M42/M44 ITB Kit Design

[Tgoode318]

I am very interested, Was going to go with dbilas but i would much rather support local members and as such have been waiting patiently! Your numbers sound good and the sound clip... sounds even better!
My only concern is that i have a LHD e36 and also an older 1.7 dme (1994). The dme isnt a big deal as i will be going to a full stand alone down the road, i also dont see lhd being to much of an issue but you never know?

[Jasonixo]

Question of curiosity - is anyone actually planning to get this kit once it's rolled out?

I'm gonna save my pennies!  I want an ITB kit for my M42 in my 2002 and this kit seems the best by far.  Any plans on US distributors?  Buying direct from Rama seems likely to be the best deal...

[lambertius]

I would buy a kit if I knew it was compatible with a LHD e30.

We'll make sure it fits the LHD E30. Rama realises LHD are the majority of the cars out there so he will be looking into it.

The kit itself will definitely fit, though the airbox we made may not. It isn't hard to make a custom airbox out of fibreglass (you just need some foam and a few days of patience) so if you want to make it fit you will definitely be able to. It would be nice to have the whole thing completed, but that is Rama's call.

I am very interested, Was going to go with dbilas but i would much rather support local members and as such have been waiting patiently! Your numbers sound good and the sound clip... sounds even better!
My only concern is that i have a LHD e36 and also an older 1.7 dme (1994). The dme isnt a big deal as i will be going to a full stand alone down the road, i also dont see lhd being to much of an issue but you never know?

The Dbilas kit definitely isn't the solution. The intake is just too short, and too large in diameter and you would still have the same ECU issues no matter what. My inclination is that the DME 1.7 will still work simply because more air in = more fuel in, so even if it isn't in total closed loop like the DME 5.2 it should still work - just less refined. That said, I have a friend who has an E30 and if he decides not to sell his car, he may end up with one of the kits and I may be able to give you results on that - no promises though. With the DME 1.7, you do have more 'tuning' options that aren't there for the newer cars, so there will be some way to make it work no matter what.

Question of curiosity - is anyone actually planning to get this kit once it's rolled out?

I'm gonna save my pennies!  I want an ITB kit for my M42 in my 2002 and this kit seems the best by far.  Any plans on US distributors?  Buying direct from Rama seems likely to be the best deal...

Still early days, but I suspect that Rama will sell the kit 'unsupported' for racing use (you buy the parts and fit it yourself) and Brintech will make a few alterations so that it bolts in properly and has instructions and what not - so you will probably end up just getting it shipped from one of them. It still isn't finalised for production, mine was the 'draft' so there are still a few changes to be made before its on sale. I don't know for sure if Brintech will get involved, but I know he is really keen to support them so as soon as Rama is ready they'll try and work something out.

[elcoy]

I have a LHD E30 with a M42 in the US!

I will volunteer as tribute for test fittings!

Actually have been emailing Rama about the intake manifold.  Was told by people who have more experience than me that the ITB's would be sort of irrelevant if I eventually want to go turbo?  I had designed a sheet metal airbox to use the stock throttle body, but don't have the fancy solidworks add-on's to test flow .  This set up and the design work/testing that went into it made my efforts look silly now. I could run this set up on my relatively stock motor in the car while I build the turbo motor on the stand, then swap it to the turbo motor!

[wazzu70]

The ITBs will still work great with a turbo engine. Think of all the S14/S38/S54 ect engines that work fantastic with ITB.

[thebrelon]

lambertius, I seriously think about it too.
may be within 6-12 months If I can sort a few things out by then.
that's for an E30 LHD tho.

[Darky]

Hi

What was your cam duration, final length and stats and picture of the exhaust manifold?

Thanks

[lambertius]

Hi

What was your cam duration, final length and stats and picture of the exhaust manifold?

Thanks

Everything internal to the engine is stock - including the cams. If you can find some information on the stock M44 cams then you will know more than me what the duration is!

As for the length to the valves - it is about 15", but I won't be able to tell you for sure till I get my car back. I will also be trying to make them a bit longer by reducing the size of the airbox, but that is a discussion for another day.

As for the exhaust...

