JBA Header question..
4th Gear Member
Joined: Jan 2007
Posts: 1,567
From: Palm Beach to South Carolina
I have a hard time believing that shorty headers will not improve performance, particularly in slicks case with all that HP. The shorty is less restrictive than the stock manifolds so there would have to be an increase in hp/tq.
That 10hp sounds about right to me and and in your case could be more like 15. It would probably be felt in the low to midrange portion of the curve with a few more ponies up top.
I was always taught that l/t's are for the track and up top performance and shorties for low to midrange torque because a certain amount of backpressure was desired to achieve performance at those rpms. But hey, I could have been brought up by idiots! (don't think so, they all had fast cars)
While the longtubes in slicks case would yield max hp numbers, drivability would suffer...with shorties it may and should (imo) improve.
Keep us posted bro with the results.
That 10hp sounds about right to me and and in your case could be more like 15. It would probably be felt in the low to midrange portion of the curve with a few more ponies up top.
I was always taught that l/t's are for the track and up top performance and shorties for low to midrange torque because a certain amount of backpressure was desired to achieve performance at those rpms. But hey, I could have been brought up by idiots! (don't think so, they all had fast cars)
While the longtubes in slicks case would yield max hp numbers, drivability would suffer...with shorties it may and should (imo) improve.
Keep us posted bro with the results.
Equal-length shorties, like JBA and BBK, have equal length primaries that help separate the exhaust pulses and improve scavenging of exhaust gases. Since I kept my factory catted h-pipe, I still have adequet back pressure to retain low-end torque while increasing hp over the entire curve (which is great for a daily driver).
Non-equal-length shorties, like FRPP and others, are mainly for under hood presentation as the front primaries are longer than the rear primaries which is exactly the same as the factory cast iron exhaust manifolds and therefore shouldn't show any gains.
Also, the money I saved going with shorties over a long tube/catted mid-pipe combo was enough to purchase cams and have them installed.
Thread Starter
5th Gear Member
Joined: Dec 2005
Posts: 2,634
From: SC
My tuner said he sees gains of around 15 to the wheels with longtubes, and ~7 when people just switch to a catless midpipe, he insists that headers are not worth the money, and he has a sweet Saleen supercharged 2008 GT, and has tuned multiple 700+ hp mustangs. I trust him and honestly wouldn't do headers again, I'd rather put the cash towards a supercharger.
Thread Starter
5th Gear Member
Joined: Dec 2005
Posts: 2,634
From: SC
Most people also forget that there are 2 types of shorties - equal-length and non-equal-length.
Equal-length shorties, like JBA and BBK, have equal length primaries that help separate the exhaust pulses and improve scavenging of exhaust gases. Since I kept my factory catted h-pipe, I still have adequet back pressure to retain low-end torque while increasing hp over the entire curve (which is great for a daily driver).
Non-equal-length shorties, like FRPP and others, are mainly for under hood presentation as the front primaries are longer than the rear primaries which is exactly the same as the factory cast iron exhaust manifolds and therefore shouldn't show any gains.
Also, the money I saved going with shorties over a long tube/catted mid-pipe combo was enough to purchase cams and have them installed.
Equal-length shorties, like JBA and BBK, have equal length primaries that help separate the exhaust pulses and improve scavenging of exhaust gases. Since I kept my factory catted h-pipe, I still have adequet back pressure to retain low-end torque while increasing hp over the entire curve (which is great for a daily driver).
Non-equal-length shorties, like FRPP and others, are mainly for under hood presentation as the front primaries are longer than the rear primaries which is exactly the same as the factory cast iron exhaust manifolds and therefore shouldn't show any gains.
Also, the money I saved going with shorties over a long tube/catted mid-pipe combo was enough to purchase cams and have them installed.
4th Gear Member
Joined: Jul 2010
Posts: 1,364
From: WV
It's where im at rightnow, thats why I have been following this thread. I'm still on the fence with the header selection with my cam install. You always have to look at selection differently with a DD. Sometimes max hp is not always the correct answer...
