i have a pair of hedman hedders. i was told it was best to get a y pipe and a high flow muffler and have a turn down at the stock cat location. is that better than true duals or a cat back system? Basically what is the best way to do my exhaust system. 87 305 camaro TPI completely stock.

 

i have the headers y-pipe highflow muffler and turn down where the cat should be. i dont know what is the best but i love the sound of mine. btw i have all 3" pipe

 

That would be so obnoxiously loud for a dd. But when i first got my car going i ran the hooker 2460's and matching y pipe with a turn down/out in the "cat area". It sounded incredible, significantly quiter than open longtubes.

 

mine isnt a dd but it is a lot quieter than i thought it was gonna be

 

Which ones? They make both shorties and long tubes for our cars.

 

I wouldn't want the exhaust gases emptying out under the car like that. Especially when you're in traffic.

 

why? lots of people run dumps. If worse came to worse and the exhaust started coming in the car, roll a window down or turn the vents on. I dont see the big difference between that, or when the wind blows the stock exhaust back under the car lol.

 

It's illegal (safety) in every state that I'm aware of.

It also makes the floor pan a noise amplifier - if that's what you think is "cool", go for it. There are better names for it, though.

 

yeah the guy i bought the headers from he said it would be really loud and sound amazing. the headers are long tube but not shorties..they are about six years old he said but there are ceramic coated and have thick flanges. the guy said they were the off road version. the part number on the headers is 6847. but wat gives the most horsepower the turn down, cat back, or true duals

 

68470 is the Hedman # for non-emissions (off-road) shorties.

You need longer tubes than open collectors for best performance.

A full exhaust system makes more sense than any alternative thus far proposed for a stock 305 TPI.

 

you should be fine with a good flowing cat back. Can you take a pic of the headers you have? It sounds like you're a little unsure as to what they are.. There really isn't much benefit from true duals or dumps as opposed to a good cat back, especially on an otherwise stock 305. It would be decent if you're going for an obnoxiously loud ticket getter that runs 14-15's..

 

ok cat back should be fine...now what sounds better trues or cat back. here's the pic of the headers

 

True duals will always sound better. But it is alot of fab work (especially on shorties) and costs alot more. Also, good luck getting them over he rear axle.

 

HI, TOPRADMAN HERE. I STRONGLY SUGGEST A BORLA CAT BACK. IF YOU LOSE THE CONVERTER YOU COULD HAVE PROBLEMS COMING SOON. I AM ALSO IN THE EXHAUST BUSINESS AS WELL AS THE RADIATOR BUSINESS AND COMING AS SOON AS THIS YEAR THERE WILL BE A 50 STATE OBD2 EMISSIONS CHECK IN ORDER TO GET A LISCENSE PLATE. THIS WILL BE ENFORCED, AS I STATED, IN ALL 50 STATES. AL GORE GREENHOUSE GAS ISSUE AND GLOBAL WARMING. THERE WILL BE ALOT OF CATS BEING REPLACED IN THE VERY NEAR FUTURE. SOME HI FLOW CATS ARE NOT OBD2 COMPLIANT EITHER SO READ THE INFO ON ALL REPLACEMENT EXHAUST COMPONENTS. THE LAW STATES THAT ALL VEHICLES ORIGINALLY BUILT WITH CATS WILL HAVE TO BE IN THE "OE CONFIGURATION" FROM THE ENGINE TO THE CAT, AFTER THAT YOU CAN DO WHAT YOU WANT BARING LOCAL NOISE LAWS. HUGE EXHAUST ON A STOCK 305 WILL NOT PAY MUCH BACK IN HP GAINS...HOWEVER, I THINK THE BORLA SOUNDS ABOUT THE BEST. I HAPPEN TO HAVE A VERY SLIGHTLY USED STAINLESS BORLA SYSTEM FOR SALE FOR 550.00 IF ANYONE IS INTERESTED. IT STARTS AFTER THE PIPE LEADING BACK FROM THE CAT CONVERTER AND IS LEGAL. NEW IS ABOUT 900.00 I THINK. SHORTIE HEADERS ARE PROBABLY THE ONLY STREET LEGAL HEADERS FOR YOUR CAR WITH SOME PERFORMANCE GAINS AVAILABLE. LONG TUBES WILL SOON BE A NO NO ON MOST VEHICLES UNFORTUNATELY. THIS SUCKS BUT IT'S THE WAY THAT IT IS. GET A PREMIUM SET OF HEADERS AS CHEAP HEADERS ARE WHAT THEY ARE, CHEAP.

 

PS.....I WOULD NOT DO TURN DOWNS UNLESS YOU LIKE THE STREET SWEEPER EFFECT. I HAD HOOKER LONG TUBE HEADERS WITH TURNDOWNS AND THERE WAS A CLOUD OF DUST WHERE EVER I WENT. HAD TO WASH THE BACK OF THE CAR ALL THE TIME. I NOW HAVE CUSTOM GROUND EFFECTS AND STAINLESS SIDEPIPES THAT I BUILT WITH MODIFIED HOOKER SUPERCOMPS FOR MY BLOWN 383. NOT TYPICALLY STREET LEGAL AND LOUD AS HELL BUT IF YOU'RE IN THE AUTO BUSINESS THERE A FEW WAYS AROUND THE EMISSION REQUIREMENTS BUT THAT'S A SECRET I CAN'T DEVULGE, SORRY.

 

ONE MORE PS....."TRUE DUALS" WONT FIT WELL, WILL DRAG THE GROUND, AND WON'T DO ALL THAT MUCH FOR YOUR STOCK 305 BESIDES NOT BEING STREET LEGAL. BEST THING I CAN TELL YOU IS TO SEE IF YOUR PARTS ARE 50 STATE LEGAL. THAT'S WHY JEGGS AND SUMMIT HEADER ADS HAVE "OFF ROAD USE ONLY" ON ALOT OF THE EXHAUST PRODUCTS THEY SELL. THIS IS A DISCLAIMER WHEN YOU GET HIT FOR YOUR EMISSIONS FAILURE AFTER YOU SPEND ALL THAT MONEY PUTTING STUFF ON!

 

thanks topradman i was looking at the borla cat back before but them i heard that u get more gains with trues. but i mean i dont have the time or money to get a custom made true dual system and there isnt much room underneath..i have been under it a few times...can barely get my chest under and im 5'5" 135lbs...thanks for the info. great help.

 

Yeah, not to much room under there.

Besides pretty much everyone that runs duals on a street car explains how the sound/power difference doesn't make up for the decrease in driveability.