m52tub20 NA tuning racecar track

[Norwegenbmw]

Hi. Are there any experts or experienced people with tuning m52tub20? I drive a racing class with restriction of 2,0L engine and maximum 160whp. I currently have 137whp with this setup:
M52tub20 engine, singlemass flywheel, exhaust headers and straight pipe, m54b30 cams and air intake, lightly ported exhaust out of engine. Chip tuned with regards to 208CC fuel nozzles with m54b30 air intake.

After reseraching on the internet my estimate would be closer to 150-155whp with my mods, and i have some questions around this.
I have an adapter plate that limits the b30 intake from i guess 3,25" to b20 3" to fit my throttlebody so i can have drive by cable, and not have to install a electronic gas pedal, can this be a big reason for limiting my whp gain, or what more can be changed.
I have my dyno charts.

I am also wondering if a better engine for me would be m52b20 because the m54b30 with be a bigger upgrade in this engine than in the m52tub20

Hope somebody can help :D

[Panici]

I drive a racing class with restriction of 2,0L engine and maximum 160whp.

Any objections to swapping in a Honda K20 engine? Seems like it would meet your criteria while being lighter and smaller then a 6 cyl.

[Norwegenbmw]

I have to use a bmw engine in a bmw chassis, max 2litre and maximum original engine hp 180. But can tune up to 160whp

[TobyB]

The b30 intake seems like it might be too big for a b20. Can you try a b25?

BMW loved working with the intakes, and some are good for real bumps at certain rpms...
...but can be restrictive in other places. The M54B30 intake is truly cavernous, but
without a functioning DISA, really hurts torque- and you're only flowing 2/3 of a b30.

Likewise, the b30 intake cam may not be doing you any favors-
and cam timing will need to be customized to get power out of the smaller displacement.
Can you play with that?

just thinking with my keyboard, here...

t
can manage close to 160 rwhp out of a 2L M10 at 7800 rpm...

[hasa]

What are rules regarding engine mods in this particular race class ? Is ITB allowed, and aftermarket engine management?

[ForcedFirebird]

The b20 is rated at 150bhp, so not surprising you are seeing 137 at the wheels.

The larger intake should make more power at the expense of low end torque. That's why the m50 manifold works well on the s52.

What are the rules as far as modifications? Larger intake valves, larger camshaft and more compression will easily net you another 20hp.

The early m54 was drive by cable, you will gain a little with a larger throttle.

[Norwegenbmw]

Thanks for replying.
b25 intake is the same size as b20. The m52tub20 head has the same size on inlet ports as m54b30(just for info).
The DISA works as normal. m52tu and m54 has the same mechanic only m54b30 is somewhat larger.

I have no real experience with these engine mods i have just started my journey following what people have said on forums :)

I am alowed to use ITB and aftermarked engine management. I am currently trying to install o2 sensors because its the most stable with the chip, gonna plug in PC in obd2 delete fault codes and adaptations, going to upload a new chip tuning file for more fuel from 6000rpm after seeing the results from dyno.

I will check the info about m54 models with drive by cable but must be m54b30 because of the size of the pipe. I am wondering about getting m54b30 Air flow meter and m54b30 trottlebody for more air to the engine but dont know if it will help or not, then i will also need pedal by wire, if no early m54b30 models have drive by wire :D

Appreciate all answers

[hasa]

How this 160whp max limit is measured in your class? Does scrutineers have a Dyno on the races?

Properly tuned M50B20 non-vanos race engine is probably best you can have, unless the real power is measured somehow.

[Norwegenbmw]

In the racing classes we drive they use "powerlog" to measure g-force and they calculate it to be around the correct whp. Some people may bend the rules and have more than 160whp and if they are chosen to use the powerlog when driving they can get busted. We use a formula 7,3 x whp and i am hoping for around 150whp for my car, then the car must weigh minimum 1095kg including driver(85kg) so at 150whp the car must weigh atleast 1010kg :D

[hasa]

Yes, my Norwegian language capabilities are limited, but I found the rules and web pages of the manufacturer: https://www.powerlog.no

Interesting concept!

I would optimise the engine producing as close as possible the 160whp and maximum torque. Probably some suitable performance cams (Schrick or similar) would get you close. And custom tune of OEM ecu.

[moatilliatta]

Are you running the MS43 DME?

What I find, is a tuned motor with race exhaust usually dynos what BMW list the factory spec.

Id just run an E46 Gas pedal and the M54 DBW throttle and fine someone who can tune MS43 and get your base line there.

What size exhaust?

Picutres of setup?

[Norwegenbmw]

I have siemens ms42. I have performance headers and straight pipe 2,5" exhaust with 1 sound muffler.

[TobyB]

Before you do anything else with the intake, measure the vacuum in the plenum.
If it is negligible at full chat at the end of the longest straight, the intake to the plenum's fine.
I suspect it is.
If you can measure vacuum at the port (harder) that will tell you if the runners are hurting you.
I strongly suspect that a 2.5l intake is not presenting much of a restriction to a 2L motor,
but have never tested it, as we didn't get the destroked version. In the 2.5,
a 3L intake can help the top end of stock.

Without being able to read your engine prep rules, I can't be a lot more help.
The M54 head is not particularly stunning- there is some port work that would
clean up flow for a 3L, but for a 2L might not gain you much.

An ITB setup may not make much more lap time on an M54- BMW did a pretty good job
extracting a pretty good compromise for torqe/ hp out of it, and as we all learn eventually,
it's area under the curve that wins races.

t

[hasa]

He has to use BMW engine, Max 2.0 litre, max 160whp which is controlled by the surveillance device. So just a cammed unopened M50B20 or M52 would do the job perfectly.

[Norwegenbmw]

Hi. Just a small update.
I had the car on a dyno last year and got the result 137,8 wheel HP.
This was in 3rd gear, dont think it matters much but in my gearbox ZF 328/m3 the ratio 1:1 is 5th gear.
The car was running lean after 5000rpm? and the horsepower gain didnt go down when reaching the limiter, so i believe there is a few more HP still to gain?

I have now installed the correct 2x lambda o2 sensors pre cat and the 2x behind is removed from ECU.
The temperature sensor on the engine is now installed, from before it was hanging out in the engine bay.

I will in the next weeks recieve a new chip tuning adjusted with more fuel on top and also rev limiter to 7200rpm.
Hoping this can better the air to fuel ratio and free up some more WHP.

m52tub20
Exhaust header, straight piped
m54b30 intake and exhaust cams
m54b30 intake but m52tub20 air intake boots
Chip 7000rpm, hardcut, 98octane fuel, better ignition,
Single mass flywheel
Car weight 1050kg





THIS IS NOT THE FINNISHED PRODUCT, NOT RACE READY :)