Help making a 99M6 a better DD
#1
TECH Apprentice
Thread Starter
iTrader: (1)
Join Date: Jul 2007
Location: henderson,ky
Posts: 344
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Alright, heres the scenario; 99M6 SLP SS. 59,xxx miles. Pro 5.0 shifter, SLP lid/exhaust, with torque thrust 2's and 275/40/17 g-forces.
I wanna use this car as a reliable DD. Im sure I will "play" in it occassionally, but mostly i want to drive it so I would like to do some light modding that would be beneficial to both HP and efficiency.
I would like some help from you guys who have actually payed attention to gas mileage as you modded your cars...
At most for now, the mods I'm thinking would be this...
Cheapie ebay Long tubes(210$ after shipping+ 02 extenders)
Either a custom, or TSP Xpipe setup with bullets(about 400 either way)
Ls6 Intake
Ported TB
Descreened MAF
And after all of that, a tune of course![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
So does that sound like a sound plan for a quicker SS, while retaining good gas mileage and driveability???
Im mainly wondering about the Headers and intake as to whether or not that will kill my gas mileage under normal driving conditions(low rpm, babying the car).
Thanks for the help guys. As you can see I've been a member here for a while but have been out of the loop for a few years now due to going to college for Mecanical Engineering. I'm trying to get back in with this car, but for now I'd like to retain the mild mannered DD attitude with it, in hopes of making it a bit faster under WOT![Devil](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_devil.gif)
I am not looking for a certain HP number or track time either, just trying to get a plan developed first and get this car where I feel like its running at its most optimal for a DD
I wanna use this car as a reliable DD. Im sure I will "play" in it occassionally, but mostly i want to drive it so I would like to do some light modding that would be beneficial to both HP and efficiency.
I would like some help from you guys who have actually payed attention to gas mileage as you modded your cars...
At most for now, the mods I'm thinking would be this...
Cheapie ebay Long tubes(210$ after shipping+ 02 extenders)
Either a custom, or TSP Xpipe setup with bullets(about 400 either way)
Ls6 Intake
Ported TB
Descreened MAF
And after all of that, a tune of course
![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
So does that sound like a sound plan for a quicker SS, while retaining good gas mileage and driveability???
Im mainly wondering about the Headers and intake as to whether or not that will kill my gas mileage under normal driving conditions(low rpm, babying the car).
Thanks for the help guys. As you can see I've been a member here for a while but have been out of the loop for a few years now due to going to college for Mecanical Engineering. I'm trying to get back in with this car, but for now I'd like to retain the mild mannered DD attitude with it, in hopes of making it a bit faster under WOT
![Devil](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_devil.gif)
I am not looking for a certain HP number or track time either, just trying to get a plan developed first and get this car where I feel like its running at its most optimal for a DD
#2
TECH Addict
iTrader: (75)
Join Date: Aug 2005
Location: South Jersey (15 miles from Atlantic City)
Posts: 2,167
Likes: 0
Received 1 Like
on
1 Post
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Perfect combo for daily driving. I have been DD f-bodies since 1998 and even a cammed LS1 car is an excellent dd i have had several. You will not notice a decrease in gas mileage with the mods you have listed
#3
12 Second Club
iTrader: (23)
Join Date: Feb 2007
Location: Fort Hood TX. 76522
Posts: 639
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
would not recommend the X pipe they are loud. Ebay headers I would pass on too, just because of where you got them. fuel milage will be better with headers beacause it helps the motor breathe better. same with the LS6 intake and MAF. Think of an engine as an air pump the more air(and fuel) you pump through it the better it will run.
#4
TECH Apprentice
Thread Starter
iTrader: (1)
Join Date: Jul 2007
Location: henderson,ky
Posts: 344
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Two contradicting opinions so far! Anyone else??? I used to DD my 94 formula M6. It's been a while tho and the ls1's seem to get quite a bit better gas mileage.
I had a y pipe dump setup on the formula and it wasn't too loud for me... I've got a buddy with the eBay headers and an x/bullet setup and it's pretty sweet and has lasted him over a year with no issues thus far. Sounds mean too![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
I'm thinking that there will be a falling point in gas mileage with mods somewhere in my list tho. I'd say the lid is a restrictor that will make the car get better mileage. It's the headers I'm concerned about... Will openin up the exhaust do more than "free" up restrictive factory parts, and in turn make mileage worse?
Obviously more air means more potential power, but if it's breathing too much there will be a loss bc more air means more fuel.
I am a former mechanic and actually have a very strong grasp of the way an engine performs, but am wondering fromthose with experience and data... Thanks again guys for the response! Anyone else?
I had a y pipe dump setup on the formula and it wasn't too loud for me... I've got a buddy with the eBay headers and an x/bullet setup and it's pretty sweet and has lasted him over a year with no issues thus far. Sounds mean too
![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
I'm thinking that there will be a falling point in gas mileage with mods somewhere in my list tho. I'd say the lid is a restrictor that will make the car get better mileage. It's the headers I'm concerned about... Will openin up the exhaust do more than "free" up restrictive factory parts, and in turn make mileage worse?
