Exhaust Experts Please

[Buick Beginner]

Gentlemen,
Good evening. Can we talk exhaust for a minute? My car has a THDP with the dump. From there the exhaust splits through what I think are standard "run of the mill" turbo mufflers. The system is all 2-1/4" pipe and not mandrel bent. Now, based on that let me pose question number one:

1. Can I gain some E.T. by working over my exhaust system?

I decided I'd call around today and talk to some local exhaust shops. One I spoke to said he had done turbo Buicks before and that his suggestion was 2.5" pipe, no bigger. He said, "If you go 3" it will kill your top end". I thought the goal was to get rid of the spent gases as quick as possible. Which brings me to question 2:

2. Is a dual 3" pipe set up too big for our cars?

Next up, are the after market systems really that much better than the local muffler shops work? It seems like you can do better on the price by having a local shop do the work. So, last question:

3. Is the ATR system, the Hooker system, and all the rest of the high dollar deals worth the extra money?

Thanks for the replies , I know this conversation will bring some interesting responses. - BB

 

[Russ Merritt]

Can you gain ET? No, your at the track, you have a dump, use it. Through the exhaust, it would help.

Dual 3" ? For what? My opinion, waste of pipe. Put em on a Mack!

ATR systems are sweet. If the car is nice, I would get one, The single shot! (I'm over the dual pipe ego trip)

I bet a muffler shop (a good one) could do a pretty good job, not better than mandrel bent ATR stainless.

Buick beginner, you are GREAT at asking questions and doing research! I bet you'll do well. Good luck!

 

[Russ Merritt]

I forgot to say, I'm not an expert!

 

[Buick Beginner]

Thanks Russ

The beat goes on.

 

[musclecar neal]

The ATR stuff sure is sweet but costly. For most guys the hooker 2.5 mandrel bent system is the way to go. The ATR single shot can be loud and drones at speed. The hooker system is built very well and I don't think a local shop could do a non mandrel system for less and believe me the mandrel bent pipe flows way better than compression bent pipe. I like the way the hookers sound. No need to go dual 3" as your downpipe is 3" so that is the most restrictive portion. I know of guys going very fast on the hooker system capped up. Buy the hooker system from summit the cheapest place to get it and install it yourself.

Hope this helps.

 

[turbodave231]

I like the ATR systems. I have had the SS 3" single system on my car (s) since 1994. Still looks like new. The 3" is drony but tolerable.

I have installed a couple 2.5 ATR dual systems with THDP's on customers' cars and I think that is the best all around street system. Of course the dump comes off at the track so the exhaust system is just along for the ride at that point.

Buy quality! You won't be sorry.

Dave

 

[gnxtc2]

Do what I did. I have the Hooker system. The Hooker mufflers are a piece of crap. Go to the Hooker website and get the measurements of their mufflers. Then go the Magnaflow website and find the same configuration and size muffler. I have done this and it was an easy swap. I believe I had to cut off an inch or two off the y-pipe.

I don't have the Magnaflow muffler part number handy, but e-mail me and I will get for you.

Billy T.
gnxtc2@aol.com

On Edit:

Oh, I forgot. There is a difference on size of the exhaust system. I have the Hooker 2 1/2 dual system with the Magnaflow straight thru mufflers. I also have a 3 1/2" THDP. The car was put on a dyno. Pulls were made with the dump capped and uncapped. I lost HP with it capped. I don't have the dyno pulls in front of me now but think there was a 25-50HP loss capped. The dyno operator is a known Stage 2 GN builder/racer. He said don't think by adding the dual 2 1/2" pipes equals 5". You also have to take into account the distance and bends the exhaust has to travel to exit. He recommended that I go with dual 3"

 

[Tim Riecks 6]

