M30b35 swap

anthony · Post by **anthony** » Thu May 19, 2011 1:27 am

Did you use the purge valve?

No. I plan on swapping engines within the next month, so I have not given any thought on running motronic 1.3 permanently on the m30b34 engine.

It feels like it runs smoother but I have no empirical evidence to prove that. I have yet to use a tank of gas.

Currently I connected the wires only to the purge valve and have it sitting in the engine bay. I now have a check engine light and I thought if it wasn't connected I might get a check engine light on, but I don't even know if it checks for that.

There was some talk on mye28.com about running motronic 1.3 on the m30b34, but the response was if you think 1.3 is great wait in till you get the b35 engine.

I also removed the diagnostic plug from the engine harness. I simply cut it off were it excited from the main part of the harness. It is useless to me and fit nowhere. I simply rapped up the stump with silicone tape into the rest of the harness you would never miss it.

Blaise · Post by **Blaise** » Thu May 19, 2011 11:22 am

anthony wrote:Did you use the purge valve?

No. I plan on swapping engines within the next month, so I have not given any thought on running motronic 1.3 permanently on the m30b34 engine.

It feels like it runs smoother but I have no empirical evidence to prove that. I have yet to use a tank of gas.

Currently I connected the wires only to the purge valve and have it sitting in the engine bay. I now have a check engine light and I thought if it wasn't connected I might get a check engine light on, but I don't even know if it checks for that.

There was some talk on mye28.com about running motronic 1.3 on the m30b34, but the response was if you think 1.3 is great wait in till you get the b35 engine.

I also removed the diagnostic plug from the engine harness. I simply cut it off were it excited from the main part of the harness. It is useless to me and fit nowhere. I simply rapped up the stump with silicone tape into the rest of the harness you would never miss it.

Good stuff. My B34 is a euro version with 10:1 compression. It has been freshly rebuilt and should give me similar performance to the B35 (if not better). I also plan to keep the L-jet intake, using the E21 runners.

I have the motor mocked up and assembled on my engine stand, but have yet to dive into the harness.

anthony · Post by **anthony** » Sun Jun 12, 2011 11:34 am

[Good stuff. My B34 is a euro version with 10:1 compression. It has been freshly rebuilt and should give me similar performance to the B35 (if not better). I also plan to keep the L-jet intake, using the E21 runners.

I have the motor mocked up and assembled on my engine stand, but have yet to dive into the harness.]

The B35 has higher compression pistons. That alone will give you more power. The problem is that if all you purchased was pistons, everyone says *while you are in there...*

Hypothetically, if you got b35 pistons and ran motronic 1.3 it would be the biggest gain for the buck.

But I am in way too deep for that now.