351W EFI Performance Mods

rcmbronc · Aug 29, 2008

I am looking to get a little more power form my 351W. Someday I will build a stroker, but not quite yet. I have a fairly stock bottem end with 69 351 heads. I use the truck lower, BC adapter, Mustang upper, stock 90 Mustang injectos, MAF anf A9 computer.

I am either going to do some porting to the 69 heads or get a set of aftermarket. I need to know what I need to do with injectors, MAF and also the computer to run it all. Also what about throttle body. Looking at getting a new intake also, not sure which one yet. It is a trail truck and mostly looking for low end power, and I know the key will get it to breath. I need to know what to match the engine for EFI if it does breath better, I have headers and a 2 into 1 exhaust.

Thanks,

COBlu77 · Aug 29, 2008

I don't believe that all the typical stuff (24lb injectors, Lightning 90 mm MAF, 70 mm throttle body) will do much for your low end. Maybe some after market heads and a custom tune along with all of the above parts, but your talking quite a bit of money to improve the top end. All those things will be necessary when you build a "stoker", but you will need to have the computer re-tuned again.

I've played with different cams and have found that the stock 93 Bronco cam works the best with a stock A9P ECU, 19lb injectors, and stock Mustang MAF. Also, with a stock computer, mine runs better with stock manifolds and a 2 into 1 exhaust than it did when I had long tube headers. With headers I ran a little on the lean side. I did find that a 65mm throttle body and advancing the base timing 3 degrees helped mine. I haven't done it yet, but I'm sure there's more power to be had by a custom tune on a Mustang 5.0 computer that's running a 5.8l engine. Until you're willing to get a dyno tune, all the other goodies will be a waste and give you a variety of issues. I've been quoted $500-600 for a chip and custom tune on a dyno.

I'm waiting until I build a 393 to spend all the money for those additional parts and get a custom tune.

rcmbronc · Aug 29, 2008

What size is the Mustang TB and where to get a 65MM.

Broncobowsher · Aug 29, 2008

Stock mustang is 60mm (except the '86 is 58mm). Explorer V8 5.0 has a factory 65mm. But remember that a larger throttle body is more sensitive to your foot off idle. If you do this and loose your off idle control consider making a progressive throttle linkage.

I would also recomend looking at cam grinds.

If you can find one, stock Gen 1 Lightening intakes are a good breathing find

24lb injectors (stock 460 will do) may be needed along with an improved MAF. Then get the computer chipped to match all these new parts. MAF tells the computer how much air is coming in, computer kows how big the injectors are. Computer looks at th air, figures the amount of fuel, looks up how long to turn the injector on for. The crude way they do it is lie about the amount of air, computer things engine is getting little air, gives less injector, but bigger injector does give a bunch of fuel. Maybe it's right, maybe not. Easy to tune for full throttle use such as a drag mustang, harder to tune for drivability (consider that these parts are marketed toward racers that only concern is full throttle)

Ryan · Aug 29, 2008

you need a new intake, that is your biggest performance problem

408mako · Aug 29, 2008

Trick flow

First of all what is your price range?? There are a lot of different EFI combos out there. How far do you want to dig into the motor? You can run the basic trick flow cam and heads kit. That works with the stock EFI mustang ECU. And also you don't have to worry about the valve/ piston clearance. What year is your block? Is your cam stock? If so you should move to a reto fit roller if you are going to change the cam out. Really simple and really smooth. Trick flow sells a pretty solid upper end set up.
The nice thing about this setup is that you can run it in your stroker motor and really wake it up 2. We ran it in a 408 stroker in a 93 mustang and hit 502hp, 525 lb of torque.
http://WWW.trickflow.com/egnsearch....4294925232+4294838998+115+325386&autoview=sku

rcmbronc · Aug 29, 2008

My block is a stock 86 F250. The small chambers on the 69 heads helped the compression. The cam is a Comp Cam 4x4 cam. This is the cam http://store.summitracing.com/partdetail.asp?part=CCA-35-235-3&autoview=sku

I would not mind buying new heads, but have also thought about porting the ones I have. I know not as good as aftermarket, but I may have too to save some money.

