You know I've always heard the opposite, that shorties produce more low end and long tubes produce the top end. I'll have to do more research on it as I've never done headers on a truck.

Ok, yeah so pistons made out of graphite lol got it. Yeah I used to do stress testing and non-destructive testing on metals for large facilities so I understand what you're putting down. Now if 6-8 psi could be doable, it's something to consider. I wouldnt want anything wild really, but I've always been a fan of the lightning and it'd be nice to do a lightning inspired build out of an extended cab.

 

So I have finally gotten this truck home, and realized it was the 4.6, as opposed to the 5.4

I'm not looking for big power anymore, I am simply interested in a little more low end grunt. It looks like only short tube headers are available for the 4.6, so are there any recommendations? Or is it still pointless and I'm not gonna get anything out of this without a couple grand? Again, not worried about big power anymore, just would like a little something something.

Also, cat delete: would this give me any power increase down low on these 4.6s?
Thanks again.

 

The cats are sized to cause a slight restriction at the highest exhaust volume the engine is set up for. Highest exhaust volume would occur at high engine speeds and wide open throttle. So pulling the cats out theoretically should amount no net change in backpressure at low RPM's.

If you play with a header calculator you'll see pretty quick that all the available headers have a low rpm torque killing large primary tube diameter. IIRC, the last time I did this for a 4.6 truck 2 valve a 16 gauge 1.5" primary tube header was in the right neighborhood to make good low RPM torque. GL finding one of those for a modular 2v.

Per dollar spent, a reworking of ignition timing will net the most low RPM torque. Here's what I'm using for 93 octane. Rows are engine load.

 

What gears does it have? Is it a 2WD of 4WD?

 

You sort of got that turned around, shorties can add very little to top end, IF anything at all. Not even worth mentioning. Definitively no gains elsewhere with these engines.

LT's on the other hand can produce better numbers everywhere in the powerband. But that depends on the Y set-up and tune. A tune isn't necessary if you adapt the factory Y and add 3" cat back w/this set up.

 

I got a local muffler shop that I'll have help me out with headers, but in the meantime, NGK platinums really made a difference. Brought the engine back from the dead. Now on to coils and an oil change.

@white89gt
I beleive it's at 3.55 gears. I'd love to move to 4.10s to make a difference in performance, but I'm not sure yet. If I go to check and find out i've got 3.08 or whatever the taller ratio is, then 3.73s would be in the future.

 

Good luck with the muffler shop...you'll need the best of that for what your inquiring about. A lot of those shops are restricted, - ONLY providing info for what they are allowed to do. This is due to state regulations. Some shops keep it book, some in the middle... Doesn't hurt to ask, -always do your own research with this subject as well.

NGK/P should be okay.

Motorcraft is best all around AFA plugs, for the modulars anyway. NGK and Denso are fine, - the only other two you should use. Stay away from Autolite and Bosch most definitely.....just these motors specifically. Make sure you torque them correctly (28' lbs). Or you'll most likely screw yourself in the future lol.

Use Motorcraft or Denso coils only. They are Ford spec builds and have the thermal protection plus proper dual build magnets for longevity. This prevents winding shear, low grade misfire problems out of the box and in the near future.

Good Luck!



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I'm not going to give away our setup, but is a 4.6L based SOHC motor running in timed events in a 98 Mustang running over 2019 5L Mustangs. The Corvette guys are even chasing us on the big tracks seeing a 23 year old car running that fast on old an suspension design.
.

Same guy came to the car after the event was over for the second year, nosing around, with his 417 cu/in, super wide slicks and still could not run the same times in a Mustang about 8 years older in the modified class..
We love it with motors nearly half the displacement and no super charging.
We won't tell him anything. All he got was looking at the car's suspension on the trailer and social talk.
All I can say is one needs to understand what is being attempted, have a bit of engineering ability and put it into practice.
Just bolting things together won't do it.
The first overhead cam motors from Ford was 1963. They ran in Indy cars as 255 cu/in Turbo Charged de-stroked 289 blocks to meet he rules.