LML Turbo suggestions needed.

[19trax95]

Ok so I'll try and bypass the longer part of this story.

So the short of it is, I currently have a sportsman cp3, stock injectors, built trans (rated to 750hp), 66mm VGT, high flow intake/exhaust piping, and a fass 165.

The 66mm turbo blew the shaft apart, so the turbo needs to come out to get sent back for warranty purposes. While it's out, I was considering changing up the setup. I have been chatting with another member on here about his setup, and I'm torn between that, and a compound setup.

So, between these 3 options, what does everything think is the best, or more desirable setup. Or if there is a different recommendation, I'm all ears.

1. Ditch the VGT and do a single S366 in the valley

2. Stick the stock VGT in the valley and do an S480 over top (still have my stock turbo)

3. Put the 66mm VGT in the valley and do an S480 over top (will hopefully be getting a new warranty unit)

In all 3 cases, I'll be getting a 10mm CP3 and then bigger injectors down the road. My goals with the truck are a street-able, and reliable 700hp. Bottom end is in my future plans, but that will not be for some time, so it would be on the stock bottom end for a while.

I do not tow super often, and the truck is my daily. I do enjoy to use the power sometimes, but I do not race or pull the truck, just some spirted driving sometimes. Main things to me are the ability to get up and go when I want(I know compounds will likely win in that one), and also be able to have the tunes be clean (again, that is dependant on tuner mostly, which I won't get into).

I'd love to go compounds, but I'm slightly concerned about the torque they can make down low in the rpm range, and the havoc that can wreak on the bottom end. So what's everyone's opinion or experience?

 

[Chevy1925]

single 66 is going to have to be driven very hard to get to 700 hp, not good for your stock engine.

66 over 480 is going to have some lag

stock vgt over 480 is going to give you the fastest response and still hit your 700hp goal without being overly smokey on the big tune. if you want a clean 700hp (IE, next to no smoke under boost), you need to go 66 over 480 and deal with the lag and possible smoke before boost comes on. a good converter matched to the 66 will help spool up with the converter unlocked but wont help when trying to tow, converter locked and you roll into it while its lugging along.

also, your trans being "built" for 750 hp doesnt say much. we are better off knowing what hard parts are inside, what pressure spring used and what clutches were used inside. also what kind of converter you have so we know stall and coupling.

 

[Bdsankey]

IMO if they will do a warranty turbo get it and sell it before it's installed and put it towards a compound setup. A S480/96/1.15 or 1.32 over a stock turbo will be easier to tune (since LMLs don't have as much vane control as a 01-10 truck) and will reach your HP goal while also providing the best driving truck and cleanest running truck. It works great on stock fueling as well as with added fueling. On any truck, tuning will make or break (literally) the truck.


700whp on an LML is getting up there in terms of what I feel comfortable with on a customer's truck but I have definitely done it. As for injectors/fueling, 60% injectors and a 10mm or 12mm would be great fueling for your goals while not asking the fuel system for 100% of it's capacity.


I also agree with James, knowing what is done inside/what converter would be some good info. If you used a reputable builder it's not of much concern but it also can help ensure there is enough pressure/proper frictions etc.

 

[19trax95]

Mike L built trans, Goerend R converter.

With the 66 in the valley, and an s480 over top, would it spool similar to how it is with just the 66 or would it slow down a bit until the big charger takes off?

I know that the different exhaust housings on the s480 would also change things as well.

Even with a single s366/73 for now, I've read where that will spool pretty darn quick with the right tuning, and even better with larger injectors. I'm really open to a bunch of options. My main thing is not annihilate the bottom end. And obviously a lot of that is good tuning and driving sensibly.

 

[Bdsankey]

Mike L built trans, Goerend R converter.

With the 66 in the valley, and an s480 over top, would it spool similar to how it is with just the 66 or would it slow down a bit until the big charger takes off?

I know that the different exhaust housings on the s480 would also change things as well.

Even with a single s366/73 for now, I've read where that will spool pretty darn quick with the right tuning, and even better with larger injectors. I'm really open to a bunch of options. My main thing is not annihilate the bottom end. And obviously a lot of that is good tuning and driving sensibly.

You'd be pretty much the same drivability now with a 66vgt/480. The part that is concerning is having a failure so soon which I've seen out of 2 turbo builders who have large notoriety (one in WI and one in MN) due to social media.

I look at it this way, to go to a S300 you'll have to buy new piping and a turbo as it is. If you sell your replacement 66mm, you'll be a decent way towards a S400 over stock kit with a turbo. A stock turbo/s400 compound setup will drive circles around any drop in vgt or single S300.


With good tuning and increased injector size you can really make them pretty darn safe as pulsewidth can be turned back quite a bit.

