On3 7875 Turbo LS1 Build Thread
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 55
Likes: 0
On3 7875 Turbo LS1 Build Thread Over the next few weeks I'll be installing the 7875 On3 turbo kit with AC on my mainly stock 99 TA with ~80,000 miles on the clock. Car dynoed at 376 RWHP in its current state (was told that might be 15-20 HP high from dyno calibration). I'm relatively new to the build world, but I like to think that I've done my homework. If you have any tips or suggestions before I get started or as I post updates, feel free to chime in. Pretty familiar with wrenching from working on my 5.3 Yukon pretty regularly, but never dealt with this tight of quarters before. So any install advice is greatly appreciated. The details of my current setup and the plans are listed below. My plan for this year is to keep the stock bottom end and drivetrain, and keep the power below 550 RWHP. The plan is to run E85 with this setup.
Current Setup
-Stock Internal 5.7L LS1
-LS6 Intake
-Pacesetter headers, Offroad Y-pipe, SLP LM1 catback
-Underdrive pulley
-B&M Shift Kit
-Tranny cooler
-UMI LCAs, LCA relocation brackets, panhard bar, torque arms, subframe connectors, and strut tower brace
Planned Build
-On3 LS1 turbo kit with AC retained
-7875 On3 journal bearing turbo
-On3 billet oil feed block
-TurboWerx Oil Scavenge Pump (have not ordered)
-PA racing tubular k member with Madman "save your ***" bars
-Tick Performance Turbo Stage 2 V2 Cam 231/231 | .63x"/.59x" | LSA115+5
-BTR .660" Lift Platinum Valve Spring Kit
-New GM Timing Chain
-Comp Cams LS Rocker Arm Trunion Upgrade (have not ordered)
-Racetronix F99 fuel pump kit with wiring kit
-FIC 1000cc High-Z Fuel Injectors with plug-n-play adapters
-Turbosmart eBoost 2 boost controller (have not ordered)
-Fuel Pressure Gauge (have not ordered)
-Gauge Pillar (have not ordered)
That's all I got for now. Let me know what you guys think. I bolded all the stuff I have not ordered and may need some advice on.
Current Setup
-Stock Internal 5.7L LS1
-LS6 Intake
-Pacesetter headers, Offroad Y-pipe, SLP LM1 catback
-Underdrive pulley
-B&M Shift Kit
-Tranny cooler
-UMI LCAs, LCA relocation brackets, panhard bar, torque arms, subframe connectors, and strut tower brace
Planned Build
-On3 LS1 turbo kit with AC retained
-7875 On3 journal bearing turbo
-On3 billet oil feed block
-TurboWerx Oil Scavenge Pump (have not ordered)
-PA racing tubular k member with Madman "save your ***" bars
-Tick Performance Turbo Stage 2 V2 Cam 231/231 | .63x"/.59x" | LSA115+5
-BTR .660" Lift Platinum Valve Spring Kit
-New GM Timing Chain
-Comp Cams LS Rocker Arm Trunion Upgrade (have not ordered)
-Racetronix F99 fuel pump kit with wiring kit
-FIC 1000cc High-Z Fuel Injectors with plug-n-play adapters
-Turbosmart eBoost 2 boost controller (have not ordered)
-Fuel Pressure Gauge (have not ordered)
-Gauge Pillar (have not ordered)
That's all I got for now. Let me know what you guys think. I bolded all the stuff I have not ordered and may need some advice on.
Well, you certainly won't need E85 to make 550rwhp. Everything looks good me except potentially going to little too far with your fueling.
And for the price, the Boost Leash is a much better piece than the eBoost2, imho.
And for the price, the Boost Leash is a much better piece than the eBoost2, imho.
Did you speak with Martin before ordering the cam? I spoke with him about a cam for a 347 I'm doing with the same turbo. Aside from a custom grind, he recommended the stage 1 cam (227/227 duration).The 75mm turbine and .96ar housing are a bit small for a motor this size. So in order to keep back pressure from getting to out of hand, it's best to keep the duration down.
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 55
Likes: 0
Did you speak with Martin before ordering the cam? I spoke with him about a cam for a 347 I'm doing with the same turbo. Aside from a custom grind, he recommended the stage 1 cam (227/227 duration).The 75mm turbine and .96ar housing are a bit small for a motor this size. So in order to keep back pressure from getting to out of hand, it's best to keep the duration down.
