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I've been battling back and forth for a while on selling the SC and I've decided I do not want to give up the timeless lines and luxury of the vehicle.

I've come to terms of the SC being a slow heavy battletank with dashing good looks, haha.

However, in keeping the car, I've saved up around $400 and I want to do some type of exhaust work. I know I don't have enough for headers, so I was wondering what else I could do.

If it fit into my budget, I was planning on doing a BFI, 2.5 inch piping from STOCK headers back, a magnaflow x-pipe and two magnaflow 14289's. (Keep/Delete resonators/cats?..)

I'm not looking for a performance increase, because that's not what I'm going for, but I've heard that removing the mufflers and going straight piped may sound better. My only issue with this is that there is probably lots of resonance inside the cabin. I want to know if it's worth it to spend the money on straight pipes or go with an actual exhaust setup. I think the setup I mentioned earlier (Pretty common) might be too quiet... I'm looking for something that sounds pretty raw, without sounding too raspy, and I definitely don't want it to be quiet either. I want something that isn't super quiet at idle, I want to hear it rumbling.

As a "side-effect" of doing exhaust/BFI, will I pick up any gains as far as MPG go? Car has been seafoamed, fluids fresh, and new spark plugs. I've been averaging 18mpg.

Lemme know, and sorry for the long-winded post!


Cliffs:
-Want to do exhaust
-Exhaust system or Straight pipes?
-BFI/Exhaust = better MPG? MAYBE better performance?

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Better yet, for the same price (Well, around the same price.) I could get some electric cutouts, because I've been kicking around that idea too...

Quicktime performance sells some, but I'm not sure exactly how it would sound with the valve closed, because there wouldn't be consistency in the exhaust system anymore.

I know with an open exhaust my torque would disintegrate into pieces, but I want it for the "Wow factor." Hell, I could wire it into the ECT switch and tell the next owner it's the sport mode, haha.

Anyone have any experience with electric cutouts? A search yielded no results.

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Thanks folks, I appreciate it.

stevechumo

iTrader: (5)

Straight pipes will actually hurt your performance, especially in the low end. A proper exhaust system will have a nice sound while still gains MPG and a few hp. You may delete the cats if you want some loud noise. A correct BFI will definitely increase MPH and hp. The reason not too many response to your thread is because this topic was discussed for a thousands times.

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^ I think I made up my mind.

For the same price, I could have electric cutouts installed and go from silent to deadly with the flip of a switch.


Now my question is what size is the stock exhaust piping?.... (I'd like to install the cutout in the midpipe right after the headers)

I know the stock exhaust is 2.25" but what about the midpipe?

Brendon

iTrader: (1)

If all you're looking for is a slightly aggressive sound, I would just swap the mufflers. There's a guy on youtube who put on rod millen mufflers and it sounds pretty damn good. If you still want it more aggressive, then move onto the resonators just behind the mufflers.

As far as performance, removing the center cat wont net much results, maybe a few HP. Going from 2.25" to 2.5" is really overkill unless you're running forced induction. 2.25" is pretty standard for V8s. Realistically, your headers are what can make the most difference. Unfortunately they're the most expensive and difficult to install.

As for fuel efficiency, I wouldnt give much weight to any claims of MPG increases from custom exhaust systems. Right now I'm on a true dual 2.25" cat-back system from the primary cats. Center cat and resonators are gone, and it exits out to rod millen magnaflow mufflers. Aside from sounding cool and a few extra horses at the high end, it hasnt made any real noticable difference in MPG. I know there are people who'll swear by it, but I'm really skeptical about anything that claims to be able to create both more power and better fuel efficiency. It just doesn't happen that way, unless you're designing a new fuel injection system or a new valve timing system, in which case you should be working for Toyota.

stevechumo

iTrader: (5)

[QUOTE=MT Photo;3741210...Now my question is what size is the stock exhaust piping?.... (I'd like to install the cutout in the midpipe right after the headers)

I know the stock exhaust is 2.25" but what about the midpipe?[/QUOTE]
The stock exhaust is actually 1.75". It's measured 2.25" is for the outer diameter. The stock pipe has very thick wall.

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Holy pewp.

So essentially if I was getting an electric cutout, I'd be looking for what diameter exactly?...

They make a 2", 2.5", 3" and so on..

stevechumo

iTrader: (5)

What do you mean by electric cutout? I haven't heard of that term before.

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Well, you know how you can have an exhaust cutout?

Instead of having to go under the car and take off the cap, you can press a button inside the car and it opens the valve automatically.

It's basically a valve attached to a pipe, attached to some point in your exhaust (Usually right after the precat or headers) and when you press a button, it opens the valve attached to your exhaust so your basically running open exhaust straight from the header out. Press the button again and it closes up...back to stock exhaust.