 

[19trax95]

Yeah likely nailed the turbo manufacturer on the head lol. Really blows. Maybe had 6k miles on it.

So with say an S480 over stock, 10mm cp3 (or would a 12mm be better?), 100% over injectors and then good, mild tuning, that would be a fairly sweet setup?

I really should have clarified my 700hp goal. That goal is NOT until I build the bottom end. So I'd really only like to be around the 550-600 mark, however, since I'm dropping the money now, I want something that will support that goal in the future.

 

[Bdsankey]

Yeah likely nailed the turbo manufacturer on the head lol. Really blows. Maybe had 6k miles on it.

So with say an S480 over stock, 10mm cp3 (or would a 12mm be better?), 100% over injectors and then good, mild tuning, that would be a fairly sweet setup?

I really should have clarified my 700hp goal. That goal is NOT until I build the bottom end. So I'd really only like to be around the 550-600 mark, however, since I'm dropping the money now, I want something that will support that goal in the future.

480/stock, 100%, 12mm, good tuning, built trans is an absolute monster even on a stock bottom end plus allows you room to increase turbo size (if you desire) on the built motor while still keeping things in check.

 

[gmduramax]

Allow me to go against the grain lol I would do a 68mm 87 turbine .9 ar ball bearing

 

[OleBlackyLBZ]

Ditch the stock vgt and go with a single danville vgt unit is my vote. 10mm pump and 60 over injectors if your never going over 700.

 

[monster50iii]

I went away from a Danville vgt, and have zero regrets. Fixed vanes free up alot of drive pressure.

 

[Bdsankey]

I went away from a Danville vgt, and have zero regrets. Fixed vanes free up alot of drive pressure.

But if there's no vanes in a S300 or S400, how can they be fixed?

In all seriousness, S300s spool well but don't handle abuse all too well from what I've seen.

 

[Chevy1925]

But if there's no vanes in a S300 or S400, how can they be fixed?

In all seriousness, S300s spool well but don't handle abuse all too well from what I've seen.

depends on how its used. you keep a 300 in its map, its a very good turbo. you start pushing it outside its range and it doesnt take it well.

 

[Bdsankey]

depends on how its used. you keep a 300 in its map, its a very good turbo. you start pushing it outside its range and it doesnt take it well.

Bingo. The hard part without additional logging equipment is knowing exactly where the charger is at. We can take a rough stab at it with a boost gauge but that will really only get us the pressure ratio and not the whole story of where the charger is in terms of efficiency on both compressor and turbine side.

 

[gmduramax]

Bingo. The hard part without additional logging equipment is knowing exactly where the charger is at. We can take a rough stab at it with a boost gauge but that will really only get us the pressure ratio and not the whole story of where the charger is in terms of efficiency on both compressor and turbine side.

Blow up S300 turn boost down 2psi and repeat until success

 

[OleBlackyLBZ]

Bingo. The hard part without additional logging equipment is knowing exactly where the charger is at. We can take a rough stab at it with a boost gauge but that will really only get us the pressure ratio and not the whole story of where the charger is in terms of efficiency on both compressor and turbine side.

Or just make sure to get a good tuner that really understands turbos and has dialed in a particular set-up before, preferably with in-seat tuning. I doubt you will ever have any issues especially if the tuner is conservative...

 

[Chevy1925]

Bingo. The hard part without additional logging equipment is knowing exactly where the charger is at. We can take a rough stab at it with a boost gauge but that will really only get us the pressure ratio and not the whole story of where the charger is in terms of efficiency on both compressor and turbine side.

na, you can figure out the CFM/flow you are at fairly easy based on mathmatics of the engine, boost and power you are after. it gets you within 80-85% of where it will actually be, then a dyno tells the rest. ive setup 3 other guys plus my tracker this way and its worked well every time.

 

[Bdsankey]

na, you can figure out the CFM/flow you are at fairly easy based on mathmatics of the engine, boost and power you are after. it gets you within 80-85% of where it will actually be, then a dyno tells the rest. ive setup 3 other guys plus my tracker this way and its worked well every time.

Nice. I still stay away from them as singles myself. I believe a properly sized S400 will do just about anything an S300 single will do. If it won't, I stay stop drop-in. There are caveats like 300/400 compounds where I think they really shine.

 

[monster50iii]

If I had my choice a 62/68sxe gated, paired with an s480 would be a fun setup imo.

I went from a Danville 3794 vgt to an s369sxe, only to try a 68mm stg2r and go right back to the fixed vane. If you have the money, go fixed vane imo. It's worth it.

 

[gmac32]

I have a 64.5 sxe with a 80 turbine and a .83 gated housing over a s480. I like it so far. I have to do more tuning but it spools well