I have been looking at the various cat-back systems available for an '01 Blazer 2dr 4.3/Auto 4x4 (Dynomax/Magnaflow/Gibson) and they are all single outlet. Gibson makes a dual outlet system, but not for my Blazer. Is there a manufacturer I have overlooked that makes a dual outlet system, or is this going to end up being a custom job for ther muffler shop?

 

No company makes a dual exit system for 2drs that I am aware of. The dual exits are either for s-10s or 4dr Blazers If someone knows of one though by all means correct me. The dual outlet thing is going to be something you get done at a local shop with the muffler of your choice. May I ask why you want a dual outlet exhaust? If for looks then check into a shop doing a custom job for you. If for performance/sound/fuel economy/whatever reasons, then there really is no distinct advantage to doing dual outlet vs single outlet.

 

The main reason I want to go with a dual outlet system is to reduce back pressure versus a single outlet system. The tonal difference and looks are secondary.

 

No benefit in that either. We've discussed that issue in depth before. These exhaust systems were designed as single outlet based on the engine requirements. If you wish to have a dual system, that's fine, but do not expect any difference in performance.

 

I know a guy who had a custom dual exhaust made for his 2nd gen blazer. Honestly it sounded like crap. A single exhaust sounds better, but not much. No real difference in performance. Sorry to say, but if you want it to perform better you should do something with the engine. Dual exhaust isn't going to do much.

If you want it for looks, that's a different thing. It does look cool but that's all it's good for.

 

I respect the opinions of all that have replied, but I believe there is a benefit to a dual outlet system versus a single outlet system. I agree that a dual outlet system (as the only modification) will not produce much of a difference, but combined with other modifications the result can be quite significant. After all, an engine is nothing more than an air pump. The easier it is to get the air in - and out - of the engine the better it will perform. The engine needs to be able to 'exhale' as freely as it can 'inhale' or you won't see the full potential of other modifications.

I was just curious if there was a manufacturer that offered a dual outlet system for the Blazer since they seem to be available for numerous other vehicles. I wanted to see if I could make life a little easier for my friend down at the muffler shop. Oh well, he'll just have to fabricate one from scratch.

Thanks again for the replies.

 

look for 10 pickup dual exhaust cat backs. you may have to shorten the pipes just a little but its all the same thing

 

While an engine is a form of air pump, the design of an engine determines its suitability for dual exhausts. Take a look at the modern ones that have true duals (not just a split after the muffler, that's just for looks) and compare those engines to the design of the GM 4.3L. See the differences? The only way duals will help you is if you port and polish the heads, add headers, get a different cam, and change the tuning. But, hey, it's your money. Just do us all a favor and dyno your truck before and after the duals and post the printouts so we can see the increase in performance.

 

Again, I respect your opinion, and agree that additional modifications (in addition to a dual outlet exhaust system) would increase overall performance gains. The only thing mentioned I don't agree with is polishing the ports/combustion chambers - or at least not for a street engine. With the variable air/fuel mixture velocity of a street engine polishing the ports/combustion chambers will promote fuel drop out. Port matching and deburring is beneficial, but I leave the rough surface of the ports/combustion chambers intact. The rougher surface promotes better fuel atomization versus a polished surface. As far as factory design is concerned, with the exception of mega dollar exotic vehicles everything coming off the assembly line is a compromise and/or a cost cutting design. A perfect example of improvement over the factory design is the K&N CAI system. By allowing the engine to 'inhale' better a 7+ HP gain was achieved by simply installing the CAI - no other modifications were done. If a free flow exhaust were installed so the engine could 'exhale' better there's no doubt in my mind that addition HP gain would be achieved. Roush Performance has been designing and testing dual outlet (single in/dual out) exhaust systems for quite some time now. Their dyno testing has shown HP gain by simply swapping out the factory single in/single out exhaust system for a single in/dual out system on various factory stock vehicles - no other modifications. In fact, they have found that a single in/dual out exhaust system performs better than a true dual exhaust system because it balances the exhaust pulses and promotes better scavenging. You're right, it's my money and I really see no need to spend $300 for a couple of dyno pulls to prove my point. The info and results are already out there for those that care to research it.

 

judt buy a unverial dual muffler and custom make a pipe for the driver side