General waste of my time

Has anyone modified the wastegate on the acert set? If so how much are they capable of? Is my thinking correct to run the 55 as a single? or would I be better to run the compounds with a modified gate?



They will make 80psi+ of extremely hot air with the gate blocked. Tune isn’t an issue just expensive (cheap by comparison to what some bigcam parts cost)
 
They will make 80psi+ of extremely hot air with the gate blocked. Tune isn’t an issue just expensive (cheap by comparison to what some bigcam parts cost)

I was actually thinking the other way. What if you made the gate bigger? Work the big turbo more.

I don't understand compound setups. Whats better; big turbo as a single or using the set? Keep in mind its on a mechanical non lugging motor.
 
I was actually thinking the other way. What if you made the gate bigger? Work the big turbo more.



I don't understand compound setups. Whats better; big turbo as a single or using the set? Keep in mind its on a mechanical non lugging motor.



Well stock it’s getting air from between the stages so it doesn’t open until like 50psi. We usually move the hose to see total boost so it opens at like 21psi but boring the gate port out and using a larger flap would be great. Just never got around to trying it. Not sure how much larger you would have to go to make a real difference.
 
I was actually thinking the other way. What if you made the gate bigger? Work the big turbo more.

I don't understand compound setups. Whats better; big turbo as a single or using the set? Keep in mind its on a mechanical non lugging motor.
Are you going to run an air to air or air/cold water? The compounds are going to make more intake air heat just by compressing the air twice, I dont know how well a jwac will deal with it. I know people run them that way though. I'd think a single would be fine on a mech cummins, mostly because you dont need it to pull down very low anyway.

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Are you going to run an air to air or air/cold water? The compounds are going to make more intake air heat just by compressing the air twice, I dont know how well a jwac will deal with it. I know people run them that way though. I'd think a single would be fine on a mech cummins, mostly because you dont need it to pull down very low anyway.

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Factory jwac. Actually still running the low flow cooling so intake temps stay lower. Keep in mind this is only a pull truck
 
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I think cody was running his that way so maybe he'll weigh in in a bit but I'd be nervous about getting the iat way hot. He had enough boost to split the cooler so he was running it pretty hard lol.

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Mostly I am confused on turbo sizing. I keep prying for acert info and jfaulkner just hinted at it here.
boring the gate port out and using a larger flap would be great. Just never got around to trying it. Not sure how much larger you would have to go to make a real difference.

I keep asking if the gt55 will support more hp as a single vs running together with the gt42 on the manifold. With his comment I am willing to believe the manifold charger is limiting what the 55 can do on its own?
 
Mostly I am confused on turbo sizing. I keep prying for acert info and jfaulkner just hinted at it here.

I keep asking if the gt55 will support more hp as a single vs running together with the gt42 on the manifold. With his comment I am willing to believe the manifold charger is limiting what the 55 can do on its own?

Too much backpressure
 
How would that c16 turbo work as a high pressure with like a s500 coupled to it? In a 15l with enough fuel to spin it
 
I keep asking if the gt55 will support more hp as a single vs running together with the gt42 on the manifold. With his comment I am willing to believe the manifold charger is limiting what the 55 can do on its own?

You will always make more PEAK power when you run a turbo as a single, but compound arrangement will have a much wider USABLE power band. If you can spool the GT55, and keep it lit, run it as a single to pull it. I don’t have any experience to know how that will go. If you were gonna work the truck, you absolutely would want to run it as a compound arrangement. Even sled pulling it you might want to just for the fact thet you won’t have to worry about getting and keeping the single 55 lit.
 
You will always make more PEAK power when you run a turbo as a single, but compound arrangement will have a much wider USABLE power band. If you can spool the GT55, and keep it lit, run it as a single to pull it. I don’t have any experience to know how that will go. If you were gonna work the truck, you absolutely would want to run it as a compound arrangement. Even sled pulling it you might want to just for the fact thet you won’t have to worry about getting and keeping the single 55 lit.

If you need more than 800 rpm usable power band, go compound.
 
gt55 on the 855ci where would this 800rpm range be with a 1.12 turbine? How much higher in rpm would a 1.24 move this powerband?

Why would you want only 800 usable rpm for a pulling truck? He doesnt sled pull and all the performance vehicles he talks about belong to someone else.

I can tell you no one is running a GT55 on a 855 currently, usually if someone goes through the trouble they go above the GT55 frame and into the holset HC5/HX82 frame.
 
Why would you want only 800 usable rpm for a pulling truck? He doesnt sled pull and all the performance vehicles he talks about belong to someone else.

I can tell you no one is running a GT55 on a 855 currently, usually if someone goes through the trouble they go above the GT55 frame and into the holset HC5/HX82 frame.

Believe me I want more than 800rpm usable. It was more a question of how turbine size affects where. I also understand nobody may be running a gt55 on a b/c so real world testing doesn't exist. Just more curious in the math/theory of it all. I currently have two different housings on the way 1.0 and 1.12 haven't found a decently priced 1.24 yet. Guess I will be the real world test subject.
 
How would that c16 turbo work as a high pressure with like a s500 coupled to it? In a 15l with enough fuel to spin it

This is a good question. I was hoping someone would shed some light. More so how does the c16 turbo handle being a hp charger? I thought I read somewhere they have a hard time staying together after someone modifies the gate for higher pressure. Is the gate capable of bypassing enough to let it live as hp in a compound set?
 
Why would you want only 800 usable rpm for a pulling truck? He doesnt sled pull and all the performance vehicles he talks about belong to someone else.

I can tell you no one is running a GT55 on a 855 currently, usually if someone goes through the trouble they go above the GT55 frame and into the holset HC5/HX82 frame.
I do sled pull, and drag race. Impossible to get wider than that with single with todays turbo technology. My Volvo had 1000-2700 rpm range but it made its max power already at 1800 rpm, after that fuel was limited to same level, so I call 1000-1800 usable rpm range.

For 855 I'd say 1800-2600 with GT55, of course you can spin it to 3500 without power increasing anymore.
 
88mm compressor is 1400 hp turbo, 855 dont have enough fuel without custom injectors or cam, and it might not make it anyway because of old inefficient and unreliable design, so I would use C16 turbo which is good for about 1000 hp. Should spool maybe from 1200 rpm and up, starts to choke around 2000 rpm.
 
Truck is running again!

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Anyone have a guess how hard I can push this gt55. Acert 88/118 6+6 compressor 1.10 a/r. With the 1.0 turbine housing I am getting 50psi. I have fuel cut back right now wondering how much harder I can spin this thing? My 1.12 housing hasn't shown up yet to try that.
 
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