472/491

B

bigkev12valve

New member
I have more experience with 300/400 compounds. I'm diving into 400/400 compounds and am wondering if a 472/83/90 is a good idea to run with a 491/96/1.32. truck has 250 overs. And how tuning on a 2005 Cummins. I'm wondering if that .90 housing with the 83 wheel is gonna be my bottle neck or create any issues. I use a 1.0 housing on my 369 but didn't know if it matters as much on s400 frame turbos
 
IMO both turbines are going to be bottle necks. More so the primary. I find it easiest to set a power goal, and pick a primary based on that. Once you have a primary picked, you can pick an effective secondary.
 
wwentzler said:
IMO both turbines are going to be bottle necks. More so the primary. I find it easiest to set a power goal, and pick a primary based on that. Once you have a primary picked, you can pick an effective secondary.
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And what turbine are you thinking is better for the atmo?


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I don't have an 80/74? I'm just asking about the 72/83/90 I'm not worried about the 491 that 1.32 housing should be fine just wondering if I should get a 87/1.0 housing for the 72 or if the 90 should flow plenty
 
bigkev12valve said:
I don't have an 80/74? I'm just asking about the 72/83/90 I'm not worried about the 491 that 1.32 housing should be fine just wondering if I should get a 87/1.0 housing for the 72 or if the 90 should flow plenty
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What blackmega is saying is; your current S369 has a 73/80 turbine wheel and 1.0 T-4 housing. That turbine/turbine housing will flow similarly to the 74/83 turbine and .90 T-4 housing the the S472 would have on it.
 
Ok thank you for clearing that up. Well then that's what I was looking for then. Probably a little tight but I wasn't having issues with the 369 so it should be ok. I'd imagine shouldn't loose too much spool up then either. Obviously won't be the same but I'm assuming should be decent on the street yet. Guess I will have to run it to really find out
 
bigkev12valve said:
I have more experience with 300/400 compounds. I'm diving into 400/400 compounds and am wondering if a 472/83/90 is a good idea to run with a 491/96/1.32. truck has 250 overs. And how tuning on a 2005 Cummins. I'm wondering if that .90 housing with the 83 wheel is gonna be my bottle neck or create any issues. I use a 1.0 housing on my 369 but didn't know if it matters as much on s400 frame turbos
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How much power are you expecting the 250% overs to be capable of?
 
Right I'm not going s500 and I'm gonna imagine I'll be upwards of 1300 s&s rates them for 1500 horse. They flow more like 275 over is what they flowed at huckstorf by me
 
I know saying an 88/96 S400 turbine can out do an S500 turbine won’t be supported by most people, but all else being equal, it will.
Borg’s map might say it flows more, and maps are a good starting place for comparisons, but quite a few dyno sessions have shown the truth of what I’m saying. Another illustration of what I’m saying about Borg’s maps is the SXE S400 stuff. Flow numbers look great on paper but they don’t work that well in real life.
There is a reason that the 88/96 turbine is so popular in SO many sled pulling applications, and to my knowledge, very few, if any, trucks have an S500 based turbo on them.
 
I knew where the logic was coming from, however I still dont agree. The reason it works on sled pull setup as a single, has to do more with the fact it spools quicker on our relatively small displacement engines. Diesel fuel is more efficient at making power at lower rpm, so quicker spool typically leads to more power. This is also demonstrated by testing with difference turbine housings on the same turbine, smallest housing usually makes most power.

The sxe map DOES work in real life, just not on a diesel as a single. This is obvious if you know how to read the map, as it doesnt make pressure (in the higher PRs) efficiently. Which again is crucial for making horsepower with diesel fuel.
 
wwentzler said:
I knew where the logic was coming from, however I still dont agree. The reason it works on sled pull setup as a single, has to do more with the fact it spools quicker on our relatively small displacement engines. Diesel fuel is more efficient at making power at lower rpm, so quicker spool typically leads to more power. This is also demonstrated by testing with difference turbine housings on the same turbine, smallest housing usually makes most power.

The sxe map DOES work in real life, just not on a diesel as a single. This is obvious if you know how to read the map, as it doesnt make pressure (in the higher PRs) efficiently. Which again is crucial for making horsepower with diesel fuel.
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Yes, I should have specified that the SXE S400 stuff doesn’t work well in a diesel application. They are primarily designed for the turbo gas world, ie, high flow, relatively low pressure.
 
Chevyguy15 said:
Seen more power with a s500/110/1.15 t6 then a 488/96/1.32 fed by a 72
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So do you think I will be hurting myself with the 83/1.0 housing? Just wondering cuz I found a decent deal from a buddy with a 72/83/.90 is the main reason why I ask about it. But if I'm actually going to be hurting myself then I might as well get the 87.1.0
 
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