Now if someone could just get me a soundclip of a Cam/Shorty combo
To me, the flatspot in the curve is between 2.2 and 3.2k rpm...that's where I would like to see an improvement in hp/tq for everyday driving.
Last edited by mayo; May 12, 2012 at 01:10 PM.
2nd Gear Member
Joined: Mar 2010
Posts: 473
From: Illinois
JD - Well said. I was going back and forth between LT's and the shorties. I'm glad I made the decision I did. I talked with JD about his car and some of the mods he has done. I have to agree, the shorties are one of my favorite mods so far. That and the cams. I wouldn't hesitate to do the JBA's again on another car.
Mayo - you'll pick up some low end TQ with the headers. I know I did. It's not a huge difference, but enough to make it noticeable. I have since dropped the idle a bit and need to get a newer video, but you'll get the idea. Stock mid pipe, JBA's and Flowmaster 40's. Here's the thread: DR Cams/JBA Headers
Mayo - you'll pick up some low end TQ with the headers. I know I did. It's not a huge difference, but enough to make it noticeable. I have since dropped the idle a bit and need to get a newer video, but you'll get the idea. Stock mid pipe, JBA's and Flowmaster 40's. Here's the thread: DR Cams/JBA Headers
4th Gear Member
Joined: Jun 2008
Posts: 1,387
From: MA
4th Gear Member
Joined: Dec 2010
Posts: 1,597
From: Gallifrey
help separate the exhaust pulses and improve scavenging of exhaust gases. Since I kept my factory catted h-pipe, I still have adequet back pressure to retain low-end torque while increasing hp over the entire curve (which is great for a daily driver).
Also, the money I saved going with shorties over a long tube/catted mid-pipe combo was enough to purchase cams and have them installed.
Also, the money I saved going with shorties over a long tube/catted mid-pipe combo was enough to purchase cams and have them installed.
Any in particular you think are "the best" from their scavenging design?
I was looking into LT's to get the best gains, but really, with a good setup, 2k /w install for 15hp? Yeah, can't do it. And with shorties I'd be able to do it myself without much trouble, yes?
Last edited by wayne613; May 12, 2012 at 03:41 PM.
4th Gear Member
Joined: Dec 2010
Posts: 1,597
From: Gallifrey
Yeah, read the rest of the thread, and some others on the shorties.. Sucks. I'd have to do jack-stands on a drive-way that has more grass to it than asphalt at this stage. Meh.
Damn house-poorness...Getting in the way of my car fun.
Damn house-poorness...Getting in the way of my car fun.
Last edited by wayne613; May 12, 2012 at 03:57 PM.
4th Gear Member
Joined: Jan 2007
Posts: 1,567
From: Palm Beach to South Carolina
I've been trying to research this as well as I can, being that I have very little past mechanical experience, but you're essentially saying the main gains minus just a bit are attainable with good exhaust scavenging (equal length)shorties, yes?
Any in particular you think are "the best" from their scavenging design?
I was looking into LT's to get the best gains, but really, with a good setup, 2k /w install for 15hp? Yeah, can't do it. And with shorties I'd be able to do it myself without much trouble, yes?
Any in particular you think are "the best" from their scavenging design?
I was looking into LT's to get the best gains, but really, with a good setup, 2k /w install for 15hp? Yeah, can't do it. And with shorties I'd be able to do it myself without much trouble, yes?
Long tubes will obviously flow better, but you lose that back pressure that gives you the low-end torque for daily driving. Long tubes make their power in the upper RPM range and is more suited for the drag strip.
Cost was a factor for me. I didn't want to spend more than the MSRP on my Mustang and so far I am still below it (cost of car and mods). It was either long tubes with high flow catted h-pipe or shorties with Detroit Rockers. I think I made the right decision...
