M10 knowledge.

[Hey_You]

Aren't u running it straight pipe.

It's 2.5" piping from the header back to the muffler, but yes, no cat or resonator.

[solo318]

This intrigues me. What would the impact be on this upgrade, do you have the ecu # by chance and the ignition modules I see seem to be for both years so what would you recommend ?

Thanks

There is an early and late 318, I'll try to source the numbers for you.

[solo318]

here is part of it, I'll find the rest later

Group 11 EngineBulletin Number 11 11 83 (788) Paqe 1 of 1Montvale, NJ December, 1983 Technical Dept.Subject: ROUGH IDLE/PERFORMANCE
Model:318i
The following changes will be introduced into production around November 1, 1983:
Rough Idle
To improve engine idle characteristics:
1.Compression reduced from 9.3 to 9.0:1
2.Vacuum source for distributor vacuum advance changed from intake manifold (i.e. full vacuum advance at idle) to ported vacuum - just above throttle plate (i.e. no vacuum advance at idle).
3. Distributor changed: Old New
I.D. # 0 237 002 080 0 237 002 096
Centrifugal Advance - Revised
Vacuum Advance - Revised
Initial Timing - Unchanged
4.Idle control valve changed to correspond with new vacuum advance source for vacuum advance. THE "NEW" VALVE (Part Number 13 42 1 705 968) MUST BE USED ONLY WITH THE NEW DISTRIBUTOR AND NEW VACUUM SOURCE.
Performance
Rear axle ratio changed from 3.64 to 3.91





© 2012 ALLDATA LLC. All rights reserved.Terms of Use

[solo318]

one of the most common problems I've seen over the years fixing 318 e30s is people mixing post update and pre update electrical parts.

[E30_Pare]

It's 2.5" piping from the header back to the muffler, but yes, no cat or resonator.

Is there a significant difference from the diameter bump in piping? My local m10 guru always strongly urged me from straying away from up sized piping. Told me to keep stock sized piping & just improve flow from an exhaust, tii exhaust mani, maybe pull the cat.

one of the most common problems I've seen over the years fixing 318 e30s is people mixing post update and pre update electrical parts.

That's interesting. Never realized they're we're significant difference between a few years. So according to your post the early/late icv's & distributors r different? As I'm looking for a different distributor. Mine keeps chunking bits from the cap contacts.

[jeffnhiscars]

I thought the upgrades improved performance rather than just idle..but here's my specs

Production date is 9\83 (so early car)
vacuum advance looks to be connected to throttle body (under the intake, so late car ?)
Im quite sure I have the early distributor
I have so many ICV's I cant tell you which one I started with but I have a c-clamp on the inlet hose so its essentially bypassed. Does idle well though :-)
My axle is a 3.46 open. Thats on the diff tag & in my manual (based on the car having been an auto trans at birth).
Its timed by ear since I dont think my aluminum flywheel has marks.

I have no idea what all this translates to but the car runs great

Group 11 EngineBulletin Number 11 11 83 (788) Paqe 1 of 1Montvale, NJ December, 1983 Technical Dept.Subject: ROUGH IDLE/PERFORMANCE
Model:318i
The following changes will be introduced into production around November 1, 1983:
Rough Idle
To improve engine idle characteristics:
1.Compression reduced from 9.3 to 9.0:1
2.Vacuum source for distributor vacuum advance changed from intake manifold (i.e. full vacuum advance at idle) to ported vacuum - just above throttle plate (i.e. no vacuum advance at idle).
3. Distributor changed: Old New
I.D. # 0 237 002 080 0 237 002 096
Centrifugal Advance - Revised
Vacuum Advance - Revised
Initial Timing - Unchanged
4.Idle control valve changed to correspond with new vacuum advance source for vacuum advance. THE "NEW" VALVE (Part Number 13 42 1 705 968) MUST BE USED ONLY WITH THE NEW DISTRIBUTOR AND NEW VACUUM SOURCE.
Performance
Rear axle ratio changed from 3.64 to 3.91





© 2012 ALLDATA LLC. All rights reserved.Terms of Use

[jeffnhiscars]

As I'm looking for a different distributor. Mine keeps chunking bits from the cap contacts.

