Hey, I'm thinking about a winter project. Which would be the better choice as far as sound and power, and most importantly, the fun to drive factor? Pacesetter headers or GMMG exhaust?

I'm thinking that the headers will give me more bang for my buck, but they're a pain to install. Plus, I already hand ported my exhaust manifolds when I had them off for a head gasket install and I have the Stainless Works Y-pipe, a pretty nice piece. Also, I drive in the winter, so Pacesetter headers/y-pipe will rust eventually being non-stainless.

The GMMG everyone says great things about, but yes they're pricey. I've already got a Flowmaster muffler that I think sounds good. My last Flowmaster lasted about 5 years before it rusted out. I would probably just have the exhaust shop install this, saving me the huge headache.

I priced both of these out and they come up within a few dollars of each other. With the Pacesetters, I would need to replace the engine mounts, buy their Y-pipe (or go true duals dumped before axle), and I would want to buy new dual cats to go with them. Also, O2 extensions and header gaskets. Just when you think Pacesetters are cheap, it starts to add up.

Your vote? Thoughts?

 

Performance vs sound. Tough decision. Can you buy stainless headers?

The GMMG is a pretty loud exhaust system. LT1's even more so. Might want to see how loud you like it before adding headers. Particularly if this is a daily driver.

 

I don't think I want to shell out the bucks at this point for stainless headers. I've been eyeing the ones from Stainless Works, even though no one on here seems to use theirs. Everyone talks about Kooks. Kooks cost even more than Stainless Works and don't LOOK any better.

From what I can understand, the GMMG will be just slightly louder than my Flowmaster. I could live with that.

 

https://www.camaroz28.com/forums/sho...MG#post4855062

I did some before and after with the Flowmaster (no cat) vs GMMG (with cat).

To give you a perspective, the Flowmaster was 88 dB at WOT at 5000 RPM. The GMMG was 88 dB at 4000 RPM and 90dB at 5000 RPM.

 

Thanks for the info, Gord's Green Z28. I had read this link before, but I forgot that you had tested the Flowmaster WITHOUT a cat and the GMMG with.

I have run my car w/o the cat and the Flowmaster, it's pretty loud, maybe too loud.

 

The numbers tell most of the story. But a few added bits help.

At idle, they're pretty much the same. The GMMG has a slight bit more volume. When I started the car after installing the muffler and let it idle, I thought hmmm this is the same.

On the highway at 55-70 mph, the GMMG is louder when you're on the gas and quieter when you're off. The Flowmaster is the same all the time. Doesn't really change that much with tiny bits of throttle or coasting.

When you stomp it, it's all GMMG. If you plan on traveling at continuous periods of time at 75+ mph, either will be loud and annoying after awhile.

The GMMG really isn't a muffler as much as it is a sound tuning device. It basically turns the cat into your muffler.

 

I traveled all the time in my old car (Pacesetter LT's, ORY, GMMG) and it wasn't a big deal at all. That was a 3.42 car.

My new car is Hooker LT's, ORY and GMMG with 4.10's and a cam, I drove the thing all the way back from Chicago and didn't think it was really too bad. The gears were louder than the exhaust!

I would get a GMMG, they have a distinct sound and I have not heard one bad thing about them from ANYONE. I always get compliments on my exhaust.

FYI, too bad you didn't post this about a month ago, I sold my GMMG for 400 bones.

 

97formulakid, what kind of RPM are you pulling on the highway?

With my 3.27's and automatic, I'm running about 2300 RPM at 75 mph.

I was doing 3700 RPM in O/D awhile back and it was 105 dB inside the car (C weight), windows closed, radio off. Crazy.

 

I keep hoping someone on LS1Tech is going to get a group purchase together on the GMMG. Someone that works for GMMG says they normally have a group purchase every year around Christmas.

 

Keep watching. I bought mine off LS1 Tech last year at Christmas time. It was so popular they ran out of exhausts. Took an extra 2 weeks or so, but no big deal.

 

In the old white car with 3.42's I was pulling around 1700 RPM. Now, with the new car, 4.10's, I was around 2300 coming back from Chicago at about 75.

 

There is now a group purchase going on at LS1Tech for the GMMG Exhaust. I hope it's OK to announce that here. If not, I'm sorry. Just delete the post.