambertius

45MM ITB

Thanks for your comments - The exhaust is home made and best guess. My target was better than oem with the knowledge I get one shot as modification for optimisation is beyond my budget.

[Warsteiner]

Very nicely done lambertius!!

I am running the 666Fabrication custom header which is 44.45mm. My downpipe is custom which mates up to a complete E30M3 exhaust with a SuperSprint muffler.

I have no idea how long my intake runners are. They can actually be lengthened or shortened depending on how you fasten them. Not much room for adjustment though.

Cheers,
~Ralph

[gooly]

Hi,

I signed up just for this thread, theres some amazing work going on here and 100% respect to both of you involved. I was just wondering; I understand the purpose and benefit of the airbox but theoretically if you were to just bolt on the throttlebodies and leave them open to air with no MAF on the standard ECU, would you still see gains?

[Darky]

Hi

The ecu would probably go into limp mode without the appropriate air device.
On a standalone ecu it would work though, but that would take a lot of tuning.

Cheers Rohan

[lambertius]

As it turns out the OEM ECU can run off any 2 of the 3 major sensors (O2/MAF/TPS). There are some issues as the engine will go into a 'safe' mode, but it operates pretty well. The big issue though is that the expected airflow for a given throttle position drastically changes, in particular at low rpm. I wouldn't try driving it without the MAF. In closed loop you honestly can't tell it isn't factory.

[Puksuttaja]

So today I Dynoed my Z3 at my engineering school! The dyno that was used was MAHA 3000, the teacher said that it gives fairly conservative power figures and that the indicated power from the engine is much more accurate than the indicated wheel horsepower because of the way it measures it. This dynometer measures all the losses occuring between the engine and the wheels independently after the dyno pull (you put the clutch in and keep it in gear) you can see it as the green line in the picture. I also asked about the DMF thing and the teacher said it shouldn't effect drivetrain losses, it simply changes the place where torque will occur.

Sorry that all the text is in finnish, there is a translation at the end of the pictures I also have an Excel file already made if you want to plot a comparison from it Lambertius!
If I forgot to mention something, ask away!

The mods that I have on my M44 Z3 (156 000 kms driven):
Fogged airbox mod
Fulda Steel 4-1 style collector 2"
2,5" Custom made mid-section pipe
2,5"  Powersprint high flow catalysator
2,5" Simons catback exhaust

Exhaust manifold

Dynoresults
Translations:
Normaaliteho, Pnorm = The power from the engine that has been corrected with ETY-norms (so not the real one!)
Moottorin teho, Pmoott = The Engine power
Pyorateho Ppyora = The wheel horsepower (not to be blindly trusted according to the teacher)
Havioteho Phavio = The measured horsepower lost from the drivetrain, wheels etc.
Suurin teho = biggest power @ 6190/172 km/h
Vaantomomentti = The Torque (this is also corrected to the ETY-norms, so out calculating the norms the real torque is 189 Nm)
Suurin saavutettu RPM = The highest achieved RPM

[lambertius]

I've put up another update on page one for you guys!

[wazzu70]

That engine note is to die for!!


To the Finnish guy, where do you go to school? Kippis

[Puksuttaja]

That engine note is to die for!!


To the Finnish guy, where do you go to school? Kippis

I go to Metropolia university of applied sciences! Are you from Finland also?

[Darky]

Hi Ralph

1.75 inch exhaust header is very large?

Cheers Rohan

[Warsteiner]

Rohan,

I don't think so.....I'm not sure what the stock header is but It's not much different in size. Maybe someone has measured the stock header?


Cheers,
~Ralph

[wladas47]

colin86325 has a very valid point. All dynos are not the same and will read differently. The so called "standard",  could be the DynoJet dyno. It's very common. I have been on Mustang, DynoJet and Dyno Dynamics dynos and they are very different. You can actually alter your numbers by the way you tie the car down!! But then you're not real anymore so what's the point.

Some dynos have programs in them to mimic other dyno numbers. This is how the Dyno Dynamics does it.

Dyno Dynamics RWHP 86kw(115HP) /.84 = DynoJet RWHP 102kw(137HP) / .85 = Crank HP 120kw(161HP). So the ITB kit and tuning gets you 20w(27HP) at the crank. Sounds about right.

Here is how one company claims their upgrades
ITBs and tuning software 116kw(156HP) at the crank.
ITBs and tuning software with sport cams 126kw(169HP).
ITBs and tuning software with sport cams and headwork 134kw(180HP)
ITBs and tuning software with sport cams and headwork with Alpha-N 142kw(190HP)

So all of these mods have to work with each other. You don't just keep adding up the numbers as bolt ons. LOL
Do I think the numbers are a bit optimistic?... Maybe a little but they are close. So now add a little more for a stroker and you're over the 200HP mark.

Remember that using more duration cams and higher lift will gain you HP and shift the curve to the right in the RPM range. The torque however might suffer in the curve to the left in the RPM range and that is daily driving. Unless you have a lead foot all the time!

Adding one more thing....Using the 45mm Dbilas set up for a stroker motor is probably a good thing combined with all the other goodies! However....lambertius' 42mm set up for more stockish applications I think is the way to go. Especially with those awesome plenums.

My stroker is 2045cc's with 10.9:1, headwork and exhaust with headers, Alpha-N and MAP, 250* cams with Dbilas 45mm's on Megasquirt II.

Dyno Dynamics 151/.84 = DynoJet 180/.85 =212HP at the crank. There is a lot of work into this motor to get to this point. Now that's using about a 18% drivetrain loss. I'm not sure a 25% loss at 225HP figure would actually be right. If it is then WoooHooo! Even at 212HP I have still crested that 100HP/L !!

So Yes ...the ITB's open up the motor and let it breathe. They give the car a great sound with the FG or Carbon fiber plenum! And also give it a bunch of HP to play around with. I would totally recommend that everyone get a set! LOL
I like lambertius' throttle cable design way more than the one I have and I would totally sport the Carbon Fiber plenum.

Great job on the whole project lambertius!!

Cheers,
~Ralph

Consumption km/l?

[wazzu70]

I go to Metropolia university of applied sciences! Are you from Finland also?

Unfortunately Im not Finnish Im from the US. My room mate in college was from Somero so I have been to Suomi a number of times to visit him and his family!

[Warsteiner]

wladas47....

It's around 6km/l city driving. I have not had any highway driving yet.


Cheers,
~Ralph

[wladas47]

wladas47....

It's around 6km/l city driving. I have not had any highway driving yet.


Cheers,
~Ralph

I wrote it wrong: D should be l/km