True Duals
08-22-2009, 11:32 AM
#21
And you blew who?
*MOST* places would charge that to just fab the Xpipe and weld it onto the xpipe, if you can find one to even do that.
It is much easier to go under the axle, but there are a lot of shops that wont do that either..
this is the more "high" class shops i guess?
I actually like the way it looks just make sure you bolt it somewhere instead of welding so you can drop your rear if need be.
*MOST* places would charge that to just fab the Xpipe and weld it onto the xpipe, if you can find one to even do that.
It is much easier to go under the axle, but there are a lot of shops that wont do that either..
this is the more "high" class shops i guess? I actually like the way it looks just make sure you bolt it somewhere instead of welding so you can drop your rear if need be.
08-22-2009, 11:40 AM
#22
i wanted true duals too but the exhaust shop said that i would need a 5 link, fuel cell, and some other stuff or else he wouldnt touch it, i laughed. but he also wouldnt even look at my exhaust since i had bought a hooker direct replacement muffler. im think i just gotta find a new exhaust shop
08-22-2009, 11:55 AM
#24
i bought my pacesetter LTs & a duals kit from Speed inc. all for just over $500 (that includes shipping). whenever i get around to selling this and get a goat, ill buy some nice ARH or something, but for nwo itll do. had some other issues and waiting on parts before i finish the install (sitting open heads right now) but when i get mine on (probably tues) ill post a clip. its through dynomax bullets so it might be too loud for some, but ive ridden in a car with the exact same setup and i like it.
fyi-i bought the kit from speed inc, i didnt buy the kit & have them install it in-house cuz thats like 400 bucks.
fyi-i bought the kit from speed inc, i didnt buy the kit & have them install it in-house cuz thats like 400 bucks.
08-22-2009, 01:51 PM
#26
Thanks man! 
I know, I know.. I got tired of hearing of him saying he had the fastest car in town and how i had been dodging him for the last 2-3 months because I was scared to race.. After I heard that I decided it was time to end it.. I saw him one day at a local food joint and did it..
I raced him on street tires and spun pretty bad.. After the race he said he wanted me on slicks from a dig (I told him that he did not) and he said it would be a good race because he had accidentally left traction control on (it wouldnt matter from a 20 roll in that car anyways).. I gave him about two weeks to think on it and he decided the outcome wouldnt be any different..
He traded his cobra in for an Srt-10 truck.. then called me GF out.. he came to the track and ran a 9.1 to her 8.3..
I raced him on street tires and spun pretty bad.. After the race he said he wanted me on slicks from a dig (I told him that he did not
) and he said it would be a good race because he had accidentally left traction control on (it wouldnt matter from a 20 roll in that car anyways).. I gave him about two weeks to think on it and he decided the outcome wouldnt be any different.. He traded his cobra in for an Srt-10 truck.. then called me GF out.. he came to the track and ran a 9.1 to her 8.3..
08-22-2009, 02:42 PM
#27
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Only problem I'm having is finding a shop that'll fab up a setup for me using mandrel bent stainless. I know the mandrel bent stuff is worth some extra breathing potential. But I'm not sure how much. I ended up settling out for standard bends, but 3" all the way out from the headers. Doesn't seem to be hurting my power production.. the 1 7/8" headers are killin me on the bottom end a bit though. I'm not sure if that is a tuning issue or physics.
08-22-2009, 02:47 PM
#28
Only problem I'm having is finding a shop that'll fab up a setup for me using mandrel bent stainless. I know the mandrel bent stuff is worth some extra breathing potential. But I'm not sure how much. I ended up settling out for standard bends, but 3" all the way out from the headers. Doesn't seem to be hurting my power production.. the 1 7/8" headers are killin me on the bottom end a bit though. I'm not sure if that is a tuning issue or physics.
EDIT: found what i was looking for..
I think I found my awnser "Hey guys I just got done reading a good article in the May 2005 issue of Popular Hot Rodding Magazine. The article was written by David Vizard who seems to be one of the most accredited and respected people in the automotive performance world. In the article he stated that CFM is a great way to help develop a zero loss exhaust system. For zero loss a exhaust must flow 2.2 CFM per horsepower(This means less than 1% of total power produced by the engine is lost due to back pressure.). From reading the article I think that a lot of people that see gains when going from a 2.5” exhaust system to a 3” dual system see them because the muffler on the 2.5” system didn’t flow enough for their application. David stated that per square inch of exhaust tubing there is 115 CFM of flow. So plugging some numbers into the good ole TI-89….. ((3.14 * radius^2)*115[*2 for a dual exhaust system])/2.2 = Max hp supported with zero loss
A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…
Now these numbers are assuming that everything else is set up perfectly. The muffler must flow as much as the open pipe or more to get zero loss at the listed hp levels. He also states that using a muffler with a larger inlet/outlet diameter than your exhaust pipe is a great way to get more out of a smaller diameter system since the muffler flow will be able to match the straight pipe flow. Now there are many other things to consider when designing an exhaust system but I figured this would give a great foundation to build on.