On another topic, I was planning on doing this build on jackstands, but I'm thinking it might make things easier to just pull the motor. What are your guys thoughts? I do not have lift access and would have to buy an engine hoist.
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This is more of a question than a statement...but is the oil scavenge pump necessary for this build? Generally you only see them used on rear mount turbo setups. I could be wrong though
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On The Tree
Joined: Apr 2011
Posts: 136
Likes: 0
From: indianapolis
last year i installed the on3 76mm turbo non a/c turbo kit, tick cam, 317s and all supporting mods. 4 psi made 490 rwhp on pump 93. the gate has the 7 psi spring but didnt have a controller in yet...
i dont know if the a/c kit you have will keep stock fans but the non a/c kit didnt. so i have 2 pushers on there that keep it pretty cool (180) on hot days in indiana. i also just taped my oil drain into the driver side pan. so you could save cash by doing that.
i dont know if the a/c kit you have will keep stock fans but the non a/c kit didnt. so i have 2 pushers on there that keep it pretty cool (180) on hot days in indiana. i also just taped my oil drain into the driver side pan. so you could save cash by doing that.
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 55
Likes: 0
I'm kind of back and forth on the scavenge pump. The turbo does sit somewhat low for a front mount, so I was gonna play it safe but I'm open to suggestions. Plus I didn't want to pull the oil pan, but if I'm gonna end up pulling the motor from the car I might just do it.
Unbolt the the k member from the car.
Disconnect the exhaust from the manifolds/headers.
Remove the driveshaft from the trans.
And lift the front with a jack. You can get it high enough to roll the whole K member with the motor and trans out. I've done it.
Disconnect the exhaust from the manifolds/headers.
Remove the driveshaft from the trans.
And lift the front with a jack. You can get it high enough to roll the whole K member with the motor and trans out. I've done it.
TECH Enthusiast
Joined: Nov 2005
Posts: 749
Likes: 21
I used this kit last year, here is my build thread -
https://ls1tech.com/forums/forced-in...long-read.html
You'll need the pushers like mentioned, get the derale's and don't look for any alternatives. For the work on the pan just pull it if you are going to dump it in the pan and make sure you have the biggest line possible.
I just got my Eboost 2 installed this last weekend and waiting on my pump setup from Squash then will turn it up a bit more and throw it on the rollers see if I don't make something go boom.
https://ls1tech.com/forums/forced-in...long-read.html
You'll need the pushers like mentioned, get the derale's and don't look for any alternatives. For the work on the pan just pull it if you are going to dump it in the pan and make sure you have the biggest line possible.
I just got my Eboost 2 installed this last weekend and waiting on my pump setup from Squash then will turn it up a bit more and throw it on the rollers see if I don't make something go boom.
TECH Enthusiast
Joined: Nov 2005
Posts: 749
Likes: 21
I've only got to play with it for one day really, will tweak with it more this week as I drive the car. My only gripe is you can't set the boost at an actual number for your target, instead you have to try and figure out which SP value to give it. Strange because things like overboost shutdown and gate pressure are all controlled by the measure of boost.
Is nice to be able to play with the boost on the move. Only downside is running low timing all the time for when it might get turned up, I can feel that it's not as strong in the lower boost range with less timing as it was with more timing, if that makes sense.
Is nice to be able to play with the boost on the move. Only downside is running low timing all the time for when it might get turned up, I can feel that it's not as strong in the lower boost range with less timing as it was with more timing, if that makes sense.
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 55
Likes: 0
I used this kit last year, here is my build thread -
https://ls1tech.com/forums/forced-in...long-read.html
You'll need the pushers like mentioned, get the derale's and don't look for any alternatives. For the work on the pan just pull it if you are going to dump it in the pan and make sure you have the biggest line possible.
I just got my Eboost 2 installed this last weekend and waiting on my pump setup from Squash then will turn it up a bit more and throw it on the rollers see if I don't make something go boom.
https://ls1tech.com/forums/forced-in...long-read.html
You'll need the pushers like mentioned, get the derale's and don't look for any alternatives. For the work on the pan just pull it if you are going to dump it in the pan and make sure you have the biggest line possible.
I just got my Eboost 2 installed this last weekend and waiting on my pump setup from Squash then will turn it up a bit more and throw it on the rollers see if I don't make something go boom.
TECH Enthusiast
Joined: Nov 2005
Posts: 749
Likes: 21
Yup snag up two of the derale kits. They come with a pull through pin setup that is easy to install. You have to slightly stagger the fans on the condenser but they should both sit on there and keep the car cool enough.
