Duramax Diesels Forum Truck of the Week
  #31  
Old 09-12-2018, 05:33 PM
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Stay at stock LB7 comp.
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  #32  
Old 09-12-2018, 05:36 PM
Blackmax123 Blackmax123 is offline
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Isnt an lmm lbz 16.8:1 stock?

I know racecar guys that did the same but only for a couple cylinders and some how those are the ones they always convinced the tech guy to pump..lol

The longevity is the ticket. The high compression motors dont last but make good power. So if you want to be one of the front runners and dont street drive the truck and have money to blow. Being air limited with a small charger I'd stay higher compression.

My new machine shop guy and I just had this same decision Monday over my lml engine that will be 16:01. But it's not gonna be a power house might see twins someday though.
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2008 Chevrolet 3500hd duramax ltz cc/lb dually (homemade handgrenade) built motor by me, Built tranny by me, big exergy pump and s&s over it, large exergy lbz injectors, ac delete, custom Danville s400 true 2.5 charger, roll pan, 8" single stack, custom hitch and a few more pulling goodies.

2015 Vw passat tdi sel premium blacked out(old lady's ride)

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  #33  
Old 09-12-2018, 05:44 PM
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Quote:
Originally Posted by Blackmax123 View Post
Isnt an lmm lbz 16.8:1 stock?

I know racecar guys that did the same but only for a couple cylinders and some how those are the ones they always convinced the tech guy to pump..lol

The longevity is the ticket. The high compression motors dont last but make good power. So if you want to be one of the front runners and dont street drive the truck and have money to blow. Being air limited with a small charger I'd stay higher compression.

My new machine shop guy and I just had this same decision Monday over my lml engine that will be 16:01. But it's not gonna be a power house might see twins someday though.
Maybe thatís why I didnít notice a difference
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  #34  
Old 09-12-2018, 06:40 PM
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Ok that all makes sense now. Kind of like how stock gas class chokes it and chokes it out but their compression ratios are so high they still scream anyhow. So how would reliability be affected by going up 1 or 2 points?
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Originally Posted by coker6303
My trucks not a whore...she doesn't lift her skirt for just anyone!

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  #35  
Old 09-12-2018, 06:42 PM
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Quote:
Originally Posted by TheBac View Post
Stay at stock LB7 comp.
could you tell me why?
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2004 chevy lly with a handshaker





Originally Posted by coker6303
My trucks not a whore...she doesn't lift her skirt for just anyone!

Originally Posted by coker6303
But she is a prostitute...she will do anything for money
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  #36  
Old 09-12-2018, 06:54 PM
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For the reasons the guys said. IMO, you'll need the little bit of power the higher comp ratio can bring with the limits on boost that you'll have. If I were to do the whole stock-turbo racing thing again, Id have left my comp ratio alone instead of cutting the pistons like I did.


Now, if you decide to go stock-appearing charger, then the lower comp ratio might help you. You need to decide which turbo/fuel avenue you're going down first, and build the engine from there.
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"BBT" -- 2003 GMC CC/SB 4x4 12.14@111.15
"The Cruzer" -- 2014 Chevy Cruze Diesel -- the fun little DD
"Kleshay" -- 2000 C5 Corvette -- the toy
"The Bigger Boat" -- 2011 Workhorse P700 - 6.0LS/Allison - what I drive at work


Two wrongs dont make a right, but three rights do make a left.

Reality is a matter of perspective.

This forum isn't for the weak of heart.....or wallet.

"Lets build a race car they said. Itll be fun they said. I don't know who "they" are.........but they need a good punch in the face!" -- mufflerguy (yb)
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  #37  
Old 09-12-2018, 07:09 PM
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Quote:
Originally Posted by TheBac View Post
For the reasons the guys said. IMO, you'll need the little bit of power the higher comp ratio can bring with the limits on boost that you'll have. If I were to do the whole stock-turbo racing thing again, Id have left my comp ratio alone instead of cutting the pistons like I did.


