Open downpipe...

[BRAD727]

i have no clue where to puts this. so if i am in the wrong section im sorry. \
1. what exactly is an open downpipe?
2. how easy is it to install?
2. lose/gain horsepower?

thanks for helpin...

[60trim]

Just as the title says. Its basically your down pipe with out the rest of your exhaust system attached. It goes

Turbo->O2 housing->Downpipe/Cat->Midpipe->Rear Dual Section.

You wouldn't have your mid pipe and rear section attached for just an open down pipe. Now know that there are what we call "electric cut outs" that open with the flip of a switch. It installs where the Downpipe is, but it's the shape of a "Y". A butterfly valve is attached to it to open or close the passage. Here ya go.

http://www.youtube.com/watch?v=uDeLypMl_ks

Its a pretty straight forward install. Unbolt the existing one and replace with the new one.

HP wise...depends on other supporting mods. Anywhere from 5-7 hp respectively.

[Wenuden]

it's also loud as shit, you're GOING to get pulled over for it, and you're going to lose gas mileage. and if you do it to a non-turbo car, you'll probably lose a ton of torque.

[BRAD727]

so to have a open down pipe all i have to do is cut everything from the down pipe back, and if i did remove the cat will a engine light or sumthin come on?? and then with an open down pipe i always here that whistlin noise

[Wenuden]

you don't have to cut anything. Take the mid-pipe and muffler off with a 5/8 spark plug socket. The cat is the downpipe. If you take that off the car will be retarded loud and run like crap.

[OB]

you don't have to cut anything. Take the mid-pipe and muffler off with a 5/8 spark plug socket.

Or you could use the correct 15mm socket...



Oh and how might running without an exhaust hurt fuel mileage?

[TN.Frank]

As long as you add a Perrin O2 simulator I can't see how removing the cat will hurt fuel mileage or make the car run bad. If anything it should run a bit better because you'll be getting rid of exhaust better. I know, ya'll have said something about Neons liking back pressure, don't understand that but I guess it's true or ya'll wouldn't say it. I'd just yank the cat, add the Perrin O2 sim and add a decent muffler like the Delta 50 FlowMaster I've got on my car and be done with it. Should sound ok and you'll NEVER have to worry about having a pluged up cat hurting your gas mileage.

[03blackrt]

^ Neons dont like back pressure.

[dysphagia]

i cant tell you right now the cutout on the srt increases gas mileage

[esteinmaier]

Do yourself a favor and leave an exhaust on the car and use a regular y-style cutout. With the exhaust exiting under the car, it's not very loud outside, but it sure rattles your brain inside.

[Wenuden]

he doesn't have an srt.

When the exhaust broke just past the merge on my v8 t-bird and I couldn't afford to get it replaced for 2 months, I lost about 4 mpg (which was huge on a car that only got about 16mpg to start with).

When I took the muffler off of my sxt for the srt rear, I lost a noticable ammount of torque, which made the car accelerate like crap for normal driving. I can only imagine what removing the whole exhaust would do.

[BRAD727]

im going to get one in a month, so im just planning and asking questions, so i wont screw anythin up. the one i seen doesnt have the rear section srt muffler,but one of these days im gonna drive out and get a better look.

[racer12306]

^ Neons dont like back pressure.

No car likes back pressure. The less back pressure the better.

[kc2005ptgt]

I can honestly say that with dyno proof, I lost NO torque and GAINED 4 hp with a cutout and no cat.

ie: I ran a dyno like so first:

LTH -> 3" Merge collector -> 2.5" Straightpipe -> 2.25" at first 90* bend through stock exhaust -> stock ACR Muffler

Then I ran the dyno like this:

LTH -> 3" Merge collector -> 3" Exhaust dump

And the results on the first run were 139.5 hp 126.0 trq, the second run is in my sig.

[BRAD727]

lets say i do want to remove the cat or remove all the way up the the cat, will a service light come on, or any light?

[kc2005ptgt]

lets say i do want to remove the cat or remove all the way up the the cat, will a service light come on, or any light?

Yes and yes... to remove the cat on an SRT4 I believe you will NOT get the CEL if you have Stage 1 or better... correct me if I am wrong.

To avoid a CEL without Stage 1 or on us N/A Cars, you can do the Spark Plug Non-fouler Mod (http://www.srtforums.com/forums/f75/how ... ode-93604/).

[racer12306]

The code may also be stored in the computer with a stage 1 + even though it doesn't show up as a CEL

[BRAD727]

what is a stage 0?, i know all the rest except that one...i ve been readin up

[MoxHair]

Stage 0 = Another way to say "Stock"

[Wenuden]

There is no stage 0. It's what losers say when they're too ashamed to say stock computer.

The code shouldn't be stored on stage 1 or better. It doesn't look at the downstream o2 period, it's not even programmed to know the car came with one. At least that's what the tech that previously owned mine explained when I talked to him last week when I ordered stage 1.

[BRAD727]

so stage "0" is stock turbo stock computer, and stage 1 is injectors and moduleand so forth ok....cool im gettin it

[MoxHair]

the only thing you need to know

Stage 3 > ALL

[TN.Frank]

You can also get the Perrin O2 smiulator and wire it into where the downstream O2 was, that'll keep the ECM happy and let you run without a cat. Of course you know, you NEED the upstream so the ECM knows how to trim the Fuel/Air mixture.

[BRAD727]

how can one tell if they havea stage 1 2 3 setup on a used srt-4, with no badges cuz i wanna look for this stuff, if the dealer doesnt say anything about it..

[racer12306]

The PCM is really easy to see, its mounted right to the radiator. The staged computers should also be labeled, like a stage 1 sticker on a stage 1 computer.

[BRAD727]

i cant really see that good as to what stage this is....i am going to buy it when i get the money in about a month and its been iup for sale for a couple of months anyway can u see it?

[racer12306]

no, its located on the engine side of the radiator. you will have to look at it in person.

[Wenuden]

the only thing you need to know

Stage 3 > ALL

60 trim > stage 3.... And a grand cheaper.