Obviously more air means more potential power, but if it's breathing too much there will be a loss bc more air means more fuel.
I am a former mechanic and actually have a very strong grasp of the way an engine performs, but am wondering fromthose with experience and data... Thanks again guys for the response! Anyone else?
#5
TECH Senior Member
iTrader: (71)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
One more for skipping on xpipe dumped. Especially if you plan on sometime getting a cam, even baby.
I would do a ypipe with magnaflow and a cutout.
Gas mileage with an m6 is going to move little to none. The only way you will see a difference (more than 2) is with a large cam or gears.
I would do a ypipe with magnaflow and a cutout.
Gas mileage with an m6 is going to move little to none. The only way you will see a difference (more than 2) is with a large cam or gears.
#6
TECH Fanatic
iTrader: (5)
Join Date: Dec 2007
Location: Rochester, NY
Posts: 1,450
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I've seen cammed M6's still get mid 20's on the highway.
If you want the drivability of a stock car with some performance.. Pasesetter LT's, ORY, cutout, LID, ported TB & LS6 intake, and a borla exhaust. If you want to go a little more crazy, go with some nitrous on top of that. You can still keep the stock drivability and have the extra power when you need it. Just dont go crazy with it. 100-125 shot.
If you want the drivability of a stock car with some performance.. Pasesetter LT's, ORY, cutout, LID, ported TB & LS6 intake, and a borla exhaust. If you want to go a little more crazy, go with some nitrous on top of that. You can still keep the stock drivability and have the extra power when you need it. Just dont go crazy with it. 100-125 shot.
#7
TECH Fanatic
iTrader: (5)
Join Date: Dec 2007
Location: Rochester, NY
Posts: 1,450
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
One more for skipping on xpipe dumped. Especially if you plan on sometime getting a cam, even baby.
I would do a ypipe with magnaflow and a cutout.
Gas mileage with an m6 is going to move little to none. The only way you will see a difference (more than 2) is with a large cam or gears.
I would do a ypipe with magnaflow and a cutout.
Gas mileage with an m6 is going to move little to none. The only way you will see a difference (more than 2) is with a large cam or gears.
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
Trending Topics
#10
TECH Fanatic
iTrader: (1)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I'm in agreement with not descreaning the MAF. I'm in agreement with the LTs, a catback of some kind (I like Magnaflow, but to each his own), the LS6 intake, and a ported TB. I'd say do the research on the exhaust, but pick what you want. The X-pipe will just grow annoying over time, as it will be loud, and most people favor a more tame noise for a DD. If anything, I'd go with a cutout for your fix of noise.
#12
TECH Addict
iTrader: (4)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I put 150+ miles a day on my 2000.
I've got QTP 1.75" "race" headers, 3" true duals with X pipe, LS6 intake, SLP lid/cai/bellows and a LOT of my own tuning work. There's no AIR or EGR on my car anymore. I happen to run mine in speed density, but that shouldn't really matter at all so long as it's a GOOD tune. I've also got an aftermarket shifter...which makes it feel nicer to drive.
I pull down at WORST 25mpg every tank, usually average 27 and once in a while break 30.
I will say though, hands down, THE BEST mod I've done, being a DD...is throwing the Monsoon stereo/amp/speakers away, and putting in better stuff. I've got all Alpine electronics (head unit and 2 amps), and all CDT audio speakers (6.5's in the doors, tweeters up by the a-pillars, upstage tweeters in the pillars firing across the dash, and a 10" sub in a stealth box)...all of that combined with good wiring and dynamat has made the car a joy to drive...all the bolt on engine stuff has made the car trap 111 in the quarter, which while not fast by any means, is a fun daily driver...but crystal clear stereo is much more important.
I've got QTP 1.75" "race" headers, 3" true duals with X pipe, LS6 intake, SLP lid/cai/bellows and a LOT of my own tuning work. There's no AIR or EGR on my car anymore. I happen to run mine in speed density, but that shouldn't really matter at all so long as it's a GOOD tune. I've also got an aftermarket shifter...which makes it feel nicer to drive.
I pull down at WORST 25mpg every tank, usually average 27 and once in a while break 30.
I will say though, hands down, THE BEST mod I've done, being a DD...is throwing the Monsoon stereo/amp/speakers away, and putting in better stuff. I've got all Alpine electronics (head unit and 2 amps), and all CDT audio speakers (6.5's in the doors, tweeters up by the a-pillars, upstage tweeters in the pillars firing across the dash, and a 10" sub in a stealth box)...all of that combined with good wiring and dynamat has made the car a joy to drive...all the bolt on engine stuff has made the car trap 111 in the quarter, which while not fast by any means, is a fun daily driver...but crystal clear stereo is much more important.