So, I kept the stock diameter. Back of the envelope and Rama's experience said that the stock 2" diameter was more than enough. That plus a bit of feedback on this forum and some reading on other forums convinced me that the stock diameter was the go. So the setup from front to back is:

• OEM RHD 4-2-1 Headers
• Aftermarket CAT. It isn't a high-flow CAT, but its straight through so better than the OEM CAT anyway. As it turned out this was on my car anyway, I wasn't aware it had been replaced in the past but after looking at it, there was no reason to go to anything better
• Stock resonator since it is also straight through
• Straight through Muffler

So, literally, all I did was change the muffler - nothing else.

Who thinks that just a muffler that is the stock diameter will have an effect on wheel power?

Well, as it turns out, I wasn't imagining that it was improving performance - it added 6% more power through the entire rev range. Talk about bang for your buck, $160 muffler...

EDIT - It turns out that before ~3000 RPM the straight through muffler actually lost some power (which makes much more sense). I made the mistake in interpreting the graph since it was all in gray scale. The important thing to take from this is thatthere is absolutely no reason to go larger than the stock diameter. These results should demonstrate that it is evident that a larger diameter will lose exhaust velocity (and hence power) further up the rev range since the stock diameter already loses exhaust velocity down low. The only reason to go larger than stock would be to build a track only car where you don't care about the power curve before 4500RPM.

Now, I don't think it is a coincident that the power drops off before 3000RPM - before this RPM is when the exhaust drones (resonates). Rama was saying that drone is a reflection of the headers not working in their ideal range yet (not the correct tuned length for that RPM) - which seems logical since when the car was totally stock, about ~3500RPM was when the car felt strongest. If I get the side resonator right, it should theoretically improve the exit velocity marginally down low (thinking ~1%, so would only be observable on a hub dyno) as it will stop the pressure waves bouncing around in the exhaust.

/EDIT

Now, the Dyno that Laurence from Brintech used for this run was a different dyno than the previous one, and is reading 5kW lower. So I did it properly and paid to have a before and after run done on the same dyno - so on the same equipment, on the same day over multiple power runs - the new muffler improved power output by 6%!

By doing it in percentage points rather than talking about the dyno results themselves, we can see the total improvement even when using different dynos!  When I get some time, I'll graph the new dyno with the old data by adjusting it for percentage change over the old graph so we can view it all on the same chart but for now, the raw data is below!



We're now at 22~23% total improvement over stock, and using the BMW power rating that would be going from 103kW (138bhp) to 126kW (170bhp)! It now has the same power output as a 323! with no internal modifications and the stock ECU!

Now I'm sure you all noticed the random spike in the dyno results

There are a couple of explanations, I'll list them from most probable to least:

• There is an issue with the dyno causing a data artefact at a particular power/torque/rpm
• There is an intermittent vacuum leak causing random spikes and odd behaviour. This is pretty damn likely considering that there was a slightly higher idle then when it was originally set up, and the amount of piping that has been altered. I even have a good guess to where it is, I think its where the injector shroud hose meets the airbox. This seems to be a reasonable explanation for everything
• The stock ECU/injectors are no longer up to the task. This is pretty unlikely since the injectors worked for the DASC kit, and that was good for 200whp

So to investigate it, I will run it on another dyno to be absolutely sure that its just an artefact.

However I've asked Laurence to look into a full aftermarket injector and ECU setup, something I know a lot of you are very keen to see.

So here is the thing, Laurence would be keen to get a proven setup going that he could sell to support the kit. The problem from my perspective is that I'm almost certain it will totally break my budget as there were overruns along the way, and there are still some things I want to do to finalise the setup.

So, how much do you really want to see this all working with an ECU alongside it?

[thebrelon]

If I ever have the bucks my plan is to use a megasquirt MS3X ECU. Cheapest/most capable ECU.
BUT I wouldn't go for a complete ITB + muffler + ECU kit as it would be to much to spend in one go. Plus my muffler is already doing the job.
But now that i think about it if you go megasquirt and provide a base map which close enough to a final tune then...

