Ram04
Member
After looking into what the best headers would be for improving low end torque and drivability and increased fuel efficiency I'm starting to narrow it down to just a few.
Lots of confusion out there about the difference between LT headers and shorty's.
Some think the shorty's give best low end power and the LT's give best top end. Others think the opposite.
So what's the truth?
Truth is there are very few apples to apples comparisons done, hence the confusion. Practically every BtB dyno test of LT's vs shorty's uses completely different primary tubing sizes! If the reader doesn't understand the difference primary tube size makes, they are going to draw their own conclusion from the results and typically be confused. lol
The truth is that LT's give the best torque gain below peak torque rpm, while the shorty's give slightly better gains in the mid to upper rpm, above the peak torque, given that they are the same primary tubing size! Change the primary tubing size and this statement goes out the window.
Easy to see where this can get confusing. Everyone tells you to get the 1 3/4" LT headers they're running and that they will give the best low end torque, so you do.
Your buddy with the exact same 5.7 Ram decides to just put some shorty's on and save the grief of install plus be emissions legal. So he gets the Flowtech's.
Trucks were identical before header swap and same mpg and now the truck with the shorty's has better low end power, better towing and get better fuel economy.
Both owners come to the conclusion that shorty's are better for low end power and the confusion remains!
So why did the Flowtech shorty's do better for low end torque and drivability when the LT's are what everyone swears by?
Simple; 1 3/4 primary LT's vs 1 1/2" primary shorty's! Yes, that 1/4" difference in primary pipe size make a huge difference!
So I'm wondering how many out there are running the Flowtech 1 1/2" shorty's? As far as I can tell it's the only name brand header for our 5.7 3rd gen Rams with 1 1/2" primary tubes and so probably the best low end efficiency header out there.
Second to running this header would most likely be a set of 1 5/8" LT's which may come close to the low end torque #'s of the Flowtechs but you would have to dyno BtB to see what difference there may be.
Then there are the JBA cat4ward shorty's with 1 5/8" primary tubes. This looks like it would be 3rd in line for best low end and drivability with better efficiency and mpg. Biggest problem I have with JBA is the fact that they use the same blanket statement of 24ft/lbs @ 2100rpm on all of their headers and only have one dyno on one set and it starts at 3000rpm! lmao!!!
I contacted JBA and asked if I could get the dyno info where it shows the gains at 2100rpm and never heard back...........
So, who's running the Flowtech shorty's and some feedback/ impressions would be awesome!
What I'm most curious about is the flange area where it transitions to the ports on the head. I haven't been able to find any pics showing the mating surface, but from the back side of the flange it appears that the round tubes of the header are opened up to more of a square shape to match ports on head.
Since the 1 1/2" tubing size is slightly smaller than the stock exhaust port, this transition would be crucial in order to maintain efficient flow through the system.
Lots of confusion out there about the difference between LT headers and shorty's.
Some think the shorty's give best low end power and the LT's give best top end. Others think the opposite.
So what's the truth?
Truth is there are very few apples to apples comparisons done, hence the confusion. Practically every BtB dyno test of LT's vs shorty's uses completely different primary tubing sizes! If the reader doesn't understand the difference primary tube size makes, they are going to draw their own conclusion from the results and typically be confused. lol
The truth is that LT's give the best torque gain below peak torque rpm, while the shorty's give slightly better gains in the mid to upper rpm, above the peak torque, given that they are the same primary tubing size! Change the primary tubing size and this statement goes out the window.
Easy to see where this can get confusing. Everyone tells you to get the 1 3/4" LT headers they're running and that they will give the best low end torque, so you do.
Your buddy with the exact same 5.7 Ram decides to just put some shorty's on and save the grief of install plus be emissions legal. So he gets the Flowtech's.
Trucks were identical before header swap and same mpg and now the truck with the shorty's has better low end power, better towing and get better fuel economy.
Both owners come to the conclusion that shorty's are better for low end power and the confusion remains!
So why did the Flowtech shorty's do better for low end torque and drivability when the LT's are what everyone swears by?
Simple; 1 3/4 primary LT's vs 1 1/2" primary shorty's! Yes, that 1/4" difference in primary pipe size make a huge difference!
So I'm wondering how many out there are running the Flowtech 1 1/2" shorty's? As far as I can tell it's the only name brand header for our 5.7 3rd gen Rams with 1 1/2" primary tubes and so probably the best low end efficiency header out there.
Second to running this header would most likely be a set of 1 5/8" LT's which may come close to the low end torque #'s of the Flowtechs but you would have to dyno BtB to see what difference there may be.
Then there are the JBA cat4ward shorty's with 1 5/8" primary tubes. This looks like it would be 3rd in line for best low end and drivability with better efficiency and mpg. Biggest problem I have with JBA is the fact that they use the same blanket statement of 24ft/lbs @ 2100rpm on all of their headers and only have one dyno on one set and it starts at 3000rpm! lmao!!!
I contacted JBA and asked if I could get the dyno info where it shows the gains at 2100rpm and never heard back...........
So, who's running the Flowtech shorty's and some feedback/ impressions would be awesome!
What I'm most curious about is the flange area where it transitions to the ports on the head. I haven't been able to find any pics showing the mating surface, but from the back side of the flange it appears that the round tubes of the header are opened up to more of a square shape to match ports on head.
Since the 1 1/2" tubing size is slightly smaller than the stock exhaust port, this transition would be crucial in order to maintain efficient flow through the system.
