Many Exhaust Questions Answered 3800 Engine
 

Found these, and decided to upload them to my photobucket. Figured I'd post these up here in case people search for downpipe or Ubend to see what the factory piece looks like.

These pictures are of the stock downpipe off my 99 GTP, but many 3800 stock downpipes are similar. I cut the cat out because I sent it in for money- figured I'd post the pics of what the restrictive parts look like.



Obviously the most restrictive part that everybody thinks of first is the U-bend, so we'll start there:

http://i5.photobucket.com/albums/y18...e/100_2102.jpg

The stock catback bolts up to the left side and the stock cat is normally attached to the right side. The rear O2 sensor screws in from the top. Obviously this is not a good piece for flow...

http://i5.photobucket.com/albums/y18...e/100_2103.jpg

View from the catback side of the Ubend- notice how 3/4 of the pipe's flow is diverted down- definitely not a straight shot.


Now for another part that people don't think of as being restrictive- the top/entry to the downpipe from the rear exhaust manifold. It looks to be pretty smooth and large diameter pipe from the factory- what could be bad about it?

Picture of the inlet of the downpipe:

http://i5.photobucket.com/albums/y18...e/100_2108.jpg

Notice there is a little collar inside that really necks down- definitely much smaller than the rest of the piping.

http://i5.photobucket.com/albums/y18...e/100_2111.jpg

Here is from the front side of the cat (cat cut off of course). You'll notice the pipe coming down from the engine is actually double wall- so the actual pipe diameter is a good bit smaller than it appears to be from the outside.


Just figured that might help people see what the stock downpipe looks like, hope I haven't posted these pics before.

Bumpin... you and I started this thread before :(

But since I can't find it, I'll throw up what a ZZP Downpipe looks like again.

http://i33.photobucket.com/albums/d5...npipe_rear.jpg

http://i33.photobucket.com/albums/d5...p_exithole.jpg
(much straighter than that U-Bend)

http://i33.photobucket.com/albums/d5..._fronthole.jpg

*edit* Let me throw up more STOCK exhaust pictures.

http://img.photobucket.com/albums/v7...austPics/4.jpg

http://img.photobucket.com/albums/v7...austPics/8.jpg

Oops, I get on so many different forums that I forget after awhile... lol

Hopefully it'll help somebody out at least?

Whats that?? Is that a cat?? I wish I had one LOL

And the u bend is a terrible thing.

Thanks for the info guys.
Stupid question, Mike or anybody for this zzp downpipe: is it bolt on or is welding required? :o sorry i am not car smart.

The ZZP is a bolt in, though a torch is handy for loosening up rusty bolts.

Ya whatever you do.... dont breakt the studs off! HAHA I crack myself up! o boy, car goes into the shop wednesday to get my mistake taken care of!

Mines going in monday to prevent just such an issue lol.

Thank you, very much. :)

If I understand, you have no exhaust right now. You should make a video of that, bet it's nice and loud ;)

hey i see some kind of screen in there, what is that?? i know its a different engine than mine but my DP dont have that screen. could this be because mine is just the offroad pipe with no cat??

I think it is part of the cat, my off road has no screen either.

oh you got the off-road too, ha how do you like the smell of the exhaust??

It smells great!!
Skip to 1:00
http://www.youtube.com/watch?v=JvdJZh1Jl60

Its part of the cat- if you have a catless off road pipe, then you would just have regular pipe in place of it.

is there any restriction with that screen??

EDITED My original post to include more pictures of the stock exhaust to the resonator.

The cat does restrict some, but it is for emissions purposes. Obviously a straight pipe will be more free flowing, but Cats are the law and I like to build my car to abide by those laws. Plus it is a high flow cat, so the restrictions are minimal (compared to the stock)

The other thing you've got to think about too wht02monte is how much is the cat really 'restricting'? Especially since most people on here just have basic bolt on's as far as power goes- even a stock cat isn't a huge deal- much less a high flow. Obviously no cat can flow as well as straight pipe- but on the cars that have a downpipe like I posted- getting rid of that other crap is the bulk of your restriction.

oh i understand. when i had my res and ubend delete i notice a decent increase, but then when i went with the offroad pipe i really didnt notice anything but sound. now i still have a question if you can bare with me here, so as you know i got a nice flowing exhaust, what will a new set of headers get me ? just sound or will i see some kind of increase in power??

