Water Injection
11-07-2003, 07:14 AM
#21
good thread...
fltsfshr
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fltsfshr
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11-07-2003, 08:41 AM
#22
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This is a good thread -- but one best left for those with an applied science background (which may be where some of the points of disagreement lie).
FPerra, while you get points for starting this lively debate (which we've all learned from reading), I'm not sure that your statement -- that the S2000 at 10psi "doesn't meet Lurker's definition of a low-boost application" -- has any basis in empirical fact.
When we were tuning my car on the dyno, we increased the boost quite a bit without seeing any evidence of knock. I suspect you could run 10 psi of boost without suffering much evidence of knock provided you threw enough fuel at the combustion cycle, particularly if you ran a combination of pump and moderate octane race gas.
While one person's experience also isn't good science, Chris Danek ran 10-11 psi of boost on pump gas on a standard Speedcraft setup for months on end. My guess is that on S2K, it's the rings and other internals -- as many of us have discovered -- that are the constraint to modestly higher boost (i.e., in the range your citing), provided the car's been properly tuned.
If POORLY tuned, however, even 7 psi of boost is enough to cause seriously damaging detonation. But if properly tuned, I don't think 10 psi of boost, based on what we observd on the dyno, represents an engine where the design's been "seriously compromised", even with our 11:1 compression.
CB
FPerra, while you get points for starting this lively debate (which we've all learned from reading), I'm not sure that your statement -- that the S2000 at 10psi "doesn't meet Lurker's definition of a low-boost application" -- has any basis in empirical fact.
When we were tuning my car on the dyno, we increased the boost quite a bit without seeing any evidence of knock. I suspect you could run 10 psi of boost without suffering much evidence of knock provided you threw enough fuel at the combustion cycle, particularly if you ran a combination of pump and moderate octane race gas.
While one person's experience also isn't good science, Chris Danek ran 10-11 psi of boost on pump gas on a standard Speedcraft setup for months on end. My guess is that on S2K, it's the rings and other internals -- as many of us have discovered -- that are the constraint to modestly higher boost (i.e., in the range your citing), provided the car's been properly tuned.
If POORLY tuned, however, even 7 psi of boost is enough to cause seriously damaging detonation. But if properly tuned, I don't think 10 psi of boost, based on what we observd on the dyno, represents an engine where the design's been "seriously compromised", even with our 11:1 compression.
CB
11-07-2003, 08:56 AM
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The effect of water injection on EGT interests me. Running WI should enable you reduce the AFR to 12.5:1 but this should increase EGT. We already know that boost levels of 7.5PSIg at 11.8:1 produce the absolute EGT maximum (750C to 800C). Does WI help reduce this? This will most likely dictate if you can run 10PSIg.
Wesmaster was running 11PSIg and suffered from much twisting of the lower end of the engine. At what PSIg do we reach the structural integrity of the engine? Experience appears to be the best (only) way to measure this. With adequate boost control (to prevent the onset of boost too quickly) and safe EGT, safe knock 10PSIg may be possible without going to route of sleeves, pistons, rods and crank.
Wesmaster was running 11PSIg and suffered from much twisting of the lower end of the engine. At what PSIg do we reach the structural integrity of the engine? Experience appears to be the best (only) way to measure this. With adequate boost control (to prevent the onset of boost too quickly) and safe EGT, safe knock 10PSIg may be possible without going to route of sleeves, pistons, rods and crank.
11-07-2003, 09:20 AM
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[QUOTE]Originally posted by cbender
This is a good thread -- but one best left for those with an applied science background (which may be where some of the points of disagreement lie).
This is a good thread -- but one best left for those with an applied science background (which may be where some of the points of disagreement lie).
11-07-2003, 11:18 AM
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Originally posted by gilbertg
Wesmaster was running 11PSIg and suffered from much twisting of the lower end of the engine.
Wesmaster was running 11PSIg and suffered from much twisting of the lower end of the engine.
11-16-2003, 04:58 PM
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Originally posted by Honda-S2000VTec
Fperra,
Where did you mount your pump?
The engine compartment is getting a little crowded with the AW cooler?
Fperra,
Where did you mount your pump?
The engine compartment is getting a little crowded with the AW cooler?
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