LM7 turbo build questions?
Thread Starter
Teching In
Joined: Jun 2019
Posts: 2
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From: Virginia
LM7 turbo build questions? What’s up guys/girls, I know this is definitely an ongoing discussion. I am in the process of getting away from my carbureted SBF days and moving onto turboing an LS. Iv never built a Turbo motor before. The builds I have seen are making 500-600HP for around $3000-$3500 and that’s what I’m interested in doing. I’d definitely appreciate any information you all could share with me on your experiences in building a turbo LS. Iv read tons of forums and articles and still haven’t found what I’m after. Looking for build sheets, parts list, ECT ECT. I want this to be a budget build. Thank you in advance!
PATRICK.
PATRICK.
TECH Regular
Joined: Nov 2018
Posts: 467
Likes: 116
I just finished mine. Welding the last of the 8.8 rear end in tonight and hopefully off to the dyno by the end of next week or so.
To make a list of all the parts it took would take me an hour or more, when you get down to all the hose clamps and hoses, electrical bits, etc...
you need a turbo from one of the sites that sells the good Chinese turbos, 75/78, gt45, etc...$500ish
You need the hot side components. Manifolds, make them or buy them it will cost you $400 at min for this crap if not up to $800-$1000 depending on how nice and tight you want it all to fit and look. A premade log manifold kit is what I'm going with if i do it again after making my own from flipped manifolds. V-band clamps, mandrel bends, flex coupler, flanges, etc...$200 in 3.5" or 4" pipe for down pipe and exhaust, couple hundred more to that for the wide band O2. I swear after the shipping on the mandrels and pipes in 2" size I would have broke even just buying the Holley log setup and saved like 30-40 hours of fabrication work...
Cold side, $300-400 get a intercooler kit from ebay or the site you get the turbo from, depending on the fuel you have access to and the HP you want you may want to set aside $600 for a water/meth injection kit.
Fuel pump, 400ish size($200) and probably a fuel pressure regulator($150) with at least a set of matched decapped injectors ($200ish) or a set of dekas($400)
MAP sensor 3bar ($30), IAT($30), Computer tune for stock ECU($150) this just gets it started enough to limp it to the dyno, you need a dyno tune after ($500)
Some sort of catch can breather system, make it or buy it for about $250, do you need to convert to an electric fan setup for room? add another $500, etc...you need a fuse block with at least 4 fuse location and a min of two 30amp relays.
That will get you to the $3500 mark and running. Things like a boost controller, heat shielding, vacuum lines, check valves, line T's and fittings, spark plug wires and spark plugs, wire harness looming and tape, crimp connectors, fuel line, special fitting to adapt after market components to stock fittings, extended oil lines and coolers, etc....lots and lots of stuff never gets mentioned when the subject of a $3000 turbo build comes up. You can do it for $3000-$3500, that was my goal too. But along the way be prepared to agonize over whether to do or install something a way you dont like because it's in budget. The sticky thread about the true cost of boost was something i looked hard at before starting, you can get into a situation pretty easy where you get forced to blow the budget to get it finished. $3000 is also banking on everything being in reusable condition as well, sometimes they are, sometimes they are not.
My best advice is save $5000 for a $3500 dollar build. Even after doing it once now I'm not sure i could do it for $3500 a second time knowing exactly what I would need from the prior experience.
To make a list of all the parts it took would take me an hour or more, when you get down to all the hose clamps and hoses, electrical bits, etc...
you need a turbo from one of the sites that sells the good Chinese turbos, 75/78, gt45, etc...$500ish
You need the hot side components. Manifolds, make them or buy them it will cost you $400 at min for this crap if not up to $800-$1000 depending on how nice and tight you want it all to fit and look. A premade log manifold kit is what I'm going with if i do it again after making my own from flipped manifolds. V-band clamps, mandrel bends, flex coupler, flanges, etc...$200 in 3.5" or 4" pipe for down pipe and exhaust, couple hundred more to that for the wide band O2. I swear after the shipping on the mandrels and pipes in 2" size I would have broke even just buying the Holley log setup and saved like 30-40 hours of fabrication work...
Cold side, $300-400 get a intercooler kit from ebay or the site you get the turbo from, depending on the fuel you have access to and the HP you want you may want to set aside $600 for a water/meth injection kit.
Fuel pump, 400ish size($200) and probably a fuel pressure regulator($150) with at least a set of matched decapped injectors ($200ish) or a set of dekas($400)
MAP sensor 3bar ($30), IAT($30), Computer tune for stock ECU($150) this just gets it started enough to limp it to the dyno, you need a dyno tune after ($500)
Some sort of catch can breather system, make it or buy it for about $250, do you need to convert to an electric fan setup for room? add another $500, etc...you need a fuse block with at least 4 fuse location and a min of two 30amp relays.
That will get you to the $3500 mark and running. Things like a boost controller, heat shielding, vacuum lines, check valves, line T's and fittings, spark plug wires and spark plugs, wire harness looming and tape, crimp connectors, fuel line, special fitting to adapt after market components to stock fittings, extended oil lines and coolers, etc....lots and lots of stuff never gets mentioned when the subject of a $3000 turbo build comes up. You can do it for $3000-$3500, that was my goal too. But along the way be prepared to agonize over whether to do or install something a way you dont like because it's in budget. The sticky thread about the true cost of boost was something i looked hard at before starting, you can get into a situation pretty easy where you get forced to blow the budget to get it finished. $3000 is also banking on everything being in reusable condition as well, sometimes they are, sometimes they are not.
My best advice is save $5000 for a $3500 dollar build. Even after doing it once now I'm not sure i could do it for $3500 a second time knowing exactly what I would need from the prior experience.
TECH Apprentice
Joined: Jul 2017
Posts: 312
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From: Stephens city VA
Thread Starter
Teching In
Joined: Jun 2019
Posts: 2
Likes: 0
From: Virginia
I appreciate it fellas! I’m mainly just trying to figure out where to start. Like I said I’m very new to this type of build. I wanna know what components work with what. Should I put a ls9 cam in the lm7. What turbo kits have people used that worked decent that were from eBay. Im doign as much research as I can to point myself in the right direction. I just don’t wanna spend money on parts that won’t work for my application.
