I have a 585 Nos engine(alpha N mode) with the sequential FAST Injection.Ive been told that you shouldnt run in closed loop with nos.But Ive heard that you can.Ive heard that a lot of the promod guys are spraying lots of nitrous and setting the a/f ratio at a target of 9.2:1.You would get near perfect plug readings every pass.Anyone else try or here of this?
Nos in Closed Loop.
- Thread starter 585bird
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The more nitrous you put in, the more you start to see diminishing returns. The engine becomes less efficient and the exhaust will become more and more saturated with unburnt fuel and gasses. The wideband O2 will become less accurate to the point where it's practically useless because it too becomes saturated. It's generally accepted that this point is about 1HP of nitrous per cubic inch displacement (500HP worth of nitrous in a 500 cid engine). Up to that point, the wideband may still be useful and repeatable even though not accurate. The absolute best feedback tool for nitrous is a magnifying glass for reading the plugs.
I agree, don't rely on the WB when using nitrous IMO.
My WB reads wicked rich on nitrous (even when using a lot less than 1HP per cu in), so if I am in closed loop the WB will try to lean out the motor (and you know the consequences of that on nitrous). Plug reading is the only way to know.
On the other hand, some people have success.
-Bob Cunningham
My WB reads wicked rich on nitrous (even when using a lot less than 1HP per cu in), so if I am in closed loop the WB will try to lean out the motor (and you know the consequences of that on nitrous). Plug reading is the only way to know.
On the other hand, some people have success.
-Bob Cunningham
QuickWrench
Don't Read This
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- Jan 28, 2002
I don't know of anyone in Pro Mod who does this. At least not Halsey, Castellana, Martin, or Jenkins, and they're the 4 fastest Nitrous cars I can think of. Only one of them is Fuel Injected, anyway.585bird said:
EightSecV6
MDBL
- Joined
- Jul 18, 2001
QuickWrench said:I don't know of anyone in Pro Mod who does this. At least not Halsey, Castellana, Martin, or Jenkins, and they're the 4 fastest Nitrous cars I can think of. Only one of them is Fuel Injected, anyway.
We have a fairly good setup on a 421 SBC, using closed loop with FAST and spraying 250hp, it is in a 4640# full size truck with an intercooled Vortech YS making 12# of boost. We target 11:1 on spray, it has run 9.70 at 151.
I've sprayed mine up to 175 shot on top of 30+ psi boost and it seems to work quite well in closed loop IME. Gewroo said above, until you get to about ~~ 1 hp of hose/ci it should work as expected.
If you run a wet system with a moderate shot, then it seems that you could still use the FAST in closed loop to fine tune the a/f ratio if you want. Or just have it do nothing. But at the very least you will need to retard the spark somehow, either in the FAST or elsewhere.
TurboTR
If you run a wet system with a moderate shot, then it seems that you could still use the FAST in closed loop to fine tune the a/f ratio if you want. Or just have it do nothing. But at the very least you will need to retard the spark somehow, either in the FAST or elsewhere.
TurboTR
sounds good,
now, does FAST need each of the NOS activation wires hooked up/installed in order for it to actually switch to NOS activation mode,
or
will it retard timing as per the NO2 activation parameters, even with the wires dangling (as in a stand alone, "manual" wet kit, ZEX etc.)
If so, a throttle switch at WOT for the NO2, and the TPS reading for WOT at FAST to trigger the "NO2 mode", I would then have the simplicity of a wet system with the timing control of FAST.
I would then simply run in Open Loop once the VE tables are accurate.
I hope its this simple...
Thanks
now, does FAST need each of the NOS activation wires hooked up/installed in order for it to actually switch to NOS activation mode,
or
will it retard timing as per the NO2 activation parameters, even with the wires dangling (as in a stand alone, "manual" wet kit, ZEX etc.)
If so, a throttle switch at WOT for the NO2, and the TPS reading for WOT at FAST to trigger the "NO2 mode", I would then have the simplicity of a wet system with the timing control of FAST.
I would then simply run in Open Loop once the VE tables are accurate.
I hope its this simple...
Thanks
Well it needs to know that the nitrous system is armed. When it sees that then, once the TPS trigger and RPM thresholds are met it will go into the nitrous activation mode. You can also tell it wet shot or dry shot. That would be the way to do it if you want to spray a wet shot; tell it wet shot. I think in wet mode it should just do the timing retard, but will have to double check.
TurboTR
TurboTR
