Shorty headers

[buzzard616]

Signature TV has been diagnosed with broken bolts and cracked exhaust manifolds. It doesn't seem to have any effect right now but I will eventually have to deal with it. Truck currently has 3" CAT back exhaust.
Stock dimension 'shorty headers' are about 40% more than stock replacements. Has anyone gotten any HP or torque improvement in the 2200 - 2500 RPM range. If I could keep the thing from downshifting at the slightest grade or headwind it would be worth the extra bucks.

Stu

[carringb]

ndrorder wrote:
I have a Mustang with JBA shorties. They have equal length runners (tuned) and CARB approved. My experience and recollection are contrary to many of the comments above. Being shorties, they do their magic in the low to mid range without altering the top.

Ford modular family is pretty much the exception to the regular header theory. The stock manifolds are so restrictive, any header will add more power across the range, except the stock tuning limits fuel delivery, so you won't see the upper end gains without a tune.

[ndrorder]

I have a Mustang with JBA shorties. They have equal length runners (tuned) and CARB approved. My experience and recollection are contrary to many of the comments above. Being shorties, they do their magic in the low to mid range without altering the top. The torque improvement was slight based on seat of the pants only. Throttle response was also noticeably improved. I went with ceramic coating to pull the heat away from the heads.

I don't know what, if any, benefit shorties will have for towing. There is internet talk in the chevy truck forums regarding exhaust bolts breaking on the 6.0L engines. I was interested as that is what is in my RV. While no one has nailed down a cause, it seemed that for many, the problem is recurring until the manifolds are replaced. On that observation, I've decided that if it is ever needed, I would replace the manifolds with JBA's. I don't thing they will hurt performance and there may be some benefit. As opposed to trying to find replacement stock manifolds that may be bolt snappers as well.

YMMV,
Cliff

BTW, dyno runs with shorties vs stock vs long tubes are difficult to interpret. On the dyno, the vehicle is usually in a gear too high for the shorties to shine in hopes to get that all important peak torque and horsepower.

[time2roll]

A step or two lower differential gears will help considerably with downshifting.

[marcsbigfoot20b]

If you do go with shorties you will most likely need or benefit from a tune anyhow.....thats where you will gain the most, the tune. You will get a few ponies, better driveability and a better tow haul mode that may by itself fix your issue of downshifting.

[BenK]

buzzard616 wrote:
Signature TV has been diagnosed with broken bolts and cracked exhaust manifolds. It doesn't seem to have any effect right now but I will eventually have to deal with it.

Suggest you find out 'why' this happened before spending much money.

Are you fording streams to splash cold water on hot metal?

Are you running WOT for long periods under lots of load?

Do you have a tune that is pushing the OEM design limits?

As what are you resolving with headers ?

Truck currently has 3" CAT back exhaust.

For a small block, even with today's computer controlled and a 'maybe' variable cam profile...this is mainly for WOT usage...at the low end of the torque/HP curve would have little scavenging...again don't know the particulars of the 6.0L of this era

This kinda sorta answers the above and am also a long time Boy Racer, but for my future big block rebuild...headers are low on my list...too much heat for an already so hot engine bay can not put my hand/arm into the air flow off the fan

Even ceramic coated headers would still be too hot for me and yes, have worked on an 8.1L with ceramic coated headers

Stock dimension 'shorty headers' are about 40% more than stock replacements.

Assume some new down tubing will be needed, unless the headers flange is in the exact placement of the OEM flange location

So there will be additional costs. Again, suggest ceramic coating and in my location, they charge around $200 bucks and your exhaust person must understand HOW2 work with it...buddy who has that 8.1L fought with his exhaust guy for cracking the ceramic coating...finally he went to my exhaust guy

Has anyone gotten any HP or torque improvement in the 2200 - 2500 RPM range. If I could keep the thing from downshifting at the slightest grade or headwind it would be worth the extra bucks.

Find the torque curve for you engine and the gear ratio's all the way down to pavement.

Then plug in the header manufacturers torque curve to compare where you will be down to pavement in whichever gear you are with that 2.2K - 2.5K range

If the HP increase is not that much...then your ECU will likewise down shift to protect itself & tranny from lugging

Again, dependent on the tune and cam profile...at 2.2K - 2.5K RPM range...long tube is the norm. Shorties are for WOT and high RPMs...generally

Stu

[mt1729]

I know I will be in the minority. But I would go to a wrecking yard and get exhaust headers that are made for your vehicle. Now if you start with enlarging the air intake so your engine gets more air, then relieving the exhaust pressure with after market headers you may gain a little hp & torque. It will still be barely noticeable. Just my experience, which is some what limited.

[carringb]

Ost shorty headers have thin flanges, because they aren't tuned for towing. Shorty headers will increase hp, but raise peak torque RPM. Long headers lower peak torque RPM. Something like Banks headers have 1/2" flanges, but shorty headers by JBA and headmen only have 3/8" flanges. I'm not sure those will hold up towing.

[eHoefler]

1 5/8" long tube headers will give the most torque.

[dodge_guy]

Not sure you will get much of anything at that rpm. A better solution is to take the extra money and get a custom tune from Black Bear tuning. That will make a difference in how many it tows.