Right now Ive just got the 40 series replacement muffler. Ive been looking to upgrade to a cat-back. The shop that sold me the 40 series is offering me a discount on the American Thunder System since I bought the other one from them. Has anyone used this and what type of gains did you get?

 

There have been number floating around that the Flowmaster catback is the worst flowing catback for LS1.

I do like the sound of the Flow, though, but I would still suggest getting a Hooker: nice sound, good flow and very nice price (~$270.00). If you like your exhaust very loud, then you should go with Loudmouth, or some similar setup.

If I ever decide to put a catback on my car, in the light of the current information available, it will defineteley be Hooker.

However, I now have cutout and a Flowmaster muffler and they are enough for me. I am also adding an electric plate for the cutout for more convenience.

TS

 

What exactly does a cut out do? From what Ive heard, theyre obscenely loud.

 

Fu*k ya they are!!!

I have the American Thunder. I didn't install it but the pervious owner did. It sounds awesome but not sure how it flows. I would of gotten somethinh like Loudmouth or Hooker

 

Cutout is just a simple Y-shape pipe which is welded on your I-pipe, usually just before the rear axle because.

When the cap is on, the exhaust gases go the regular route, i.e. through your muffler. When you take the cap off, the gases do not go through the muffler but are dumped through the cutout. In other words, you do not have a muffler at all and it is loud.

With electric valve, you can adjust the opening electronically from inside of the car. Very convenient, I would say. Otherwise you have to always unbolt the cap from the outside of the car.

I am pretty sure you will get the best performance gains with a cutout and not with a catback. And it definetely is LOUD.

TS

 

where is a good place to get the electric cut out and where to get them installed? I can do most things myself, but welding is not one of them . About how much does it run? I've been getting piggy problems recently so I'm not too big on getting a cat-back right away on my next car.

 

flowmaster flows HORRIBLY......the reason it sounds the way it does is because its engineered for tone not performance...
LT1 go with Corsa exhaust for sound and performance (expensive route) or hooker for a little less sound and good performance (cheap route)
LS1 cars sound great with the SLP loudmouth for only about 300 bucks and also very good with Borla for about 7-800.... performance wise no catback can touch the loudmouth becuase it doesnt use a muffler at all...just a resonator tube.

cutouts can be fun too... INSANELY LOUD WHEN OPEN especially on an LT1 and able to be used wityh stock exhaust for NO sound when closed....i think the company is called flowtech or flo-tech or something like that...

 

Yep, thats why it's, "Flowmaster, the sound of performance."

Never says anything about just the performance

 

There are plenty of manufacturers for the electric cutout valves: McCord, QTEC and DMH, just to name a few.

I am ordering my electric cutout valve from McCord (MPP2). After doing plenty of research I've come to the conclusion that they are, if not best, at least as good as any other out there.

But first you have to buy the cutout itself. Flow Tech is the one most people are using. It is welded on to your I-pipe, just before it goes over the axle. If you take a look underneath your car, you know what I mean.

After the cutout is welded on, you can bolt the electric valve to it and run the wires to the cockpit and install the switch. Pretty straightforward and simple installation.

There have been many posts about the electric cutouts in the past couple of weeks, so do some searches here and you'll find plenty of info.

TS

 

I had the american thunder system, i put it on when i first got my car... I didnt like the sound, it was to quiet and didnt have any type of a deep rumble to it at all. i really think its one of the quieter mufflers on that catback... But i wasent happy with the sound, i ended up getting a cutout. But thats personial opinion... I later bought a Borla adjustable and then an SLP Loud Mouth after Borla so on two comparing pertformance... The Borla Tips look ten times better then the flowmaster chrome slash cut tips as well, but then again its personial opinion. So now on to performance comparision.

While i had the flowmatser i was running 13.3 to 13.5 on motor consistantly... After i put on the borla i was running 13.0-13.20s consistantly. It was obvious the borla performed better. Id rather shell out the extra $$ for a borla instead of getting a flomaster. I didnt quiet like the sound of Borla.. So i bought the SLP loud mouth...
Loudmouth Vs. Flowmaster, performance wise... I havent ran on motor yet to compare Borla to L/M. But my nitrous passes were two tenths quicker then when i had the flowmaster for all its worth to you... Test results showed my car ran two tenths slower with the flowmaster catback.

 

on my LT1 i had flowmaster first-single exit to the left-and I liked it better than stock but it was UGLY so I replaced it w/ borla and could not be more pleased with sound and performance. Except that borla fits like a bloddy glove on OJ.

 

What type of gains performance wise will I see from a cutout?

 

Im having some difficulty finding a retailer for this MPP2 or any other for that matter. Where did you find the info for yours?

 

Here you go.

I don't think there are any retailers selling it... Therefore I'm going to order mine directly from McCord.

TS

 

i've read that the cross-flow mufflers in general (single inlet, opposite side outlets, like oem) do not flow well. but with our cars it's popular because everybody loves the look of dual tailpipes. personally, i like the single in, single out setup with the single tailpipe hidden. i have this setup on my '84, but my '98 has the flowmaster american thunder, which sounds good but probably flows like crap. the mufflex systems use the single in/single out setup on their 3 and 4 inch systems.