How much tuning really?

[TC]

Lol. Anyone else here besides Alex with more questions? I don't mind answering questions from legitimate car guys.

Yap just laugh it off, though that doesn't answer my question..... But then we all know you don't have the manuals, that's why your beating around the bush...... Caught you in a lie again.......

[Barry Donovan]

I have one question, hope it is legit.

if maf creates a restriction and speed density rides a manifold pressure...

when it is time to say to the hell with both?

I really want to inject a rumbling double timing belt boxer...but wow. it purposely tries to defy the modern things going. I went back to a carb (and it is a difficult chore there too- although easier)

a set map is impossible..so restricting to a maf is the way to go?

[dieselgeek]

I have one question, hope it is legit.

if maf creates a restriction and speed density rides a manifold pressure...

when it is time to say to the hell with both?

Never, IMO. The MAP is a great reference for load, the engine's fuel needs depend on that. The MAF takes that info, and refines it a tiny bit to make the engine run more consistent - that's why any modern EFI car runs its best in all weather conditions.

Lots of companies have tried "alternative methods" for fueling, and they all arrived at what we have today. It's pretty good stuff, you should look into it a bit. Barry, I am sure once you got into homemade EFI you'd be very good at it, and happy how your car runs.

[Barry Donovan]

Never, IMO. The MAP is a great reference for load, the engine's fuel needs depend on that. The MAF takes that info, and refines it a tiny bit to make the engine run more consistent - that's why any modern EFI car runs its best in all weather conditions.

Lots of companies have tried "alternative methods" for fueling, and they all arrived at what we have today. It's pretty good stuff, you should look into it a bit. Barry, I am sure once you got into homemade EFI you'd be very good at it, and happy how your car runs.

I'd like to..
I am winding down on an older mechanical project.
was looking at breadboards, electronic sources.
I was going to start with a 555 timer, and one injector from a spfi Subaru (one injector did the whole engine). the one number I got is resistance from their own manual. Found a program that narrowed down some of it on a 555 setup, the rest would be a potentiometer.. and then feed it a changing o2 signal.
not exactly main stream, but seemed fun to try a backup injector if to blow through the monojet.

[dieselgeek]

People have tried the same idea long ago, the reason it doesn't work is because your O2 sensor is downstream in the exhaust - by time the signal gets to your supplemental injector its too late, so you end up with a feedback loop of "too rich, too lean, too rich, too lean" and then you end up needing intelligent software to control that loop and "look ahead"

Since you are intent on keeping the carb, I'd add a single supplemntal injector but use a cheap standalone like a Megasquirt 1, because it'll actually pulse the injector in proper sync with your engine RPMs and will take your O2 sensor signal, apply a PID loop, and really let you control the AFRs the way you want to. Otherwise, without load and RPM reference, you're going to spend a lot more time and money trying to rig up something that won't work than if you'd have gone with something that's been developed already.

It's a neat idea, but think of it this way - if all the OEMs had to do was hook up a wideband and a single injector and get good AFR control, that's exactly how they'd be doing it. They are masters of figuring out how to make something work while being low cost as possible.

[NewEnglandRaceFan]

Lol. Anyone else here besides Alex with more questions? I don't mind answering questions from legitimate car guys.

At what point do you need to go to the dominator ecu instead of the hp(holley) I understand the hp has 4 input/outputs and the dominator has 8. but what type engine would use more than 4? Seems that they stopped at 4 for the kits, and the dominator is an upgrade.

[dieselgeek]

At what point do you need to go to the dominator ecu instead of the hp(holley) I understand the hp has 4 input/outputs and the dominator has 8. but what type engine would use more than 4? Seems that they stopped at 4 for the kits, and the dominator is an upgrade.

Trans control is the major reason. But, the Dominator has a TON of spare inputs that can be used for all different types of datalogging. Suspension travel, wheel speed, you name it - it's configurable. The Dominator is complex just like a motec or megasquirt but if you're willing to make the effort, all those extra inputs can be used for something.