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I'm reading all these hype and conjecture threads regarding EFRs so I figured I'd extend an offer of an hour of free dyno pulls (actually as many as you want within reason but someone is bound to try to take advantage of this to completely tune their car or some such) to anyone in southern California (or really anywhere as long as the car comes here) with a not-half assed install of an EFR (new, old, small frame, larger frame) on a couple of Dynapack hubs so long as they're cool with their setup, pulls, basic tunes etc being public knowledge afterwards.
I'm not a vendor, I don't make manifolds, I'm semi-private and mainly work on my own projects so I really don't have any agenda other than curiosity and getting somewhat empirical data gathered to prove (or disprove as the case may be) my and others claims based on pure numbers.
Because Backpressure and resulting high EGTs aren't a total bear.
9280 will undoubtedly make more power, but it's less safe. At that point you're better off with a S472SX-E or Garrett GTX40 series.
Data proves this point, but go ahead... Do what makes you happy.
I'd be willing to bet that a 9280 at 25psi has less back pressure and is more safe than a 9180 at 40 psi. Same fuel, same manifold, same motor, same car, same dyno.
I see a few mention "data" in reference to back pressure. Well let's compare an apple to an orange, well inside the range of efficiency vs the limit.
9280 -25psi = ? back pressure
9180-40 psi = ? Back pressure
Let's put some money on this, or better yet, Let's put any of the experts on this forum credentials on the line instead.
For those who are searching for 600rwhp, the turbo that gets there with less boost should be the better and safer of the two, which I'd say a 9180 can make that power on average at 30psi, but the 9280 should hit 600 with less boost pressure, but Let's see that experience shine, any takers?
Back to back turbo comparisons on same car... we wish. Never seems to come to fruition even with best intentions.
I think the motor porting and manifold design and fuel are really the only things that need to be the same. Dyno really shouldn't matter either, but an EGT/EMAP log will tell all.
Again, I'd like to see the proof or even the math explained that the 9280 at less boost making the same measured power is producing more emap then the 9180 at the same power level.
So, there is transient emap as the compressoe builds boost and there is peak boost threshold and on emap.
Larger compressor with same turbine wheel and same ar exhaust housing will always have more emap while building boost as the exhaust wheel is having to do more physical work to spin the larger diameter compressor wheel and the larger co.pressor is flowing more air which makes more exhaust gasses.
Emap while building boost is of an order higher than than peak boost emap untill you get to the nutty boost #s or you have an exhaust choked set-up.
9180 would likely have lower emap while building boost and then slightly higher emap at 30psi vs 9480 at 25-30psi for the 600rwhp on streetport/gasoline/watermeth set-up.
Bridge/semi p-port and or e85 and the 9180 is more like 20-25psi for 600hp depending on port size, peripherals, etc- whoch is going to be way better on emap.
So, probably depends on gearing and other factors which turbo will spend more TIME at the higher emap.
More time spent building boost or more time spent at peak boost?
So, there is transient emap as the compressoe builds boost and there is peak boost threshold and on emap.
Larger compressor with same turbine wheel and same ar exhaust housing will always have more emap while building boost as the exhaust wheel is having to do more physical work to spin the larger diameter compressor wheel and the larger co.pressor is flowing more air which makes more exhaust gasses.
Emap while building boost is of an order higher than than peak boost emap untill you get to the nutty boost #s or you have an exhaust choked set-up.
9180 would likely have lower emap while building boost and then slightly higher emap at 30psi vs 9480 at 25-30psi for the 600rwhp on streetport/gasoline/watermeth set-up.
Bridge/semi p-port and or e85 and the 9180 is more like 20-25psi for 600hp depending on port size, peripherals, etc- whoch is going to be way better on emap.
So, probably depends on gearing and other factors which turbo will spend more TIME at the higher emap.
More time spent building boost or more time spent at peak boost?
Unlikely that the emap building boost will raise EGT's enough to even get close to causing damage to ANY internal part of a built rotary. It definately can't cause detonation if you are tuned correctly and especially on E85, which I'm really leaning towards since I already have 3 fuel pumps.
As many others have said, EMAP and EGT logs and how they overcame the emap weather it was E85 or something else. Also, it would be nice to see someone push the 9280 over 35psi just to see if there is a choke point with the unit. If it's an 830 rotary hp turbo.
Or instead of saying that, just show your calculated results to everyone.
First chart shows the chart unaltered from what you would see if you opened matchbot . Note in column #6 compressor efficiency of 66 and exhaust manifold pressure of 21.3psi
In chart below , I changed the compressor efficiency in column #6 up 10% to 76% and then adjusted the turbine map to realign it as per matchbot instructions.
Exhaust manifold pressure now shows 19.3 . A reduction of 2psi EMAP with the only change being improved compressor efficiency.
First chart shows the chart unaltered from what you would see if you opened matchbot . Note in column #6 compressor efficiency of 66 and exhaust manifold pressure of 21.3psi
In chart below , I changed the compressor efficiency in column #6 up 10% to 76% and then adjusted the turbine map to realign it as per matchbot instructions.
Exhaust manifold pressure now shows 19.3 . A reduction of 2psi EMAP with the only change being improved compressor efficiency.
