Lb7 Estimated hp

wwm

wwm

TO MANY TRUCKS
Joined
Mar 22, 2009
Messages
801
A buddy of mine has an 03 Duramax with 90 hp injectors, dual cp3, tranny, headstuds, and ppe.

He want to know two things,

Which would be better to go with efi or ppe hot+2. And why

How much horsepower will he has with hot+2 and what can he have with efi live tuning for horsepower.
 
Well EFI will be better for durability purposes. Does it have a bigger turbo? Id say 600hp considering dual fuelers, but the stock motor is going to sh!t soon at that level.
 
He will be getting a bigger turbo. What do you mean the motor will fail, what is needed to prevent that
 
You might be able to do 600hp on a Hot+2 since they do have "dual fueler" tunes IIRC. At this HP level engine durability is a hit and miss, some stock shortblocks may live at close to 700hp, some fail at 500hp. EFI tuning will let you tune "safer".
 
I would say on a stock turbo he is closer to 550-575. Now If you add some air to that equation he could easily be at 700+Hp. Anything more then 600hp and your definitely gonna want to invest it rods and hone the center of the pistons out for durability and you might as well go ahead and put studs in it depending on the turbo he decides to go with and the boost it's making. For tuning I would go with EFI live. You can't go wrong there.
 
If trying to push over 550hp with stock turbo and dual cp3's on a LB7 and your rods will make an exit through you block at some point down the road, may be a month, may be a year. You can tune out the dual cp3's to make it live with efi, but then not taking advantage.
 
LB7 and LLY engines do not much like running for extended periods over 500 RwHp. Doesn't matter what you use to get there, and it's not a matter of if it will break but when it will break. Save your buddy time and money and unless he is willing to get into the motor stick to 450 RwHp and enjoy the truck.
 
After the dual cp3 and twinns we exploded block. Bad mistake! Got a lot of "I told you so"Better listen to idaho Rob and Diesel Tech! If not you will be makeing very expensive paper weights!
 
Now just for conversations sake. While were on the subject. What would an lb7 stand up to with all stock components and cut pistons? IE, you scatter a stocker mid season, dont have money for a real build, take a donor stock short block and lower the compression ratio to try and keep it together.
 
its not worth cutting corners. the time it takes to pull a duramax and tear it apart and what not, is not all that worth it. at a minimum i recommend doing nozzles to lower timing and PW to get the spray back in the bowl. but as Rob and everyone else said, hes on borrowed time.

and since he has "90hp nozzles" and the PPE hot+2 tunes run 31* timing on the 310 and higher levels, plus the dual fuelers...he can kiss it goodbye! efi is the way to go. tuners are for generic things (exhaust, intake, fuel pumps) but once you start tackling the fuel system and added air, it best to get a tune made for the mods on the truck to correspond with everything else done.
 
qssc said:
its not worth cutting corners. the time it takes to pull a duramax and tear it apart and what not, is not all that worth it. at a minimum i recommend doing nozzles to lower timing and PW to get the spray back in the bowl. but as Rob and everyone else said, hes on borrowed time.

and since he has "90hp nozzles" and the PPE hot+2 tunes run 31* timing on the 310 and higher levels, plus the dual fuelers...he can kiss it goodbye! efi is the way to go. tuners are for generic things (exhaust, intake, fuel pumps) but once you start tackling the fuel system and added air, it best to get a tune made for the mods on the truck to correspond with everything else done.
Click to expand...


I understand what your saying about cutting corners. It was a hypothetical question, say one doesn't have money for a build but they have a spare short block and its going in to finish out a pulling season whether the pistons get cut or not....would it be worthwhile to cut the pistons?
 
1pieceatatime. said:
I understand what your saying about cutting corners. It was a hypothetical question, say one doesn't have money for a build but they have a spare short block and its going in to finish out a pulling season whether the pistons get cut or not....would it be worthwhile to cut the pistons?
Click to expand...
If your trying to do a cheap build to get by I'd keep the stock pistons and get a set of LBZ rods. You can find a set for a couple hundred dollars and they will allow you to run probably about 100 HP more.
 
LWATSON said:
If your trying to do a cheap build to get by I'd keep the stock pistons and get a set of LBZ rods. You can find a set for a couple hundred dollars and they will allow you to run probably about 100 HP more.
Click to expand...

Well im not really trying to do anything. Just kind of thinking out loud and looking for feed back in the event that my 200k mile lb7 decides its had enough abuse and i need to do something on the fly.
 
i agree on the LBZ rods as well. remember that with proper tuning, and knowing how to drive and when to let of contributes a bunchs to how ANY truck will last. there were 2 trucks i remember from last season one called "outta control" and his son drives "almost outta control" and i talked to him at a pull in PA and he said that the "almost outta control" truck has a stock LBZ bottom end with just head studs and was north of the 900 mark. will it last forever? of course not. but it seemed super strong last season and as a dedicated puller its not like it sees street abuse
 
Agreed, its all in the tuning. Also to help make a stock block live at high HP levels is to run a big single charger. This moves the power up in the RPMs in return you get less stress on the bottom end. With proper tuning twins will work also, but the massive low end torque that can be produced with twins can be a rod killer.
 
Cylinder Pressures and Low timing will save the rods. A PPE on level 10 with all that fuel will probably hurt the rods quick. A healthy CP3 stock injector stock turbo LB7 will run out around 530-545 depending on supporting mods, the truck and the tuner. I would atleast invest in a larger IHI turbo so you can do something useful with all the extra fuel.
 
You must log in or register to reply here.
Back
Top