Best Exhaust Option For L98?
08-03-2005, 07:03 PM
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Best Exhaust Option For L98?
After much review on this forum and a lot of thought, I have come down to three options for my 91 A4. It has the 3:07 rear, hi-flow main cat, and magnaflow SS catback. Other than a K&N the car is bone stock.
Option #1: LT 1 5/8 headers into 2 small cats to an Xpipe into duals. I am assuming that this would be purely custom work by a muffler shop.
Option #2: LT 1 5/8 headers into 2 1/2 in pipe to my hi-flow cat into my magnaflow SS catback.
Option #3: Bolt on 2 1/2 SS Y-pipe into my hi-flow cat into my magnaflow SS catback.
Immediate mods will be:
Cut Air filter lid
Remove frisbee
shift kit (which one?)
torque converter (stall ?)
possibly different gears (3:73 ?)
Initially, I will be doing mostly bolt-ons since my motor only has 75k. Down the road I will most likely have my heads ported and polished and the intake setup ported with a suitable cam when I do my rebuild or crate replacement.
What do you think and which option makes the most sense?!
Option #1: LT 1 5/8 headers into 2 small cats to an Xpipe into duals. I am assuming that this would be purely custom work by a muffler shop.
Option #2: LT 1 5/8 headers into 2 1/2 in pipe to my hi-flow cat into my magnaflow SS catback.
Option #3: Bolt on 2 1/2 SS Y-pipe into my hi-flow cat into my magnaflow SS catback.
Immediate mods will be:
Cut Air filter lid
Remove frisbee
shift kit (which one?)
torque converter (stall ?)
possibly different gears (3:73 ?)
Initially, I will be doing mostly bolt-ons since my motor only has 75k. Down the road I will most likely have my heads ported and polished and the intake setup ported with a suitable cam when I do my rebuild or crate replacement.
What do you think and which option makes the most sense?!
08-03-2005, 09:56 PM
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That Corsa for the L98 sounds nice but I already have a magnaflow. I really would like some of the boards experts to respond because I want to do right by my corvette.
08-04-2005, 01:56 AM
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Hmm, Ive got an L98 and it is bone stock, doesn't even have K&N. Was wondering If those L98 setups Corsa designs are any good. Lost the site a while ago, and it would be great if someone could put up a link. Saw it advertised as 142% air flow or something.
I really need something to boost the hp. Those '05 mustangs and ricers need to stay back and a nice sound would be good at WOT or when reving it a bit. So I'm just wondering if I should go with the header, mufler, ect. package Corsa gives or should I mix it up for optimum performance? Also what is this "frisbee" I keep hearing about and where can I Find it.
Thnx guys.
I really need something to boost the hp. Those '05 mustangs and ricers need to stay back and a nice sound would be good at WOT or when reving it a bit. So I'm just wondering if I should go with the header, mufler, ect. package Corsa gives or should I mix it up for optimum performance? Also what is this "frisbee" I keep hearing about and where can I Find it.
Thnx guys.
08-04-2005, 06:08 AM
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I was thinking about going LT header, aftermarket hi-flow cats right after the headers then back to x-pipe and mufflers. This would be a custom and probably cheaper, better sounding, and better flow than a corsa. Corsa systems are great, but obscenely expensive. That said, I do have to pass smog here in NE Ohio.
I know the 92- 96 LT-1 Vette has only 2 cats. I was trying to find out if that flows better than if I just use my one main cat (minus the power robbing pre cats) or if it doesn't make that big of a difference. I also want to make sure it is legal to switch to a custom LT1 type exhaust with 2 cats. I just want to optimize HP, not make it sound overly loud. I would keep my magnaflows. I just need someone with this level experience to chime in.
The frisbee is a large heavy round device on your water pump that robs horsepower. It is an easy , free mod to remove it. They say 10 hp worth.
I know the 92- 96 LT-1 Vette has only 2 cats. I was trying to find out if that flows better than if I just use my one main cat (minus the power robbing pre cats) or if it doesn't make that big of a difference. I also want to make sure it is legal to switch to a custom LT1 type exhaust with 2 cats. I just want to optimize HP, not make it sound overly loud. I would keep my magnaflows. I just need someone with this level experience to chime in.
The frisbee is a large heavy round device on your water pump that robs horsepower. It is an easy , free mod to remove it. They say 10 hp worth.
08-04-2005, 10:18 AM
#6
Option #1
True duals are always better.
With LT headers, it would be easy for any descent exhaust shop to build you a 2.5" system (or whatever size you want) from the headers back.
You wouldn't be able to use the LTx system's cats anyway. If you want to use a cat with LT headers, then you'll need to either purchase some high-flow cats for a dual system, or keep a single exhaust and keep your main cat.
