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I have been doing a bit of reading on turbocharging my ls1 and have been interested in doing it for the last 10 years but due to lack of mechanical knowledge and deep pockets I have held off till now.
Now I am not totally clueless on turbocharging these vehicles or any as i have a compound turbo Cummins running a 63/80mm combo. I build it from the ground up as far as motor work and just everything else to make it work fuel and such. Now on to my questions I will probably be buying most of my stuff from texas-speed and using the DIY truck manifold turbo build for my reference. A huge question is why most folks on here use ball bearing turbo instead of the regular journal bearing besides spool up??? Journal bearing turbos are easier to install and dont need liquid to cool down just want to know what everyone thoughts are on it?? Boost is restriction of air so do boost numbers have to be that high for big hp??
List so far:
Truck manifold no EGR ports.
PRC dual Valve springs
ARP Studs
Torquer Cam V3 or V4 need more research on this
turbo K member..... Which one to buy???
Traction bars
Tial 40mm wastegate 7psi limited
66mm BW T4 .91 A/R
Walbro 340lph pump
Dana 60 rear
I have ran nothing but standard bearing turbos for decades. Most dramatic response gains in the last decade have come by way of more efficient turbine whelels. Don't get me wrong, BB may help, but I have yet to see a major difference all things being equal. If you are pushing the turbo hard, & I mean hard, I could maybe see a value there, maybe, but to fret over it when you are doing a budget build doesnt make cents. (Pun intended)
I have bought uber expensive turbos & cheapies. I have been lucky both ways. I am even not afraid of running used stock turbos if it fits the budget & build. Only turbo I had let go, ever, was a old stock GN turbo I got off Ebay for a twin turbo build. That turbo even lasted a couple years of hard drags before puking a seal. So then I got online & found another one for $150.
A periodic check of the bearing/shaft tightness, meaning end & radial play, is a good way to monitor how the turbo is doing. You'll feel it when it starts to get too loose. Once you get more than a few thou play in it it is time to start searching for a replacement.
Yeah I really dont see any advantages to it but very slight spooling response on the Garrett turbos but other than that i see alot of folks running that turbonetics ****. I run both BW on my cummins and have close to 800 to the wheels I need more fuel though so I top off at about 60 psi.
Just give the guys over at Huron Speed a call or shoot them an email. They will be able to answer all your questions and get you any of the parts you may need at a great price.
Gettibg a turbo does any one recommend a welder for me i was lookibg only at licoln i was something great that i can expand with sso far i like the power mig family and the st100
Honestly where you are with knowledge on this you either need to sit down and read this site and other similar sites for a few days. Read up on a lot of build threads.
Or you can just call a place like huron speed, tell them your goals and give them your credit card number.
But you have a basic idea.
Truck manifold kit with a cheap ebay intercooler
Get a tc78 or precision 76 t4 turbo with like a .96 ar
Get a custom spec cam, not the ones you listed.
80lbs injectors, dual fuel pump kit, good fuel rails and a return line.
3 bar map sensor will give you room to grow
Any turbo k-member will work, just ask the place you get you turbo kit from what they like to use.
Get gm mls head gaskets and arp head studs.
Get a good tune
You are going to probably want to upgrade transmission and rear end and suspension but thats a whole other subject.
Honestly where you are with knowledge on this you either need to sit down and read this site and other similar sites for a few days. Read up on a lot of build threads.
Or you can just call a place like huron speed, tell them your goals and give them your credit card number.
But you have a basic idea.
Truck manifold kit with a cheap ebay intercooler
Get a tc78 or precision 76 t4 turbo with like a .96 ar
Get a custom spec cam, not the ones you listed.
80lbs injectors, dual fuel pump kit, good fuel rails and a return line.
3 bar map sensor will give you room to grow
Any turbo k-member will work, just ask the place you get you turbo kit from what they like to use.
Get gm mls head gaskets and arp head studs.
Get a good tune
You are going to probably want to upgrade transmission and rear end and suspension but thats a whole other subject.
Yeah i am not gonna buy a shitty turbo I rather have a bw like the one above. I have read a few threads on here on turbo builds the most detailed one so far is from killer ls1 with the army grren camaro. He has a bunch of engine work done to his i would lile to keep the bottom end pretty much stock till it blows then i will get a 5.3 in there. I dont want to push more then 7 psi through the block so i am straying away from a high hp build
I ran a 125 NOS kit in my 98 C5 for a couple of years before finally pulling it out and installing a twin turbo. In the last five years I've put over 65k miles on the car with the turbos (125k currently) and haven't had any issues.
My motor is bone stock, not a gasket has been opened since it came from the factory.
When I installed the turbos I added an intercooler, 42lb injectors, and changed the spark plugs. For the first month while tuning with HP Tuners I kept it around 4psi which made 468rwhp but once I was comfortable with the software I got it tuned for 8psi and haven't touched it since.
I'm a software guy, not hardware. I'm sure I could have really gotten an amazing build with a little more time/money invested but for my skills I'm more than happy with the bolt ons
I ran a 125 NOS kit in my 98 C5 for a couple of years before finally pulling it out and installing a twin turbo. In the last five years I've put over 65k miles on the car with the turbos (125k currently) and haven't had any issues.
