Why is 3,000 RPM the magic number??
05-21-2010, 02:43 PM
#21
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I have a small outlook on this and it depends on shot size. If you're spraying a 50 shot you probably can do that anytime, bigger the shot the more rpm that are needed, here's why:
Intake overlap. If you have a cam with no overlap at all (I don't think even a factory cam has this) then you probably can spray at a really low rpm, compared to a cam with alot of overlap.. you don't want the fire getting out of the cyl's and into the intake, and a cam with alot of overlap can allow that to happen at a low rpm.
So, the 3000 rpm mark, probably came abotu due to cam overlap, the velocity in the intake carrying the fuel/nos mixture, and the speed which the cyl's are getting filled, preventing any fire from getting into the intake.
Say on a race car, you are spraying 500 hp, you probably need to start spraying that into the 4000 rpm range due to overlap, and the overall shot size and tq creation like mentioned above, for example.
Hopefully that makes sense.
Intake overlap. If you have a cam with no overlap at all (I don't think even a factory cam has this) then you probably can spray at a really low rpm, compared to a cam with alot of overlap.. you don't want the fire getting out of the cyl's and into the intake, and a cam with alot of overlap can allow that to happen at a low rpm.
So, the 3000 rpm mark, probably came abotu due to cam overlap, the velocity in the intake carrying the fuel/nos mixture, and the speed which the cyl's are getting filled, preventing any fire from getting into the intake.
Say on a race car, you are spraying 500 hp, you probably need to start spraying that into the 4000 rpm range due to overlap, and the overall shot size and tq creation like mentioned above, for example.
Hopefully that makes sense.
Way overthought here. But very amusing nonetheless. You think those guys spraying their pro mods with 2-500's are waiting to 8000 to spray it all?
........................yet!!
:jest :
05-21-2010, 06:25 PM
#24
Also.. promod cars aren't running 2 500 hp kits either, they usually have 4 to 6 kits on them and they're all different size power levels, and they mix/match for track conditions, and they're all coming in one at a time, total shot might be over 1000 hp, but that's in at least 3, probably 4 maybe 5 stages.
05-22-2010, 06:58 PM
#26
was out last night and I found that if the 2-step is set at 2500, nitrous at 2500, when i leave off the brake it took off great...i would post times but there system was F--cked last night (as usual). thanks for all the info guys!!!!!!!!!!!!!!!!
CW
(Canada)
CW
(Canada)
05-24-2010, 01:21 PM
#33
depends on tire size and gear ratio. its all about wheel speed. 5K on some stups in first would be 20mph LOL. you want to try not to bog them otor in the box and get some tire speed. some go to 2nd to get that but we like to stay in first with the glide.
Very good point, I have a th400 so JL's post made sense but my god if somebody took a glide into second at 5k RPM things might just get interesting
05-25-2010, 11:13 AM
#38
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