stock or upgrade????

Manifolds, flexpipe, catalytic converters, mufflers, hangers, piping, EGR etc.
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scarecrow
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stock or upgrade????

Post by scarecrow »

the exhaust on my 95 is gone. so with that said is it worth the money for the gidson catback system or just stick with the stock replacement....is there any power gains or better MPG....and i will save yas the time now. NO FLOWMASTER so dont even tell me that what i need....thanks in advance......
SOLD and missing my 1995 Astro AWD 5 1/2 lift and 31 inch tires...
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kings-x59
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Re: stock or upgrade????

Post by kings-x59 »

If you want a more butch sound then go for it. Just doing the exhaust from the cat back won't get you much in the way of horsepower. It will benefit more in the higher rpm range than the low, at the expense of low end torque. the horsepower increases advertised by all the performance exhaust manufacturers occur at very high rpm 4000-5000. Many people complain about their engine feeling "sucked out" after installing any cat back system. They hear noticably louder roar from the engine with a simultaneous loss of torque. If you have are running a scangage, you might see a slight increase in highway gas mileage. I will be so small, the exhaust system will rust to pieces before it every pays for itself.
All the performance exhausts systems produce an invasive drone in the passenger compartment at some point in the rpm range. For less money and the same effect you could bump your pipe diameter, and find the biggest stock muffler you can fit, get the same result and skip the noise in the cab. I'm running a high flow cat, 2.5" pipe from there back and a flowmaster 40 muffler. As soon as I get the cash, the flowmaster is going in the trash and being replaced by the biggest stock muffler I can fit. I'm tired of having to yell to have a conversation in my van, and having to jack the volume on he stereo at highway speeds.
Unless you install performance headers, mostly what you are going to get is a robust sound out of your exhaust.
that's my $2 (inflation).
Next? :swords:
'89 Astro, 4.3L, TBI. Minor intake and exhaust mods. Rebuilt 700R4 trans (by me). Corvette servo, 0.5" boost valve, police grade 1-2 accumulator spring (shifts fast and solid). B&M stacked plate trans cooler. Bilstein shocks. Belltech sway bars front and back. New head unit, speakers and subwoofer. Needs paint and a new headliner.

name's Steve
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Topic author
scarecrow
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Re: stock or upgrade????

Post by scarecrow »

thank you.................
SOLD and missing my 1995 Astro AWD 5 1/2 lift and 31 inch tires...

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Re: stock or upgrade????

Post by Cobra »

funny my cat is gone now so i need to work on my exhaust i was looking at adding a magnaflow DIRECT-FIT CATALYTIC CONVERTER http://www.car-sound.com./02product/dis ... tfit=23410 and the gibson stainless steel catback but from the above it would only be loud and would only benifit if there are headers with it? is that correct?
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone
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kings-x59
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Re: stock or upgrade????

Post by kings-x59 »

In theory, there is some improvement, but not enough to really feel it in the seat of your pants. The benefit is only realized at really high rpm, which few of us reach in our daily driving...at least I don't typically rap my engine up to 4000 rpm on a regular basis. For example, I recently removed a flowmaster muffler from one of my jeeps and replaced it with a stock midas muffler. There is absolutely no difference in performance, with the exception of the noise.
'89 Astro, 4.3L, TBI. Minor intake and exhaust mods. Rebuilt 700R4 trans (by me). Corvette servo, 0.5" boost valve, police grade 1-2 accumulator spring (shifts fast and solid). B&M stacked plate trans cooler. Bilstein shocks. Belltech sway bars front and back. New head unit, speakers and subwoofer. Needs paint and a new headliner.

name's Steve
I can't remember all I've forgotten about that....

phr1$k37
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Re: stock or upgrade????

Post by phr1$k37 »


Depends with your usage?
I do rev my all the way to redline and more (tuned) -
Running DynoMax (walker) stuff and for my catback it is a "hi-flo" but without paying the cost of a "hi-flo" ... just go buy a cat for a 7.4L V8 ... hah ha. Click on the sig for the numbers to the parts I used.
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kings-x59
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Re: stock or upgrade????

Post by kings-x59 »

phr1$k37 wrote:
Depends with your usage?

Exactly.
And like I said to begin with, if you want a more robust sound then by all means go for it. Just don't expect perceptible performance gains in the low rpm ranges.


[Edit] Nice Van Phrisk - just checked out Princess' secrets on your link.
'89 Astro, 4.3L, TBI. Minor intake and exhaust mods. Rebuilt 700R4 trans (by me). Corvette servo, 0.5" boost valve, police grade 1-2 accumulator spring (shifts fast and solid). B&M stacked plate trans cooler. Bilstein shocks. Belltech sway bars front and back. New head unit, speakers and subwoofer. Needs paint and a new headliner.

name's Steve
I can't remember all I've forgotten about that....

phr1$k37
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Re: stock or upgrade????

Post by phr1$k37 »


LOL Thanks. There are other things I have listed / updated - but I get a lot of local comments on her. Today going for lunch I had a dude in his 2500HD stare eye level with me, roll down window "hey that is not stock!?" I told him no and that I had the same brake calipers as he does hah ha. Wish I had my camera to catch his expression :p
97' Safari AWD SLT - Nicknamed "Princess" cause of all the TLC she begs from me!
Location: West Coast, B.C., Canada eh?
Photos and Specs of "Princess"

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Re: stock or upgrade????

Post by Cobra »

I revv my van up close to 4000 everyday just getting out of my driveway but i'll probably just get a universal cat for now
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone
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GEJ
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Re: stock or upgrade????

Post by GEJ »

kings-x59 wrote:If you want a more butch sound then go for it. Just doing the exhaust from the cat back won't get you much in the way of horsepower. It will benefit more in the higher rpm range than the low, at the expense of low end torque. the horsepower increases advertised by all the performance exhaust manufacturers occur at very high rpm 4000-5000. Many people complain about their engine feeling "sucked out" after installing any cat back system. They hear noticably louder roar from the engine with a simultaneous loss of torque. If you have are running a scangage, you might see a slight increase in highway gas mileage. I will be so small, the exhaust system will rust to pieces before it every pays for itself.
All the performance exhausts systems produce an invasive drone in the passenger compartment at some point in the rpm range. For less money and the same effect you could bump your pipe diameter, and find the biggest stock muffler you can fit, get the same result and skip the noise in the cab. I'm running a high flow cat, 2.5" pipe from there back and a flowmaster 40 muffler. As soon as I get the cash, the flowmaster is going in the trash and being replaced by the biggest stock muffler I can fit. I'm tired of having to yell to have a conversation in my van, and having to jack the volume on he stereo at highway speeds.
Unless you install performance headers, mostly what you are going to get is a robust sound out of your exhaust.
that's my $2 (inflation).
Next? :swords:

Completely correct and great write-up. =D> =D>
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Re: stock or upgrade????

Post by MD/Astro\CL »

My van's got the Magnaflow cat and Flowmaster 40 series muffler, the new cat definitely gave the van better gas mileage and a slight power increase but that might have also had something to do with me being used to the old, beat up stock exhaust.
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