Latest project - boring out a throttle body! - Page 2

John V · 05-20-2013, 10:01 AM

Peter Florance at PFTuning down in VA Beach. He got Doug Keiler's car megasquirted successfully. Greg drove it at one of the last DC events and said it's pretty flawless.

I can't really discuss cost, but I can have Pete contact you if you want...?

John V · 07-11-2013, 08:47 AM

This weekend is the trip down to PF Tuning to get the megasquirt installed. It has been a long road getting here and the throttle body was just the first step.

We decided back in June to do the whole thing in one shot - convert to Megasquirt and tune WOT on gas, then pump out the tank, fill with E85 and do the WOT and part-throttle E85 tuning to see the difference.

E85 adds a bunch of complication. It is a very effective solvent, so when added to a system that previously had gasoline in it, the E85 will bring up all sorts of sludge, sediment and moisture. So really the entire fuel system should be replaced. I chose not to do this because this is still kind of an experiment. I did replace a few key components:

Injectors: The stock injectors don't flow enough fuel for E85, which requires about 35% more volume than gas for the same power level. Given that the E85 should boost torque by 10-15%, I needed an additional 10-15% overhead on the injectors. A set of Bosch "green giant" injectors rated at 42lb/hr took care of that. I had to fabricate some fuel rail spacers since they're about an inch taller than the stock injectors but that was easy.

Fuel pump: The stock pump is only rated to 170L/h and that's when it's new. The injectors will require that much flow so for insurance I bought the infamous Walbro 255L/h pump.

Flex fuel sensor: This is where it gets tricky. The Megasquirt community has come up with code to read from a GM flex fuel sensor which gets plumbed in the fuel feed or return line. I had to fashion up a bunch of AN fittings to connect to the BMW fuel system. This was a pain, but I did get it installed down near the fuel filter. With the sensor, I can put 100% gas, 100% ethanol or any mix in between and the tune tables will adjust accordingly.

A throttle cable, pedal and assorted fixings from a 1999-2000 BMW 323i, which was the last E46 to ship with a throttle cable. Of course, that cable doesn't connect to the M50 throttle body, so I had to make a bunch of little brackets and stuff to make that work. And the M50 throttle doesn't bolt up to the M54 manifold, so I had to make an adapter for that as well.

All very fun stuff, to be sure. Hopefully this weekend goes as planned

John V · 07-14-2013, 06:39 AM

Well two days of labor installing the Megasquirt, street tuning and dyno tuning yielded this. Not bad considering the car left the factory with 225 horsepower... At the crankshaft. I'm more enamored with the midrange torque, though. Yowza :-)

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Optimus Prime · 07-14-2013, 07:30 AM

Quote:

Originally Posted by John V

Well two days of labor installing the Megasquirt, street tuning and dyno tuning yielded this. Not bad considering the car left the factory with 225 horsepower... At the crankshaft. I'm more enamored with the midrange torque, though. Yowza :-)

Attachment 8703

That is a really nice torque plateau. Is that on E85?

John V · 07-14-2013, 07:09 PM

Quote:

Originally Posted by Optimus Prime

That is a really nice torque plateau. Is that on E85?

Yep. Annoyingly, I'm not sure the E85 did that much. Compared to a similar car also running Megasquirt, it made noticeably more torque but only about 5hp more on top.

We had done 28 or so dyno runs before this one with not much break, so the car was certainly heat soaked. If we had let it cool I know the numbers would have been higher but we were going for a good tune and didn't really care about the numbers.

There is also more power to be had below 2500 RPM but the car is never driven there in anger so it wasn't worth the extra time on the rollers.

05-20-2013, 10:01 AM	#11
John V No more BMWs Join Date: Apr 2005 Carmudgeonly Ride: Ram, MS3, CX-5, RX-8 Location: Glenwood, MD Posts: 14,753	Peter Florance at PFTuning down in VA Beach. He got Doug Keiler's car megasquirted successfully. Greg drove it at one of the last DC events and said it's pretty flawless. I can't really discuss cost, but I can have Pete contact you if you want...?

07-11-2013, 08:47 AM	#12
John V No more BMWs Join Date: Apr 2005 Carmudgeonly Ride: Ram, MS3, CX-5, RX-8 Location: Glenwood, MD Posts: 14,753	This weekend is the trip down to PF Tuning to get the megasquirt installed. It has been a long road getting here and the throttle body was just the first step. We decided back in June to do the whole thing in one shot - convert to Megasquirt and tune WOT on gas, then pump out the tank, fill with E85 and do the WOT and part-throttle E85 tuning to see the difference. E85 adds a bunch of complication. It is a very effective solvent, so when added to a system that previously had gasoline in it, the E85 will bring up all sorts of sludge, sediment and moisture. So really the entire fuel system should be replaced. I chose not to do this because this is still kind of an experiment. I did replace a few key components: Injectors: The stock injectors don't flow enough fuel for E85, which requires about 35% more volume than gas for the same power level. Given that the E85 should boost torque by 10-15%, I needed an additional 10-15% overhead on the injectors. A set of Bosch "green giant" injectors rated at 42lb/hr took care of that. I had to fabricate some fuel rail spacers since they're about an inch taller than the stock injectors but that was easy. Fuel pump: The stock pump is only rated to 170L/h and that's when it's new. The injectors will require that much flow so for insurance I bought the infamous Walbro 255L/h pump. Flex fuel sensor: This is where it gets tricky. The Megasquirt community has come up with code to read from a GM flex fuel sensor which gets plumbed in the fuel feed or return line. I had to fashion up a bunch of AN fittings to connect to the BMW fuel system. This was a pain, but I did get it installed down near the fuel filter. With the sensor, I can put 100% gas, 100% ethanol or any mix in between and the tune tables will adjust accordingly. A throttle cable, pedal and assorted fixings from a 1999-2000 BMW 323i, which was the last E46 to ship with a throttle cable. Of course, that cable doesn't connect to the M50 throttle body, so I had to make a bunch of little brackets and stuff to make that work. And the M50 throttle doesn't bolt up to the M54 manifold, so I had to make an adapter for that as well. All very fun stuff, to be sure. Hopefully this weekend goes as planned

07-14-2013, 06:39 AM	#13
John V No more BMWs Join Date: Apr 2005 Carmudgeonly Ride: Ram, MS3, CX-5, RX-8 Location: Glenwood, MD Posts: 14,753	Well two days of labor installing the Megasquirt, street tuning and dyno tuning yielded this. Not bad considering the car left the factory with 225 horsepower... At the crankshaft. I'm more enamored with the midrange torque, though. Yowza :-)