Lm7 turbo daily driver
Thread Starter
Teching In
Joined: Jul 2019
Posts: 18
Likes: 1
Lm7 turbo daily driver I’m looking to build a DD turbo lm7. Looking to be around the 600 hp range. Have a list and wondering what I’m missing, need to upgrade, or don’t need. Guessing around 10-15 psi for my goal. Wondering pistons, connecting rods, values with my cam, and reason for meth? Want it reliable and get the weak links.
Gap rings for boost
PAC 1218
Trunnion valve upgrade
Cam .585 lift .050 228/230 lope 112
Cast 7875
44mm wg
50mm bov
Deka 80
ARP head studs, main studs
Stronger rods
Lq9 head gasket
(Have to get stronger fuel pump, Tranny, and good tune)
Thanks
Gap rings for boost
PAC 1218
Trunnion valve upgrade
Cam .585 lift .050 228/230 lope 112
Cast 7875
44mm wg
50mm bov
Deka 80
ARP head studs, main studs
Stronger rods
Lq9 head gasket
(Have to get stronger fuel pump, Tranny, and good tune)
Thanks
Find a higher mileage good running Gen IV 5.3, add head studs and leave it alone, put in a reputable turbo cam (LJMS, Tick, BTR) with matching springs and push rods, maybe a new oil pump.
Trunion upgrade is a good idea but not mandatory.
600 hp on a Gen IV 5.3 is a breeze on pump gas only and will live forever with a good tune.
I'm making 700whp with the same turbo on a SBE LS1 with the smaller Gen III rods for going on five years now pump gas only, a good tune is key, look up Pat G.
Trunion upgrade is a good idea but not mandatory.
600 hp on a Gen IV 5.3 is a breeze on pump gas only and will live forever with a good tune.
I'm making 700whp with the same turbo on a SBE LS1 with the smaller Gen III rods for going on five years now pump gas only, a good tune is key, look up Pat G.
Thread Starter
Teching In
Joined: Jul 2019
Posts: 18
Likes: 1
Find a higher mileage good running Gen IV 5.3, add head studs and leave it alone, put in a reputable turbo cam (LJMS, Tick, BTR) with matching springs and push rods, maybe a new oil pump.
Trunion upgrade is a good idea but not mandatory.
600 hp on a Gen IV 5.3 is a breeze on pump gas only and will live forever with a good tune.
I'm making 700whp with the same turbo on a SBE LS1 with the smaller Gen III rods for going on five years now pump gas only, a good tune is key, look up Pat G.
Trunion upgrade is a good idea but not mandatory.
600 hp on a Gen IV 5.3 is a breeze on pump gas only and will live forever with a good tune.
I'm making 700whp with the same turbo on a SBE LS1 with the smaller Gen III rods for going on five years now pump gas only, a good tune is key, look up Pat G.
TECH Regular
Joined: Nov 2018
Posts: 467
Likes: 116
You should use a stock bottom end including ring gaps. You put forged stuff in there and then its all on the machinist to make sure its matched better than the stock stuff was. There just is no practical reason to change anything in the bottom end for anything 600-700hp. A factory lm7 from a junk yard will make 600hp with a turbo on all stock internals with the exception of maybe changing the valve springs. I ran mine totally stock at 10psi on 91 octane with no ping.
TECH Resident
Joined: Jun 2011
Posts: 936
Likes: 472
Did you mean LS9 gaskets? I've never heard of anyone use LQ9 gaskets for boost (unless they had an LQ9 and decided to run stock gaskets).
If your choice of cam is driven mainly by price rather than getting a dedicated turbo cam, you'd be better off with the SummitRacing SUM-8715 Ghost Cam.
If your choice of cam is driven mainly by price rather than getting a dedicated turbo cam, you'd be better off with the SummitRacing SUM-8715 Ghost Cam.
Staging Lane
Joined: Feb 2020
Posts: 75
Likes: 15
I've ran stock engine/fully unopened/stock HG. Only thing I change is Valve springs and cam. Valve springs you would want due to valve float, Cam is just for a better matched setup(turbo cam)
600whp daily.
I dont think its worth the trouble opening up the engine just for 600. Unless you want to for fun
600whp daily.
I dont think its worth the trouble opening up the engine just for 600. Unless you want to for fun
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I'd splurge on a good turbo cam and springs though, it'll make the number easier with less boost required.
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TECH Enthusiast
Joined: Feb 2020
Posts: 734
Likes: 209
As already stated, if it's already apart you might as well gap the rings
for a daily driver my preference would be a smaller cam ( something in the 21x dur) allowing a lower stall or stock converter and better fuel economy. Depending on vehicle weight and gearing of course.
have you considered using decapped injectors ? Eric Derr the guy to talk with. Save some money for other stuff
I think you asked about water/meth injection - I'm a big fan for both short term benefits
- charge cooling , maybe don't need the best intercooler
- increased octane from the meth
- anti detonation properties of the water
and the long term benefits
- steam cleaning of the combustion chambers , no carbon to create hot spots and pre-ignition
if nothing else it's good insurance and could save you the trouble of swapping in another engine
for a daily driver my preference would be a smaller cam ( something in the 21x dur) allowing a lower stall or stock converter and better fuel economy. Depending on vehicle weight and gearing of course.