Your lbs/min figure is off, massively. At 7000 RPM and 17psi, that turbo is going to churn out WAY more than 40lbs/min. In fact, naturally aspirated with a streetport should be mid-30s. I'd suspect this number (for the turbo and pressure ratio) somewhere in the 60-70lbs/min range which dictates the X-Axis (and therefore where efficiency really is).
Your lbs/min figure is off, massively. At 7000 RPM and 17psi, that turbo is going to churn out WAY more than 40lbs/min. In fact, naturally aspirated with a streetport should be mid-30s. I'd suspect this number (for the turbo and pressure ratio) somewhere in the 60-70lbs/min range which dictates the X-Axis (and therefore where efficiency really is).
However, I see the point you're trying to make.
The chart is for a 2.0L piston engine ...... it's the default chart Borg Warner use. Was just trying to make the point ....compressor efficiency affects EMAP. Which is very relevant to the 8374vs8474 and 9180vs9280 comparison.
The chart is for a 2.0L piston engine ...... it's the default chart Borg Warner use. Was just trying to make the point ....compressor efficiency affects EMAP. Which is very relevant to the 8374vs8474 and 9180vs9280 comparison.
The difference between the 9180/9280 Is 6mm on the compressor inducer. This hardly makes the turbo "inefficient". The exhuast wheel is still 80mm, it doesn't need to be larger dispite the "theories" of the experts on this forum.
The comparison above was a 10mm difference vs 6mm difference. That's not even in the ballpark vs the actual size difference between 9180/9280.
The difference between the 9180/9280 Is 6mm on the compressor exducer. This hardly makes the turbo "inefficient". The exhuast wheel is still 80mm, it doesn't need to be larger dispite the "theories" of the experts on this forum.
The comparison above was a 10mm difference vs 6mm difference. That's not even in the ballpark vs the actual size difference between 9180/9280.
How many mm difference is not relevant . It's % efficiency at a comparable point on the compressors efficiency chart .
Looking at 8374vs8474 on the chart below :
So if we want something relatable to the dynos above :
Follow the line at Pr 3.0 (approx. 30psi) and intersect it with 75lb/min which is in the ballpark for those dynos. You will see 8374 at 62% efficiency and the 8474 at 72%. At lower power levels the difference is insignificant , but when you are looking at maxing out the 8374 ...... the 8474 starts to become the much better choice.
How many mm difference is not relevant . It's % efficiency at a comparable point on the compressors efficiency chart .
Looking at 8374vs8474 on the chart below :
So if we want something relatable to the dynos above :
Follow the line at Pr 3.0 (approx. 30psi) and intersect it with 75lb/min which is in the ballpark for those dynos. You will see 8374 at 62% efficiency and the 8474 at 72%. Coincidentally ,the same 10% difference I picked for the matchbot charts.
Pull up the 9280 compressor map and do the same as you did on this 8474 map, see if it shows the same 10% increase.
Unless im miss reading the blue line and black lines accross the 3.0 scale where they intersect, it appears both turbos have the same #'s at roughly .72
At 90lbs it looks like both blue and black numbers are the same at .66.
I'm just guessing................................... but at 90lbs you might be on the 3.4Pr line which gives 60% for the 9180 and around 69% for the 9280 .
I'm just guessing................................... but at 90lbs you might be on the 3.4Pr line which gives 60% for the 9180 and around 69% for the 9280 .
Do you see that same difference at 20-25psi, 9%?
The 9180 is widely considered ideal for rotary engines EGT wise, so at 3.4 , do you consider the 9280 not rotary safe? (60% vs 69%)
It seems to me that % isn't that large , I mean, if I was considering pump gas and AI, going to E85 could drop EGT's enough to offset the temps.
No ...agree with what you said , at that level they are identical so 9280 wouldn't do anything for you.
Not gunna pretend I know enough to suggest what is safe and what isn't but at 90lbs the 9280 is ....better than the 9180 by a good margin.
My target is power in the 90-100 lb range, and rather then running the 9180 near or at its limit, the 9280 was my plan. I don't like the 8474, mainly because of the turbine wheel size.
My argument in favor of the 9280 has always been that at 25-30 psi, it's safer for the rotary engine than a 9180 at 30 to 40 psi. All things in the build being equal.
My target is power in the 90-100 lb range, and rather then running the 9180 near or at its limit, the 9280 was my plan. I don't like the 8474, mainly because of the turbine wheel size.
My argument in favor of the 9280 has always been that at 25-30 psi, it's safer for the rotary engine than a 9180 at 30 to 40 psi. All things in the build being equal.
Not really following your logic there ................. at 25-30 there is nothing between them so you may as well go with the one that should spool better and has the superior surge line ...the 9180 . At 30-40 the 9280 becomes the better choice .....
Not really following your logic there ................. at 25-30 there is nothing between them so you may as well go with the one that should spool better and has the superior surge line ...the 9180 . At 30-40 the 9280 becomes the better choice .....
My understanding is +50hp between 25 and 30 and +130hp at 40.
But perhaps I was misinformed, but knowing myself, I'm the type that would rather have something I can turn up, way up.
10-02-19, 02:28 AM
