s400 turbine wheel question

T

Todd W

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I have been running exclusively garret chargers up to this point. Right now I am considering picking up an s480. The turbine wheel in this turbo is the 92mm inducer 82mm exducer wheel. this will be an atmosphere charger in a compound set up. I have seen people run the 83, 87 and 96mm wheels but haven't seen much info on the 92mm wheel. Anyone have any info/experience with these? Good/Bad from a performance standpoint?

also anybody know about the map on the 80mm BW compressor? I have read that it is good to 120 Lbs./min. what kind of PR's does it like?

Thanks
 
Also am wondering about the cheap box s475 96/88/1.32 and how it would compare to the s480 92/82/1.10 which would make more power, does the larger turbine make more or does the larger compressor make more? would the larger turbine/housing on the 475 make it spool much later than the 80mm with the smaller hotside? and finally how much power am I leaving on the table going with the 92/82/1.1 vs the 96/88/1.32 both with the cast 80mm wheel?
 
Weston is about the only one I've seen speak of the 92mm turbine from Borg. Couldn't really percieve if it was good or bad though.

The 80mm FMW wheel is actually a pretty badass wheel. But I've grown more fond of the 484 with a .72 A/R cover vs the 80mm and .66 Cover. I will be running the 84 and .72 cover for my primary in my compounds.
 
Boss man's sled truck isn't here or I'd take a picture and show ya. If you seen one you'd know it haha
 
The 92mm turbine wheel is usually used in the Caterpillar applications, same goes for the 0.72AR compressor cover.
 
0.72 cover.

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I believe Mike is running a s478 with the 92mm wheel now in his compounds. He seems to love it.
 
The 74/83mm, 81/87mm, and 82/92mm turbine wheels are straight blade.
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The 80/87mm and 88/96mm turbine wheels are cast clipped.
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Generally speaking the straight blade will spool a bit quicker, but not flow quite as well as the cast clipped wheel given they are the same size.
 
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Thanks for all the replies, from the above info and my own opinions here is what I think so far, correct me if I am wrong.

1.) Being that the turbine wheel is rather large I think it should do a fine job driving the 80mm compressor.

2.) If #1 us true then this turbine wheel design should yield a desirable spoolup time for an 80mm turbo based on Westons description of the wheel design.

3.) Yes this turbine wheel is giving up on total power compared the the typical 96/88/1.32 do to both size and wheel design, but spoolup will be earlier.

My final question which may not be known without having had someone try both is this.

Per Weston the 80/87 is a higher flowing/ slower spooling design than the 82/92. So does the larger size of the 92 make up for the lower flow design, or would the smaller 87wheel outperform the 92 wheel? I know that optimal performance is highly subjective some prefer spoolup, others all out power.

My guess is that the 92 will spool a little slower and make a little more power than the 87 wheel and I am going to have to just decide which one to go with on my own. But on the off chance someone has had experience with both and have strong opinions we would love to hear it.
 
I run the 92mm in my 2.5 turbo. It makes good power for sure. I however am going with the 96mm come winter. Being a puller I need all I can get out of the turbine as we're limited on the compressor side.
 
Turbine selection is based on the rpm you plan to run the engine at. Running a really big turbine doesnt mean you will make more horsepower.
 
kjpcummins said:
Turbine selection is based on the rpm you plan to run the engine at. Running a really big turbine doesnt mean you will make more horsepower.
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That is true, but the difficulty in determining how rpm effects turbine flow is compounded in a compound system.







Sorry, terrible I know. I couldn't resist.


But to an atmosphere charger rpm is not the only variable, how hard you run the manifold charger also plays a role in how big a turbine the big guy will need. Is it desirable to have 1:1 on both stages? simple waste gate adjustments to the manifold will yield different results in atmosphere drive to boost ratios at the same rpm.
 
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Not sure what the max power goals are but I'd never go smaller than the 96mm/1.32 in a first stage.

You might remember the fellow that went by Charles on here found spool and low rpm power actually pickup when he went to a larger primary turbine. Better expansion across the second stage turbine under low flow.

Look at Pius setup's. Big primary turbine flow and you can even hear the two stages spooling at different rpm's. Rather than at the same time. Not a huge spread but even audibly perceivable.

The 96mm/1.32 is full on by 2500 as a first stage and has no problem blowing the rods out of a stock block. Really how much lower do you need it to be all in?
 
Joesixpack said:
Not sure what the max power goals are but I'd never go smaller than the 96mm/1.32 in a first stage.
You might remember the fellow that went by Charles on here found spool and low rpm power actually pickup when he went to a larger primary turbine. Better expansion across the second stage turbine under low flow.

Look at Pius setup's. Big primary turbine flow and you can even hear the two stages spooling at different rpm's. Rather than at the same time. Not a huge spread but even audibly perceivable.

The 96mm/1.32 is full on by 2500 as a first stage and has no problem blowing the rods out of a stock block. Really how much lower do you need it to be all in?
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What if you planned to use 2 of them for the first stage? would you still only consider the large wheel and turbine housing?
 
LOL...now that's another can of worms. Our goals just got way bigger. I can tell you the drive on my pair of Garret's is 80psi+ and boost is 55-58. I would have liked to have seen 1:1 there or less. Now I can go bigger on the housings but likely more turbine would be better. Seems to me your challenged on elevation and that likely puts you into the larger compressor vs turbine area though.
 
Joesixpack said:
LOL...now that's another can of worms. Our goals just got way bigger. I can tell you the drive on my pair of Garret's is 80psi+ and boost is 55-58. I would have liked to have seen 1:1 there or less. Now I can go bigger on the housings but likely more turbine would be better. Seems to me your challenged on elevation and that likely puts you into the larger compressor vs turbine area though.
Click to expand...

Or a slight bump in compression.
 
Joesixpack said:
LOL...now that's another can of worms. Our goals just got way bigger. I can tell you the drive on my pair of Garret's is 80psi+ and boost is 55-58. I would have liked to have seen 1:1 there or less. Now I can go bigger on the housings but likely more turbine would be better. Seems to me your challenged on elevation and that likely puts you into the larger compressor vs turbine area though.
Click to expand...

Bigger is better right?

I am glad to hear the info on your setup. That seems like pretty high boost from your primary, but if you ran the manifold harder it would likely make the ratios even further off across the atmosphere stage. I was very close to running a pair of gt45's like yourself but the dang compressor housing on them is so big. I could have some made with the gt42 compressor housing so they would fit better, but by the time you add up the additional machining costs the turbo, the s400's start to look pretty good. although I will say the non gtx ball bearing turbos have dropped in price pretty dramatically. I was shocked at how cheap I could get a new gt4508r.

It is good to know you would like a bit more turbine flow on the 45's. Obviously the 92 wheel is bigger than the 45 wheel and probably compares closer to the gt47 turbine wheel. Do you think that a gtx4708 would have worked better in your truck if you could have fit them in?

I know the info I desire is not going to be given here. This is what I want to know, will I like the 92/1.0 better or the 96/1.32? No one can answer that but me. Obviously the large turbine flow of 2 turbo's makes me question what to do.

I know I will be able to spool either set just fine and that the 96 will make more power, just wish I had more knowledge on the compromises of both options.
 
Its going to be purely academic comparing results from a single first stage to a parallel first stage but you might check out one of Extended Power's threads. I'm pretty sure he switched from the 96mm big housing to the 92/1.0 then back to the 96mm again.

The hot side is still in my mind in the black art category. I'd love to say I've got a good grip on it but there's nothing like putting it together and see what happens.
 
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