Exhaust help

[blackstang04]

Originally Posted by Gotian

hey here is another question, what about side exhausts? is there any actual performance difference between that and a normal one?

Performance difference is doubtful. It will sound lounder though because of the pipes coming out closer to the cabin. That and the tips would sit a lot lower than a rear exit setup, you'd probably end up dragging them on speedbumps/getting the car on lifts/etc. Roman has that problem with his Mustang.

[Gotian]

i would think a side exhaust would be alot less restrictive considering there is less travelling to be done.

[Igovert500]

Yes it would be a tad less restrictive. It will also be quite loud...ALL the time. If you run a turboback exhaust straight out the side, you will get every cops' attention, and you will scrape it on every speed bump. Some jackass at my old job had an srt4 with side exhaust, and it was always great seeing him bottom out just trying to pull into our washbays.

[Gotian]

Originally Posted by Igovert500

Yes it would be a tad less restrictive. It will also be quite loud...ALL the time. If you run a turboback exhaust straight out the side, you will get every cops' attention, and you will scrape it on every speed bump. Some jackass at my old job had an srt4 with side exhaust, and it was always great seeing him bottom out just trying to pull into our washbays.

lol, i know it would be loud, im just curious about it all. the thing i like about the side exhaust is that on the 1.8t you get flames when you shift at 4k or higher

[Polygon]

There are some simple things to looks at when picking an exhaust for a turbo-charged car.

1. Bigger is better. Get at least a 3" mandrel bent system. Matierial isn't improtant unless you want bragging rights.

2. You do NOT need backpressure. Especially when the turbo itself is a huge restriction. Once the exhaust has left the manifold it has all the inertia it needs. Exhaaust simply needs velocity. It is your job give it the least restrictive path out.

So a side exit would be more powerful. It is quite simple, less bends and less changes in direction means more power.

[Gotian]

Originally Posted by Polygon

There are some simple things to looks at when picking an exhaust for a turbo-charged car.

1. Bigger is better. Get at least a 3" mandrel bent system. Matierial isn't improtant unless you want bragging rights.

2. You do NOT need backpressure. Especially when the turbo itself is a huge restriction. Once the exhaust has left the manifold it has all the inertia it needs. Exhaaust simply needs velocity. It is your job give it the least restrictive path out.

So a side exit would be more powerful. It is quite simple, less bends and less changes in direction means more power.

no offense to you other guys, but i probably hold his opinion above alot of the resposes, though they were good and informative, reason is cause his exhaust system for the baron was just as restrictive as the jetta is and im sure he got alot of power off of it when he upgraded. so thanks and please keep the info coming.

[Polygon]

Yeah, enough that the clutch slips. I wish I had done a baseline dyno before and do another run after to see what I gained. Most TD guys have shown between 30-40HP was freed up from dumping the restrictive exhaust.

I wish I could get rid of the cat.

[Gotian]

most 1.8t guys free up boost and get about 15whp and usually around 30wtq, but that is with keeping a cat on the car, if i were to do an exhaust i would dump the cat and have one of those small mufflers at the end to keep sound a bit lower.

[Polygon]

Yeah, the turbo will do a bit to help muffle as well. It would be nice if I could dump my cat, damn emissions.

Another thing I forgot to mention is the turbo is MUCH more responsive.

[blackstang04]

You want the least amount of restriction? Don't do side exhaust even, just get dumps.

Have a straight 3" pipe come off the turbo, no cats, no muffler, straight out to where the cabin ends, with a little turndown to angle the exhaust out.

Talk about loud.

[midgetracing28]

if u take out the muffler u kill gas mileage and low end torque. removing just the cats so long as u still have a muffler doesnt do to much maybea power gain of a few horsepower not really worth taking it off.

[Igovert500]

Originally Posted by midgetracing28

if u take out the muffler u kill gas mileage and low end torque. removing just the cats so long as u still have a muffler doesnt do to much maybea power gain of a few horsepower not really worth taking it off.

Not sure how you are getting a link between gas mileage and a muffler, so I'll just skip that one. As far as the lowend torque, it's not so much the muffler, it's the restriction which causes some backpressure. Generally the muffler isn't considered as much as the diameter of the piping, but regardless, this doesn't apply to turbo cars, only NA, as mentioned previously a couple of times.

[Gotian]

Originally Posted by Igovert500

Not sure how you are getting a link between gas mileage and a muffler, so I'll just skip that one. As far as the lowend torque, it's not so much the muffler, it's the restriction which causes some backpressure. Generally the muffler isn't considered as much as the diameter of the piping, but regardless, this doesn't apply to turbo cars, only NA, as mentioned previously a couple of times.

And as for the gas milage i wouldnt care, not like it would urt it too much, When I got the car I was getting 350 miles to the tanks, now that I've increased the boost, added the CAI and increased the fuel I get 400 to the tank, which confuses the hell out of me, so i wouldnt mind if the average went back down to 350 on my car. But yeah from what i was told by alot of people, it doesnt hurt the low end torque on a turbo car.

Here is another question for you guys, does the piping have to be perfectly smooth like intake systems? because i know intake systems need to be smooth to get the best delivery into the engine, but what about exhausts? Or it doesnt matter, it just needs to vent out? Hope thats not a stupid question cause like I said i dont know.

[Igovert500]

Yes you want smooth. Leaks, or uneven piping, or anything else that causes turbulence screws up the flow...creating bottlenecks or restrictions.

As far as you getting higher gas mileage, that probably came with the accompanying tune that you should have gotten when you installed larger injectors. Most cars come pretty rich from the factory, to be safe from knock. When you add larger injectors, generally you add some sort of air/fuel controller or swap/alter the ECU to account for the extra fuel. With these devices you can lean out the mixture for more power (to an extent of course...too lean = kaboom) But when leaned out a bit, you will see increased gas mileage.

[slideways...]

Originally Posted by turtlecrxsi

A muffler is just that... a muffler... it muffles sound so you don't hear the resonance of the engine's output. I've always heard that on FI cars no exhaust at all is best.

The lightest material would be titanium. But like Blu said it would only really serve for weight reduction. I only have seen one person go the titanium route. That was Emil from Slovenia with his low 13 second 4g civic. He had an exhaust custom made by DeVito that was titanium with mandrel bends with a removable muffler section for track days. Stainless steel would be be high quality and probably outlast the car. Alumnized piping works well and can be found at most muffler shops if you decide to go the custom route.

you only saw 1 person with a titanium exhaust? you dont get out much. i already have my titanium exhaust picked out, and its super sick. just waiting on money to buy it.
chuki_breath has the same one on his car.
http://www.automotiveforums.com/vbul...d.php?t=538903
cat back, no welds on the entire exhaust, all one piece, 10 lbs. compared to usually 25 or more for a stainless system. every pound counts, especially when the price tag is not a whole lot more. but all this is moot, because i dont know anyone who makes a cheap Ti exhaust for a jetta.