|04-05-2013 07:08 PM|
A carburetor works pretty well. That would be simpler.
EFI being complicated, get into it. In most circumstances you have total control over fuel management. Time investment to learn could be worth it.
My supercharged 305 is going strong almost a year later. Very mechanical.
|04-05-2013 06:36 PM|
This is the main reason I have not persued the EFI on the Roots blower. I agree that the fuel demands are much different than the blown sbc equal to some larger cu in motor.
You can see this when you start tuning the blower motor with the O2 sensor and a vac boost gage. At light throttle there probably is not much difference than NA but as soon as you get on the gas harder and not even into boost there is a radical shift in fuel requirement. The transition circuit becomes very important as well as the power circuit. Often idle feeds and high speed feeds need to be adjusted and of course the main jets. Not that EFI can't handle it but the standard maps don't allow for this and I don't think most of the self learn ones do either. Then when you jump the throttle and get boost quickly, the amount of fuel change is huge. It's surprising that the carb can even handle this. In reality the fuel requirement gets covered by being excessively rich. The EFI should be able to adjust for this better and quicker but it takes the laptop to get to the map requirements. Lots of keyboarding.
I'll see most of the suppliers at Back to the 50's this summer and hit them face to face about the blower EFI.
My son says I could save hours of mechanical work by going EFI but then it just becomes hours of keyboarding plus changing injectors and sensors and a half a mile of wire harness.
Don't get me wrong, I'd jump on the EFI if I could be assured that it woulod tune as easily as advertized but so far that has not been the case. I've been around for too long to fall for this advertizing......after all dynosaurs lived for 260 million years and we have only been around for a heartbeat on the time line. haha they must have known something.
I'm going to wait it out. My 2 x 4's run too well now.
|04-05-2013 05:58 AM|
|alanmurfee||Illenema, I totally agree with you. This is indeed too complicated. Anyone knows what can be done to make this task simpler?|
|04-05-2013 01:00 AM|
I contacted holley about it they said the hp 550-412 would work fine with a roots style blower.
I looked up the wiring ect on that kit. it needs a o2 sensor and a tach signal to work, laptop ect. Too complicated.
|04-04-2013 08:26 PM|
From what I have researched, the newer self tuning EFI systems (atomic efi, ez-efi, avenger efi, prof. products efi, etc) won't work on top of a roots type blower.
I've got a SBC running a 177 and I looked into it last year and found that unless I go with a more complex injection system, it won't do what I want it to do. I've talked to FAST and to MSD regarding their injection systems and they both tell me their system will not work on that blower.
The MAP sensor built into the throttle body housing is one factor, and the other is the needs of a blower engine is not the same as a large displacement n/a motor. So the mapping is completely different and is not supported by their systems.
The new FAST EZ-EFI 2.0 is supposed to support blower motors, but I don't know anything about it.
FAST XFI and the Holley HP EFI system are supposed to work, but they are not a self tuning unit and will have to be set up with a laptop. If I am having to do that, I might as well go with Port Fuel Injection, and that's cost prohibitive for me.
If you find something out, I would be really interested.
|04-02-2013 10:01 PM|
|bentwings||Load it on let's hear what you get.|
|04-02-2013 06:13 PM|
Holley injection and Weiand 177
Installing a weiand 177. Anybody done this with their new stand alone injection systems?