I run the Hooker 2 1/2 and am very happy with it. It DEFINITELY has a drone at 60 mph (and around 2200 in each gear), but I am running with NO MUFFLERS, and also no catalytic converter. It is definitely not too loud in my opinion and also in the opinions of quite a few people I've asked. Has a really sweet sound, and you can hear the turbo spool so easily, even with very light throttle.
Before I had the Hooker system the stock exhaust was still on, minus the cat. The crossflow muffler blew out so I rigged up two small mufflers in its place. Didn't seem to make much difference. When I put the Hooker system on and got rid of the restrictive bends, WOW! Granted, a shop bent system will be better than a stock crimp bent system. But for the price of that compared to the Hooker system, you definitely can't go wrong with the Hooker system, especially getting mandrel bent for about the same price.
The system does sound good with mufflers also. I had to run that way for a couple days until I got the fix-it ticket taken care of (apparently a cop thought it was too loud contrary to everyone else). I was going to leave it - the thought crossed my mind for about a half second, but I wanted to have the awesome sound of the turbo spooling through the exhaust. I'm addicted to that. If I knew of someplace to post videos I have some clips with drivebys of my car. I could post them.
Sorry so long, just trying to help out. Good luck with everything.
BTW - also got a vid of me re-blacking portions of a parking lot donut and figure 8 style . If only I knew where I could post them.

 

[Buick Beginner]

Thanks for the replies

Very interesting.

 

[TurboDave]

Re: Thanks for the replies

Originally posted by Buick Beginner
Very interesting.

You've received a lot of good advice, and I just wanted to jump in with my .02

Your muffler shop guy is still living with N/A rules (normally aspirated) obviously. He may have worked on Turbo Buicks but he certainly doesn't fully understand turbo cars at all. The thought that opening up the pipe larger will kill top end is simply NOT true. Not on a turbo car anyway. While it may be true on a N/A car.

Number one exhaust rule on turbo cars: Reduce the downstream backpressure to as near zero as possible. Zero being ideal, but not very practical (for noise, etc).

The dual 3" system from ATR is my favorite system. I've had the single shot systems, and didn't like the noise level.

 

[Buick Beginner]

Very Good

Thanks Dave.

 

[strikeeagle]

Simple proposition. There are only 2 systems to consider. Both are ATR. Both are SS. One is the 3" single shot. It's for racing. The 2nd is 3" duals. They're for the street.

The rest of the stuff is garbage - don't fit and/or don't sound good and/or rots.

Now how hard is that?

 

[77tech9]

electric exhaust cutout....

highly recommended

 

[turbojimmy]

I have a Torque Tech 3" "aluminized" system with dual "turbo" type mufflers. It's still in great shape, but the problem with this system is that there aren't enough attachment points. It hangs a lot of weight off the "cat" and has a couple of small brackets at the back of the mufflers to hold the back of the system up. It's always sagging and I have to tuck it back up at least a couple of times a year. Both mufflers are beat from snagging raised manholes and other things an exhaust system should clear.

I was thinking about the ATR 3" crossflow - stock location muffler with dual tailpipes (I really like the dual tailpipe look). Will this be significantly louder than the dual mufflers? The dual mufflers are kind of loud and I think I'm at a point in my life where quiet wouldn't really be such a bad idea.

TIA,
Jim

 

[strikeeagle]

The fit of the crossflow is very unforgiving and it ties up the whole back of the car, just like the OEM muffler does.

Something to consider...

 

[salvageV6]

I've got the ATR crossflow on my GN.

Sounds great deep and low, not overly loud just deeper than the 2.5" duals on salvageV6 the WE4.

Anyway I thought it would get in the way a bit for things such as the HR Parts swaybar install and everything but it doesn't.

Swaybar and arms fit in there fine and I also fit a 3.5" aluminum driveshaft in there that wouldn't have fit with the duals.

Even did a gas tank swap in it with the muffler in there.

It's a good system especially since it's stainless.

Fitment was tricky but once in place... no issues.

Bought mine used it was mint and holds up real well.

 

[Buick Beginner]

Thanks

Lots of good discussion here gentlemen, lots to learn. - BB

 

[strikeeagle]

Salvage lies. He knows it jams up the whole back end of the car, and wishes he had the dual 3's...

 

[Tim Riecks 6]

Back to what was said about not wanting to go with too large of pipe...
I've heard this a couple of times too. Then I have to explain to the people that in a turbocharged car the turbo is already placing a restriction in the exhaust flow. The more free flowing you have after the turbo, the better.

 

[salvageV6]

I lie all the time but not about ATR stuff.

True Dual 3" would be nice but I doubt the 3.5" driveshaft would fit.