Flowmaster Mufflers! and H-pipe...
Thread Starter
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
Flowmaster Mufflers! and H-pipe...
Just got my 40 series flowmasters in today, going to be putting the exhaust on next week, i was wondering if anyone here had them, and what they thought of them, and what kind of performance i can expect from them, i currently have a really crappy 1-3/4 inch exhaust with some horrible mufflers....will i notice a differnece? i'm putting in 2-1/4 inch aluminized exhaust with these, and going to be installing an H-pipe as well, what exactly
will the h-pipe do for me? Sorry, i know just about every little thing on that car, spent a few years under it, just had a few exhaust questions, any input would be greatly apreciated :)
will the h-pipe do for me? Sorry, i know just about every little thing on that car, spent a few years under it, just had a few exhaust questions, any input would be greatly apreciated :)
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: Flowmaster Mufflers! and H-pipe... (VETDRMS)
You must have a free flowing system from block to muffler tip to get the full benefit you seek. So if you're not using headers, you're somewhat restricted to start with.
That said, you will get much higher flow with the 2.25 pipes - figure the increase in cross section of the pipe vs 1.75". Install the h pipe at the hot point in the forward part of the pipes. Install them and spray them with Krylon. Bring up to operating temp and the paint will peel first at the hot point of most restriction. Place your h pipe there.
Your 40 series FMs will greatly increase flow but also greatly increase noise level. Expect some resonance at lower rpm. Be sure to use isolator hangers to reduce resonance thru the frame.
Corvette tips have 2" holes so be sure to open them up.
That said, you will get much higher flow with the 2.25 pipes - figure the increase in cross section of the pipe vs 1.75". Install the h pipe at the hot point in the forward part of the pipes. Install them and spray them with Krylon. Bring up to operating temp and the paint will peel first at the hot point of most restriction. Place your h pipe there.
Your 40 series FMs will greatly increase flow but also greatly increase noise level. Expect some resonance at lower rpm. Be sure to use isolator hangers to reduce resonance thru the frame.
Corvette tips have 2" holes so be sure to open them up.
Team Owner
Joined: Jun 2001
Posts: 43,136
Likes: 155
From: Thomson Georgia
Re: Flowmaster Mufflers! and H-pipe... (VETDRMS)
It will sound better FOR SURE....As far as performance I really do not think u will notice a huge change.I did not notice hardly anything.....It all depends on your engine setup and power...I did not see any real gains from my flowmasters till I changed the heads and cam....Then I noticed a HUGE en change when compression went from 8.5:1 to 10.5:1
Thread Starter
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
Re: Flowmaster Mufflers! and H-pipe... (flynhi)
Thanks! I'm having a shop install the entire exhaust system, they were going to put the H-pipe behind the tranny cross member i believe...Which headers would you suggest i get? i wanted to put some on with the new exhaust, would like a block-hugger type be best, and which ones would fit correctly?
Thanks again for your input, i'm going to be putting some vortec heads on this in a few months, so compression/power will go up for sure :)
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Thanks again for your input, i'm going to be putting some vortec heads on this in a few months, so compression/power will go up for sure :)
-------------------------------------------------------------------------------
You must have a free flowing system from block to muffler tip to get the full benefit you seek. So if you're not using headers, you're somewhat restricted to start with.
That said, you will get much higher flow with the 2.25 pipes - figure the increase in cross section of the pipe vs 1.75". Install the h pipe at the hot point in the forward part of the pipes. Install them and spray them with Krylon. Bring up to operating temp and the paint will peel first at the hot point of most restriction. Place your h pipe there.
Your 40 series FMs will greatly increase flow but also greatly increase noise level. Expect some resonance at lower rpm. Be sure to use isolator hangers to reduce resonance thru the frame.
Corvette tips have 2" holes so be sure to open them up.
That said, you will get much higher flow with the 2.25 pipes - figure the increase in cross section of the pipe vs 1.75". Install the h pipe at the hot point in the forward part of the pipes. Install them and spray them with Krylon. Bring up to operating temp and the paint will peel first at the hot point of most restriction. Place your h pipe there.
Your 40 series FMs will greatly increase flow but also greatly increase noise level. Expect some resonance at lower rpm. Be sure to use isolator hangers to reduce resonance thru the frame.
Corvette tips have 2" holes so be sure to open them up.
Racer
Joined: Jun 2000
Posts: 439
Likes: 0
From: North Carolina
Re: Flowmaster Mufflers! and H-pipe... (VETDRMS)
VETDRMS....I went with the whole works. I installed Flowmaster 40's Hooker full length headers, true duels with a cross over and low restriction cats. I don't know if any one item gave me more HP then the other but as a package I have plenty of torque. I was upset at first with the sound of the 40's but once they got broken in they sound sweet :D
[Modified by SILVRTOY, 6:12 PM 12/24/2001]
[Modified by SILVRTOY, 6:12 PM 12/24/2001]
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: Flowmaster Mufflers! and H-pipe... (VETDRMS)
block huggers are not as efficient as equal length primary headers. I'm running Hooker but there are several good makes. Get heavy gauge tubing and have them coated. Primary length will vary depending on whether the headers are designed for torque or HP. Headers with 4into 2into 1 transitions flow better.
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