SNAFU; high performance 318is build that lives up to the name, Turbo M42 ➞ Turbo M20

[varg]

but I would try and get some sort of slim pusher fan to put on the AC condenser to get more airflow through that thing when you're at idle.

No space. See previous posts with pics of the intercooler->condenser->radiator stack. There's about 3/4" in between the intercooler and the condenser and less than 7" between the top of the IC and the frame surrounding the condenser.

Would you mind sharing your timing map? I'm going be getting my turbo megasquirt going soon and want to make sure it doesnt go boom.

I'm not in the habit of sharing timing maps because they require a huge disclaimer. Too many variables. It's not hard to make a safe base map yourself as ForcedFirebird described.

[driftxsequence]

I understand. That gives me a base to start with thanks. At the moment I have nothing except for whatever comes pre-loaded on the mspnp2 ECU. Thanks!

[ForcedFirebird]

Would you mind sharing your timing map? I'm going be getting my turbo megasquirt going soon and want to make sure it doesnt go boom.

It's not wise to just share a map like that and expect it to work on another car. Take your NA table and subtract 1° per 10kpa above 100 and you will have a safe base. That will put you in the teens at 200kpa which is low, but safe in both directions. There's a couple of threads here and e30tech where maps are shared, just beware. Some of those maps posted are 10-ish@200kpa which will create a lot of unnecessary heat in the turbine. Also, if you have a different base timing than them in your MS, you could very well go boom...

[driftxsequence]

Would you mind sharing your timing map? I'm going be getting my turbo megasquirt going soon and want to make sure it doesnt go boom.

[ccsdo5]

I have a 160* thermostat in my m42 and just because it opens at 160* my cooling system can only keep my car around 180ish. On hot days on track my car idling with just the clutch fan gets up 185-195* I have to put the electric fan on get it to stay around 180* at idle when it is 90*+ outside. After hot lapping the car on limiter though I'll get up to 210-215* and it'll cool back down pretty quick. But at nights if I am driving down the highway I see temps of like 155* because of all the airflow.

I obviously don't have AC like you, but I would try and get some sort of slim pusher fan to put on the AC condenser to get more airflow through that thing when you're at idle. I find my car cools off the fastest with the clutch fan when I drive around track high rpm second gear since it is spinning faster. Also bummer about the roof rust :( I have a few spots on my car that need to be addressed soon as well which sucks.

[ForcedFirebird]

That spot on the roof is common, and not really the sunroofs fault. E30's came with a stupid plastic slipstream deflector,and they all have problems right there at the corner that always trapped water...

http://www.realoem.com/bmw/enUS/showparts?id=1113-USA-02-1991-E30-BMW-325i&diagId=54_0044

[varg]

I cut the bottom right corner and center section off of my fan shroud, it wouldn't fit between the fan and the radiator core intact, so now it's 3/4 of a shroud. Better than nothing, right? I also sat in front of my car with it running, burning stuff so I could see the airflow going through the grille. Not impressed considering the fact that my old Turbo Volvo would hold a sheet of paper against the grille with the electric fan on, and you could feel the air moving towards the grille with your hand on my old pickup trucks.



And I made an unfortunate discovery, it's not just my sunroof panel that is rusting, the roof is too. This repair just got 10x more painful.

Fuck sunroofs. If I have to drop the headliner to fix the roof rust, the whole damn sunroof assembly is coming out for good.

160 isn't warm enough, though. For reference, my van with an ls variant runs constant at 205, the ls1 Mercedes was always 210 at the track, didn't stop it from completing 14hr races, the e30's run at 200-210 for hours on end too. We consider 215 and up to be "overheating".

Where is the stock gauge reading (if yours is still fairly accurate)?

We discussed this over text, but for the purposes of the thread:
-200° happens approximately at the halfway mark of the gauge
-I've never seen the gauge go past 3/4 mark, even when the M42 overheated after the cylinder head crack, which was around 220°
-I just prefer the engine to run cooler than it does, as long as it's consistently above my WUE cutoff point of 160° and never above 200° I'd call it good
-I'm not as worried about the head after hearing that you've seen M20s survive higher temps than 220°, but I'm still trying to keep temperatures below 200° out of an abundance of caution.