What intake does everyone recommend. Trick Flow, Edelbrock etc. Seems like finding the Lightning intake is pretty tough.

Who's throttle body? 65 or 70?

flousberg · Aug 29, 2008

How about this intake. If you are on a budget get an explorer TB and MAF and tune the computer.

rcmbronc · Aug 29, 2008

flousberg said:
How about this intake. If you are on a budget get an explorer TB and MAF and tune the computer.

Which one?

408mako · Aug 29, 2008

The trick flow intake is one of the best EFI intakes out there. BBK is the best but they dont make it for a 351w.
http://store.summitracing.com/partd...925239+4294839079+4294840125+115&autoview=sku

The best throttle body you could use would be a 75mm BBK

http://store.summitracing.com/partd...&N=700+4294859865+4294908331+115&autoview=sku

Why buy twice? You could use the Lightning intake but they really dont flow to well, why tune old ford parts? Why save a couple bucks now, when you could use the better parts on your stroker motor down the road? Plus you never know what your getting with old EFI parts.
As for the mass air flow sensor use the C&L 76mm. You can match it for the size injectors you have, 19lbs.
http://www.cnlperformance.com/76mm_86-93.html

408mako · Aug 29, 2008

The cam you have is a decent 4x4 cam, but the best way about getting the right cam is to call the manufacture. I had ISKY make me a custom ground cam! Thats what they do, just call them and tell them where you want your power and what you are using your rig for! Just give them all of your specs and they will make one for you.

Ryan · Aug 29, 2008

rcmbronc said:
What intake does everyone recommend. Trick Flow, Edelbrock etc. Seems like finding the Lightning intake is pretty tough.

Who's throttle body? 65 or 70?

Edelbrock Performer & Ford GT40 are the best intakes for low end torque.
65mm is perfect for those intakes

slcpunk · Aug 29, 2008

408mako said:
First of all what is your price range?? There are a lot of different EFI combos out there. How far do you want to dig into the motor? You can run the basic trick flow cam and heads kit. That works with the stock EFI mustang ECU. And also you don't have to worry about the valve/ piston clearance. What year is your block? Is your cam stock? If so you should move to a reto fit roller if you are going to change the cam out. Really simple and really smooth. Trick flow sells a pretty solid upper end set up.
The nice thing about this setup is that you can run it in your stroker motor and really wake it up 2. We ran it in a 408 stroker in a 93 mustang and hit 502hp, 525 lb of torque.
http://WWW.trickflow.com/egnsearch....4294925232+4294838998+115+325386&autoview=sku

what was red line on that thing and what was the compression ratio? 500hp is good real good

408mako · Aug 30, 2008

10:5:1 comp, Red line @ 6500

needabronco · Aug 30, 2008

I'd either look for a performer efi manifold or the lightning GT40. I'm not sure that edelbrock makes the performer efi for a 351(?). I'd also suggest that you run an explorer 65mm throttle body and run a matched MAF for 24 lb injectors. I think you'll gain your low end back, you might lose a bit off the top end though...

Be careful looking at speed parts! Most of the time they make power at high rpm and will lose torque down low. This will also happen if your not careful and remove too much material if you port your heads. Ask me how I know this one%). You might be alright if you just 'open up' the exhaust side a little bit, and run a quality header and exhaust.

The only draw back to the 351 GT40 intakes is the cost of the lowers, they seem to hover around $400 on evilbay. I've been looking for a deal for a someday 351 swap.

Good luck.

351W EFI Performance Mods

rcmbronc

Bronco Guru

COBlu77

Sr. Member

rcmbronc

Bronco Guru

Broncobowsher

Total hack

Ryan

Sr. Member

408mako

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rcmbronc

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flousberg

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rcmbronc

Bronco Guru

408mako

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408mako

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Ryan

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slcpunk

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408mako

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needabronco

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