19lb injectors without computer swap

[turbo2256b]

Speed density can out perform mass air but mass air is easier to tune. IE years back we adapted Honda FI SD to a Alfa Romeo track car it took a bit over 200 dyno runs to map the SD ecm before believing we were fairly sure it was correct.

[Giraffe]

I'm gonna try it with my Mark VII computer whenever I get around to building a new engine for the '90. If it doesn't work, I'll just go with a Megasquirt. A9P computers are just getting too expensive these days to justify a MAF conversion.

[gadget73]

Unfortunately I'm inclined to agree. The prices have gotten dumb. Mine was like 75 bucks, last I knew they're getting near twice that.

[Giraffe]

I haven't seen a single one one eBay for less than $275. They're non-existent on the local CL.

[sly]

Best prices are probably still on corral.net. I know I got mine (for the Mark VI before I sold it on) for $50, but that's because some guy had like 40 to unload. Mine was an A9M technically, but close enough. Works just as well. A9M/P/T all work just fine.

[merc91]

The comp xe258-12 needs 1.6 rockers for the .533-.544 full lift and the xe258-14 needs 1.7's for the same rated lift. I wish they didn't do that.

Could have the smoothest cam ever made, but with more hp (flow via geads/intakes/exhaust/cam) speed density can not detect it. Speed density only measures manifold pressure, that's it, it has zero way to measure flow quantities of air. The motor is measured at ford for air flow numbers at 18inhg idle vac on up to wot (negligable vac) and a table is written so the computer gets the manifold pressure reading in the moment which the computer uses to check the pre-set air flow consumption and add the correct fuel.

With 150hp stock, wot is reading 0inhg manifold vaccume which ford found that motor was consuming say 300cfm and injects the perfect amount of fuel for that quantity of air...

Do an explorer top end swap for 300hp now, at wot the computer's only sensor input is still reading 0inhg manifold vaccume but the motor is actually consuming 600cfm of air at that same manifold pressure of atmosphere. The computer has no way to know this and still injects fuel for the 300cfm and you end up with a super lean condition.

Mass air has a meter in the intake ducting that actually measures the air flow which is the only way to go with any degree of hp gains (flow gains) from the factory numbers.

It's like a blind deaf mall manager hires someone watch for 5 afternoon weekdays, to find 100 customers an hour come in when he uses his only sense (feels the doors to be wide open) he then schedules enough staff everyday in the same quantitys for those customer numbers.
Then the weekend comes and he again feels the doors wide open as always, but now there's 300 customers an hour walking through them... with so few employees and a manager who has no idea based on his only input, we sit and wait until a worker blows a gasket.

[DerekTheGreat]

And here I thought I had something decently valuable with my SD Mark VII computer.. LoL, at least it will help with Ashley's TC when we go to do the HO swap.. ::nudgenudgeStidman&VCV::

[knucklehead0202]

And here I thought I had something decently valuable with my SD Mark VII computer.. LoL, at least it will help with Ashley's TC when we go to do the HO swap.. ::nudgenudgeStidman&VCV::

Not sure what emissions requirements you have there buddy but these days aftermarket computers are getting super-cheap. If you can grab a megasquirt PnP or similar for cheap, i'd go for that. The PnP is just what it sounds like, Plug and Play, and it's fully tuneable, but also will auto-tune. The auto-tune isn't all that great for the record, but it'll give you a starting point. This may be easier and cost about the same as finding the factory computer you need. Just throwing it out there.

[VicCrownVic]

Not sure what emissions requirements you have there buddy but these days aftermarket computers are getting super-cheap. If you can grab a megasquirt PnP or similar for cheap, i'd go for that. The PnP is just what it sounds like, Plug and Play, and it's fully tuneable, but also will auto-tune. The auto-tune isn't all that great for the record, but it'll give you a starting point. This may be easier and cost about the same as finding the factory computer you need. Just throwing it out there.

Emissions requirements? None in Michigan.

Derek, just let me know when that day approaches, we can work on a list of things you'll need to get or borrow.