[ForcedFirebird]

160 isn't warm enough, though. For reference, my van with an ls variant runs constant at 205, the ls1 Mercedes was always 210 at the track, didn't stop it from completing 14hr races, the e30's run at 200-210 for hours on end too. We consider 215 and up to be "overheating".

Where is the stock gauge reading (if yours is still fairly accurate)?

[varg]

From reading Maximum Boost (Corky Bell) and Forced Induction Performance Tuning ( A. Graham Bell), the core thickness produces less and less performance gains as it increases. Frontal surface area is the most important and there are some diagrams that include ducting and shrouding for the front of the intercooler for maximum air flow through it. Another consideration is airflow out of the radiator, around the engine and out of the engine bay. I wouldn't worry about the core thickness much. I would look for a 24" x 8"2.5 if you think the intercooler is causing problems.

Are you sure your thermostat isn't a 180 F thermostat? That is is the normal temp thermostat and unless you test it in boiling water, I wouldn't be sure it is a 160 F t-stat. My car usually runs 180-190 and it is perfectly healthy, I only worry if it gets up to 200 F. If the AC isn't cool enough, I believe you can add more refrigerant to lower the temperature.

Also, the Span fan is a good option for about $150 with mounts and bracket. You wants the puller fan. There were an old and new version and sometime you can find it cheaper with the old part number.

Old number VA18-AP71/LL-59A

Here is one for $99 shipped: http://www.ebay.com/itm/SPAL-16-Curv...ZZrfut&vxp=mtr

New number 30102049

I doubt we're in an area of diminishing returns with regards to core thickness in an intercooler as small as the one I'm talking about, and of the quality I can afford. I'm more concerned with the smaller core creating significant pressure drop when I turn the boost up though. I've been searching for intercoolers that fit the bill and have only found the one 24x6x2.5 that seems like it would work for me. If I could weld aluminum I'd just cut the core and end tanks down on my big cheapo that I have now, but I'm not going to spend a quality intercooler's worth of money getting a cheapo core cut and welded.

As for the thermostat, I specifically chose the 160° to replace my 180° thermostat. The plan was to run closer to 160° on the highway, giving me more headroom when I stop at a long light and the temperature starts climbing because the condenser is heating the already restricted airflow that is going through the radiator. Obviously a cooler thermostat won't fix a problem like this, but I was hoping for at least 10° more headroom for those times when I'm stopped and the temperature starts to climb. I do not like to see anything close to 200°, but if I'm stopped with the AC on it will get there in a couple of minutes and keep rising until I have to shut the AC off, open the windows and blast the heater to bring it back down. It's a hateful thing to have to do but M20 heads seem to crack at the slightest hint of overheating so ideally I do not want to see temperatures higher than 200°, ever. Thanks for the tip on the fan, but I'm probably not going for it, I can't see it fixing my problem and I've already thrown a new radiator, fan, fan clutch and thermostat at this problem. I think it's time to stop trying to cool well in spite of the restriction and fix the restriction.

As for the AC, the charge was done by weight and pressure, adding more wouldn't do me any good, the condenser heat soaks at a stop. Since there's no aux fan to prevent it, it can't be helped until I can fit one.

Totally normal. The m20 makes it's most power at 190, even, I have dyno tested this on spec e30's...

I wouldn't even be mentioning it if the car sat at 190° all of the time, I don't think that's too hot, but I don't like seeing 200°, let alone more. My warmup enrichment is off at 160°, so if I could run it closer to that I would.

[ForcedFirebird]

(typically 185-190° on a hot day)

Totally normal. The m20 makes it's most power at 190, even, I have dyno tested this on spec e30's...

[downforce22]

From reading Maximum Boost (Corky Bell) and Forced Induction Performance Tuning ( A. Graham Bell), the core thickness produces less and less performance gains as it increases. Frontal surface area is the most important and there are some diagrams that include ducting and shrouding for the front of the intercooler for maximum air flow through it. Another consideration is airflow out of the radiator, around the engine and out of the engine bay. I wouldn't worry about the core thickness much. I would look for a 24" x 8"x 2.5" if you think the intercooler is causing problems.