#13
TECH Apprentice
iTrader: (6)
Join Date: Feb 2009
Location: florence,al
Posts: 300
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
i agree with the x pipe and dumps gets annoying,i only drive my car on the weekends or i would pull off my tsp tds with sweet thunders.it sounds mean as hell but if your feeling like **** or have a headace it sucks.ive had a few catbacks,magnaflow was my fav because it was quite crusin and when you wanted it to it sounded loud and nasty.i wouldnt descreen the maf no gains and it might make your car run weird to.
#14
TECH Apprentice
Thread Starter
iTrader: (1)
Join Date: Jul 2007
Location: henderson,ky
Posts: 344
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Thanks a ton guys! Much more to think about now, but I'll definitely be lookin into all ideas.
I figured a y and cutout would be a bit better for driving daily.
One question on that tho... Say I run open headers into a y pipe and muffler out the back(no cats). I'm assuming it would be best to put the cutout somewhere behind the muffler to keep it cleaner sounding? Or are people going open headers with cutouts?
I ran my formula with just a y dumped with a single muffler. No cats
I figured a y and cutout would be a bit better for driving daily.
One question on that tho... Say I run open headers into a y pipe and muffler out the back(no cats). I'm assuming it would be best to put the cutout somewhere behind the muffler to keep it cleaner sounding? Or are people going open headers with cutouts?
I ran my formula with just a y dumped with a single muffler. No cats
#15
TECH Senior Member
iTrader: (71)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Thanks a ton guys! Much more to think about now, but I'll definitely be lookin into all ideas.
I figured a y and cutout would be a bit better for driving daily.
One question on that tho... Say I run open headers into a y pipe and muffler out the back(no cats). I'm assuming it would be best to put the cutout somewhere behind the muffler to keep it cleaner sounding? Or are people going open headers with cutouts?
I ran my formula with just a y dumped with a single muffler. No cats
I figured a y and cutout would be a bit better for driving daily.
One question on that tho... Say I run open headers into a y pipe and muffler out the back(no cats). I'm assuming it would be best to put the cutout somewhere behind the muffler to keep it cleaner sounding? Or are people going open headers with cutouts?
I ran my formula with just a y dumped with a single muffler. No cats
To answer the question you put it under the rear passenger seat when the y pipe comes into one, before the axle.
#16
TECH Apprentice
Thread Starter
iTrader: (1)
Join Date: Jul 2007
Location: henderson,ky
Posts: 344
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
![Rolleyes](https://ls1tech.com/forums/images/smilies/LS1Tech/rolleyes.gif)
What I intended to ask was are most people running the cutout off of the Y pipe before the muffler? I was just curious as to whether or not headers into the y with no other restrictor would hurt it or throw a code?
#17
TECH Fanatic
iTrader: (5)
Join Date: Dec 2007
Location: Rochester, NY
Posts: 1,450
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
The cutout basically allows you to be loud and obnoxious when you want (eliminates forcing the air to go through the muffler and allows it to exit freely before it) or quieter (sending the air through the muffler) when you want.
I'm happy with mine.
Heres a clip of what mine sounds like. (I open the cutout around 20 seconds).
I have pasesetter coated LT's, ORY, QTP cutout, and a Magnaflow exhaust.
http://s582.photobucket.com/albums/s...afilter=videos
#18
TECH Apprentice
Thread Starter
iTrader: (1)
Join Date: Jul 2007
Location: henderson,ky
Posts: 344
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Exactly. Thats where mine is.
The cutout basically allows you to be loud and obnoxious when you want (eliminates forcing the air to go through the muffler and allows it to exit freely before it) or quieter (sending the air through the muffler) when you want.
I'm happy with mine.
Heres a clip of what mine sounds like. (I open the cutout around 20 seconds).
I have pasesetter coated LT's, ORY, QTP cutout, and a Magnaflow exhaust.
http://s582.photobucket.com/albums/s...afilter=videos
The cutout basically allows you to be loud and obnoxious when you want (eliminates forcing the air to go through the muffler and allows it to exit freely before it) or quieter (sending the air through the muffler) when you want.
I'm happy with mine.
Heres a clip of what mine sounds like. (I open the cutout around 20 seconds).
I have pasesetter coated LT's, ORY, QTP cutout, and a Magnaflow exhaust.
http://s582.photobucket.com/albums/s...afilter=videos
#19
TECH Fanatic
iTrader: (5)
Join Date: Dec 2007
Location: Rochester, NY
Posts: 1,450
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Just make sure they have a good trader rating and only use paypal or pay with cash in person.
If you want to buy new, check out some of our sponsors on the right ---->
I've been using New Era Performance for years and they've always been great to deal with and their prices are usually the same as everyone else (but they do price match too). Mike and the crew over there are nice guys and always come through for me.
#20
TECH Senior Member
iTrader: (71)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Camaro 94 has you covered.. if you are interested I have a kooks ory with a cutout going into magnaflow, exactly what we have been talking about. It is all stainless and 3".
Mine is not a dd so i am going to an xpipe with 1 chambers, i miss it. I had it on my last car but it was a dd and it sucked!
Mine is not a dd so i am going to an xpipe with 1 chambers, i miss it. I had it on my last car but it was a dd and it sucked!