hey fellas i have a 89 trans am...im going to put a vortec motor in out of a 99 tahoe..w/mods of course..the particulars are being worked out lol... so i was wondering is it possible to to have straight pipe going back to flowmaster exhaust? the way i bought the car the exhaust runs down passenger side to the flowmaster

 

Most people dont run stright pipe down the middle of the car because it mostly will bottom out over a speed bump. What im going to look into is you have a Y-Pipe back to a muffler, and thats in the stock location. Running long tubes could bottom out depending on how low your car is. What you could do is if your wanting a full exhaust is custom make your piping to where you have two pipes side by side running down the stock location and then splitting into two flowmaster mufflers. You might use a x pipe.

 

Is that the only possibility on the 3rd gen? If it is cool no issue just was wondering. And using an x pipe that's when the pipe gets to the rear for stability?

 

You can run pipes straight down the driveshaft tunnel, its been done. But you have to watch your ground clearance, particularly around the transmission crossmember. You also have to watch clearance with the driveshaft and pipe diameter as well. Its definitely a custom job. There are dual kits available that follow the stock routing(I just installed one on my Camaro last winter), but none that go straight down the tunnel. I would HIGHLY recommend a driveshaft loop as well. You don't want a broken U-joint causing the driveshaft to flop around and destroy your exhaust pipes.

An X-pipe, H-pipe, or crossover pipe is used to balance the flow of exhaust gasses through the pipes and helps with scavenging. Its usually mounted in about the same location as the stock catalytic converter if you're following the stock routing. It also helps to even out the sound pulses from the tailpipes, resulting in a more constant rumble than a putt-putt-putt type sound(sorry, don't know how else to describe it).

 

Makes sense I did prety well in physics and how sound travels lol...ok well how much would a custom job like that cost in general? Is it that difficult as far as pipe bending?

 

I'm in the same predicament with my car. but I was dumb enough to go out and put in Subframe connectors and forgot to incorporate that with the exhaust. I also have a larger oil pan too. I called up a local exhaust specialty shop and they told me that dual exhaust can not be put on it's not applicable. Than told me to stop by and drop the car off. Suspicious... I think it still can be put on. Call me stubborn but I have a will damnit lol.

 

duals are possible, but take a bit of work and fab to install without loosing a lot of ride height. They are also not emissions legal anywhere, which would be an issue if you have inspections.

In reality the only "benefit" they have is sound, thats about it. You can fit up to, and probably exceeding a 4" single in the stock routing and without loosing any ground clearance. Much easier to install and will support a lot of power. For that matter a stock style single 3 will easily support 500+ horsepower with little loss, and have seen it support just of 600 WHP without any massive noticeable loss.

FWIW, there is a sticky at the top of the page with pics and info on duals.

 

One of two possible translations:

Translation 1: Dual exhaust is not legal per emissions regulations, but drop it off and we'll see if you're exempt and if it will fit.

Translation 2: Dual exhaust is not legal per emissions regulations, but drop it off and we'll overcharge you for a stock exhaust system which you apparently need anyhow.



That being said, subframe connectors typically do interfere with dual exhaust setups that use the stock routing. I took that into account when I installed mine. Just one of the reasons the kit was not a bolt-on installation for me.


To the OP: Sorry, I have no idea how much a shop would charge to make one for you.

 

Member is doing an engine swap, I don't think this applies to their area... I mean otherwise they wouldn't be doing an engine swap from a Tahoe, or would they?

To OP, do you or don't you have emissions in your area? If you do, you may want to look into the guidelines as far as engine swaps... Here in California the only legal swap there is or was is from the same Body Style, so anything from a newer year of your car, now there is the LS3 Erod emissions legal package, which I believe does call for dual exhaust... by the information I have been gathering, I will need a custom made crossmember, the panhard bar will need to be relocated so that the duals can be installed with a bit more ease over the rearend, at this point I've been debating on bullet mufflers, SLP LM2, Moroso Spiral, or Flowmaster Hushpower... I still have some time to narrow down my choices...

 

Since when is dual exhaust illegal in Pa?

 

If you have to pass a visual or tailpipe emissions inspection in PA it is illegal because it is "not a factory-authorized configuration." Basically it means that its illegal because the EPA never certified a Thirdgen with that type of exhaust. Also, the kit that I used does not leave room for catalytic converters to be installed.

HOWEVER, not all counties in PA do emissions inspections(sux for me cause I live literally 500 yards from the border of one of those counties). There are also exceptions for vehicles registered as classic or antique. There is also an exemption for cars that have been titled for at least a year and are driven less than 5k miles/year.

 

on a 3rd gen its illegal everywhere in the US, its not the factory routing and is tampering. Its a federal offense.

whether you get away with it, or have any kind of "real" emissions inspection is a different story.

 

I dont see what it doesnt have to do with the OP, engine swap or not. If you want to get overly technical, the only engines you can legally swap in to the car are ones offered in the same platform (fbody), from the same year or newer car of the same platform. Maybe you can get away with a 4th gen drivetrain, its still technically a fbody.

Exhaust would be the same deal, if the cat is not in the stock location, its wrong. If you have duals, the cat wont be in the stock location, so its illegal. You may or may not ever have an issue depending on what state inspections you have.