OK, I've done some searches on this subject and see both opinions. I've just aquired a set of BBK shortys, slighty used for a great deal (free). As some of you know I'm doing a mild 5.0 (efi) build for my 94 F150 short bed. Crane 444211, ported E7 heads, and custom exhaust with catbacks. So, can I spend the $250 bucks or so that I was going to spend on long tubes on something else and go with the shortys?

The guy I got them from builds 5.0 and 5.8 engines for drag cars says that for a mild build (less than 350 hp or so) you dont gain a whole lot with long tubes over shortys.

Opinions? (I know there are plenty of them out there!)

 

Well.. a guy that builds drag cars never worries about what the motor does below 3000rpm, so his experience doesn't really apply. It's been proven longtubes deliver more low rpm TQ than shorties, and that's TQ from idle to 3000rpm just to be clear, but they can be a bigger headache to install. Shorties will deliver similar HP through the mid and upper rpms... if the Y-pipe and cat(if equipped) are also upgraded, so you could spend some money on that instead.

 

https://www.ford-trucks.com/forums/77...rgggghhhh.html Hopefully this will not be you.These things leak like a sieve too.I guess they didn't weld two of the primaries for installation reasons,but once on the truck,you can't get in to weld them for sh .I personally hate them.
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Thanks all, Paul, good point on the drag engines. This guy builds a lot of mustang stuff too but point taken on RPM. As you know I do no hauling or towing with this truck. I think I'll spend the money on the doing the rest of the exhaust right.

gearhed, I couldnt get your link to work.....

 

Long tubes....I went though the same stuff with my truck... The mustang guys are good but what works on a stang dosnt always work on a truck... Need all the low end tourq you can get ..I used the headman coated headers there nice ..

 

Lew,
Did you run shortys first? Appreciable difference in power with the long tubes?

 

No we went strait to the long tubes so i dont know...Nice looking truck..you have I just knew the long tubes made more tourq so we went with them...because we were doing exhaust to....

 

VERY WELL PUT!

For the street, shorties aren't even worth the bother IMHO!

 

I dont know if I would go that far, shorties surely flow much better than those blocks of cast iron know as exhaust manifolds.....

 

Lew, I went in and looked at your pictures, your truck looks great! I need to post up some of my pictures.

 

Yes, shorties FLOW better than most all cast iron manifolds, but that's not the issue when it comes to low and midrange torque. Full length headers don't simply ALLOW exhaust to flow through them, they SCAVENGE the exhaust.

This is because the long individual runner has uninterrupted exhaust gas velocity that uses the gas velocity momentum to literally SUCK the exhaust gas out of the port.

The low and midrange torque advantage gained by shorties is barely measurable, while the low and midrange torque gain from full length small tube headers is SIGNIFICANT!

 

Tri-Y's can also bring additional torque to long tubes. "Stan's Headers" are well made if they work for your application. With that said your application and budget will dictate your choice, shorties won't hurt you but as everyone is pointing out the long tube will reap further benefits.

 

I have been debating keeping long tubes on my 472 only because I have been told by several wise old men that headers, in any fashion, rob the necessary back pressure needed to maintain that highly desired low RPM torque. I may be comparing apples to oranges here (Carb vs. EFI and 5.0L vs. 7.7L), but this might also apply. You might look into modifying your stock manifolds to allow better flow, but manage the much needed back pressure. Let the group know how things go.

 

I hope you will pardon me for slamming your "buddies" but NEEDING back pressure is HOG WASH! I, for the life of me, can NOT understand where the myth that back pressure is a GOOD THING!

The ONLY thing that could explain the development of such a myth or a mindset, MIGHT be that an ignorant, non savvy motor head, put on a set of headers or otherwise improved their exhaust flow without rejetting the carb setup to compensate. When they lost power, they then must have assumed that it was that blasted high flow exhaust system.

Don't fall for such Horse Sh.... well you know! If your engine is not developing low speed torque with full length headers, look for the problem somewhere besides the exhaust system. Maybe before completely discounting the exhaust system as the culprit, you should make sure that nothing is stopping it up, but other than that. Full length headers are a good thing power wise. You might have to mess with them to keep them from leaking, but they will NOT rob low speed torque if the engine is properly tuned. Period!

 

Thanks for the info. And no offense taken to the opinion. I have yet to run different exhaust systems on the simulator, but I have always thought that headers (regardless of system) offer more flow and thus allow the engine to "breathe" a little better. I have ported the exhaust ports on my stock heads to get rid of that pesky hump, and I am currently running long tube headers. I will have to run some numbers and review the outcome on the torque curve to make a final decision. Thanks again for the input. Sorry if I stole the original thread, I will start my own thread and see what I get. The only problem is, I am having new exhaust welded up on Thursday and I need to make a decision quick. Have a good one.