Big Bore
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Ok I'm convinced and looking for good deal on a GT47
Twins for dumbies
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Tree Trimmer
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before you just go, thats the one i want, where's it at, i would talk to some ppl who have/had it, or know about it. ask if you can call charles and talk to him, or HRT, or any sponser for that matter. because for the goals you give to them of what you want for your truck, there might be a better option(s) out there.
just because charles had a 38/47 and it worked fabulous for him, does not mean it will work fabulous for you. just to throw this out, charles' truck is 600+hp, day in, day out, everyday. its what he wants. ask about the motors, trans, input shafts, and drive line issues that go along with that. if you do not want to dd 550-600+ day in, day out, everyday like he does, and now you turn the knob down on your chip for a different program, whats that do for spool.
build your compounds around where your goin to be driving 95% of the time, not where you will be 5% of the time. imo, you will be happier in the end. if 95% of your time is on the track, hells ya, go big or go home. but if 95% of your time is hooked to a trailer/dd'ing, thats more than likely a different setup.
just saying....
just because charles had a 38/47 and it worked fabulous for him, does not mean it will work fabulous for you. just to throw this out, charles' truck is 600+hp, day in, day out, everyday. its what he wants. ask about the motors, trans, input shafts, and drive line issues that go along with that. if you do not want to dd 550-600+ day in, day out, everyday like he does, and now you turn the knob down on your chip for a different program, whats that do for spool.
build your compounds around where your goin to be driving 95% of the time, not where you will be 5% of the time. imo, you will be happier in the end. if 95% of your time is on the track, hells ya, go big or go home. but if 95% of your time is hooked to a trailer/dd'ing, thats more than likely a different setup.
just saying....
The combo of mid 60mm manifold turbo with a 47ish size atmosphere turbo allows for as little or much power as you want. With proper waste gating you are not going to stay in the sweet spot of both maps the whole time. What you can make max does not correlate to what you actually use for towing unless LIKE CHARLES you treat the go pedal like a on off switch. Honestly how many people do that other than him. If you do you have to expect things to break with anything over 300-350HP 800tq But unless you only drive with your foot either to the floor board or on the brake its not an issue. IIIRC Pius called a similar sized compound setup he built a good towing setup.
silverpsd_06
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By the go big or go home comment i meant that anything under 88mil is pretty much a waste.. A: generally speaking the turbine side will not keep up with demand to get rid of the gas thus you'll need a much larger heavier gate. B: it just won't be a smooth transition from one to the other it'll be more punchy than anything and hooked to a trailer with that kind of response = broken chit.
No one would expect a 38r to sit behind a PT-106 and spool that large of a turbo, if you wanted to get really rediculous stack that 4202 in behind the 106 your gonna spool the same as what you have now, maybe a tit faster, now your talking flowing 90lbs up to 175lbs. That's for the makings of some serious numbers.
I would think that as long as you tuned your gates within the ranges of your hottest setting then you should be alright to take fuel away and still have decent response out of it...
No one would expect a 38r to sit behind a PT-106 and spool that large of a turbo, if you wanted to get really rediculous stack that 4202 in behind the 106 your gonna spool the same as what you have now, maybe a tit faster, now your talking flowing 90lbs up to 175lbs. That's for the makings of some serious numbers.
I would think that as long as you tuned your gates within the ranges of your hottest setting then you should be alright to take fuel away and still have decent response out of it...
juniort444e
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So hypothetically speaking if i wanted a 4288/55xx, i could tune the gates for a hot tune, if i wanted more then one, and run any other tune and it should act fine. I understand it wont spool as fast but it still drivable. And from what your saying tarm helps my worries from what someone else said.
If i remember correctly they were saying that you wanted to be on the right side of the dotted line on the turbo map. Im still trying to figure all that out. But lets say in a non hot tune or maybe a econo tune those turbos were on the left side what would happen. Or would it even matter.
If i remember correctly they were saying that you wanted to be on the right side of the dotted line on the turbo map. Im still trying to figure all that out. But lets say in a non hot tune or maybe a econo tune those turbos were on the left side what would happen. Or would it even matter.
