The Ultimate 3.8 Exhaust
 

[Note: Sound at the bottom of the post.]

Normally, when one hears of a V6 F-Body owner putting an exhaust system on their car, the initial reaction is to run, cringe, and hope they aren't within immediate earshot of the offending vehicle.

If GM's current generation of 60* V6s do not sound 'good' with after-market exhaust, the GM 90* 3800 V6 sounds absolutely horrible... if done improperly.

Unlike the smaller engines which just don't have the displacement to really have a chance at sounding aggressive and beefy... just limp and whiny... the 3800 V6 has a full 231 cubic inches of displacement; and would all the small block V8 owners stop laughing now, please. 231 cubic inches, or 3.8 litres of displacement. That's a fairly big V6, especially when there are V6s on the market with a mere 2.5L of displacement.

The problem lies in the initial exhaust setup. You've got exhaust manifolds that make a boa constrictor feel like a 'firm' hug, a y-pipe with more ripples and rolls than a new applicant for Fat Camp (yes, a South Park reference), and a cat-back setup that offers nothing more than a means of quieting down the unpleasant 'noise' made by the previous components.

And to top it all off, the GM 3800 doesn't exactly make the most pleasant noise anyway. Most have compared it to a chainsaw on steroids. Others feel the engine forgot to take its steroids entirely. At least the 3400 sounds like a boat motor, so it sounds like it belong in some sort of vehicle, whether it be marine or otherwise. Many try, and almost all of them fail to make the 3800 an aggressive sounding motor with no rasp up top. This is because of the word 'performance'.

A good exhaust system must both perform well AND sound good. Try researching exhaust flow, and you will find the straight-thru mufflers are excellent for CFM. You will find chambered mufflers to be the lowest. The key to the exhaust setup is the Flowmaster 80 series muffler, which is one of the lowest flowing aftermarket mufflers available, despite their reputation. Flowmaster is about sound first, and performance as an added benefit. Remember that compared to stock, an I-pipe with a potato stuck in it would flow better. The Flowmaster is an excellent performing muffler in both sound and lessening the restriction.

Flow isn't the be-all end-all, especially where our engines are concerned. 3800s like a bit of backpressure. Too much, and you'll have a top speed of 30 MPH (this happened to me when my catalytic converter died). Too little, and you'll find yourself putting your foot into the throttle a bit more than you'd like... just to get the car moving, due to the apparent lack of torque you've created.

Remember those manifolds I was talking about? They're junk, toss them. Or better yet, sell them on eBay, because there are actually fabricators around the continent that could quite possibly have a use for them. I recommend Pacesetter Headers for the 3.8 F-Body. Install was a breeze, with no leaks. The flanges are excellent, and very durable. They also come with their own Y-pipe that will mate to the existing catalytic converter. And for your pollution controlled boys, yes, there are already provisions for the EGR.

The next step is a mix of personal choice or state law, depending on area. For my purposes, I removed the catalytic converter entirely, and used an oxygen sensor simulator to fool the PCM into thinking the cat was still alive and kickin'. Emission controlled states will need a catalytic converter that passes state inspection, either an OEM unit (booooooo) or a high-flow unit, such as CarSound or Catco. I recommend using the LS1 part numbers for ordering these units, as you'll need them in 3" in/out diameter. Again, I run straight pipe.

And finally, the most important part... the cat-back system. This is where the whole thing really comes to life. I went with a 3" custom built mandrel bent intermediate pipe, Flowmaster 80 series muffler 3" in, and dual 2.5" tailpipes with stock Z28 exhaust tips. If getting a system custom made is too much hassle for you, or you know of a Flowmaster dealer you can get a price break on, the Flowmaster American Thunder 3" catback for the LS1 F-Body will bolt up, and is essentially the same thing.

All these things come together to create the Ultimate 3.8 Exhaust system. Enclosed is a video (albeit a poorly filmed one) that, more importantly, has good enough sound quality to hear the exhaust system in action... both at cruising speed, and during acceleration.

Click here to watch/listen/learn.

Pros: Aggressive sound with no rasp, in gear deceleration is orgasmic, could almost pass for being an 8 cylinder in some instances, great performance both in the city and on the highway.
Cons: Neighbors may have trouble sleeping (Flowmaster flows the least, but produces one of the highest volume levels... you didn't buy a sports car to be stealthy, let's be honest.), some states do not allow such a level of modification (regarding catalytic converter and headers; though sound levels should not be an issue), and can be expensive if you don't plan your course of action.

Word to the wise, get everything installed ALL AT ONCE. You do not want to keep paying an exhaust shop to install things in bits and pieces.

Very nice write up....sounds like good advice.

that sounds **** good man, nice write up and good job

cool. the wind at first sucks in the video but the last stomp you can hear it well. good job.

i believe it is the lt1 from 93-97 or so that will bolt right up. The ls1 wound need some exhaust shop help to get it on good as well as a new s pipe. That is at least how it is with the magnaflow. I also disagree with the manifold statement. While pre 2000 log style manifolds would be much better replaced,the 2000+ are not worth upgrading to headers. They actually flow very well and performance wise wouldnt notice a difference. Sound wise, they may be worth the headers.

Also, mine sounds like a beast 99% of the time. Better than many of the v8 camaro's around here. The bullet makes a huge difference. I do have to give more throttle to get going well due to my full 3" set up (which is overkill for a na v6 imho) , but with the higher range power mixed with the 3.73's i am putting of as well as a future turbo setup it will fix the volume problem as well as putting the power right where i want it. Still a good article :)

LT1 or LS1 Flowmaster catbacks both fit fine, there is really no big problem with using either.

The log manifolds from the 99 and previous 3800 F-Bodies are garbage, and while the 2000+ manifolds flow slightly better, you are still missing the point I capitalized on... an exhaust system should sound good AND perform well.

I've had a full 3" setup, and it's not overkill if you do all the supporting modifications. And even though mine sounds beefy, a 3800 will NEVER sound as good as an LT1/LS1. Even I will admit that. Look at all the work I had to do just to not make it sound like a chainsaw.

yea that sounds pretty sick at the end there stompin on it... good write up

Thanks from the V6 crowd! Nicely done :)

I have Pacesetter ceramic headers and y-pipe, Magnaglow 3in hi-flow cat, Flowmaster muffler and mine sounds pretty good.

you have a 6?



old thread

yep

Yah, look at his engine bay is a simple way to find out.

yes, old thread digging day.

I can't hear it... But nice write up.

Probably because the thread is a year old.

lol def an old dig up..

i have a rare flowmaster v-force series muffler made specifically for the v6's.. with no cat and stock headers and it does sound pretty amazing.. esp below 3000k has been mistaken for a v8 many many times.. im waiting on the pacesetters and a new cam will finish off the sound for me