Megasquirt Questions... John Allen???

Megasquirt Questions... John Allen???

Joined: December 18th, 2004, 1:50 am

March 24th, 2008, 10:34 pm #1

Over the winter in my limited spare time I made the manifold posted below from StainLess Steel.

The Throttle body is from a D15B Hond 1.5 litre engine and the injectors are Bosch units from a GM 3800CC engine. The injectors (Bosch) have an ohm value of 18.4 each and are rated according to the Megasquirt web site at 214cc. I should not need a fly back or resistor board to run these. Correct?

I also picked up a megasquirt 1 unit new and assembled with 12 foot cable. I have the air temp sensor on the manifold and I am piping in the cold start water heated valve on the bottom of the throttle body. I am going to make up a block with 2 fittings in this same water circuit and install the engine heat sensor in the water circuit as well.

I also purchased a small compac lap top with 11 inch screen to just load the program and mega tune software.

I also picked up an electric fuel pump from a volvo 740 and will be building the surge tank next.

First off, where should I mount the contoller? I was thinking of the front trunk as my 79 does not have the large washer bottle or possibly in the spare tire well. This way it is close to the battery.

Should I use the cold start valve on the throttle body, currently is is blocked off by the gasket, I only need to cut the holes for it to work.

Any other comments and guidance is surely needed.

Thanks.







TonyK Grimsby Ont Canada.
Last edited by TonyK2 on March 24th, 2008, 10:42 pm, edited 1 time in total.
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Joined: June 24th, 2004, 12:00 am

March 25th, 2008, 12:05 pm #2

Wow, I wish you lived this side of the water! I'd have plenty of requests for fabrication favours ready!

Re your MS install:

You won't need the flyback daughterboard or resistors with your injectors.

If you use a stock FI tank, I don't think you need a surge tank, simply replicate the stock FI plumbing. Your fuel rail looks neat, but I don't see a fuel inlet! You will need a vacuum tapping from the manifold to the top connection on your fuel pressure regulator.

For fast idle with MS1, use a stock Bosch Auxiliary Air Valve, supplied by the fuel pump relay (i.e. tap off the fuel pump supply). The MS "fast idle" output is not used in this case, as it is all handled by the stock AAV.

Also tap your Lambda sensor heater supply off the fuel pump relay too. Then just like the stock Bosch L-Jet does, MS manages the fuel pump, the AAV and Lambda sensor heater so that they are only powered up when required (i.e. engine cranking and running - if the engine is stalled with ignition left on for any reason, MS cuts power to the fuel pump relay after a couple of seconds).

If you want to get sophisticated and use a Bosch two or three-wire motorised Idle Air Valve, you will need to upgrade the MS firmware to MSnSExtra, and make some minor internal hardware changes (a beefier transistor is all that's needed). Then the MSnSE "fast idle" output will be able operate the IAV correctly.

I have no spare wheel, so my MS lives in the wheel well, along with the Microplex ignition ecu.

Cheers R
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John Allen
John Allen

March 25th, 2008, 5:22 pm #3

you are correct.... I would still opt for the MS-Extra code however....

I would place the ECU in the spare tire well, I think there is enough room in the 'central' area clear of the tire - near where the dual relay usually sits... Keep the wires short, you don't have to be near the battery - it doesn't use that much juice...
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Cesare
Cesare

March 25th, 2008, 8:36 pm #4

Over the winter in my limited spare time I made the manifold posted below from StainLess Steel.

The Throttle body is from a D15B Hond 1.5 litre engine and the injectors are Bosch units from a GM 3800CC engine. The injectors (Bosch) have an ohm value of 18.4 each and are rated according to the Megasquirt web site at 214cc. I should not need a fly back or resistor board to run these. Correct?

I also picked up a megasquirt 1 unit new and assembled with 12 foot cable. I have the air temp sensor on the manifold and I am piping in the cold start water heated valve on the bottom of the throttle body. I am going to make up a block with 2 fittings in this same water circuit and install the engine heat sensor in the water circuit as well.

I also purchased a small compac lap top with 11 inch screen to just load the program and mega tune software.

I also picked up an electric fuel pump from a volvo 740 and will be building the surge tank next.

First off, where should I mount the contoller? I was thinking of the front trunk as my 79 does not have the large washer bottle or possibly in the spare tire well. This way it is close to the battery.

Should I use the cold start valve on the throttle body, currently is is blocked off by the gasket, I only need to cut the holes for it to work.

Any other comments and guidance is surely needed.

Thanks.







TonyK Grimsby Ont Canada.
Very interesting. You have the injectors mounted on the top of the plenum aiming down at the runners. Good atomization. Sometimes, it takes another perspective to showcase a design or find a simpler way to do things. I would have taken a more complex route, but this is a good little twist to the design. What's the distance from the injector tip to the runner mouth?
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Joined: December 18th, 2004, 1:50 am

March 25th, 2008, 8:37 pm #5

Wow, I wish you lived this side of the water! I'd have plenty of requests for fabrication favours ready!

Re your MS install:

You won't need the flyback daughterboard or resistors with your injectors.

If you use a stock FI tank, I don't think you need a surge tank, simply replicate the stock FI plumbing. Your fuel rail looks neat, but I don't see a fuel inlet! You will need a vacuum tapping from the manifold to the top connection on your fuel pressure regulator.

For fast idle with MS1, use a stock Bosch Auxiliary Air Valve, supplied by the fuel pump relay (i.e. tap off the fuel pump supply). The MS "fast idle" output is not used in this case, as it is all handled by the stock AAV.

Also tap your Lambda sensor heater supply off the fuel pump relay too. Then just like the stock Bosch L-Jet does, MS manages the fuel pump, the AAV and Lambda sensor heater so that they are only powered up when required (i.e. engine cranking and running - if the engine is stalled with ignition left on for any reason, MS cuts power to the fuel pump relay after a couple of seconds).