No clue on the 3400's. I have no idea how bad the stock manifolds are, or how good the aftermarket headers you're looking for are.

Most cars see a decent power gain with headers because many factory designs have to compromise flow in some areas for one reason or another (production costs, easier production line install, etc).

My SSAC headers seemed to give me a bit of power, better low end mainly, or its just ment. Sounds beastly too.

now whats that crossover pipe for?? do you still have that if you have aftermarket headers?? whats the difficulty level on installing aftermarket headers??
and a question for enzo354 what motor do you have??

A crossover pipe brings the exhaust from the front 3 cylinders and dumps it either into the rear header- or into a Y collector with the other branch coming from the rear 3 cylinders.

Obviously you still have to use it with aftermarket headers- where else are you going to run the exhaust from the front 3 cylinders?

It can be a real pain- its somewhat of a struggle getting the new headers in position- and depending on the headers- each style seems to have its own stumbling blocks and problems (for example- the pacesetter headers for the 3800's having a leakage issue and needing welded on the Y collector).

oh okay thanks, but what if i decide to go the route of true duals?? will i still need to use the cross over pipe?? no right?

You can't go true duals on a sideways motor with no room to run any piping.

Well, yeah- you still do need some sort of cross over pipe- you still need some way to get the front 3 cylinders over the transmission and to your downpipe area.

It kinda depends how your headers are designed though- for example, the pacesetter headers for the 3800 runs each bank of cylinders into a single tube- and then combines the two front and rear tubes in a Y in the downpipe area. Thats why people tend to use those headers for doing true duals, because they alreay have two separate pipes halfway down the downpipe area- so all you need are two custom shorty downpipes, and then the rest of the exhaust which any exhaust shop could do.

However, I really don't recommend true duals- you add a ton of extra weight for no power gain- especially on a nearly stock car. You can still go much bigger than stock on a single exhaust (I mean heck, they make up to 4" single exhaust tubing and components) than your engine would ever need- I mean the Supra guys are doing 1000whp on single 4" exhaust with a 6 cylinder.

You can, and it has been done. I've seen at least 3 people with true dual wbodys posted on the various forums.

The only thing is- I haven't seen any that had cat's- so it would be hard to do in an emissions testing area. Two of the setups I saw were rear outlet with just mufflers at the rear- the other one was side exhaust- forget what he did for mufflers.

The thing is, doing a true dual you can go much smaller on the piping size. Obviously some pipe hangs down below the floor board- but so do all people with side pipes, people with cutouts, etc etc. I mean there are people that daily drive with side pipes on wbodys- and the whole pipe is hanging below the floor pan and is running almost perpendicular to any objects in the roadway that may hit it.

I really always have dreamed of doing true duals on my GXP- just so it doesn't sound like a truck through the single exhaust.

I'm looking for advice on how to make my 02 monte ss sound nice (deep, powerful, masculine, strong) without being too loud. I only want a little sound. Can someone suggest a few ideas please?

Also... Can someone please give me advice on K&N cold air intake system? I'm very interested and want to know more about it. Best and cheapest place to buy the system, advantages to the system, easy do it yourself? Thanks!

It's terrible, the heat shield is a joke, there is no cheap place to buy it, it sounds good (only advantage) very easy to do first mod.

zzperformance.com sells one called the wizaired, much better.

coldairinductions.com actually has one for the 3800 now, and looks like a really good system too.

thanks a lot bud. so you really think k&n isnt worth the money? i really appreciate your advice but i love the way the k&n sounds and its almost an automatic 13+hp. what should i do?

The wizaired and the coldairinductions kit give the same HP, but when your engine is hot it won't heat soak like the K&N

Also, it's not really 13HP, it's maybe 13hp CRANK, which is only like 2 to the wheels.

really, CAI has one! Nice catch Mike......:D

lol yes, a good find Chris ;)

I am experiencing a rotted resonator with holes and leaks.

