5.0 combo for EFI-noob questions

[junkyardwarrior]

I'm doing a 4-8 swap on my '93 LX. I have the shortblock almost ready all but the camshaft (which will be one of the last things to get). Mahle flat tops and stock length rods/3" stroke (306"). Heads will be AFR165's unless I should go with 185's? I have an RPM II intake and will be getting a 70mm TB/EGR spacer. I'd like to somewhat duplicate this:

Edelbrock Performer RPM II EFI Intake Install and Test - Muscle Mustangs and Fast Fords Magazine

That is impressive for a little 302" engine. If I could get 350-370 HP I'd be tickled BUT it needs to be streetable-as I drive quite a bit for work, etc.

My questions. The article mentions 24lb injectors, but doesn't say what computer to use? I currently do not have injectors nor a computer. I also have a stock MAF-which is probably going to have to be changed as well (I planned for it). What about the 24's? Do you think they will be enough? Or should I go 30's? Driveability takes precedence over maximum HP-but I don't want a slouch. For the cam, I'll more than likely go custom cam-FTI or I know another guy who can grind whatever I want. I like Ed's stuff though. Rest of the car is just a typical Fox body-T5 (2.95), haven't decided on a clutch yet, 8.8 w/3.73's, etc. I also have a Fidanza aluminum flywheel that'll be going on it-I already have it so that's what I'm using. I can change to a steel FW later if I don't like the Aluminum one.

The main goals here are 1: driveability, 2: crisp response, and 3: decent HP. I don't need to get carried away with a 500 HP monster-I have race cars for that. My goals are to have a car that drives like my old '84 GT. Little choppy at idle, but lays down some decent power. Any suggestions you guys can give will be helpful-I'm a bit of a greenhorn when it comes to 5.0 EFI stuff. 2.3 turbos I can mess with some but I've never done a 5.0, and I know carbs fairly well and mechanical constant flow injection.

 

[stykthyn]

Sounds like you are headed in the right direction. Custom cam, 24s, and get a calibrated maf and use the stock computer.

 

[NIKwoaC]

I would do the 185s. IMHO, 165s are a waste of time.

If you play your cards right, an AFR185 headed, RPM II, custom cam engine is 30lb injector territory. Run an A9L computer.

Drivability will be ENTIRELY in the cam.

 

[Sicarius428]

For a 306 I would do 165s but that is just me. If it were a stroker or 351 I would go with 185s. Custom cam for sure. 24lbs injectors with a MAF calibrated for 24s should be good. For driveability, I would go with a steel flywheel but if you already have the AL one, use it. For a clutch, a Centerforc DF would make for an easy drive.
Kevin

 

[junkyardwarrior]

forgive me for asking a possibly redundant question. Can an A9L be used with 24's without a custom tune? I was thinking it was 19's only?

I realize the MAF will have to be calibrated for 24's but I'm still in the dark with the ECU's vs. injectors.

 

[stykthyn]

It seems to be hit and miss with the injectors, but it seems that the maf companies quality control is on the rise and most everyone I know is satisfied.

 

[junkyardwarrior]

Friend of mine said something to me earlier; he had stated something about a 7.5L EFI engine had 24 lb injectors.

I have a 7.5 complete that has a rod sticking out of it-but it ran purr-fect when I replaced it. Will these injectors work?

 

[2000xp8]

165's, custom cam, 24's DBX meter (pretty much the only good meter left on the market at this point)
A recent stock 302 at my buddies shop with 165's, custom cam, rpmII, dbx meter made 334rwhp, that's a good chunk of change for box stock heads on a stock 302.
Use either computer that came out of your year car with a 5.0, the auto or manual is fine.
No dyno tune needed, you leave the computer alone, the meter calibration and injectors have to match.

 

[NIKwoaC]

For a 306 I would do 165s but that is just me. If it were a stroker or 351 I would go with 185s. Custom cam for sure. 24lbs injectors with a MAF calibrated for 24s should be good. For driveability, I would go with a steel flywheel but if you already have the AL one, use it. For a clutch, a Centerforc DF would make for an easy drive.
Kevin

The reason I say 185s is because they can do everything the 165s can and more, and will allow room to grow should he ever consider a stroker. They will also allow him to run a milder cam on the 306 and still achieve the same results that a more aggressive cam and the 165s would.

 

[Noobz347]

The reason I say 185s is because they can do everything the 165s can and more, and will allow room to grow should he ever consider a stroker. They will also allow him to run a milder cam on the 306 and still achieve the same results that a more aggressive cam and the 165s would.

I'm with this logic. It's large enough so that you'll only need to buy them once but not oversized so that end up with a lazy inlet tract. Cam selection will make or break either head selection.

As for tuning... it's sounds to me like you're in the midst of, or at least contemplating other mods. My pick for tuning would probably be an Anderson PMS and a wideband. Running 24s with that combo shouldn't be much of an issue and the Anderson will allow you to fine tune and MORE.

 

[NIKwoaC]

I'm with this logic. It's large enough so that you'll only need to buy them once but not oversized so that end up with a lazy inlet tract. Cam selection will make or break either head selection.

I've seen more and more examples and proof that you almost can't go too "big" with the cylinder heads on an EFI engine with the right combination of parts. I'm planning a stock bottom end build that I'll be starting after tax returns and I'm looking at heads that flow north of 300CFM @.600". AFR 185s do what... 27X ish? And I think 165s are in the 240-250 range.

Not that flow numbers are the ultimate determining factor for a head... Just a piece of the puzzle.

Sorry, I don't mean to turn this into a cylinder head debate. I'm just a supporter of the big head/small cam movement.

 

[Noobz347]

Were it me... I def go with the larger head. As for cam selection, thank god there are much smarter folks than I, to do that brain work and tie the whole combination together.

To the OP:

What are your plans for a power adder? If none, what compression are you planning to run? I've always wanted to toss together a high compression street monster upwards of 11:1 or higher.

 

[2000xp8]

I've seen more and more examples and proof that you almost can't go too "big" with the cylinder heads on an EFI engine with the right combination of parts.

See, i've seen otherwise, in person.

My best example would be the old school 1970 boss mustang.
Ports on the heads are well beyond anything i've ever seen on a 302. Dyno tested the car made barely 200rwhp if i remember correctly, made absolutely no low end torque.
They changed the shorblock only to a 347 with a mild cam to maintain engine originality, and picked up like 175rwhp.

 

[NIKwoaC]

See, i've seen otherwise, in person.

My best example would be the old school 1970 boss mustang.
Ports on the heads are well beyond anything i've ever seen on a 302. Dyno tested the car made barely 200rwhp if i remember correctly, made absolutely no low end torque.
They changed the shorblock only to a 347 with a mild cam to maintain engine originality, and picked up like 175rwhp.

The Boss 302 is the engine that everybody likes to point out, but that thing was engineered 40 years ago. With EFI (and even modern carb setups), modern roller cam and cylinder head designs, "big" heads can be made to perform with stellar results on smaller engines.

The OEMs are making it happen, like with Ford's new Coyote and GM's LS engines. Granted, VVT and more complex engine management help the effort, but that kind of thinking CAN trickle down to our old pushrods with great success.

 

[Noobz347]

Can it be done LeWrong? Oh yeah... but then there are folks who put ketchup on eggs too. lol