I've heard quite a few LT1 cars with GMMG on LT and ORY setups and it sounds absolutly amazing to me. Thats what I plan to put on my bird in the near future.

 

What set-up do you have on your LT1? Stock manifolds & cats? Stock engine internals? Have you ever listened to both systems outside the car?

I just don't understand how anyone could not like the DEEP sound of the GMMG at WOT...It amazes me how much bass it has up near redline (whereas the Borla gets high-pitched and a little raspy up top). Trust me, it may sound one way inside the car while you're driving, but it sounds totally different outside.

When I had the GMMG on my LT1, it was rather quiet inside the car (no drone) and noticeably loud when I floored it, but certainly not any louder than an open Borla (which is just basically the same thing as running an open cutout FYI).

To each their own and I agree...You won't have any problem selling the GMMG if you dislike it that much...But I'd stick some longtube headers + highflow cats on that car and never look back...

 

I have SLP midlength headers and Random Tech cat, Hotcam, 1.6 RR, 11.1:1 compression, PP, etc.
I've listened to them with the top down and the top up, revving it up in the barn, revving it up outside, standing behind the car when idling.

The GMMG (or I should say "My GMMG") has a deeper sound than the Borla only at idle, the rest of the RPM range the GMMG is just LOUD.
As far as sounding different outside of the car vs. inside the car....inside is what matters most because that is where I drive the car from


"Open Borla" that is the problem, I think too many people always compare something to an "Open Borla" which is what it is....OPEN I'm comparing the GMMG to a Borla with the block off plate installed, with 100% of the exhaust through the muffler.

My vote.....Borla

KO

 

Borla all the way!!

 

i've always loved my borla, but after the mac mids and then no cats and wide open i dind't really like it at idle. now after the cam i love it at any and every rpm.

 

KOsletten,

I didn't realize you ran your Borla system entirely through the muffler with the full-block off plate (you're right; most just run it wide-open like a cutout). Of course the GMMG system is going to be a LOT louder throughout the rpm range than a closed-off Borla! Did you expect the GMMG to be quiet?! But honestly, the way your car's exhaust sounds inside the vehicle sounds TOTALLY different from the outside. Have someone you trust drive your car down the street slowly and then again punching it...I truly bet you'll be amazed at the sound "quality" of the GMMG on your set-up and not just think it's only "loud." Make sure your hear it at WOT from the outside. But again, I cannot stress how different an exhaust set-up can sound inside from out. I used to think the SLP Loudmouth sounded great for the longest time on my old LS1 until I finally heard it from the outside...No thanks (it sounded like crap)!!! That's my point although I don't think you wasted your money though.

Regardless, I checked out your Formula and that is one really nice looking '95 (especially with the original black paint). Interior set-up is badA$$ too!

Good luck,

Mike

 

I just installed my Loudmouth, and learned something..................

The clamps with the kit DID NOT work for me. Before i installed my kit, i polished all my pipes to make them shine like a mo fo, and they did! Damn, they looked nice... Well, I think this added to the slipperyness of the finish, and the clamps could not squeeze tight enough to hold them in place. While i was un-decided what to do, i drove it for a couple days, trying to fix it everyway possible, but could not stop the shifting of the system. So, I ended up getting it welded on. The muffler shop guy says he sees this all the time, especially with the Stainless steel truck kits. He says the clamps just cant squeeze this strong Stainless pipe well enough, and the correct way is to just get it welded. (piece of mind). I did notice a significant sound loss once welded, telling me the system was leaking.. However, it sounded VERY nice when the clamps were on. It does sound the same welded, but not as loud. When i got home at night, the combination of wind noise/ exhaust, i found my ears to have a slight ring... This sounds bad, but just not used to the extra noise. Over 2,500 rpms with a load (driving) the kit just sounds mean as hell.. Idle is nice too! So is just revving it! The SLP loudmouth Modular kit is built damn good, Looks damn good (polish before you install (looks chrome now!) I have had soooo many compliments i will NEVER regret putting this on. after hearing this, there is no way i would look elsewhere for exhaust.. LMPERFORMANCE.com hooked me up with this kit, $315 and FREE SHIPPING! Great buy, and good service from this company. Thanks alot!

The only downfall to this kit is on COLD startup... When engine temp is under 100 degrees.... If you exceed 3,000 on a rev, or while driving, you will most likely hear some popping that doesnt sound too attractive... This is easy to avoid. Use common sense, and not floor the car when the engine is not warmed up. If you have an automatic, you have nothing to worry about, unless you are revving it in park, neutral. The M6s may hear it between gears if revved over 3,000 while cold; it will only last for 1 minute i would say running/driving time.. With every exhaust system, each have their own Cold start characteristics..

 

On my 94 z28, I went for the Loudmouth. I had stock manifolds and stock cat. It sounded great. So I thought "hmm.. gut the cat, it'll sound even better, right?" wrong. After gutting the cat, it popped and rasped on the highway major drone. So I bought a dynomax bullet to replace the resinator, cleaned up a little bit of the popping, but still very loud (obnoxious loud, not good loud) I eventually sold it and bought a SLP Dual/Dual. Much better, at the time.

Now I've got my 94 Formula with pacesetter longtubes ORY and stock catback. Too quite. I've heard nothing but good things about the hooker, and I've heard a couple, one on a stock z28, and another on a LT+ORY+CC306. And you just cant beat the price. $290 shipped on summit and jegs. Give or take a few bucks. Take that + some hitemp paint to paint the welds and you should have a quality catback for years.

 

hooker catback and gutted cat sounds mean as hell. Makes my exhaust smell really good too.

 

Same here. I gutted my cat and now it just smells illegal. I love it.

 

Stroker, big *** cam, long tube headers, dual cats through a Borla with a custom plate = sexy sounds.

 

love my Borlaz

 

just wanted to chime in here....i got an EDELBROCK catback on my car....i was out of money but wanted some sound. the stock formula **** was too quiet. i found an edelbrock only used for 2 monthes then the guy bought a loudmouth.
http://www.cardomain.com/ride/667186/4

here it is when i got it. 100 bucks. the y pipe is a random technolgy with gutted cats 2.5 inch to 3 inch. this system sounds great , really for the money it sounds great. deep tone all the way through the rpm range. i dont know how well it flows though but they do sound great and no one ever talks about them....when i get rich i am going to run a GMMG

 

I have a Texas Speed and Performance (TSP) exhaust. I have to say that I'm very satisfied with it, although I opted to have them weld the entire kit instead of using the clamps that came with the kit. And I chose different exhaust tips from the shop. Having a resonator sure does look cleaner under the car than the old stock muffler.

Cost: About $200 shipped.

 

You LT1 guy's have it easy.....anything sounds good on an LT1.

 

stroker, 12.5:1 comp, mild cam, coated long tubes, ory and magnaflow cat back! it'll make your ears melt!! i have run people on the street and if i get them at my bumper around 6k rpm they let off. when the first guy said it was so loud and that is why he quit i thought it was BS but the when like 5 different people did it then i knew i loved this combo

 

Not quite bro...You'd usually think that, but I've heard a few nasty (in a bad way) sounding LT1's...

It's just all in how you set up your car from the motor back...

 

am i the only guy that has an edelbrock??????????????????????????????????????

 

Just installed the Hooker catback on mine and absolutly love the sound. Quite at idle, absolutly growls at WOT. Cannot be beat for $290 shipped.

 

Everything except the LM in my opinion.