I'm just curious what every who's making this kind of power running for exhaust, headers to tips? I'm building a Superrammed 383, and I think that topping out at 450 hp insn't completely unrealistic. My thinking on what I want my exhaust to be is a dual cat set of headers (currently single cat) which have 2.5" pipes for the cats I believe, and then to merge that into a 3.5" cat-back. I have to dump a bunch of money into the exhaust regardless, so if I'm gonna pay, I don't want it to restrict the motor at all, and I think the torque of the SR will be sufficient that I don't have to worry TOO much about losing a little low end torque. I'd like to hear what everyone has, and pictures are always welcome. Thank you, and sorry for the length.

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'89 Camaro RS 6cyl. auto, don't know how much longer I'll have it.
'90 Iroc TPI 305, 5 spd B&M Ripper shifter, hopefully I can rob a bank or something and get more
www.geocities.com/irocnroll90

 

get an exhaust shop to make you a set of true dual exhausts from header back

 

Screw the exhuast shop. Get a set of full length Summit headers ($80) 1 ten foot section of 2.5 inch diameter pipe ($48), and one mandrel u bend ($38), and lastly a set of mufflers, and universal hangers.

Cut the 10 foot section of pipe into two four foot sections and throw the rest away. Cut the mandrel bend exactly in the middle of the bend. Run the header to the 4 foot pipes, to the muffler, then use half og the U bend (90 degree bend now) to route the gases out in front of the rear tires. Get a set of Camaro LT1 tips, dip them in chrome, and use those, they look great!

 

There is nothing wrong with your original plan. Lots of guys are making good power with just a 3" exhaust from the headers back.

 

Mufflex 4" system. we have a guy running 9's in the MFBA with that exhaust.

 

If you plan on making serious future power, use a dual exhaust.

People will point to fluid dynamics to say that a single pipe is better...

A) Fluid and air do not travel the same
B) There is more to how an exhuast can create or destroy power than fluid based equations can explain.

The dual exhuast will be cheaper, there are more serious guys in the 10's, 9's, and a twin turbo 95 Z28 in the 6's running duals than those who run a single pipe. Sure it can be done, by why not save yourself a few bucks, and build more potential for power now anyway?

(BTW, what good is a 4 inch cat back if the Y pipe destroys flow and is only 3 inches to boot?)

 

Not trying to support one side or the other here, but air is a fluid.

Mike

 

I agree with slow, duals rule. Treat it like a muscle car, put duals on it. 2 into 1 systems should have been put on rice and fwd's. And also fluid is liquid, air is gas, (remember science class..the chemical states; solid, liquid, gas, plasma).

 

http://www.mufflex-performance.com//brochure\fbody.html

They have a single 4" catback that should be more than sufficient for your build.

They also have an offroad Y pipe for use with Hooker super comp long tube headers.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

EFI Performance Club on Yahoo

 

(remember science class..the chemical states; solid, liquid, gas, plasma).

Yes, I remember very well. The term "fluid" includes both liquids and gasses.

 

The great exhaust debate continues! Well, here goes; a few years back a magazine built a 420" SR'd small block for their 91' Z28. It was blue with a 5 speed. Does that ring a bell for anyone? It had Hooker long tubes, a y-pipe that dumped into a SLP cat back. This car ran mid 10's all motor through closed exhaust. This was before the 4" Mufflex systems were available. I think it boils down to a matter of choice in this case. Consider all of the factors: i.e. ground clearence, fit, and noise suppression. I have a true dual set up on my car, and it is very close to the ground even though I used oval exhaust tubing. I might go with a 4" Mufflex on the next car. BTW, the $80 Summit headers are not long tubes, they are shorties that require welding to attach them to a y-pipe. I have installed 2 sets of them, and I am familiar with them. They work fine for most applications though.

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"I know why you want to hate me, cause hate is all the world can seem to see lately....." L.B.