Mine has done that 2x in the last 2 weeks. At first I thought the accident may have bent the dist shaft when the battery crashed thru the cap, but now Im thinking the new #91 battery is too big so when I'm revved (engine torqued over) and hit a bump the battery bumps the cap and knocks out my rotor by stripping the lock tab inside it. I moved the spacer and slid the battery over another 3\8" or so and hope that solves it.

I keep a spare rotor on me now so am interested in how you resolve this

[E30_Pare]

It maybe my batt hitting my cap. Never thought about that. Since my battery isn't secured. I need to make a new clamp to hold it in place hopefully that solves it. My wires r so close to the terminals I can sometimes see it ark between the terminal & wire. I also burned one of my wire because of this.

[jeffnhiscars]

It maybe my batt hitting my cap. Never thought about that. Since my battery isn't secured. I need to make a new clamp to hold it in place hopefully that solves it. My wires r so close to the terminals I can sometimes see it ark between the terminal & wire. I also burned one of my wire because of this.

Which wires are arcing ? My distributor has an insulated 1 pc cover as well as a grounded clam shell that never made sense to me. Now it does.

I have a type91 battery rather then the 48 and Im not sure Ill keep it despite the higher cranking power. Def clamp that baby down.

[E30_Pare]

That cover is long gone. Totally forgot about that piece. Its the closet wire to the battery. Freaks me out when it arcs. Been planing a battery relocate for a while. Just need to spend the time at the yard

[thebutterson]

Its timed by ear since I dont think my aluminum flywheel has marks.

What aluminum flywheel / clutch setup do you have? How do you like it?

[Jaxx_]

It maybe my batt hitting my cap. Never thought about that.

I had a similar problem. may not be the battery hitting the cap -- it was a bit of a stretch for me. come to find out that it was a worn dizzy that had about 3-5mm of play in it. I imagine the runout was bad and caused the rotor to smash into the cap with hard launches. First time it happened was at the drag strip with a very hard launch.


the result on the first rotor.

[jeffnhiscars]

That cover is long gone. Totally forgot about that piece. Its the closet wire to the battery. Freaks me out when it arcs. Been planing a battery relocate for a while. Just need to spend the time at the yard

You would actually have to rework the trunk compt to make the battery fit as that well is narrower than on cars that were built that way. Its also up front to maintain proper weight distribution so keep that in mind too. Thats another reason Im thinking too go back to the stock #48 battery...its 10lbs lighter.

[jeffnhiscars]

What aluminum flywheel / clutch setup do you have? How do you like it?

JB Racing. It weighs 8lbs VS 16.5 so it makes a huge difference in a zero hp engine. Keep in mind that you also lose rev momentum when you back off the throttle so it cuts both ways. Its not an actual hp gain but rather a percieved gain that is well worth it IMO. Who wants to spin 16lbs w 105hp

Stock Sachs clutch, PP etc

[Smelser]

It maybe my batt hitting my cap. Never thought about that. Since my battery isn't secured. I need to make a new clamp to hold it in place hopefully that solves it. My wires r so close to the terminals I can sometimes see it ark between the terminal & wire. I also burned one of my wire because of this.

When we were getting the car fired up, the main coil wire had a break, and it was arcing to the fender wall. we moved it away and up into the air. however we cranked so much that the batt discharged some and with the charger on it, had a buildup of highly flamable gas, when the key was hit again, KABOOM, the arc ignited the gas, blowing the top of the battery clean off. quick 15 min eyeflush then a trip to the hospital. acid is gone but now the battery has been relocated to where it should be, In the trunk in a marine container. next to the fuel cell.