Are you sure your thermostat isn't a 180 F thermostat? That is is the normal temp thermostat and unless you test it in boiling water, I wouldn't be sure it is a 160 F t-stat. My car usually runs 180-190 and it is perfectly healthy, I only worry if it gets up to 200 F. If the AC isn't cool enough, I believe you can add more refrigerant to lower the temperature.

Also, the Span fan is a good option for about $150 with mounts and bracket. You want the puller fan. There were an old and new version and sometime you can find it cheaper with the old part number.

Old number VA18-AP71/LL-59A

Here is one for $99 shipped: http://www.ebay.com/itm/SPAL-16-Curv...ZZrfut&vxp=mtr

New number 30102049

[varg]

Haven't been doing much of any interest with my E30 lately, most of my time with it is spent commuting. Fun car stuff is too expensive (have to take a day off of work + pay entry to do an autocross, track days are completely out of the question), so I've been getting better mileage out of my money with other hobbies. I can get a lot more fun than one autocross by spending one autocross worth of money on RC airplane stuff.




Hurricane Irma wasn't too rough on us here, we got lucky, and the E30 sat safely in the garage the whole time with all of the patio furniture and stuff.



I've been fighting these coolant temp issues all summer. I replaced the fan clutch this week, so everything in the cooling system is now new, and the problem persists. Temps are still fine at freeway speeds, though a little higher than I would expect with a 160° thermostat (typically 185-190° on a hot day), but the coolant temp needle parks at the second mark when I'm cruising even with the AC on and that's a good place for it. I'm convinced the issue is due to the intercooler restricting fresh air flow, enough is forced through to keep cool while driving, but the fan doesn't create that kind of pressure differential, and it doesn't have a shroud to help it either. I cut a couple of pieces of corrugated plastic and some foam to act as ducting between radiator condenser/radiator stack ducting but it didn't help. I haven't been able to find any powerful electric fans that I'm sure will fit in place of the mechanical fan, and I'm not about to drop another $200 on a nice fan only to have it do no better than the unshrouded mechanical fan is.

At this point I'm pretty sure I'm going to install a smaller intercooler so I can run an aux fan and have less flow restriction. I'd like to find something with a 24" wide, 3" deep core like my current IC, but 6-8" tall instead of 12", closest I've found is 24x6x2.5 core. An IC that small might not be sufficient for my power goals without some sort of supplementary charge cooling like a water/methanol injection system, but another problem is it flowing well enough to not create significant pressure drop. Even if my 24x12x3 intercooler is only cooling as well as a 24x6x2.5 intercooler would due to having poor air flow over the top half, the larger core still supports more flow.

As usual I'm in uncharted territory here, nobody builds a turbo E30 and keeps the AC. In an ideal world I'd have the tools, time and skills to hack the core support and sheet metal behind the valance to bits and replace it with a welded up tube frame and some good ducting, but I don't have the tools, time or skills to do it.

No I can't get a reading on the high pressure side, I'm assuming the valve needs to be replaced but I don't want to have to refill the system. I'm going to start adding some insulation to the low-pressure line that runs next to the turbo. I'll let you know if it makes a difference. What temps are you seeing at the vents?

Mid 50s when driving on the highway, they climb at idle to mid 60s/low 70s. For reference that is with outside temperatures in the low 90s and humidity levels typically over 70%.

[megu2ice]

No I can't get a reading on the high pressure side, I'm assuming the valve needs to be replaced but I don't want to have to refill the system. I'm going to start adding some insulation to the low-pressure line that runs next to the turbo. I'll let you know if it makes a difference. What temps are you seeing at the vents?

[varg]

No, the pressures are ok so it doesn't need it. That's the diagnostic test for a bad compressor, have you checked your pressures?

[megu2ice]

Did you ever rebuild your compressor? My AC system is similar to yours and doesn't cool enough to deal with the afternoon temps. Rebuilding the compressor is my next option.