07 Silverado with Rear mount TC78 on a LQ9/LS3/LS7
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correct me if im wrong (im no pro at v8 turbo setups) but the smaller the internal area is in front of the turbo (ie: manifold/header size and pipping size) the more back pressure your going to create in front of the turbo, the higher your back pressure the more your choking the engine?? Kinda the sum of what i've heard?? Like i said im no pro so feel free to correct this lol. I know that you want to keep your back pressure right around or below your current boost level. I also know that the turbo/turbine housing setup can effect this too right?
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The biggest restriction and cause of back pressure will be the turbo itself.
With rearmounts it can be benfitial to run std manifolds and smaller exhaust to keep gas velocity up and help retain heat back at the turbo.
This helps reduce lag and spool up time.
but if your happy with how quick your turbo spools its all good
With rearmounts it can be benfitial to run std manifolds and smaller exhaust to keep gas velocity up and help retain heat back at the turbo.
This helps reduce lag and spool up time.
but if your happy with how quick your turbo spools its all good
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The biggest restriction and cause of back pressure will be the turbo itself.
With rearmounts it can be benfitial to run std manifolds and smaller exhaust to keep gas velocity up and help retain heat back at the turbo.
This helps reduce lag and spool up time.
but if your happy with how quick your turbo spools its all good![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
With rearmounts it can be benfitial to run std manifolds and smaller exhaust to keep gas velocity up and help retain heat back at the turbo.
This helps reduce lag and spool up time.
but if your happy with how quick your turbo spools its all good
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
nice truck and setup
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sounds good, i guess i'll see how it does with my forged 370 and yank 3400 that im getting ready to put in, im running the loing tubes now with a 3" off road pipe off of each header in to a flowmaster dual 3" to single 3" scavenger y pipe before the turbo. If i have to much trouble ill down size the off road y pipe to 2.5" with a dual 2.5" to 3" scavenger y pipe. Thanks for the info and props guys!
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Turbos are really designed to be up front, where there is a LOT of heat and velocity, if you used a smaller pipe back to the turbo, it could make up for the fact that there isnt as much heat there, by increasing exhaust velocity.
It is worth it bro. 2.5 inches back will do you good..
It is worth it bro. 2.5 inches back will do you good..
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wow haven,t seen this thread in a few months, lol, i did go back down to hpc coated stock manifolds that i ported out a bit and also down sized my y pipe outlets to 2.5" which goes in to a dual 2.5" in 3" out y right before the turbo, couldn't tell a real big difference in lag but i could tell it was building a lot more velocity in the higher rpms. When i put in my Pro yank 3600....
wow whole new world lol, i went from 14.5s/2.7 60' to 11.66s/1.6 60' with just the stall and some tune adjustments! I did run the lq9/ls3/ls7 all season with out a hitch, i would peak 11.0 lbs of boost at the most. Very fun season, all i had to do was throw some new plugs at it every once in a while and keep fresh mobil one in her! Hands down the funnest race season i've ever had, i love the ls motors
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here is the best videos i have at this point lol they are both 11.9 runs from earlier this season, and here is my best time slip for this season, corrected da was between 9800-7800 all year lol.
me vs my buddies lq4 76mm turbo silverado, he is waiting at the line trying to build more boodt
http://www.youtube.com/watch?v=aeimyPuvFuI
me vs a bone stock c6 zo6, beat him barely lol
http://www.youtube.com/watch?v=izZUV_DjTYY
me vs a stock maxima!
http://www.youtube.com/watch?v=KdLw_khkQT8
me vs my buddies lq4 76mm turbo silverado, he is waiting at the line trying to build more boodt
http://www.youtube.com/watch?v=aeimyPuvFuI
me vs a bone stock c6 zo6, beat him barely lol
http://www.youtube.com/watch?v=izZUV_DjTYY
me vs a stock maxima!
http://www.youtube.com/watch?v=KdLw_khkQT8
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some dark burnout action, before the stall lol
http://www.youtube.com/watch?v=LP3CvNW_LdQ
my best time of the season along with my best 60' time, 7800 ft DA this night, this was at street wars 1, we were leaving off of a normal street light they mounted on top of the tree, that is why my reaction times suck lol
http://www.youtube.com/watch?v=LP3CvNW_LdQ
my best time of the season along with my best 60' time, 7800 ft DA this night, this was at street wars 1, we were leaving off of a normal street light they mounted on top of the tree, that is why my reaction times suck lol
![](http://i799.photobucket.com/albums/yy278/chargedlq4/newtimes.jpg)
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Yeah thats what i've been told but i don't really have any spooling issues and i just cant stand opening the hood and having some rusty stock manifolds on there. I figure its better in the long run any ways since the headers will keep my back pressure (before the turbo) low which helps all around performance on a turbo setup.
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Nice job on the kit! Actually your headers will disapate exhaust heat, which inturn reduces exhaust energy/velocity to spool the turbo. Your turbo will spool alot quicker with truck manifolds, and also if you wrap your exhaust pipe back to the turbo, you will also increase your spool time. Guys on here have run 7 sec 1/4 mile pass's with truck manifolds. No back pressure issues. Just a thought for you.
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Thanks! If you read up just a couple posts i did switch over to stock ported 6.0 truck manifolds and 2.5" primaries, made a pretty good difference in the way it pulled, i wrapped all piping pre turbo also to keep the temp and velocity up! The major difference was the stall though!
Chris
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No worries lol, yeah it should be fun, i wish it wasn't being built by the world's slowest machine shop though lol, its been at my uncles machine shop for a year and a half! Its a lq9 based 370 with manley pistons/rods, coated clevitte rod/mains, coated dura bond cam bearings, stock machined lq9 crank, P&P L92 heads with tsp dual springs and titanium retainers, comp push rods, comp rocker upgrade, custom turbo spec'd cam by PAT G./EPS/COMP, probably gonna run that new holley high ram intake too. Im thinking two aeromotive stealth 340's intank with a a1000 boost ref. regulator and -8/-6 fuel line combo should do the trick, i wanna go back to e85 too.
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Just a word of caution. When you install those TSP Double Valve springs, make sure you have atleast 160lbs of seat pressure when installed. If not when you turn up the boost you will float the valves. Not sure how much seat pressure those valve springs provide. Very important on your setup.
Chris
Chris