sx vs sxe turbine

Poulina

Poulina

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borg warner 300 series SX turbine (clipped) flows more exhaust than the SXE (unclipped) turbine?
 
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That what I have understand as well, you give up a bit of spool with the clipped wheel but it flows more. I am at the point of going back to the clipped wheel because I am having minor DP issues on S369/S488 compounds.
 
It's intended purpose in the John Deere application was to counter a harmonic issue. A ground clip can increase flow, but will also reduce efficiency, there is no free lunch.
 
Smokem said:
It's intended purpose in the John Deere application was to counter a harmonic issue. A ground clip can increase flow, but will also reduce efficiency, there is no free lunch.
Click to expand...

So is that reduced efficiency everywhere in the Map?
 
Also wondering which turbine would be best for a high PR compound setup lol
 
If the compressor wheel/housing is held constant, than using a ground clipped turbine vs the original casting, the difference in flow would not have a large impact on power directly. Clipping a turbine as such often reacts very similar to running a larger turbine housing on an unclipped turbine, and if drive pressure were a concern this would be a simpler option and or using a wastegate.

A turbine wheel with what is known as a cast clip increases the trailing edge length allowing a larger area of pressure drop, which in turn can create more shaft power. Grinding the turbine to increase this angle as shown below can increase flow, but again comes at a reduction in efficiency, many times the result is just a trade off.

CT.jpg

Depending on the turbine housing design, it is possible to increase the overall flow while retaining efficiency, but this would be dependent on the available options for the specific turbine in question. Below you can see a comparison chart that shows both values. A good example would be to compare the 1.33AR and 1.44AR housings, although the mass flow is very similar the efficiency is quite different.

TM.jpg
 
Smokem said:
If the compressor wheel/housing is held constant, than using a ground clipped turbine vs the original casting, the difference in flow would not have a large impact on power directly. Clipping a turbine as such often reacts very similar to running a larger turbine housing on an unclipped turbine, and if drive pressure were a concern this would be a simpler option and or using a wastegate.

A turbine wheel with what is known as a cast clip increases the trailing edge length allowing a larger area of pressure drop, which in turn can create more shaft power. Grinding the turbine to increase this angle as shown below can increase flow, but again comes at a reduction in efficiency, many times the result is just a trade off.

View attachment 74500

Depending on the turbine housing design, it is possible to increase the overall flow while retaining efficiency, but this would be dependent on the available options for the specific turbine in question. Below you can see a comparison chart that shows both values. A good example would be to compare the 1.33AR and 1.44AR housings, although the mass flow is very similar the efficiency is quite different.

View attachment 74501
Click to expand...


So I might see more a benefit to swapping to a 1.0 AR exhaust housing vs going back the older Box Stock S366 turbo/turbine wheel. Currently my HP turbo is a S369 with a .91 AR housing and no waste-gate, max boost is 60 PSI with 83 PSI of Drive pressure and 22PSI from the S488 with a 1.15 AR housing. I switched to a 1.32 housing to try to drive the HP turbo harder and overall boost and DP stayed the same, but the S488 boost dropped to 20 PSI. So I am not sure if its at the point where the .91 housing just can't flow enough exhaust.
 
Increasing the turbine AR on the primary certainly won't "drive" the manifold charger harder, in a compound setup the primary should be doing the work as it limits what the system is capable of. Are you against running a wastegate? At some point no matter how large of turbine housing or clipped turbine you utilize, the turbine diffuser will still be the choke point.
 
MAXX IT OUT said:
So I might see more a benefit to swapping to a 1.0 AR exhaust housing vs going back the older Box Stock S366 turbo/turbine wheel. Currently my HP turbo is a S369 with a .91 AR housing and no waste-gate, max boost is 60 PSI with 83 PSI of Drive pressure and 22PSI from the S488 with a 1.15 AR housing. I switched to a 1.32 housing to try to drive the HP turbo harder and overall boost and DP stayed the same, but the S488 boost dropped to 20 PSI. So I am not sure if its at the point where the .91 housing just can't flow enough exhaust.
Click to expand...

only 60lbs overall? It sounds to me like you have other problems, youre barely breaking either of those chargers into any kind of efficiency advantage over a single.
 
Smokem said:
Increasing the turbine AR on the primary certainly won't "drive" the manifold charger harder, in a compound setup the primary should be doing the work as it limits what the system is capable of. Are you against running a wastegate? At some point no matter how large of turbine housing or clipped turbine you utilize, the turbine diffuser will still be the choke point.
Click to expand...
Mainly I am not running a Wastegate because on a daily driver that isn't making more than 800HP they aren't worth the potential issues. I don't really think that the DP is out of line, but I would expect the boost to be in around 70 psi.

wwentzler said:
only 60lbs overall? It sounds to me like you have other problems, youre barely breaking either of those chargers into any kind of efficiency advantage over a single.
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That's what my data logger is reading, I need to build a big plug so I can pressure test the system, but its possible that the intercooler has leak or possibly that the air filter just can't flow enough air. So far they drive way better than the single S369 ever did, and dropped the EGT's when towing by over 500 Degrees.
 
MAXX IT OUT said:
Mainly I am not running a Wastegate because on a daily driver that isn't making more than 800HP they aren't worth the potential issues. I don't really think that the DP is out of line, but I would expect the boost to be in around 70 psi.
Click to expand...

Without knowing more about the setup I would entertain a T4 1.00AR on the manifold and a T6 1.15AR on the primary.
 
Crazy backpressure, your engine cant breath.

Why use +1200 hp turbo for 800 hp ?
 
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