Turbo setup to make 1000hp

ZeroGravity58

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Mar 23, 2008
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I had a couple questions. Currently the truck had a 68vgt/s480 T6 1.32 housing. Talked to a couple turbo guys and they are trying to steer me into a s369 or s372 under the s480 or s485. I keep hearing drive pressure is to much to push a vgt over 4 digit power. I was thinking of running my 68vgt with a s485 5 blade. If a s300 would be better in the valley how hard would it be to modify my current twin kit to fit?
 

MAXX IT OUT

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Whats your Current DP ratio and how long will the truck be at or above the 1000HP? As far as modifying your kit, its do able, not sure if it would be worth it the effort or not.
 

Chevy1925

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This might be a good thread for you to read. i was deciding this route when i had the OG Limo.


you should be able to get to 1000 with the 68 in the valley and a 85 on top. drive pressure will be high though. it seems a 72vgt with the 85 or larger would be a better bet. Best is to swap in a fixed vane charger but you will have to change your intake pipe to the valley charger, feed line, drain line, possibly charge pipe out of valley charger and the exhaust out of the valley charger. if you can weld, not a huge deal. if you cant, better off getting a new kit or trading.
 

Bdsankey

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You certainly can do 1000whp on a VGT/S400 kit but as stated drive pressure will be high. A 369/485-488 works very very well for those goals and maintains drivability.


Some of the larger turbine VGTs may be able to help bring drive pressure into a bit better zone but nothing like an S3 or S4 can.
 

ZeroGravity58

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Understood, I talked to a well known turbo guy and asked him about the smeding drop in charger, if I could get one I'd send it to him and have him go through it. The only thing I would have to change is the hot side pipe. It's hard to justify spending 2k in a smeding turbo then spending another 1k having it gone through but that's the price of a decent vgt anyways. I'm not a good welder but I can tack it all together and have someone else weld it up. To bad no one else makes a drop in.
 

Bdsankey

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Understood, I talked to a well know turbo guy and asked him about the sending drop in charger, if I could get one I'd send it to him and have him go through it. The only thing I would have to change is the hot side pipe. It's hard to justify spending 2k in a smeding turbo then spending another 1k having it gone through but that's the price of a decent vgt anyways. I'm not a good welder but I can tack it all together and have someone else weld it up.
Personally I wouldn't buy the Smeding drop ins but that's just me. The 3-4 I've sold 2 have had issues. Both leaked oil, both killed bearings, both were on mid 500hp files.

Everything I've installed at our shop Smeding wise has been the cheapest Chinese thing on the market with various fitment and QC issues (IE sending the wrong oil drain twice).
 

ZeroGravity58

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That's the biggest problem with them, you don't know what your going to get. I was told to run a s369 and keep my current s480 and it will make over the 4 digit mark. Fuel will be 300's and a 14mm pump. Who still makes s300/s400 kits or s300/s400 kits?
 

Bdsankey

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That's the biggest problem with them, you don't know what your going to get. I was told to run a s369 and keep my current s480 and it will make over the 4 digit mark. Fuel will be 300's and a 14mm pump. Who still makes s300/s400 kits or s300/s400 kits?
I know I can still get SDP kits but their timelines are long.

Personally if you want over 1k I would run a larger atmospheric charger. A 480 will do 1k but it's trying to get there in compounds IMO.
 

ZeroGravity58

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Well I went with a HTT gated S366 66/74/.91 and a Work S488SXE 88/88/1.32. motor has empire stg 2 cam. When do you guys upgrade rocker bridges and stud rockers? Have springs and pushrods
 

Bdsankey

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Well I went with a HTT gated S366 66/74/.91 and a Work S488SXE 88/88/1.32. motor has empire stg 2 cam. When do you guys upgrade rocker bridges and stud rockers? Have springs and pushrods
I've never done rocker studs, only the Merchant/ARP bolts. My race truck motor that made 1340/2200 had OEM rocker arms and bridges with just good springs/pushrods/Merchant bolts.


My tow rig motor has all Manton valve train with their billet bridges, rocker shafts, valve springs, and pushrods with ARP/Merchant bolts again.
 

ZeroGravity58

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I've never done rocker studs, only the Merchant/ARP bolts. My race truck motor that made 1340/2200 had OEM rocker arms and bridges with just good springs/pushrods/Merchant bolts.


My tow rig motor has all Manton valve train with their billet bridges, rocker shafts, valve springs, and pushrods with ARP/Merchant bolts again.
I would love to have all their valve train but it's definitely not in the budget this time around 😂. I may pick up a set of the bolts for piece of mind
 

Bdsankey

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I would love to have all their valve train but it's definitely not in the budget this time around 😂. I may pick up a set of the bolts for piece of mind
What I was more so getting at is stronger bolts with OEM rockers/shafts etc (good springs/pushrods) has been a reliable setup for me and many customers. Rocker studs are nice but I haven't seen a need for them. I've also never had an OEM rocker shaft bolt fail, I've always done the Merchant/ARP bolts as they're cheap and a nice little strength upgrade over OEM.
 

Chevy1925

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if im going to make valvetrain changes beyond just springs and pushrods, i would want to lighten everything up as much as possible. that would be my main reason for doing it.
 
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