I haven't run the car in 100+ temps with AC on yet but with 80+ temps at an idle when they kick on it pulls the temps down under target temp pretty fast. There was enough room on the radiator side I figure if there are cooling issues I can throw in some small pullers to help keep it cool. Will find out this summer.
When I first installed the kit I was getting oil burning through the turbo using the size line that was sent with the On3 setup so I had a local hose shop make up a larger size hose (think it was just over 3/4) and run that. It helped but I still got some oil pushing through if I stayed in the throttle for a while. Eventually ran a reducer and that solved all of my issues. I'm running a Turbonetics Ball Bearing so the oil demand isn't as big as it is on a journal type turbo. Not sure which you got but I say get a restrict or if you have a ball bearing and just keep it on the side. If you don't need it, just $20 blown, if you need it, have it right there to throw on.
I haven't run the car in 100+ temps with AC on yet but with 80+ temps at an idle when they kick on it pulls the temps down under target temp pretty fast. There was enough room on the radiator side I figure if there are cooling issues I can throw in some small pullers to help keep it cool. Will find out this summer.
When I first installed the kit I was getting oil burning through the turbo using the size line that was sent with the On3 setup so I had a local hose shop make up a larger size hose (think it was just over 3/4) and run that. It helped but I still got some oil pushing through if I stayed in the throttle for a while. Eventually ran a reducer and that solved all of my issues. I'm running a Turbonetics Ball Bearing so the oil demand isn't as big as it is on a journal type turbo. Not sure which you got but I say get a restrict or if you have a ball bearing and just keep it on the side. If you don't need it, just $20 blown, if you need it, have it right there to throw on.
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 55
Likes: 0
Yup snag up two of the derale kits. They come with a pull through pin setup that is easy to install. You have to slightly stagger the fans on the condenser but they should both sit on there and keep the car cool enough.
I haven't run the car in 100+ temps with AC on yet but with 80+ temps at an idle when they kick on it pulls the temps down under target temp pretty fast. There was enough room on the radiator side I figure if there are cooling issues I can throw in some small pullers to help keep it cool. Will find out this summer.
When I first installed the kit I was getting oil burning through the turbo using the size line that was sent with the On3 setup so I had a local hose shop make up a larger size hose (think it was just over 3/4) and run that. It helped but I still got some oil pushing through if I stayed in the throttle for a while. Eventually ran a reducer and that solved all of my issues. I'm running a Turbonetics Ball Bearing so the oil demand isn't as big as it is on a journal type turbo. Not sure which you got but I say get a restrict or if you have a ball bearing and just keep it on the side. If you don't need it, just $20 blown, if you need it, have it right there to throw on.
I haven't run the car in 100+ temps with AC on yet but with 80+ temps at an idle when they kick on it pulls the temps down under target temp pretty fast. There was enough room on the radiator side I figure if there are cooling issues I can throw in some small pullers to help keep it cool. Will find out this summer.
When I first installed the kit I was getting oil burning through the turbo using the size line that was sent with the On3 setup so I had a local hose shop make up a larger size hose (think it was just over 3/4) and run that. It helped but I still got some oil pushing through if I stayed in the throttle for a while. Eventually ran a reducer and that solved all of my issues. I'm running a Turbonetics Ball Bearing so the oil demand isn't as big as it is on a journal type turbo. Not sure which you got but I say get a restrict or if you have a ball bearing and just keep it on the side. If you don't need it, just $20 blown, if you need it, have it right there to throw on.
I've only got to play with it for one day really, will tweak with it more this week as I drive the car. My only gripe is you can't set the boost at an actual number for your target, instead you have to try and figure out which SP value to give it. Strange because things like overboost shutdown and gate pressure are all controlled by the measure of boost.
Is nice to be able to play with the boost on the move. Only downside is running low timing all the time for when it might get turned up, I can feel that it's not as strong in the lower boost range with less timing as it was with more timing, if that makes sense.
Is nice to be able to play with the boost on the move. Only downside is running low timing all the time for when it might get turned up, I can feel that it's not as strong in the lower boost range with less timing as it was with more timing, if that makes sense.
I use notepad in a table format on my laptop to keep track of all of the Set Points and Gate Pressure. I then do a pull write down how much boost was logged on the HPtuners and then enter that into notepad. This way I can keep track of all my set points and am not guessing ever again.
Gate Pressure will control boost spikes and how hard the boost comes in.