My uncle is a mechanic and said he would put a straight pipe in for me ($50) and there would be no sound change (supposedly, he does speak from experience tho and also is hard of hearing lol).

He said another option would be replacing the resonator with an aftermarket one ($100 installed).

Currently my exhaust is stock and I've always wanted a borla exhaust with some nice deep rumble. I have a friend who wants to dump a brand new system for my car on me for only $400 (plus my uncles install).

Additionally, should i do a u-bend delete while im working there? is there any purpose to either keeping it or deleting it?

Is now the time to upgrade? Should I just straight pipe it? Exchange it? Idk what to do. Any advice would be greatly appreciated. Thanks in advance.

bump^^^^^

3" downpipe with cat (just to reduce smells of exhaust and meet most emission standards), and ubend delete. There back, 3" straight with high flow mufflers of your choosing. The car sounds horny without mufflers but it will be too loud for most.

While you are in there, you may want to consider headers or a powerlog.


I want to add my 2 cents about removing the old exhaust bolts. Those bolts are tight and rusted. For those do it yourselfers, don't use WD40.


Penetrating Fluid
I used a combination of acetone and cutting fluid (1:1) to get the bolts penetrated. After sitting for an hour with that stuff sprayed on, I tried a bit of back and forth (tightening and loosening the bolts), they came off with no trouble!

For the heck of it, I tried one bolt that was easy to get to with just WD40 and it did sweet nothing but smell bad. The bolt right beside it had the acetone and cutting fluid and it worked great. We're talking the difference of about 200lbs or torque to about 50.


Vehicle Lift
I don't have a lift so this was all with one side of the car lifted with the jack and one jack stand which left about 3 inches to spare to get my arms through. My second tip: Lift you car as high as she'll go. Most ramps are too steep for our low cars and the lowpro ramps don't get it high enough. Get some jack-stands and a hydraulic jack or find a 'friend' with a lift (by far the best option)


Use the Right Tools
For the most part, you should be able to get away with a couple of different sized extensions, a socket set (it was 1/2" socket for the 2 manifold side bolts and 9/16" for the cat back bolts), a breaker bar (super handy for the first turn of the cat back bolts IF your car is high enough). I used a impact ratchet to get the bolts off quickly but I used general non-power tools to get the bolts loose.

O2 Sensors
Don't forget about these. Disconnect them so you don't damage the wires when you pull out your downpipe. Remember, there are 2 of them. One at the front and one at the ubend at the back.

Have an Escape Plan
One day many moons ago, a car fell on me when a passing vehicle side swiped my car I was working on. The driver didn't stop but a neighbour saw me. He was able to call 911 and get the jack to get the car off of me. I broke 3 ribs and could not breath but before I blanked out, I was reaching for my cell phone to call 911. Problem was, I took my cell phone out because I didn't want to lie on it while I was working. I grabbed and grabbed for it hoping it was under the car. I can't tell you how many sockets I was able to pick up. Have your phone near you or work with others around you. I wish I did. I'll rent a shop before I work on my car near other drivers again (that includes parking lots).

Don't do Stupid Stuff
Common sense: Don't rest a hot worklight on the plastic parts of the fuel rail. It will melt some good ole parts you don't want to melt. Don't jar the car too much with it on limited support (ie: stock jack). Those bolts will take your efforts and your car may shake a bit too much for your jack. Use the proper equipment. Swear all you want. It helps past the frustrating parts.

FINAL TIP
Take it to a shop. If I had only done that, I would have saved a bunch of time and done less damage. Yes, it is only 4 bolts to get the downpipe out but it's also 2x O2 sensors, gaskets, retainers, etc etc (actually, that's about it) but a shop is prepared for most every situation that you are not prepared for. Also, they can work really fast under the card with it on a lift so the charge out will be tiny. I'm talking <$50.

And if you have any old head bolts they work good for exhaust

I would go with borla.

What me dad did on our old work truck is drill a hole in the back side of the cat and with the exhaust still off floor the engine. It blows the internals out of the cat. Put exhaust back on and bingo. You look like you have a cat but noone is the wiser. Sept emissions ppl.

You guys realize this thread is super old and basically just a reference thread right?

yep
he never got an answer so 5 months better then nothin