If you want to get sophisticated and use a Bosch two or three-wire motorised Idle Air Valve, you will need to upgrade the MS firmware to MSnSExtra, and make some minor internal hardware changes (a beefier transistor is all that's needed). Then the MSnSE "fast idle" output will be able operate the IAV correctly.

I have no spare wheel, so my MS lives in the wheel well, along with the Microplex ignition ecu.

Cheers R
I will next build a surge tank for the car and feed the surge tank with a thumper low pressure pump. I was using this pump to fuel my 36 DCNF Weber.

Take a close look at the pictures and the fuel rail, it has 2 ports one at each end. 1/8" and 1/4" NPT for fuel in and a plug to measure fuel pressure for trouble shooting.

The other picture is of the D15B Throttle body, see the AAV mounted below it. I will use it as it is a simple installation and works from water heat.

Just in case you are interested, this is what the inside of the box looks like.

I am currently doing a complete step by step post on the UK board.

I have about 70 hours into this manifold as I had like always had to make the tooling to make the components for it. However those that know my work also realize that won't stop me from building what I want to build.






TonyK Grimsby Ont Canada.
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Joined: December 18th, 2004, 1:50 am

March 25th, 2008, 8:42 pm #6

Very interesting. You have the injectors mounted on the top of the plenum aiming down at the runners. Good atomization. Sometimes, it takes another perspective to showcase a design or find a simpler way to do things. I would have taken a more complex route, but this is a good little twist to the design. What's the distance from the injector tip to the runner mouth?
My objectives were.

Easy change of injectors with most common types from the junk yard.

Increased heat path so that the injectors will not heat soak from the manifold. No fan required to cool injectors.

Use Stainless Steel as it is a terrible conductor of heat in comparison to alumium and thus keep the air charge cooler from the high heat of the X engine bay.

Longer spray path so that the raw fuel can mix with the air charge and not just dump raw fuel into the hot head and valve stems. Should minimize coking of the valves.

TonyK Grimsby Ont Canada.
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Joined: August 6th, 2005, 6:03 pm

March 25th, 2008, 9:07 pm #7

Over the winter in my limited spare time I made the manifold posted below from StainLess Steel.

The Throttle body is from a D15B Hond 1.5 litre engine and the injectors are Bosch units from a GM 3800CC engine. The injectors (Bosch) have an ohm value of 18.4 each and are rated according to the Megasquirt web site at 214cc. I should not need a fly back or resistor board to run these. Correct?

I also picked up a megasquirt 1 unit new and assembled with 12 foot cable. I have the air temp sensor on the manifold and I am piping in the cold start water heated valve on the bottom of the throttle body. I am going to make up a block with 2 fittings in this same water circuit and install the engine heat sensor in the water circuit as well.

I also purchased a small compac lap top with 11 inch screen to just load the program and mega tune software.

I also picked up an electric fuel pump from a volvo 740 and will be building the surge tank next.

First off, where should I mount the contoller? I was thinking of the front trunk as my 79 does not have the large washer bottle or possibly in the spare tire well. This way it is close to the battery.

Should I use the cold start valve on the throttle body, currently is is blocked off by the gasket, I only need to cut the holes for it to work.

Any other comments and guidance is surely needed.

Thanks.







TonyK Grimsby Ont Canada.
looks good. I think that is a very smart approach. Not conventional at all, but I like it.

On the fuel rail, did you find a fitting to let you connect the stock fuel pressure regulator? What fitting/thread/style/etc is it? I am going to attack my turbo fuel rail shortly.

From the glass lined tanks of old Bertone

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TonyK
TonyK

March 25th, 2008, 11:00 pm #8

Just a couple of points.

First thanks for the positive comments. I am still waiting for someone to say what the hell were you thinking, nobody would build a manifold because... and I would then face 14 reasons of my own stupidity.

My thought process was greatly influenced by that of the Carburetter, complete with velocity stacks and tapered venturies.

Getting back to your question. First off Damon you should know by now if I can't buy it I will make it. Take a close look at the fittings on the bench. These are Parker fittings.

The thread is .550 x 18 now in metric that works our very close to 14mm x 1.5. Also look at the ferruel, I have machined it shorter so that it seats with the Bosch regulator. I have pressure tested it with air and it is holding no leaks with the soapy water.

While you are looking down at the rail take a look at the runners and manifold flange. Not machined to fit but swagged with a 10 ton press to obtain the shape.





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TonyK
TonyK

March 25th, 2008, 11:18 pm #9

For some reason the edit is shut off, the tube size for the fitting in the pictures of the post before is 3/8"

TonyK.
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John Allen
John Allen

March 25th, 2008, 11:48 pm #10

Just a couple of points.

First thanks for the positive comments. I am still waiting for someone to say what the hell were you thinking, nobody would build a manifold because... and I would then face 14 reasons of my own stupidity.

My thought process was greatly influenced by that of the Carburetter, complete with velocity stacks and tapered venturies.

Getting back to your question. First off Damon you should know by now if I can't buy it I will make it. Take a close look at the fittings on the bench. These are Parker fittings.

The thread is .550 x 18 now in metric that works our very close to 14mm x 1.5. Also look at the ferruel, I have machined it shorter so that it seats with the Bosch regulator. I have pressure tested it with air and it is holding no leaks with the soapy water.

While you are looking down at the rail take a look at the runners and manifold flange. Not machined to fit but swagged with a 10 ton press to obtain the shape.




You might check to see if the fitting is a BSP type fitting, as used on a lot of British stuff (British Standard Pipe). I think it may be a 3/8"BSP, though I'm not sure...
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