have you considered using decapped injectors ? Eric Derr the guy to talk with. Save some money for other stuff
I think you asked about water/meth injection - I'm a big fan for both short term benefits
- charge cooling , maybe don't need the best intercooler
- increased octane from the meth
- anti detonation properties of the water
and the long term benefits
- steam cleaning of the combustion chambers , no carbon to create hot spots and pre-ignition
if nothing else it's good insurance and could save you the trouble of swapping in another engine
As already stated, if it's already apart you might as well gap the rings
for a daily driver my preference would be a smaller cam ( something in the 21x dur) allowing a lower stall or stock converter and better fuel economy. Depending on vehicle weight and gearing of course.
have you considered using decapped injectors ? Eric Derr the guy to talk with. Save some money for other stuff
I think you asked about water/meth injection - I'm a big fan for both short term benefits
- charge cooling , maybe don't need the best intercooler
- increased octane from the meth
- anti detonation properties of the water
and the long term benefits
- steam cleaning of the combustion chambers , no carbon to create hot spots and pre-ignition
if nothing else it's good insurance and could save you the trouble of swapping in another engine
for a daily driver my preference would be a smaller cam ( something in the 21x dur) allowing a lower stall or stock converter and better fuel economy. Depending on vehicle weight and gearing of course.
have you considered using decapped injectors ? Eric Derr the guy to talk with. Save some money for other stuff
I think you asked about water/meth injection - I'm a big fan for both short term benefits
- charge cooling , maybe don't need the best intercooler
- increased octane from the meth
- anti detonation properties of the water
and the long term benefits
- steam cleaning of the combustion chambers , no carbon to create hot spots and pre-ignition
if nothing else it's good insurance and could save you the trouble of swapping in another engine
Do spray water only or meth only because I didn't think you could do both?
I know very little about eithe rbut have been considering it for my boosted car lately.
Thanks.
TECH Enthusiast
Joined: Feb 2020
Posts: 734
Likes: 209
No expert here, just read a lot on here and in some older books on turbocharging. I'm using a basic snow stage one kit , currently using the big nozzle 625ml/min I think. The fact that I haven't blown my **** up is probably proof that it works !!! -first time hp tuners here. Anyone who's done even a few head gasket repairs on higher mileage engines has seen how a bit of coolant in the combustion chamber can completely clean all deposits away . I've never been able to get more than 4 passes in at time ,no need to add to the reservoir for that. I use the blue washer fluid , mixed with methyl hydrate (used for truck air dryers - about 7$ Can/gal) to get close to 50/50.
The El cheapo windshield washer fluid that is blue without additives is about 30% meth to 70% water....and $3 a gallon. Add a bottle of HEET and you end up closer to 50/50. Works great and is easy to do.
Thread Starter
Teching In
Joined: Jul 2019
Posts: 18
Likes: 1
As already stated, if it's already apart you might as well gap the rings
for a daily driver my preference would be a smaller cam ( something in the 21x dur) allowing a lower stall or stock converter and better fuel economy. Depending on vehicle weight and gearing of course.
have you considered using decapped injectors ? Eric Derr the guy to talk with. Save some money for other stuff
I think you asked about water/meth injection - I'm a big fan for both short term benefits
- charge cooling , maybe don't need the best intercooler
- increased octane from the meth
- anti detonation properties of the water
and the long term benefits
- steam cleaning of the combustion chambers , no carbon to create hot spots and pre-ignition
if nothing else it's good insurance and could save you the trouble of swapping in another engine
for a daily driver my preference would be a smaller cam ( something in the 21x dur) allowing a lower stall or stock converter and better fuel economy. Depending on vehicle weight and gearing of course.
have you considered using decapped injectors ? Eric Derr the guy to talk with. Save some money for other stuff
I think you asked about water/meth injection - I'm a big fan for both short term benefits
- charge cooling , maybe don't need the best intercooler
- increased octane from the meth
- anti detonation properties of the water
and the long term benefits
- steam cleaning of the combustion chambers , no carbon to create hot spots and pre-ignition
if nothing else it's good insurance and could save you the trouble of swapping in another engine
TECH Enthusiast
Joined: Feb 2020
Posts: 734
Likes: 209
I used to overhaul ,replace everything - until I was injured and watched sloppy mechanics . If you know any history on the engine , heard it run? Know previous owner? Service records ect... my new opinion on the subject would be to leave it alone. Cam , valve springs and valve seals while doing the springs. You said it's apart already so if no visible problems clean it up (especially ring grooves) and reassemble. If the pan isn't off you can put the drain in the timing cover while it's off for the cam change - if that suits your application.
Staging Lane
Joined: Feb 2020
Posts: 75
Likes: 15
I would say the best way of running 50/50 is finding a local race gas shop in your area that sells straight methanol in barrels. Then mix desired ratio %.
The way I decided on 50/50 is I Data log my IAT to see how much it climb at boost. I wanted to drop it since temp was high so I run 50/50.
Keep in mind you need to calculate your nozzle size, decide if you want to run pre-turbo or post only.
Buy a new stock pump, shim the spring with a washer or two to boost pressure and port the passage ways inside.
Plenty of guys going crazy fast on big power doing just that, plus its cheap insurance.