exhaust mod questions

[DeafVX]

Does putting on a catback and pv muffler void the warranty? How do you install it? Where can you have it installed and does anyone know approx how much?
Hoe much is the cat back and the pv? should a person do either one or both?
And where do I get them?
I have only put in a K&M drop in filter, but found a calimiti cone filer for the VX online (don't know if I should trade up). Taken off the air intake elbows and mass airflow sensor screen. I don't know what else aside from the exhaust and a SC (I don't have THAT much money) to boost power/performance. Can someone please help.
Thanks!

[Tone]

Muffler will not void the warranty and a cat back is extra money just to be able to bolt it on and off yourself - sound and performance are essentially the same. To cut and weld in a new muffler is around $40 and takes any muffler shop maybe 20 minutes. Mufflers are in stock wne you are ready. There really isn’t much else you can do except run max air pressure in your tires and all synthetic fluids.

[DeafVX]

do you get more power or a better growl with the cat back or is it merely the same sound and performance you get with out it and just a pv muffler?

[paultvx]

Do a search on this site and you will find plenty of hard data. The PV does yield a performance gain on the dyno as well as a difference in sound. I do not believe you will gain much power with a cone filter or with the removal of the elbow. Intake sounds may increase, which can be misleading, but a naturally aspirated motor is essentially a fixed displacement air pump. It can only pump as much air as it displaces. Realistically, you'd be lucky to see a 5 HP gain by the most optimistic estimate with intake mods. Force induction is the only way to go to gain significant power without changing the engine's internals (ie altering compression ratio etc.).

[paultvx]

It is almost impossible to get big gains on intake mods alone unless the vehicle is already supercharged (either with a turbo or a supercharger). Force induction vehicles can typically see 20HP to 30HP gain. Same is true for exhaust mods. I've personally witnessed dyno runs of a turbo MR2 (with and without factor airbox, with and without exhaust silencer), several BMWs, Porsches, turbo Supras, and VW GTI's and Corrados (NA, turbo, and supercharged). It isn't a theory, it's a fact.

On typical normally aspirated vehicle, you'll get 5HP at best for intake and 10HP at best for exhaust. There are exceptions, of course. Some cars come with very restrictive intakes and/or exhausts. The VX may be one of the exceptions, but I doubt it... the exhaust perhaps, but not the intake (the PV has shown around 15-20 HP gain on the dyno).

Look at the factory intake system. The duct is fairly straight aside from the 90 degree bend at the throttle body. The diameter stays fairly consistent throughout. There are no pinches, no drastic bends to cause air to get backed up. The passage is smooth. The airbox is straight forward. The elbow guides cooler air from the fender. That leaves the intake manifold to be one possible source of restriction. Porting and extrude honing it will probably yield a decent amount of power, but that'll cost $ and isn't a bolt-on job.

When it comes to modding a NA car for power, there is no such thing as cheap, bolt-on, big power mods. For significant power increases without alterning the engine's internals, forced induction is the only way to go (I'm not a fan of NOS.) Any experienced speed shop will tell you exactly the same.

Also, power gained from mods are not additive. The intake alone may give you 5 HP and the exhaust alone may give you 20 HP. But, that doesn't mean on the dyno you'll see +25 HP with both installed. It's most likely less than that. Butt-dyno is about as good as what comes out of the butt.

http://www.doodie.com/pics/ceiling3.gif.08152003

>>> Edited [img] tag.. you can click on link if curious but, it's tasteless....WSG

With a bit of time and ingenuity, you can make your own cone fitler intake kit for far less than what shops charge for their kits. It's just a cone filter and metal bracket.

[Dallas4u]

I have to agree. From my perspective, my opinion is the cone K&N didn't do much for me in way of HP before my SC. I tried many different designs... plain exhaust tube running to cone filter in engine compartment, tube running into firewall and connecting to filter, intake running through firewall and into front of VX connecting to filter. Nothing did much, if anything. In fact, half the time it even FELT like it was hindering performance. Sometimes I thought I could feel a difference when the VX was somewhat cold, but after that... nothing.

I ended up just staying with the air box and a drop in filter (AMSOil or K&N. I have both and seem to notice better performance from the K&N, but am aware I am probably dirtying my engine a bit more).