Z3 M52Tub25 Supercharged build

[Brady7B]

I thought there might be some interest in the Z3 I'm building. It's a 2000 Z3 m52tub25 2.5 l. Ms42 ECU DME. I'm an old school mechanic and this is my first time trying to tune a vehicle on my own. Talk about a learning curve, but it's interesting. As far as work done to the engine, it's been taken apart and rebuilt, absolutely nothing wrong with it. I swapped out the stock injectors for Siemens part number 6900371 44 lb injectors 440 cc's. I've installed a Vortec V 5G centrifugal supercharger. Blow through MAF. Secondary air delete. PCV delete. Hand built custom exhaust with cat delete and wideband O2 sensor. I rebuilt the rear differential with a torsion limited slip with 4.11 gear ratio. Rebuilt all the bushings in the rear. The subframe has not come apart at all where there is a weak point. I haven't even seen any crackings on this one so I'm leaving it alone until I do. This is not a Vortech kit this is all hand-built piping hand-built mounting brackets and everything that goes with it I did myself. I even rebuilt the supercharger itself. Rebuilt the front end new struts shocks all bushings and tie rods. The front end was messed up when I got the car so it's got the front bumper of a 98 Z3. After getting it running with ByteTuner on the new injectors I hit a wall with the Stock MAF at 777 kg/h. I'm fixing to install a Bosch MAF that is used on the Audi RS4 B5 part # 0 280 218 067. It sounds like they have used this particular MAF sensor with some success on BMW builds using ms43 but I can't find any help with building a MAF table on ms42 with this particular sensor. I could sure use some guidance on how to do this or at least where to start.
I'm going to post pictures of the build if you'd like to see them. Forgive me if I'm not doing this correctly because like I said I'm fairly old school in this is all new to me but I'm a pretty quick learner when I have to be. If you have any questions don't hesitate to ask. Right now I'm in the process of transferring the stock seat warmers, electric adjustment mechanisms and airbag sensors from the stock Z3 seats to the new racing seats I'm installing. Any help would be appreciated. Thanks.

[Brady7B]

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[Renovelo]

Very impressive build! I love that this build is completely DIY! Given your attention to detail and patience, I'm sure you'll have no issues getting this sorted.

As for some tuning advice, we recommend anybody (beginners to seasoned experts) to read the books by Greg Banish:

• https://www.amazon.com/Engine-Managemen ... 1932494421
• https://www.amazon.com/Designing-Tuning ... 1932494901

Both of these books go through a lot of details for tuning engines. Although most of his examples are domestic (Ford, GM), his process can be applied to any engine tuning. If I had to recommend one of the books above the other, it would be his first one (Engine Management). This one focuses on both MAF and MAP based systems whereas his second one focuses primarily on MAP.

As you'll read in these books, you should only tune the MAF curve once you have the fueling perfectly tuned. This way your only variable is the new MAF sensor itself. If you're trying to also tune fuel in parallel, you'll end up chasing your tail and cause other issues in the tune elsewhere (like transient fueling). When we do MAF swaps, we rarely trust any published values. We attach the new MAF directly ahead of the old MAF, attach the voltage output to a data acquisition tool (like DATAQ DI-1100), then use ByteLogger or ByteTuner to log both the original MAF and new MAF. We then use the old MAF (and known curve) to create the new MAF curve almost perfectly. The only thing this won't help with will be the higher MAF range (since the new MAF usually has a higher capacity). We will create an article on our forums about this!

You can also read some info here (viewtopic.php?f=11&t=19). Although this is for OBD1, the same process can be followed for OBD2. This process would help you dial the upper end of the MAF curve after following the process of using your old MAF in parallel.

As for some advice on the RS4 MAF, check out the MS43 wiki (https://www.ms4x.net/index.php?title=MA ... r_Scalings). We have no association with this website, but it has a lot of good info on "how" to tune. We generally do not provide tuning advice unless we've tuned a particular vehicle/modification with our own hands. We have not confirmed if the values on the MS43 Wiki are correct, so you'll have to assume they are for now. You should be able to dump those directly into the MAF curve parameter in ByteTuner. However, you'll notice that the Wiki presents this in a 16x16 table whereas ByteTuner presents it in a 256x1 table. You'll have to take this into account when modifying this parameter. One of our other customers (Juuso on this forum) noticed that the values in the Wiki were slightly incorrect (~50kg/hr off in some parts of the curve).

[Brady7B]

Got the interior of the Z3 just about finished. The last two photos are the before pics. I transferred the stock BMW heating elements and airbag sensors into the new racing seats and mounted the new seats on the stock electric bases. It took a bit of engineering and some fabrication but they work perfectly.

[Brady7B]

Just got done

20200510_215752.jpg

[h82crash]

Very nice work! Now you should do a manual conversion.

[Zagatocoupe]

Awesome build! I’m just starting a BMW Z3 Coupe with an supercharged M54B30