Knock under boost when ECT higher than 215F
08-24-2007, 05:36 AM
#1
Knock under boost when ECT higher than 215F As long the ECT is around 210 - 215F I see no KR, but higher than that it starts to ping! (KR + audible).
Is it possible that the engine temperature alone causes that?
Stock 98 LS1 (80'000 miles), stock exhaust
Vortech SC non intercooled (5 PSI)
Water / alcohol injection (5 GPH 50% alcohol)
17* timing at WOT
AFR around 11.7
Stock thermostat
Plugs: Champion RS 12 PYP (#7401) (gapped 0.04")
No misfire
Fuel trims +/- 2% (with MAF or in SD, so I guess it's tuned)
Stefano
Is it possible that the engine temperature alone causes that?
Stock 98 LS1 (80'000 miles), stock exhaust
Vortech SC non intercooled (5 PSI)
Water / alcohol injection (5 GPH 50% alcohol)
17* timing at WOT
AFR around 11.7
Stock thermostat
Plugs: Champion RS 12 PYP (#7401) (gapped 0.04")
No misfire
Fuel trims +/- 2% (with MAF or in SD, so I guess it's tuned)
Stefano
08-24-2007, 11:05 AM
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Originally Posted by tici
I was thinking the sweet point of those engines was 200F 
Not with boost....plus a 160 stat will cruise at 178F IF all your radiator shrouds are perfect.
Heat kills
08-24-2007, 01:17 PM
#7
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Originally Posted by onfire
Buy a 160 stat. Have the fans reprogrammed. Low speed on at 188 off at 184. High speed on at 195 off at 190. Your engine will thank you.
Last edited by JAvenger007; 08-24-2007 at 01:38 PM.
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08-24-2007, 03:52 PM
#8
i have my fans stay on pretty much constantly at the track to keep ect cool. On the street, i have them come on later so i do get some heat in the engine for gas mileage...oil condensation burnoff etc... If you cant do your own programming, set the fans for 200 deg and use a manual fan switch at the track
08-25-2007, 03:25 AM
#10
Originally Posted by Frost
trying replacing your fluid mixture with PURE methanol.
I'm too scary to carry pure alcohol around.
What I can do is to install a bigger nozzle: I can go from 4 to 10 gallons per minute.
08-25-2007, 04:16 AM
#11
If you do the bigger nozzle with a water mix, you will get a large power robbing bog when it sprays. BTW, these all aluminum engines are best between 180-190*F. 160 isn't enough, and 200 is bordering on too much. Also, pure methanol may mess up your WW fluid pump seals. Try using a separate reservoir.
Last edited by gametech; 08-25-2007 at 03:14 PM.
08-26-2007, 12:55 AM
#12
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Originally Posted by gametech
If you do the bigger nozzle with a water mix, you will get a large power robbing bog when it sprays. BTW, these all aluminum engines are best between 180-190*F. 160 isn't enough, and 200 is bordering on too much. Also, pure methanol may mess up your WW fluid pump seals. Try using a separate reservoir.
Are you using the stock WW pump?
08-26-2007, 02:53 AM
#14
Originally Posted by JAvenger007
Are you using the stock WW pump?
No problems with the seal: there is a magnetic coupling between motor and pump.
So what would be a good temperature for a boosted engine?
08-26-2007, 05:58 AM
#16
OK, I reduced the engine temperature (at WOT ist stays below 210F) and there is just 2* KR right at the precise moment I mash the pedal. It lasts a fraction of a second and it's still audible.
Better reduce the coolant temperature a little more or start playing with the WI nozzle?
I onestly prefer a short bog when WI kicks in than a broken piston...
Fan settings, here the values installed by the Vortech programmer:
1. stage on = 193
1. stage off = 187
2. stage on = 200
2. stage off = 193
I think they are too low for a daily drive, that's why I increased them for an average temperature of 200F.
But maybe that's the settings this supercharger really needs...
Better reduce the coolant temperature a little more or start playing with the WI nozzle?
I onestly prefer a short bog when WI kicks in than a broken piston...
Fan settings, here the values installed by the Vortech programmer:
1. stage on = 193
1. stage off = 187
2. stage on = 200
2. stage off = 193
I think they are too low for a daily drive, that's why I increased them for an average temperature of 200F.
But maybe that's the settings this supercharger really needs...
08-26-2007, 06:21 AM
#17
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An adjustable WI setup might be better. That would allow you to use more water, but inject it progressively.
Some of the controllers from the US might control your own pump. eg. Snow,Alkycontrol,Coolingmist,Devil's own...
That way you only buy a controller.
The debate is still only about water vs meth.... I was recently chatting to a guy who runs one of the fastest street cars in the world....and he says pure water is best.
I have never done much experimenting myself...but I am now tending to think about using 50/50 as opposed to straight meth.
Some of the controllers from the US might control your own pump. eg. Snow,Alkycontrol,Coolingmist,Devil's own...
That way you only buy a controller.
The debate is still only about water vs meth.... I was recently chatting to a guy who runs one of the fastest street cars in the world....and he says pure water is best.
I have never done much experimenting myself...but I am now tending to think about using 50/50 as opposed to straight meth.
08-26-2007, 07:12 AM
#18
Originally Posted by stevieturbo
An adjustable WI setup might be better. That would allow you to use more water, but inject it progressively.
Some of the controllers from the US might control your own pump. eg. Snow,Alkycontrol,Coolingmist,Devil's own...
That way you only buy a controller.
The debate is still only about water vs meth.... I was recently chatting to a guy who runs one of the fastest street cars in the world....and he says pure water is best.
I have never done much experimenting myself...but I am now tending to think about using 50/50 as opposed to straight meth.
Some of the controllers from the US might control your own pump. eg. Snow,Alkycontrol,Coolingmist,Devil's own...
That way you only buy a controller.
The debate is still only about water vs meth.... I was recently chatting to a guy who runs one of the fastest street cars in the world....and he says pure water is best.
I have never done much experimenting myself...but I am now tending to think about using 50/50 as opposed to straight meth.
50 / 50 is what has been used in the WW2 planes: I guess those guys made some more serious research than us.
08-26-2007, 11:48 AM
#19
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I would recommend the coolingmist controller for your setup since you need more control over the flow. Its a fully programmable controller that connects through serial port to a computer and lets you run their software for literally any flow curve possible. costs $230 and will replace your current one.
08-26-2007, 12:14 PM
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Originally Posted by JAvenger007
just curious, a 160*stat keeps the car around 180 correct? So 160* constant shouldn't be an issue for him?
Are you using the stock WW pump?
Are you using the stock WW pump?
Exactly....160 stat is perfect for these engines since the lowest it will cruise is around 178. FI cars need all the help they can get keeping the heat down since they build heat quickly.....I'd drop my fans down as posted above and add a 160 stat....KR will hurt parts down the road.