GT Bob

Normally... I find myself nodding in 100% agreement with just about everything you post... But on this comment, I could not disagree more. The stock Manifolds are a damn sight different from short tube headers. The design is alot better for scavenging (tho again, not as optimal as a long tube), and the primaries are individual primaries up to the collector, unlike the manifolds which are basically just ports on a log. You may be thinking of the old 5.0 shorties that were basically a log manifold with a velocity stack on it...

Will you end up with the top end like a long tube header will give you with a set of shorties? no, of course not. Where shorties really shine are down low, in offpeak power and torque gains. I've run time and again against cars with identical mods, except for the long tubes/short tubes difference, and without fail the only time they pull on me is when I am over 5K rpm's, and usually I reel them back in about half the distance I lost between when we shift and hit 5K again.

desslok40

Hell after 6 years if you are like me you will turn this sucker into a drag car and get a truck for DD!!!

At the very least you will probably get the new Mustang coming out in 09, so why worry about emissions??

mygt500

I agree...great companies and headers!

techmanBDsStang

I have a truck actually, but no, I want to keep this one. To tell you the truth I am tired of having a car payment, so this will be it for me I think. I have blood an sweat(and of course cash) into what I have done so far and plan on more stuff, so getting rid of it, would kill me.

And also(probably get flamed) if I were to get a new car, I would go with the Challenger. I like it, I was trying to wait, but didn't have the patients to wait, and the Mustang is a good looking retro car so I am happy with my purchase.

Mishri

I didn't realize AZ had to do emmisions at all.. must be for cars registered in Phoenix area? I lived in flagstaff for about7 years.. never had to do emmisions on my 5 year old + cars.. so there maybe a way around emissions after all.. my dad used to commute from payson tophx everyday.. 1.5 hours a day, but atleast he didn't have to live in phoenix (but also worked out at rosevelt, not in the city)

F1Fan

Hey Zellanor,

If you are still reading this thread what I found out with all my various testing and dyno pulls is that on a bone stock car a good set of long tubes withan O/R X-pipe will usuallymakesomewhere between 15-20RWHP and a set of JBA shortys on the stock catted H-pipe willonly give you 6-10RWHP.If you consider the complete frontpart of the exhaust systemby combininga set of JBA shortys anda MagnaFlow Tru-X Pipe with OBDII complianthigh-flow catsthe differences become much smaller and you can stay emissions legalwith cats AND O2 sensorsin the stock locations.The combination of the JBA shortys and MagnaFlow Tru-X Pipe with the OBDII high-flow cats netted 16RWHP on mycar.But the really interesting thing isthat as you add other mods to your intake tracksay a large CAI with a 90mm+ MAF housing, T/B CMCV deltes etc.is that the difference between long tubes and shortys becomes smaller and it never goes back on an N/A car even with cams installed. My 5sp car pulls 316-318RWHP on a Mustang Dyno using SAE correction and smoothing set to 5 which gives you the lowest average readings for a given pull. These numbers are within 2-5RWHP of the other cars dyno'd the sameday with a good CAI kit, CMCV deletes andgood O/R long tubes. Mystock 5sp car with 10,000+ miles on the odometer on this same dyno pulled 260RWHP so it's a very average car as far as '05 5speeds go. So don't think that you have to go with a set of long tubes unless you are really building a maximum effort bolt-on car. The differences are just not that big in the end as the torque and peak power numbes areabout the same asare the costs. But the big differenceis in emissions issues are where the shorty/Tru-X combo has the hands down advantage over even a catted LT setup.

HTH!

modaddict

I would be very interested to see what those mods with the stock manifolds netted to see an accurate number on what specifically the shorties gave. The problem is 99% of the numbers we here about with a specific part are never just that specific part so it's never really 'accurate' what the part gives. What if you made 14 with the same set-up on the stock manifolds - then that would certainly show that the shorties were not worth the money for 2 HP?

CK

modaddict

Bob, believe me, I WANT to believe...lol The problem is what I just posted in the post above to F1^^^^

I have yet to see just bone stock shorties to stock manifolds comparisons. I will advocate whatever the results are but no one has ever given that comparison yet to know exactly what gains the shorties have over the stock manifolds. That's my main problem with them. You could very well be correct, I just have not seen it yet personally.

F1Fan

Hi modaddict,

CK? is this ChevyKiller?

It might be interesting but it would prove little for the average folks becausetypically theaverage folks don't add just the catted X-pipe on stock manifolds. But I did install the JBA shortys first and dyno them which is where I got the first number from. Once I had made a few pulls on the JBA shortys only I installed the MagnaFlow Tru-X Pipe w/OBDII compliant cats and ran it again. I also installed installed a MagnaFlow MagnaPack cat back and the numbers were up again to 18-20RWHP depending on th pull you looked at. I though MagnaFlow's claimed advertised numbers were B.S. and said so but I've been wrong before and I was wrong this time too. Of course that was on a bone stock motor and as usual by the time most people add a CAI kit and tuner they get all pissed off that they didn't get the 30RWHP that the manufacture claimed their productmakes.

But as you know all later bolt-on part eat away at thepotential powerimprovement of the next bolt-on part to be added due to the overlaping improvements they eachhave to contribute. The exceptions seem to be hotter cams/springs and items that reduce parasitic losses like water pumps, drive shafts lighter wheels etc. becausethey are not upstream of the parts that are limiting power but downstream. It always surprises me how many folksare surprised at how little the very expensive cams they just installed produced on their stock engine only to be very surprised at the bigger than usual gains from a CAI kit and a tune. This is because theydid not improve thebiggest bottleneck in the intake tract, they only made the problem bigger with cams which only later cold do their job once given an intake tract that was capable of showing what the cams could deliver. So when the engine is opened up with aCAI kit and 90mm + MAF housing, T/B and CMCV delete plates much to their surprise for some reason they got larger gains than other folks didwho did not have the cams installed first. They missed the real problem but ultimately if you add all of the intakemods, cams and exhaustyou always end up with the samenumbers no matter what the indivual increases were along the way due tothe order of intallation. What I'm saying is that the gains that people see are highly dependent on the order of installation and is the only reason people think that they got lower numbers out of a particular part.

HTH!

F1Fan

Hi modaddict,

What could be more direct? As I posted previously years ago, Iinstalled a set of JBA Ti coated shorty headers on my car and dyno'd it. The results were as posted with only a moderate gain in power. The problem is that folks for some reason want to comparea set of shorty headers bolted up to the stock catted H-pipe directly to a set of long tubes with an O/R orcattedX or H-pipe. This is stupid, you need to consider the entire system which is why I laterinstalled and dyno'da MagnaFlow Tru-Xpipe withhigh-flow OBDII cats. Taken as a system just as any longtube/O/R X-pipe would bethis combination produces nearly the same power and torque as a longtube header with an O/R X pipe installed. The proof is in the pudding so to speak.

HTH!