Standard M10B18 engine Maximum boost pressure
Posted: Thu Oct 22, 2020 7:49 am
Hello friends.
The last year my '84 318i has been standing still in the shop, because it is receiving some new equipment
- I have installed a Haltech e8 ECU which I've mapped up to 100Kpa (relative)
- Installed 250cc/min EV6 injectors (I have to see how long these will hold up)
- Stainless steel log manifold
- K04(-023) turbo (from Audi TT/A3, Seat Leon)
- 480X180X65mm front mounted Air-Air intercooler
Other than that the engine is bone stock..
It has done 200k km but is still in excellent condition. Gas-mileage is exactly what is written in the books, and compression-test results are also almost spot-on.
Now I want to know, how far I can push this engine without breaking it.
Compression ratio is 9.5:1 (some of the internet says 10:1, but the owners manual says 9.5, so that is what I trust)
In the Netherlands 95 octane is the standard, but 98 is readily available for a few cents extra.
I did some searching on the 2002 forum (they do 10psi with no problems), but none of those guys have the compression ratio's we deal with. So that stuff is not comparable.
Combining the following picture, with the information from this website: https://wuling.id/en/blog/autotips/choo ... o%2012%3A1.
Leads me to believe I can go to 4-5psi
But if I would trust this website I could go muuuuch higher.
So summary:
what is the maximum amount of boost-pressure an M10 can take with
- 9,5:1 compression
- stock internals (alu head)
- 98 octane
- lambda 0.80
The last year my '84 318i has been standing still in the shop, because it is receiving some new equipment
- I have installed a Haltech e8 ECU which I've mapped up to 100Kpa (relative)
- Installed 250cc/min EV6 injectors (I have to see how long these will hold up)
- Stainless steel log manifold
- K04(-023) turbo (from Audi TT/A3, Seat Leon)
- 480X180X65mm front mounted Air-Air intercooler
Other than that the engine is bone stock..
It has done 200k km but is still in excellent condition. Gas-mileage is exactly what is written in the books, and compression-test results are also almost spot-on.
Now I want to know, how far I can push this engine without breaking it.
Compression ratio is 9.5:1 (some of the internet says 10:1, but the owners manual says 9.5, so that is what I trust)
In the Netherlands 95 octane is the standard, but 98 is readily available for a few cents extra.
I did some searching on the 2002 forum (they do 10psi with no problems), but none of those guys have the compression ratio's we deal with. So that stuff is not comparable.
Combining the following picture, with the information from this website: https://wuling.id/en/blog/autotips/choo ... o%2012%3A1.
Leads me to believe I can go to 4-5psi
But if I would trust this website I could go muuuuch higher.
So summary:
what is the maximum amount of boost-pressure an M10 can take with
- 9,5:1 compression
- stock internals (alu head)
- 98 octane
- lambda 0.80