[gadget73]

The comp xe258-12 needs 1.6 rockers for the .533-.544 full lift and the xe258-14 needs 1.7's for the same rated lift. I wish they didn't do that.

It was a used cam that was gifted to me. Frankly I don't know which it is, and honestly I didn't know there were two possible options. I suppose I could take it apart and put a dial indicator on there to measure valve lift but I'm not real inclined to take things apart again.

[knucklehead0202]

It was a used cam that was gifted to me. Frankly I don't know which it is, and honestly I didn't know there were two possible options. I suppose I could take it apart and put a dial indicator on there to measure valve lift but I'm not real inclined to take things apart again.

Yeah, sod that shit. If it runs alright, go with it i'd say.

In other news, had a look at corral yesterday and there's a shedload of A9 computers for sale on there, most in the 200-250 range, but they're around. If you kept an eye out you could probably snag one a bit cheaper. My brother got his megasquirt on there for dirt cheap. He may end up selling it too as I believe he's switching to Holley once the big motor goes in. I'll keep y'all informed.

[Giraffe]

The comp xe258-12 needs 1.6 rockers for the .533-.544 full lift and the xe258-14 needs 1.7's for the same rated lift. I wish they didn't do that.

Could have the smoothest cam ever made, but with more hp (flow via geads/intakes/exhaust/cam) speed density can not detect it. Speed density only measures manifold pressure, that's it, it has zero way to measure flow quantities of air. The motor is measured at ford for air flow numbers at 18inhg idle vac on up to wot (negligable vac) and a table is written so the computer gets the manifold pressure reading in the moment which the computer uses to check the pre-set air flow consumption and add the correct fuel.

With 150hp stock, wot is reading 0inhg manifold vaccume which ford found that motor was consuming say 300cfm and injects the perfect amount of fuel for that quantity of air...

Do an explorer top end swap for 300hp now, at wot the computer's only sensor input is still reading 0inhg manifold vaccume but the motor is actually consuming 600cfm of air at that same manifold pressure of atmosphere. The computer has no way to know this and still injects fuel for the 300cfm and you end up with a super lean condition.

Mass air has a meter in the intake ducting that actually measures the air flow which is the only way to go with any degree of hp gains (flow gains) from the factory numbers.

It's like a blind deaf mall manager hires someone watch for 5 afternoon weekdays, to find 100 customers an hour come in when he uses his only sense (feels the doors to be wide open) he then schedules enough staff everyday in the same quantitys for those customer numbers.
Then the weekend comes and he again feels the doors wide open as always, but now there's 300 customers an hour walking through them... with so few employees and a manager who has no idea based on his only input, we sit and wait until a worker blows a gasket.

A lot of this makes sense, but would the O2 sensors not detect a lean condition which the computer could then attempt to correct? If there is no correctional capability built into the system, then the O2 sensor would be kind of pointless.

[gadget73]

It doesn't have enough compensation from the oxygen sensors to make it work unfortunately. The o2 sensor is for fine trim, not gross adjustment. The oxygen sensors also do not operate at wide open throttle or when cold, so you're stuck with the programmed fuel tables at that point.

[turbo2256b]

A lot of this makes sense, but would the O2 sensors not detect a lean condition which the computer could then attempt to correct? If there is no correctional capability built into the system, then the O2 sensor would be kind of pointless.

There is a 10 or 15% ability to adjust In a mass air built in. There is a setting in the programming that allows for a 25% but need a tweecer or such to changes that setting.

[DerekTheGreat]

Emissions requirements? None in Michigan.

Derek, just let me know when that day approaches, we can work on a list of things you'll need to get or borrow.

Thank you kindly, good sir! I shall relay the good news to Ashley. We currently picked up another rotbox GMT400 for her to tool around in until we get that squared away since we don't know how long all that's gonna be or how involved. Stidman has a Mark VII with a good HO in it and I've got most of the HO manifold swap stuff taken care of except for the EGR spacer. When Khead sends me his old LoPo EGR spacer I'll then forward that to gadget to bore it..