[thebrelon]

There are 2 features of interrest regarding your project (well, actually one as the second is for my project but can be interresting to others) on megasquirt 3 ECU:
1- there is an ITB mode which is a blend of MAP/MAF speed density algorithm. MAF is used at low RPM as ITB don't produce as much vaccum as OEM intake systems and make it difficult to tune the low RPM part of the map on MAP sensor, and MAP at HI RPM.
2- you just have to hook up a 50$ fuel composition sensor to make your car a flex fuel one. E85 can bring some more power....

I'm looking at e85 as I would like to raise Cr to 12.
Add all together and the 200hp mark may be reached!

[lambertius]

Everything about the progress of this setup tells me that BMW made the M42/4 engines to be much more aggressive than what hit the shelves. It strikes me that somewhere late in the process they were told to restrict the engine's performance for some reason or another. Too much has been gained by fairly straight-forward modifications - and what I mean by that, is it was well within BMW's capability to make this intake even with a single throttle body on the end of the pulse chamber, but they didn't.

I think that emissions wasn't the primary focus, considering the age of the M42, I actually think that they held it back for marketability. This is totally wild speculation here, but I suspect that BMW may have seen the market fading for a noisy sports car and repurposed the engine late in the development cycle to be one of their low-powered economy offerings. The easiest way to do that is put on a massive muffler and choke the intake. This engine has made the 320i and 323i redundant which would be bad for product line marketability as well. All guess work, but I think that BMW saw a larger market for the more luxury oriented cars and repurposed the M42 late in the design stage to be more budget. To me that seems like the most reasonable explanation for why so much as been unlocked while still NA and stock internally.

If I ever have the bucks my plan is to use a megasquirt MS3X ECU. Cheapest/most capable ECU.
BUT I wouldn't go for a complete ITB + muffler + ECU kit as it would be to much to spend in one go. Plus my muffler is already doing the job.
But now that i think about it if you go megasquirt and provide a base map which close enough to a final tune then...

That is a valid point, I'll pass it onto Laurence.

[lambertius]

So I spoke to Laurence, and he has found a place that can reflash the stock ECU.

This is pretty much the ideal solution. No wiring issues, keeps costs down, everything plays nice with everything else. However, this is Australia and cheap is a relative term, unlike some of the stuff in the US.

I've been quoted $2200 which is by far the cheapest solution I've encountered so far, but is at least $1200 more than I can reasonably afford - so that pretty much sinks my prospects of getting a tune. It is a bit disappointing to be so close to completion, but money doesn't just appear. A stand alone ECU and tune is much more expensive. Who wants to donate to the cause for the greater good?

In other news, I'm getting my final drive on the LSD changed from 3.45 to the stock open ratio of 3.38 because first gear isn't very useful anymore, but you still need it to take off. I'm hoping that it will bring the 0-100 down to the low 8s times as it is about 9.5s now, whereas it was 9.3s with the stock engine and final drive! Silly physics!

I'll also be making my own smaller volume airbox. This should suit street use better since it will increase the strength of the wave tuning and I'm not increasing displacement or RPM so it shouldn't run out of air. That will be a few months away though.

[Darky]

Hi

I'm suprised you used the oem e36 rhd oem exhaust manifold like this. Makes me wonder the % increase this kit would do on a lhd car, substantially more I suspect.
I'd be guessing, but there's another 6%. Rhd oem exhaust manifolds are really bad, the e30 one is even worse!

Cheers Rohan

[lambertius]

Hi

I'm suprised you used the oem e36 rhd oem exhaust manifold like this. Makes me wonder the % increase this kit would do on a lhd car, substantially more I suspect.
I'd be guessing, but there's another 6%. Rhd oem exhaust manifolds are really bad, the e30 one is even worse!

Cheers Rohan

When Rama had a look at it, he said that it wouldn't be likely to see any gains for street use. Unless I went to the effort of making a 4-1 manifold, the RHD M44 manifold is all equal length and is much nicer than the image you've got there!

[Jasonixo]

The euro S50 is what- 315hp?  If an M42 is set up to be basically 2/3rds of a euro S50, wouldn't breaking the 200hp mark be readily achievable?  I have an M42 on a stand here, along with the complete driveline to put it all in my 2002.  I already have an M47 crank, so top end work including itbs is part of the plan.  Megasquirt is local to me so that is a goal as well. It seems to me, at least with regards to runner length, that these itbs are more properly-sized than the euro S50.