It's pretty neat.

http://www.youtube.com/watch?v=QNfHH...eature=related

There's a video, starts out closed, then open.

cbrasian

your not gonna see any gains in fact you will lose hp as theres more backpressure than need its pointless to change the exhaust other than noise as airflow is still going to be choked at the manifold and dp, all you will be doing is increasing the backpressure causing the car to lag a bit more off the line yet it maynot be noticable, you may also feel a slight gain in topend but it may also not be as noticable it all depends on how big you go, but technically as for running a cut out i prefer the manual cutout from hks as the electronic ones are known to have the motor go bad and then your really screwed esp when rolling next to a cop... also the cable one is faster to close than the electronic one...also know that they do tend to go bad and not close all the way, honestly imo if your gonna dump that kind of cash go with a upgraded manifold all the way back if your not going that route then your honestly wasting your money just for sound... also just for info if your obdII aka 96+ you have to do it after the o2s if your running off the stock ecu... only time you'd wanna run a straight pipe is if your racing and turbo for better breathing

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I'm getting my cutout from DMH Performance, they are the highest rated for customer service and build quality.

Lots of people have been running them for a year or more with absolutely no problem and the motors are waterproof as well. They have a 4 year no questions asked warranty.

I know with a cutout I'm not gaining any power, that's not why I'm doing it, but IMO I'm not "wasting my money" for sound, because that's exactly what I want. Stock, and then open exhaust at the flip of a switch. As far as cable being faster, the DMH cutouts close in 2-3 seconds.

Also, I'm OBD1, no smog.

An upgraded manifold for the SC400?...lmao.
Only option really is headers, and I'm not spending THAT much money.
Once again, as I said. I'm not doing it for HP gains, I'm doing it for the WTF factor of a lexus V8 running open header at a stoplight.

SClean4

I believe the center/mid-pipe is 2.5" (my cutout is 2.5") and the rest is (I think, correct me if I'm wrong) mostly 2.25" with some parts of the pipe throughout (bends, I guess) slightly less in diameter for clearance, etc., but I always found conflicting information about the entire exhaust pipe diameters and wasn't even really 100% sure if I was getting the right size when I bought my cutout.

It decreases torque but is supposed to increase horsepower slightly (i.e. higher RPMs, etc.) from what I've read. It's supposed to be most benefical for turbo/FI cars, performance-wise, but obviously we like hearing the V8 sound more. I never have mine fully-open (way too loud), unless I could control it with an electric cutout, which I have thought about getting recently for the same reasons you want one, to open it up for the crazy-loud sound when needed but mostly having it closed or halfway-open, etc. Fully-open it's extremely loud and for daily driving you basically have to rev the engine up a little higher than you normally would without one because of the torque loss. I have been using modified block-off plates with basically holes drilled in them to control the volume how I want it, equivalent to about halfway-open. You could do this with an electric cutout, too, having it halfway-open, etc., which improves your torque performance more as well (close to stock) compared to fully-open.

Here's the options I think you should consider:

Electric cutout: Yes, the DMH are supposed to be great (better than the popular QTP/QTEC e-cutouts even) or I'd also recommend the Pypes cutout (link), which are supposed to be just as good if not slightly better than DMH from what I've read. You can't go wrong with either one. I might get a DMH or Pypes electric addition soon.

Flowmasters 40-series mufflers: Louder than most or all Magnaflows and most mufflers and sound very mean, while keeping your torque (compared to a cutout). Or you could go with some Magnaflows.

Some Tips:

Get it welded as far down the mid-pipe as possible, close to the rear Y-pipe, and have it welded in where the cutout exit is facing the right. I made a newbie mistake and did it on the left just because I wanted more people to hear it better, but it exits right under the driver's *** (lol, d'oh) so not the best placement for the least amount of cabin sound (drone) the driver hears. If I ever get my cats replaced with Magnaflow cats I'll probably have it re-welded facing the right.

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I surely do appreciate your response, it's the most informative for sure.

So I'd be good with getting a 2.5" cutout?

I never thought about the side exiting problem, but it makes complete sense.

After researching the different companies (QTP it seems, being the most popular) I chose DMH because of the customer service and mainly the 4 year warranty. I'll look into pypes for sure though. QTP has the most hype and least deliverance it seems. Shoddy construction.

I appreciate your response!

cbrasian

cable is instant v.s your 2-3 seconds as for your response of lmao an upgraded manifold yes an upgraded exhaust manifold is also known as what you guys call headers... I've already had one designed and flow tested for a supercharger kit and there are plenty around for stock cars as well so i guess the lmao is on you as you don't know your terminology because insead of trying to figure out what a exhaust manifold means you try to personally attack me with your supossed knowledge of .....nothing.... as for the sound whats the point of sound if you still can't go anywhere other than a referee station since your cars loud but even slower off the line there is no wtf factor when your still slow its more like poor poor car what did your owner do to you