jba carb legal longtubes!?!

[eric n]

It was my understanding that NO ONE is currently making a carb legal longtube. Then while cruising around summit racing's site I find these jba headers

"JBA-6675SJS
Increased horsepower and torque for all 50 states.
Bolt on extra horsepower and torque with 50-state smog legal JBA Cat4ward headers."

Does anyone know if these will produce sizable hp increase with the cat's still in place?

Are there high flow cats I should replace mine with?

 

[adnlyn]

kooks makes a catted long tube if i am not mistaken

 

[351CJ]

The OEM Ford cats are supposedly high flow. I doubt that you would gain much HP with after market "high flow" cats.

The JBA web site does not say anything about the long tubes being 50 state legal. If you look at the JBA product page you will see

Notes
22 - Long tube header. For off-road use only. This product is not emissions legal.

3 - Installation requires modification to exhaust system

It appears that only the Cat4ward shorty headers which are a direct replacement for the stock mainfolds are emissions lega.

Here is a dynograph from JBA's web site which I belive uses the long tubes and the stock H pipe, mufflers and cats. They are claiming 23 more HP and 28 more lb ft. But the info on the JBA web site is confusing so I'm not sure I belive the chart has the right title.

http://www.jbaheaders.com/images/dyno/05mustangdyno.jpg


Here is another dyno graph supposedly of the cat4ward headers, but is has CAI, SCT tune, JAB axleback etc. It shows a 21 HP gain, but both the before and after #s are really high due to all the other mods.
http://www.jbaheaders.com/images/dyno/05must_1675.jpg

 

[eric n]

I sent an email to jba to ask if there was any chance the summit site had it right. Sadly I was told NO. JBA however insists that their shorty headers provide substantial gains. Here is the response:

Eric,
There is not such thing as a California smog legal long tube header for your Mustang. (I'll have Summit correct their website.)There is only about 9 RWHP difference between our shorty and long tube header. Please check out 1675SJS. These are a direct bolt in replacement, are 50 state smog legal and still kick butt. Thank you for checking with us.



That along with the jba dyno implies some very real gains 20+ hp on a modded 05. It was my understanding the shorties were pretty much a waste, which is the truth?

 

[tomustang]

That along with the jba dyno implies some very real gains 20+ hp on a modded 05. It was my understanding the shorties were pretty much a waste, which is the truth?

they pretty much are, unless you plan on adding cams or a S/C you'll see a bit more gain from them

 

[351CJ]

Eric,

The problem with long tube headers is that even if you do have cats, the cats get moved so far away from the engine that the exhaust gasses are already cooling so the cats are not as effective.

Also warm up time for the cats is increased when they get moved away from the engine, which greatly increases emissions during cat warm up time and increases the warm up time.

I am suspicious about 20 HP gain for shorties. If all the runners are the same length on the shorties they may give some HP gain, but I'd only expect 10 HP at best. Again the problem with the Cat4ward dyno graph is that the car has so many modifications that dynograp is of little use to tell us how much HP gain would be had from just bolting on JBAs shorties.

Why don't you e-mail JBA again and see if they will give you any specific claims on how much more HP the Cat4ward shorties give.

 

[1fastz]

THEY ARE NOT CARB LEGAL if they are full lengths

ven if you add cars you can not be legal in california

its against the california emisions law to move the cats at ALL this is why the ONLY turbo kit that was ever carb legal was the incon kit wich bolted to the stock H pipe on earlier mustangs

you may not eliminate OR MOVE any cats to have a carb legal exhaust..