Just a side note that he stated that I thought was neat... “Just as fish don’t feel the weight of water, we don’t readily appreciate the weight of air. Just to set the record straight, a cube of air 100 feet square will weigh 38 tons!”
Hopefully I’ll get some more understanding of flow in a closed space in my fluid dynamics class next semester.
- OldSchoolSS"
I'm guessing 4" out of the flowmaster y-pipe ( thanks Mike ) over the axle to a slp dual/dual copy I make. Later Art
08-22-2009, 04:08 PM
#29
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I was wondering if imperfections in a standard bend cause eddying of the exhaust flow and actually hurt performance. If this is the case, than even going to a full 3" with a 346 ain't helping. lol I'm also not planning on staying with the 346 for long.
08-22-2009, 05:52 PM
#30
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i got mine done for 400$ catless and custom made 3" mandrel bent tubing with a custome x-pipe made also but i supplied my own mufflers... (powersticks) Quite loud but sounds mean as hell
08-23-2009, 12:43 PM
#31
i have 3" true duals all the way back under the axle with a H pipe and cost me less than $250 to have done
and here'a vid when i had LT's with LM1 resonators
with sweet thunder chambered resonators
and now back to manifold and cats but with my 3" true duals and the sweet thunder chambered resonators
and here'a vid when i had LT's with LM1 resonators
with sweet thunder chambered resonators
and now back to manifold and cats but with my 3" true duals and the sweet thunder chambered resonators
08-23-2009, 09:59 PM
#32
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based on what i've seen so far, under the axle is a piece of cake. it's much more expensive if you go over the axle and tuck things out of the way. my understanding is that you lose ground clearance with the under vs. the over the axle approach
08-24-2009, 12:29 AM
#33
Ground clearance isn't that big of an issue still, though. I've never had a problem with the piping being under the axle on my Camaro. I only had problems, because the shop didn't tuck up the single chambers well enough, under the back seats. But, I just had them moved to right under the gas tank. Haven't scraped anything since.
08-24-2009, 10:40 AM
#35
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Ground clearance isn't that big of an issue still, though. I've never had a problem with the piping being under the axle on my Camaro. I only had problems, because the shop didn't tuck up the single chambers well enough, under the back seats. But, I just had them moved to right under the gas tank. Haven't scraped anything since.
, but...I'm considering a TSP true dual kit.
08-24-2009, 03:09 PM
#36
A lot of people with fbodies lower thier cars. It then becomes a major issue. I had to go back to my stock springs to clear my pipes and SLP loudmouths, and I'm running side exhaust. I have to admit, 3 1/2" header collectors ain't helping matters either, but...
I'm considering a TSP true dual kit.
, but...I'm considering a TSP true dual kit.
08-27-2009, 12:10 AM
#39
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lemons, your car sounds really mean 
I have the QTP headers and the TSP rumbler TD's and I must say, they sound really badass
That is what I would reccomend if you are planning on going with TD's. Many shops can do exhaust work, but not all of them can do it *well*. That's why I wound up buying my setup prefabbed from a company we all know and trust.
I have the QTP headers and the TSP rumbler TD's and I must say, they sound really badass
That is what I would reccomend if you are planning on going with TD's. Many shops can do exhaust work, but not all of them can do it *well*. That's why I wound up buying my setup prefabbed from a company we all know and trust.
08-27-2009, 08:38 AM
#40
lemons, your car sounds really mean
I have the QTP headers and the TSP rumbler TD's and I must say, they sound really badass
That is what I would reccomend if you are planning on going with TD's. Many shops can do exhaust work, but not all of them can do it *well*. That's why I wound up buying my setup prefabbed from a company we all know and trust.
I have the QTP headers and the TSP rumbler TD's and I must say, they sound really badass
That is what I would reccomend if you are planning on going with TD's. Many shops can do exhaust work, but not all of them can do it *well*. That's why I wound up buying my setup prefabbed from a company we all know and trust.