 

Just a reminder, there are pipe sizes for HP
a single 3" will support 300 HP!
Yea, there are a lot of fast f-bodys single 3" but think about it, that stock, and when has stock been enought? Say thay run 12.0 and make 450HP well with a single 3 1/2" the car may go 11.60 but the guy may never try it because he is always told a single 3" will do. A dual 2 1/2" is good for 450HP so after the dual 2 1/2" you will need a single 3 1/2" (which flow about the same as the dual 2 1/2") Why do you think muscle cars use dual exhaust like 2 1/2" or 3" duals, or look at all those fastest street car shoot-out cars - huge exhaust systems. Here is an example I like to use, my friends 70 chevelle 454, it ran 12.09@110 with dual 2 1/2" and turbo mufflers. With only an exhaust change to dual 3" and dynamax mufflers the car went 11.59@115 back to back same weather and track conditions. I make all my own exhaust systems, and didnt even expect a 1/2 second better ET, I expected like 3 tenths and 2 to 3 mph. People just underestimate the power of a good exhaust! My car is another good example - big block with dual 4", yea thats right 4", 10.90 on ET streets and exhaust. Some people laugh at it till I tell them it goes high 10s, I'm not saying it runs that because of the exhaust, but it sure aint holding it back.

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91 B4C 305 TPI - SOON TO BE 383
TREMEC 5-SP, STOCK 1-BOLT REAREAND w/342 GEARS
K&N, AIRFOIL
EDELBROCK HEADERS, DUAL CAT TO HOMEMADE Y-PIPE & 3.5" SINGLE PIPE W/ FLOWMASTER
CRANK PULLEY, MSD, FUEL PRESS REG
COWL HOOD, WELD WHEELS
14.1@ 98MPH
-------------
OTHER RIDE
67 CAMARO - STREET CAR
BIG BLOCK, PUMP GAS
350TH w/ATI 10"
12-BOLT w/373 GEARS
10.90s ON MOTOR - ET-STREETs w/MUFFLERS

 

Hey slow iroc have you done anything like that before? I've wanted the true dual with the exits in front of the rear tires and that sounds like a good way to do it. I know there's a member (forgot name) who just made a custom setup where both pipes exit on the passenger side but it's still dual and he even fit cats and mufflers in there! I don't think I'd bother with cats though.

Does anyone know if the emissions gestapo cares about custom exhaust setups like this as long as the emissions themselves are ok? I'm moving to CT soon that's why I ask. Thanks guys...

 

Good info. I agree that you can run a single system to more than your hearts content. Those of you who still rather have duals for show, here is my advise.

If you really are running 500+ hp, invest in some 1 5/8 or 1 3/4 full headers. I'm running some super comps. I had someone give the area under the back seat a slight lift(still can retain seats perfectly) to be able to tuck the mufflers up as high as possible.

I think that turn downs are the way to go, but just my opinion.




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Michael Graeber

My Garage

1)83 Z-28 T-Top: Full cage, 9" w/ lad.bars, Midwest Engine Tech 406sbc,Strip Dominator, 1000-CFM Demon Carb, Phase VI Chevy Bowtie Heads 2.05/1.60, .630" Crower roller set-up, 1 3/4 coated Hookers 3" true dual exhaust th400, fuel cell & still not running

2)89 Formula WS-6 305 TPI Auto Daily Driver: minor motor mods, more suspension stuff. MODS

 

I ROCK,

I've always heard that if you alter the converter set up in any way, you would not pass i.e. switching from the single set to dual set-up like the late TA's had .... a muffler shop in Chicago told me that they could not do that. That they could only put on OEM stuff.

But if you can get it done, and pass w/o any problems, the EPA techs should not really think twice that it is illegal.

 

You should get good performance out of 3" exaust as long as it is free flowing. But like what was said above 4" might add some HP. I had 3" exaust on my car and it ran great. I dont know if 4" would have helped any. Here is a clip of me racing a mildly moded stang and an 11sec LS1.
http://uts.cc.utexas.edu/~ws6luvr/mo...tangRaping.mpg

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1989 Irocz
350 T-5

 

I have hooker 1 3/4" long tubes. Mufflex y-pipe and a 4" mufflex exhaust system.
it works fine for me. I will be making around 650 crank HP when I bolt my vortech back on in a couple of weeks. Its a sufficient exhaust.

Id love to run 3" duals, but I dont want to hack up my floor boards and its too hard to fit a drivers side 3" pipe with the torque arm in the way.

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-86 IROC
Jacked up like a mother!
this years goal: 10.50 @ 130+ mph
-=ICON Motorsports=-