Anybody running it on a full-sized Bronco/460? The 2.5 was a pain, so any advice would be appreciated.

 

If it is under 500 hp i would run 2.5 for more low and mid range torque.


Evan Shockey
'84 F-150 HD

 

It's right at 500hp and 575ftlb of torque. The car guys are saying a switch from 2.5 the 3" is something the 460 likes at all rpms.

 

Yea 3 inch is in order than.

My uncle's 1978 F-150 Ranger Hi-boy has a 750 hp 514c.u. with flows and damn does that sound sweet!!

Evan Shockey
'84 F-150 4x4 HD 355w

 

Hey Evan
that 750 HP motor sounds waaaay cool--however, that F150, is NOT a so-called Hi-Boy. 'Hi-boys' are only F250's from 1959-pre 77 ONLY. Just wanted to clarify a point here!

regards
Ben

 

I sure would like to see some scientific data that supports the old wives tale of keeping the exhaust smaller for extra hp and torque. If that were true, why wouldn't a 1" exhaust be superior?

Dynos certainly prove otherwise. We're talking about engine exhaust pulses that leave the combustion chamber and any restriction is bound to slow them down, creating back pressure, which doesn't offer any benefit and certainly restricts the breathing. The idea is to get those gases away from the chamber asap.

 

George, I too am skeptical of the "larger exhaust robs low end torque" statements. If 3" is bad, would a three foot diameter exhaust pipe stop the engine cold?

Uh, no.

The idea that you lose velocity, because the gas cools, fails to see that if you lose heat (thus velocity) you also lose pressure. Theoretically, you could install heat fins on your exhaust tips, and cool them by routing the fuel lines (fuel supercooled, of course) across them, to create a vacuum effect.

Go with 3", or three feet if you can...

 

The big dragsters have no exhausts.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.

Then theres:
99' Mustang GT 4.6L
88' F-250 Heavyduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Weighs around 7,000lbs w. 65mph top speed, who wants to race me!

 

Well, barely one.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.

Then theres:
99' Mustang GT 4.6L
88' F-250 Heavyduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Weighs around 7,000lbs w. 65mph top speed, who wants to race me!