My motor is bone stock, not a gasket has been opened since it came from the factory.
When I installed the turbos I added an intercooler, 42lb injectors, and changed the spark plugs. For the first month while tuning with HP Tuners I kept it around 4psi which made 468rwhp but once I was comfortable with the software I got it tuned for 8psi and haven't touched it since.
I'm a software guy, not hardware. I'm sure I could have really gotten an amazing build with a little more time/money invested but for my skills I'm more than happy with the bolt ons
I am very happy to hear that i was looking at the tunning software I am debating on whether to go to HP tuner or EFI live as I have heard great things about both. I dont want to overbuild ill be happy with a 10 sec car my bike can run 8s so I dont need more speed and my truck is faster than my trans am since the compounds are in so I just need to get the trans am up to speed. The truck in itself has close to 800rwhp so if I can get 600 or 700 from the trans am ill be one happy man. mini freight train is what imma call it lmao
I am very happy to hear that i was looking at the tunning software I am debating on whether to go to HP tuner or EFI live as I have heard great things about both. I dont want to overbuild ill be happy with a 10 sec car my bike can run 8s so I dont need more speed and my truck is faster than my trans am since the compounds are in so I just need to get the trans am up to speed. The truck in itself has close to 800rwhp so if I can get 600 or 700 from the trans am ill be one happy man. mini freight train is what imma call it lmao
If you only want 6-700whp just get a tc78 or a 7875 turbonetics and be done. Plus with those and a properly designed kit, you won't need an aftermarket k member.
Its crazy how different types of site think differently the a/r on those turbonetics is a bit high for me I want the boost to come up sooner than that. I probably wouldnt buy a turbonetics anyways arent they ball bearing?? I rather do a good ole trusty S475
Its crazy how different types of site think differently the a/r on those turbonetics is a bit high for me I want the boost to come up sooner than that. I probably wouldnt buy a turbonetics anyways arent they ball bearing?? I rather do a good ole trusty S475
Not all of them are ball bearing. My 7575 is but it doesn't add any more complexity as its not water cooled, its oil cooled like a standard journal turbo would be.
An s475 is huge compared to the TC series or the midframe 7875 or 7575 and will be MUCH harder to package and will also spool slower. I have read threads on here talking about .96 a/r TC76 and TC78 units spooling around or before 3000 rpms depending on setup. Most say the TC series is the perfect street turbo setup under 700whp for an LS powered car.
Not all of them are ball bearing. My 7575 is but it doesn't add any more complexity as its not water cooled, its oil cooled like a standard journal turbo would be.
An s475 is huge compared to the TC series or the midframe 7875 or 7575 and will be MUCH harder to package and will also spool slower. I have read threads on here talking about .96 a/r TC76 and TC78 units spooling around or before 3000 rpms depending on setup. Most say the TC series is the perfect street turbo setup under 700whp for an LS powered car.
Though the physical size of the borgwarner is larger, its a nice, well priced, reliable choice. with proper camshaft and tuning- spool up should be an absolute non-issue.
my ls1 has yet to be tuned *damn Canadian winters* but the S475 that i purchased came off a 331ci foxbody mustang (5 speed) was told the car was fully spooled ~ 3000 RPM- car made 73X to the tire
t4 s475 83 turbine .96 a/r
to OP honestly just check out as many build threads as you can between now and throwing the car together. You'll be very glad you did. and if not give huron speed a call and I'm confident they'll help steer you in the right direction.
Not all of them are ball bearing. My 7575 is but it doesn't add any more complexity as its not water cooled, its oil cooled like a standard journal turbo would be.
An s475 is huge compared to the TC series or the midframe 7875 or 7575 and will be MUCH harder to package and will also spool slower. I have read threads on here talking about .96 a/r TC76 and TC78 units spooling around or before 3000 rpms depending on setup. Most say the TC series is the perfect street turbo setup under 700whp for an LS powered car.
Your probably right about the frame being a bit large as I know the S480 in my truck is pretty effin large turbo but in the truck its really a non issue since there is so much space. i will definetely take a better look if Turbonetics wins me over I may swap over the turbos on the cummins
Though the physical size of the borgwarner is larger, its a nice, well priced, reliable choice. with proper camshaft and tuning- spool up should be an absolute non-issue.
my ls1 has yet to be tuned *damn Canadian winters* but the S475 that i purchased came off a 331ci foxbody mustang (5 speed) was told the car was fully spooled ~ 3000 RPM- car made 73X to the tire
t4 s475 83 turbine .96 a/r
to OP honestly just check out as many build threads as you can between now and throwing the car together. You'll be very glad you did. and if not give huron speed a call and I'm confident they'll help steer you in the right direction.
Did you have if issues on fitting it?? I still dont know if I would go that large maybe a s366 as I dont need a monster of a car just something to get in the 10 second range
11-01-2015, 09:52 PM
Questions on Turbocharging my 98 LS1 
