Kotobuki

I do so love constantly hearing that exhaust systems do nothing for power, etc. etc. without anything showing that. Anyway, here's some information to help you make a decision.

JBA Shorties. Note, Dyno graph in on a modded engine, before and after shorties. A stock engine will probably not get QUITE as much difference.


JBA Long Tubes, and basically a full exhaust to go with it... should be a stock engine according to the Dyno.


Dynatech SuperMAXX long tube exhaust system



BBK Shorties, modded engine before and after headers. Numbers taken from an article with dyno readings, made into a dyno graph by me.


As you can see, just like any other performance mod, some products get you more than others. I can't speak to the difference in power between an O/R midpipe and a Catted midpipe, but that's the information I have at hand. I've tried to find more dyno charts, but haven't had any luck just claims of added power. So, look around when deciding on what to go with, see if you can find more information, and go with the best bang of your buck, or the best you can afford, or whatever other criteria yo want to use. But, do your research.

Mikes_BLK_GT

Im only going by what Ive read on this and other forums. Part of my research entails reading these forums and other people's first hand experience. Part of it is going to the compaines themselves as well as other reviews. HP claims made by the company trying to sell their product will be the best output they could possibly get under the best of conditions. Also bear in mind on the JBA graphs the shorties are on a slightly modified engine where as your assuming(fair assumption)the LT's are on a stock motor making that comparison between thier LT's and shortiesinvalid. Kooks I believe hasa dyno vid on a jdm saleen before and after. Like other mods this one works much better when combined with other mods such as cai/tune or an sc.

06Redfire3V

Go with Long Tube over shortys period.

WAYYYYYYYYYY better gains.

Long Tubes can give you a good 18+ to the wheels even higher in some applications. I've seen as much as 25RWHPN/Aand even 30+RWHP on blown cars. Make your car sound nice mean.

Shorties don't expect to get more than 10RWHP if you do, I'd be suprised.. They make your car sounds good tho.

Gene K

On Semi-Stock Engine.

Shorties
0-1% Peak Power Gain
1-2% more midrange torque.

LongTubes
3-4% Peak Power Gain
5-8% more midrange torque

Shorties aint worth it in a semi-stock car.
The Longtubes can really help the performance but its more from the power under the curve than the peak numbers.
The car just picks up the next gear with much more authority.

Nowif your making 450+ rwhp already with a blower Im sure your numbers will be different.

JMHO that and a buck will buy you a cheap cup of coffee.

Kotobuki

Mike, I don't see how the comparison is invalid. He asked what the difference in gains between shorties and L/Ts would be. By those charts, comparing similar quality headers (as they're made by the same company of the same materials) it shows that L/Ts perform better. They produce both more HP and more useable torque on a stock engine, than their shorties do on a modified engine that was running 10% more power to begin with. While you're right that it isn't an optimal comparison, it is still useful and valid. On this topic, I'd like to again note that the L/T chart there includes HiFlow Cats, as you need to add a midpipe to the L/Ts, obviously the stock one won't fit.

That said, on the Modded engine, JBA shorties gained 7.2% HP, and 8.9% TQ. The L/T with Catted H provided an 8.9% increase in HP and a 10% increase in TQ. That said, the L/Ts appear to be measurably more efficient. Whether or not you're going to FEEL the difference is something else entirely, as is how much of those gains come from the Cats.

Assuming the percentage gains would not chage on a stock motor (which seems unlikely to me), the JBA shorties come up looking like they're good for about 19 HP and roughly 25LB/FT. This would probably be less in actuality, if I had to guess. But I'm no engineer, so take all this speculation with a rather large grain of salt.

All that being said... different exhaust systems do have measurable (if not huge) differences within the same manufacturer, not to mention the significant differences between manufacturers.

Sancho805

even though many say shorties aint worth it on a N/A car, seems like every one on these forums that has installed the shorties have been completely satisfied with them. they usually say that there is no big performance boost but that they do feel a little bit more kick and together with better sound, they are happy customers.

i didnt make this up . i've read MANY threads on shorty headers on our S197's (considering a set myself) and all reviews are very similar.