I would too, if i owned a dinosour engine thats the exact turbo would pick for a primary... probably the same thing i would run on my 6.4 then size the secondary so the truck is still fun to drive, and not a complete turd on the street (cuz thats whats important)
From what i have read you guys are kinda over complicating things a bit IMHO, primary turbo selection is alot more forgiveable than say the secondary.
also, proper gate tuning shouldnt make the truck more or less laggy...
Big Bore
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Secondary is a 38r that spools very well even here at high altitude.
That is what I was starting to think also. And since the 47/38r according to Charles had gasser response off the line, and after lookinng more carefully at the maps as suggested earlier, I came to the 47 decision, not just haphazardly as suggested earlier.
Yea that confused me and I didn't think it was right, but didn't know enough to argue the point. If my 38r already spools well, I dont think the 47 is going to lag things out since one of its functions is to feed the secondary higher atmosphere, which in turn is going to help it spool even faster, and the 38r is going to be feeding the drive side of the 47 pressurized exhaust and I dont see the size of the 47 drive side being a choke point at all. And Charles has stepped up to a 55/38r that is apparently even more wicked than the 47/38r, telling me that the 47/38r is probably going to work very well at altitude. The gates seem to be more for the top end so I don't send the heads into orbit. If the gates being closed do create a lag situation, HRT gave some good information on how to set them to pop open a bit when stabbing the throttle.
I think you are on the right track. Most people don't understand how bad altitude effects spool up... we do and I say go for the 38r combo...
You will see slightly more lag because the exahsut flow across the 38 will be slowed down a bit due to the fact that now it has a 47 wheel to go against... it shouldn't be much tho.
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Tree Trimmer
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thats a new one...... skittles more lag? LOL i like that.
Big Bore
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No, no, I like skittles as new terminology for slightly. I'm going to start using it.
As to the skittles more lag issue, based on another convo I'm wondering if a non WG 1.0 wouldn't solve that. I'm also starting to lean toward a single 38mm WG in each up pipe, thats 76mm of wastegate and a very economical way to get it.
As to the skittles more lag issue, based on another convo I'm wondering if a non WG 1.0 wouldn't solve that. I'm also starting to lean toward a single 38mm WG in each up pipe, thats 76mm of wastegate and a very economical way to get it.
Big Bore
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Thats still a huge gate. And two 38's are a lot less expensive.
Conversely a single is less plumbing and less parts.
Interesting quandary.
Big Bore
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You are correct.
Area = 3.14xdia^2
38mm A=4534.16x2gates = 9068.32
54mm A=9156.24
Area = 3.14xdia^2
38mm A=4534.16x2gates = 9068.32
54mm A=9156.24
Big Bore
Active member
Two 44mm A=12158.08 = $700+/-
One 60mm A=11304 = $600+/-
One caveat, 44's are available in water cooled MV-S/R, 60mm is not. Not sure how much difference that would make, but seems like in our hi temp application it would make a difference in lifetime of the WG's.
One 60mm A=11304 = $600+/-
One caveat, 44's are available in water cooled MV-S/R, 60mm is not. Not sure how much difference that would make, but seems like in our hi temp application it would make a difference in lifetime of the WG's.
What i have gathered from set ups like brian's truck is the reason you run two gates is because a single big gate tends to dump pressure too fast, which can make the gate surge and chatter opened and closed, because the gate even opened very slightly is dumping a TON of air, i have no experience with it tho. but it makes sense, if you can basically open on gate wide open, and then start to bring a gate in at the higher rpm to blead any additional back pressure up top if the rpm range.
Im running a single 46mm gate for now, and then if i need more i will add another gate. I also like two gates because there is no real reason two tie both uppipes together (for flow reasons) where with a 60 gate you would have to.
Im running a single 46mm gate for now, and then if i need more i will add another gate. I also like two gates because there is no real reason two tie both uppipes together (for flow reasons) where with a 60 gate you would have to.
