Tune BMW M30B35 correctly please help

Discussion pertaining to positive pressure E28s.
lummpy69
Posts: 16
Joined: Mar 26, 2020 2:04 PM
Location: Österreich

Re: Tune BMW M30B35 correctly please help

Post by lummpy69 »

Hello, there is some news.

I installed a camshaft sensor.

Because my opening times for the injectors were too low. Before they were at 1.9 ms and now we are at 3 ms when idle. So I got an even better idle.

Now I wanted to set closed loop. I just can't get it to work with you.

As soon as the load arrives it starts to swing and God knows.

I've also read certain instructions but nothing leads to success.

Now I pinned my hopes on the forum.


https://share-your-photo.com/efd0d61c04

Image
M. Holtmeier
Posts: 3025
Joined: Mar 11, 2007 3:06 AM
Location: Dallas, Texas

Re: Tune BMW M30B35 correctly please help

Post by M. Holtmeier »

Watch these videos and perform the ignition and idle valve sweep tuning. This should get you going, but I'm not a fan of the Bosch 3 wire IAC working with closed loop.

https://youtu.be/5odey_8U3OM?si=CPX-8B9SPQ7b72CW
russc
Posts: 1759
Joined: Feb 12, 2006 12:00 PM
Location: SF Bay Area, CA
Contact:

Re: Tune BMW M30B35 correctly please help

Post by russc »

For a M30b35, 12:1 under boost is perfect. any richer you sacrafice HP, any leaner, detonation.

From above, I ran MS in my E28 with MS and a M30b35. Max boost on 91, 10-11psi with Dinan's AtA IC. TCD's WtA set up gets you to a full BAR. To get the full BAR, you need his turbo and exhaust manifold. That the only way to get the exhaust flow restrictions out, and get faster cleaner boost with his T04E sized properly.

RussC
Panici wrote: Dec 06, 2023 10:11 AM
lummpy69 wrote: Nov 12, 2023 5:17 AMAt full boost I have an AFR of 12.3 and I think that's not bad.
To me this is WAY too lean under boost.
If you have an uneven injector or a bad tank of gas, there is no room for error and you'll melt a cylinder.


Two points of data:
--On my turbo miata (for which I have a spare engine) I run high 11s (11.5-11.9) at 10psi.

--On my M52B28 E30, I run 11.5 just getting into boost, down to 11.0 at 160kpa.



Extra fuel should help cool things down and prevent detonation.
Last edited by russc on Feb 26, 2024 6:42 PM, edited 1 time in total.
russc
Posts: 1759
Joined: Feb 12, 2006 12:00 PM
Location: SF Bay Area, CA
Contact:

Re: Tune BMW M30B35 correctly please help

Post by russc »

That is a f'g great YT channel for E28 MS and tuning. One of the best Ive seen.

RussC
Tiit wrote: Dec 13, 2023 7:55 PM Have you seen this yet?
https://youtu.be/3XEp3HnbFZ8?si=_qYSAgN-yKJROlW_
Panici
Posts: 221
Joined: Aug 07, 2014 2:04 AM
Location: Canada

Re: Tune BMW M30B35 correctly please help

Post by Panici »

russc wrote: Feb 26, 2024 6:27 PM For a M30b35, 12:1 under boost is perfect. any richer you sacrifice HP, any leaner, detonation.
I prefer safety over max power for my cars, but everyone is different.
Also since OP is a beginner it's better to err on the side of caution.

As I said, if you have bad fuel or a weak injector then you are taking a risk targeting 12:1 under full boost.
That will run the cyl leaner then 12:1 and detonate as you mentioned.

Perhaps if you have knock detection you could pull timing and get away with it.

Edit:
The video link you posted shows him targeting 11.5:1 in the 7psi range...
Post Reply