Corsa's L98 system looks nice... but that's a whole lot of money for a single exhaust cat-back... You could put on a good exhaust for that amount of cash.
True duals are always better.
With LT headers, it would be easy for any descent exhaust shop to build you a 2.5" system (or whatever size you want) from the headers back.
You wouldn't be able to use the LTx system's cats anyway. If you want to use a cat with LT headers, then you'll need to either purchase some high-flow cats for a dual system, or keep a single exhaust and keep your main cat.
Corsa's L98 system looks nice... but that's a whole lot of money for a single exhaust cat-back... You could put on a good exhaust for that amount of cash.
Last edited by mikey whipreck; 08-04-2005 at 11:51 AM.
08-04-2005, 10:29 AM
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Originally Posted by mikey whipreck
Option #1
Corsa's L98 system looks nice... but that's a whole lot of money for a single exhaust cat-back... You could put on a good exhaust for that amount of cash.
Corsa's L98 system looks nice... but that's a whole lot of money for a single exhaust cat-back... You could put on a good exhaust for that amount of cash.
more flow + less money = the way to go 
08-04-2005, 11:47 AM
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I have a Borla System, and very happy. A while back Corsa's didn't make anything for L98. Nice to see they finally got on the band wagon.
08-04-2005, 12:54 PM
#9
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For a different view: I went with Headman 1 5/8 headers into 2 1/2 pipe all the way back to mufflers. There is a cross pipe where the cat was. Sounds just fine and a noticable quickness in revs.
08-05-2005, 03:56 AM
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Originally Posted by mash2k
The frisbee is a large heavy round device on your water pump that robs horsepower. It is an easy , free mod to remove it. They say 10 hp worth.
08-05-2005, 04:06 AM
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Originally Posted by Shawn_65
what is the function of this device? anything important? Is this just a weight issue or..? sry, I'm a noob :o
08-05-2005, 04:14 AM
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I agree that option 1 is the best; since you plan on heads & cam down the road go with 1 3/4" LTs. If you live near Trenton, NJ give a call to Denny at Mufflex (link on my site), his guys are wizards at this stuff.
The "frisbee" is a heavy disc added to the water pump pully of '88-'91 L98s to prevent belt squeal which was discovered to sometimes occur after the General changed A/C compressors for '88. The inertia of this device sucks up the 10chp gain from the move to #113 D-port heads in '88.
The "frisbee" is a heavy disc added to the water pump pully of '88-'91 L98s to prevent belt squeal which was discovered to sometimes occur after the General changed A/C compressors for '88. The inertia of this device sucks up the 10chp gain from the move to #113 D-port heads in '88.
08-05-2005, 04:41 PM
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Thanks for the insight guys.
What kind of hi-flow cats do you recommend for me to install after the headers. I guess fitment would be the main concern. Also, from the cats I was thinking an X-pipe and I would guess the exhaust shop would have to remove the Magnaflow Y-pie and only be able to use the Magnaflow SS mufflers. Does this sound correct?
What kind of hi-flow cats do you recommend for me to install after the headers. I guess fitment would be the main concern. Also, from the cats I was thinking an X-pipe and I would guess the exhaust shop would have to remove the Magnaflow Y-pie and only be able to use the Magnaflow SS mufflers. Does this sound correct?
08-05-2005, 06:23 PM
#16
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I'd go with option 2.Its what I had on my 12 second 90(except flowmaster mufflers.)its plenty for a stock or mildly modded 350.The gains and $$ of going to duals with x pipe and cats isnt worth it IMO.(maybe 15hp)You already have the catback,so all you need is the headers and highflow main(I had a $80 carsound)I had 2 1/4 duals on my 87,straight back(no cats)to flowmasters,it sounded good,gained top end,but I lost low end torque.I liked the setup on my 90 better.I would however go with 1 3/4 headers like 65Z01 said,but wait till you do cam and heads.
09-03-2005, 10:22 PM
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Originally Posted by cuisinartvette
Similar to a dampner-Absorbs vibration/harmonics, supposedly helps the accessories bearings live longer and keep from throwing the belt off the pulley. Took mine off, no problems. 4 bolts and 10 minutes takes care of it. Remove the belt first.
02-20-2015, 05:16 PM
#19
Team Owner
Option one is my choice also. I ended up with a completely custom system, but there are options from a few manufacturers for true dual exhaust systems.
http://pypesexhaust.com/i-12200821-8...em-scc40r.html
http://www.mamotorworks.com/Corvette...steel-603492-1
http://pypesexhaust.com/i-12200821-8...em-scc40r.html
http://www.mamotorworks.com/Corvette...steel-603492-1
