I'm trying to find a balance between a good exhaust system and a decent price and I'm considering building it myself. If I went in this direction, I would probably use Hooker super competition long tubes. Exhaust tubing is pretty cheap. These headers use a flange between the collector and reducer, so I think I could pretty easily build a header back dual exhaust. If not, theres some good header back kits from summit. I have never welded before, but I have access to a welder if needed. What do you guys think of this idea?

 

theres alot of bending of pipe and patience envolved with making a full header back exhaust system. if you are up to it id say go for it, that would be quite an accomplishment. im a do it yourselfer kind of guy and im into that kindof stuff but exhausts are really tricky, if it were me id have an exhaust shop do it.

i had my car quoted at $235 for a y-pipe back 3" single exhaust, and that included a $90 catalytic converter, they have to put one on otherwise they wont work on my car, you just kinda have to work that into the cost

 

I would probably buy pre-bent pipe, if I want bent pipe at all. It would definately be reducers straight back to mufflers, but I was thinking about routing the tailpipes to in front of the rear wheels after the mufflers instead of just turndowns.

 

I am not sure what your plans are for your car, but shorties headers and a good cat back will flow more than enough for most motors, unlease you going to be make a whole lot of power, I wouldn't both with the full length headers.

 

how bout something like this...has most everything you need:

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Speed Inc
X-Pipe Race Exhaust
This kit includes the necessary components to build a true dual, X-pipe RACE exhaust system that ends at the rear axle. This kit requires some fabrication and welding, so we would reccomend professional installation.

Includes:
-Mandrel bent 3" aluminuzed tubing w/3" X-pipe
-Additional 90* bend which will allow installation with most Long tubes
-Race Magnum 3" Bullet mufflers, pair
-Pair of universal exhaust hangers

itemno description price buy
IZM-RaceX X-pipe RACE exhaust system $229.99

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or since you have a smaller hp motor, you may want smaller pipes. i would look into either the 2.25" or 2.5" pipes...

mate them to a pair of race mufflers and you're all set.

 

I'm looking to put down around 400 hp to the wheels. Headers control more than just flow, they also help determine your engine's power band much like an intake manifold. The length of the primary tubes(and whether or not they are equal length) play a big part in this equation. I've don't think I've ever seen equal length shorties. I may end up going with shorties due to ease of installation, however. I really don't want to cheap out but I also want to be able to do most of the work myself. When I do the work myself, I usually end up getting it right (eventually) and learning a lot in the process. I'm trying to perform a big balancing act between cost effectivness and quality. I'm also trying to get all the information I can before making a decision.

 

400hp through shorties sounds like an oximoron to me

at that power level you'll be sacraficing a reasonable amount of power for your stated "ease of installation"

and what part of a LT install is difficult compared to shorties?? only thing i can think of is what to do for a Ypipe. and that is easily remedied with a small tube dual exhaust.

 

The Hooker long tubes that I want require lifting of the engine and replacement of the starter with a mini-starter. Also, with the long tubes I would have to build the rest of the exhaust instead of just buying it. That part is really not too big of a deal though.

 

I don't think that 400hp on shorties is a big stretch. I have a friend running 600hp on a 350 block with shorties! I think shorties are fine as long as you select the proper primary size. I'd recommend 1-5/8" up to 450hp and 1-3/4" for anything higher.

Also, one thing you may want to consider is ground clearance. If you every plan to lower the car, you may occassionally scrape the Long-Tube exhaust when driving on the street. As far as I know shorties do not have any ground clearance issues in 3rd gens.

 

You mentioned the primaires affecting the powerband (unequal,equal), which is possible, but from what I know negligable. They make both unequal, and equal length shorties for 5.O mustangs and they seem to affect the power band very little. It is obvious the full lengths will flow better, but for a NA 400hp small block, I would think that some shorties and maybe a 4" cat back would be sufficient and cost effective.

 

Yes, my understanding is that if you go with primaries sized to large for your application, you will get worse performance than a smaller primary.

Example:
Let's say you have 375hp at the flywheel. 1-5/8" may give you a 32hp gain, but a 1-3/4" may give you a 25hp gain at a particular rpm.

Too me this kinda makes sense. If you image the primaries being much larger than the exhaust ports, there is bound to be some air turbulence right at the ports (air trying to fold backwards into the pockets). The ideal situation is that the headers match the exhaust ports exactly and then their would be no turbulence. For a 350, the best fist you're going to get a 1-5/8" tube.

For Higher HP engines I think the turbulence issue no longer matters because of the force of the exhaust gases. at 500HP the gas pressure would be higher and it kinda "pushes past" the turbulence spot. Not to mention that the larger primaries handle the higher pressure better.

 

Small tube primaries create faster exhaust speeds at lower RPM but provide less flow at higher RPM and vice versa, sorta like an intake manifold. Theres a relationship between tube length and the location of peak torque as well, but I forgot exactly what it was. Also, as far as the equal length deal... being equal length means that the exhaust pulses will reach the collector at evenly spaced intervals, thus minimally interfereing with each other.