EFI conversion thread, another one... |
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EFI conversion thread, another one... |
'73-914kid |
Mar 10 2014, 05:34 PM
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#1
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Senior Member Group: Members Posts: 1,473 Joined: 1-November 08 From: Vista, CA Member No.: 9,714 Region Association: Southern California |
I seem to constantly bounce back and forth between carbs and EFI.
I used to be really pleased with the fuel economy of my 4-cylinder with carbs. I really couldn't complain about 30mpg on a carb'd 2.1L type 4. Well, with gas prices going back up, and having installed the 6, I'm getting a whopping 16-18 at freeway cruise, which is unacceptable for me. The motor is a 2.7 built to RS specs with S cams, and it really does go quick, but either the jetting is off, throttle shafts are worn (I know for a fact they are based upon carbon deposits on the butterflies), or I'm suffering from the fact that the 40's were never really meant for a 2.7, so the transition circuit is hugely rich.. becasue fuel mileage is awful. Anyways, I have this vision in my head of removing the fuel lines, closing off all of the unnecessary ports in the carbs sans the air bleed screws, and essentially converting them into ITB's. I would adapt a TPS onto one of the throttle shafts, plumb the intake manifolds for vacuum for the MAP, and then weld in injector bosses/bungs which are readily available, and cheap, from various websites for the standard 14mm bosch style o-ring sealing injector. There would be no permanent modifications to the carbs, just to to the intake manifolds. Am crazy for even trying to attempt to start collecting parts for something like this? The hope is to not spend a whole lot of money on everything, and keep it bare bones with no ignition control, just fuel control. Brain would be megasquirt, not sure what version yet, but I was also tossing around the idea of microsquirt. I'm not sure what would be the best avenue for something like this. Any thoughts on this? Don't do it, don't waste your time? etc. |
aircooledtechguy |
Apr 29 2015, 09:27 AM
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#2
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The Aircooledtech Guy Group: Members Posts: 1,966 Joined: 8-November 08 From: Anacortes, WA Member No.: 9,730 Region Association: Pacific Northwest |
MS1 can handle spark, and it's upgradable to whatever you need. I can't imagine using it today though unless it was practically free since the later versions do it all and more right out of the box.
I'm a huge fan of Megasquirt and currently run MS3X in my car. I love the tuneability that it offers. |
toon1 |
Apr 29 2015, 10:06 AM
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#3
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
MS1 can handle spark, and it's upgradable to whatever you need. I can't imagine using it today though unless it was practically free since the later versions do it all and more right out of the box. I'm a huge fan of Megasquirt and currently run MS3X in my car. I love the tuneability that it offers. I'm also a huge fan of MS.....BUT....instead of going through all the gyrations of EFI at this point, why not install an 02 sensor and see if you can do better with the carbs. For $190, you'll get real time readings. You can then try some jetting to see if the MPG's get better. If it's still not to your liking and decide to go the EFI route, the 02 sensor will be there for you to tune the EFI. |
'73-914kid |
Apr 29 2015, 10:21 AM
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#4
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Senior Member Group: Members Posts: 1,473 Joined: 1-November 08 From: Vista, CA Member No.: 9,714 Region Association: Southern California |
MS1 can handle spark, and it's upgradable to whatever you need. I can't imagine using it today though unless it was practically free since the later versions do it all and more right out of the box. I'm a huge fan of Megasquirt and currently run MS3X in my car. I love the tuneability that it offers. I'm also a huge fan of MS.....BUT....instead of going through all the gyrations of EFI at this point, why not install an 02 sensor and see if you can do better with the carbs. For $190, you'll get real time readings. You can then try some jetting to see if the MPG's get better. If it's still not to your liking and decide to go the EFI route, the 02 sensor will be there for you to tune the EFI. Unfortunately with S cams, there's really no way to get good fuel economy with carbs. I bit the bullet and had them rebuilt and rebushed by Paul Abbott of performance oriented, and the car runs absolutely spectacular, and the gas mileage is definitely better, but it's still not to my liking. I think I just have too high of expectations for fuel economy. haha |
mepstein |
Apr 29 2015, 12:17 PM
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#5
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914-6 GT in waiting Group: Members Posts: 19,512 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region |
MS1 can handle spark, and it's upgradable to whatever you need. I can't imagine using it today though unless it was practically free since the later versions do it all and more right out of the box. I'm a huge fan of Megasquirt and currently run MS3X in my car. I love the tuneability that it offers. I'm also a huge fan of MS.....BUT....instead of going through all the gyrations of EFI at this point, why not install an 02 sensor and see if you can do better with the carbs. For $190, you'll get real time readings. You can then try some jetting to see if the MPG's get better. If it's still not to your liking and decide to go the EFI route, the 02 sensor will be there for you to tune the EFI. Unfortunately with S cams, there's really no way to get good fuel economy with carbs. I bit the bullet and had them rebuilt and rebushed by Paul Abbott of performance oriented, and the car runs absolutely spectacular, and the gas mileage is definitely better, but it's still not to my liking. I think I just have too high of expectations for fuel economy. haha (IMG:style_emoticons/default/agree.gif) your setup was never intended for fuel economy. I would leave the engine the way it is, enjoy it and economize somewhere else. |
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