Now, if you decide to go stock-appearing charger, then the lower comp ratio might help you. You need to decide which turbo/fuel avenue you're going down first, and build the engine from there.
Ok i got you, your saying don't delip the pistons to stay stock compression? What do you think about going up in compression? Turbo will be factory turbo. We have 2 different classes for stock turbos. Factory and stock appearing. I will run a factory charger. I was also thinking 10mm pump and 60 overs for fuel. But what i don't want to do is get this thing built and have a ton of money sank in it and look back wishing i would have done something else. That is why i am asking all you guys who have been down this road. The truck will rarely be driven on the road, maybe 1000 or 2000 miles a year. Thats about all it gets now anyways.
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2004 chevy lly with a handshaker





Originally Posted by coker6303
My trucks not a whore...she doesn't lift her skirt for just anyone!

Originally Posted by coker6303
But she is a prostitute...she will do anything for money
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  #38  
Old 09-12-2018, 07:19 PM
Blackmax123 Blackmax123 is offline
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I really dont think there is a true answer that someday you won't look back and wish you did something different. I built my lmm with that though thinking someday itd gonna be a 2.6 truck. Now with how that class has got I built the total wrong truck to start with and lowered compression so I get my ass kicked in 2.5 plus is a heavy pig...lol so there all kinds of things I wish I have done different. But what I truly should've done was built it for what my goals were at the time not for dreams in the future.

I'd stay at least with the stock 17.5:1 if you want to run lb7/lly pistons but if I was going to buy pistons I'd look into about 18.5:1. If your gonna stay true stock turbo and not stock appearing big differences there..
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2013 Chevrolet 3500hd duramax loaded ltz cc/lb dually (tow pig)- danville 2.5 stg1.5 charger, 5" afe exhaust, wehrli charge piping and egr delete,wehrli stainless downpipe and danville tuned. 5" zone lift, 315/70r17. 2" hub centric front spacers 3" hubcentric rear spacers between duals.

2008 Chevrolet 3500hd duramax ltz cc/lb dually (homemade handgrenade) built motor by me, Built tranny by me, big exergy pump and s&s over it, large exergy lbz injectors, ac delete, custom Danville s400 true 2.5 charger, roll pan, 8" single stack, custom hitch and a few more pulling goodies.

2015 Vw passat tdi sel premium blacked out(old lady's ride)

2014 chevrolet cruze diesel work car.

Special thanks to Danville Performace & Limitless Diesel
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  #39  
Old 09-12-2018, 07:30 PM
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TheBac TheBac is offline
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Amen to that ^^

There's always something you learn later that makes you think, "Damnit, why'd I do that"...but you make your decision based on what you know at the time. I still made 580 the way I built mine.
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"BBT" -- 2003 GMC CC/SB 4x4 12.14@111.15
"The Cruzer" -- 2014 Chevy Cruze Diesel -- the fun little DD
"Kleshay" -- 2000 C5 Corvette -- the toy
"The Bigger Boat" -- 2011 Workhorse P700 - 6.0LS/Allison - what I drive at work


Two wrongs dont make a right, but three rights do make a left.

Reality is a matter of perspective.

This forum isn't for the weak of heart.....or wallet.

"Lets build a race car they said. Itll be fun they said. I don't know who "they" are.........but they need a good punch in the face!" -- mufflerguy (yb)
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  #40  
Old 09-13-2018, 04:48 AM
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Your compression ratio will not be the reason you win or lose. Assuming it's within reason.

Sent from my XT1585 using Tapatalk
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  #41  
Old 09-13-2018, 07:54 PM
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Quote:
Originally Posted by ikeG View Post
Your compression ratio will not be the reason you win or lose. Assuming it's within reason.

Sent from my XT1585 using Tapatalk
You are correct. But like i said, im trying to get opinions on making the most power out of my very limited air
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2004 chevy lly with a handshaker





Originally Posted by coker6303
My trucks not a whore...she doesn't lift her skirt for just anyone!

Originally Posted by coker6303
But she is a prostitute...she will do anything for money
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  #42  
Old 09-14-2018, 11:41 AM
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Anything you can do to improve air flow and efficiency will begin to add up in overall power. Things like cam, heads, intake, intercooler, etc. Rods and such are supporting mods to handle the power and associated pressures.
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