"switching off" horsepower on a p1sc LQ4
04-19-2014, 10:13 AM
#1
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"switching off" horsepower on a p1sc LQ4 yep guys i know that´s a weird question. background is that i´m building a pro-touring 69 Camaro here in Austria/europe and part of it is a 416cui LQ4 with a p1sc. to keep it somehow "historic", at least if somebody takes a look into the engine bay, i built the engine carbed (Holley HP EFI). the lq4 was planned as a FI engine so it doesn´t make that much power without the procharger. my problem is that the cops in austria ocassionally cut off roads just to check cars and sometimes they even have mobile Dyno´s with them. my car was original licensed with 350HP and if the lq4 makes a bit more it won´t be a big deal but if it cranks almost double of that it starts to get nasty to deal with those guys. so i´m looking for a way to "weaken" my engine just for short time if i get into one of those roadblocks. do i hurt the engine when i set a switch as a timing retard into the HP EFI so i don´t have to mess with the charger and wastegates to bleed off the air?
04-19-2014, 11:13 AM
#3
should be easy to do this with a toggle switch using the holley efi.
just wire the toggle and relay (with whatever resistor value needed) into the IAT sensor to max out its reading. then configure a major timing retard safty vrs IAT in the holley software.
just wire the toggle and relay (with whatever resistor value needed) into the IAT sensor to max out its reading. then configure a major timing retard safty vrs IAT in the holley software.
04-19-2014, 11:31 AM
#6
yep guys i know that´s a weird question. background is that i´m building a pro-touring 69 Camaro here in Austria/europe and part of it is a 416cui LQ4 with a p1sc. to keep it somehow "historic", at least if somebody takes a look into the engine bay, i built the engine carbed (Holley HP EFI). the lq4 was planned as a FI engine so it doesn´t make that much power without the procharger. my problem is that the cops in austria ocassionally cut off roads just to check cars and sometimes they even have mobile Dyno´s with them. my car was original licensed with 350HP and if the lq4 makes a bit more it won´t be a big deal but if it cranks almost double of that it starts to get nasty to deal with those guys. so i´m looking for a way to "weaken" my engine just for short time if i get into one of those roadblocks. do i hurt the engine when i set a switch as a timing retard into the HP EFI so i don´t have to mess with the charger and wastegates to bleed off the air?
Mobil dynos? that nuts. I didnt know Australia had HP restrictions
04-19-2014, 01:27 PM
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austria is in europe haha that´s where the kangaroos go skiing and a weird former californian governor is from but seems he´s better acting in terminator movies than politics 
yeah it´s kinda tough here. the only way to get a old car registrated is a historic liscence plate but that means the car needs to be older than 25 years and there is a list of "rare and valuable cars" and it needs to be bone stock. so i´m doing pro-touring and i need to "hide" as much as possible. engine is no problem at all cause people here can´t tell a carbed LS or LQ from a smallblock cause it looks like a v8 a procharger can be used legal as "historic tuning" but i need to be able to keep the power level down if i get into those police checkstations. the toggle switch using the IAT is exactly what i´m looking into and sounds good and also keeping the rev limiter at 4k is no problem cause nobody here expects an american engine to rev like a new BMW or Mercedes AMG 
do i have to use the IAT sensor? i used one of the global folders from holley and the timing chart is at 20° idle and up to 44° all in. so if i set a timing retard that won´t get timing over 25° with all the boost is there a possibility that i damage something in the engine or is just a lot of fuel and air unburned leaving through the exhaust?
yeah it´s kinda tough here. the only way to get a old car registrated is a historic liscence plate but that means the car needs to be older than 25 years and there is a list of "rare and valuable cars" and it needs to be bone stock. so i´m doing pro-touring and i need to "hide" as much as possible. engine is no problem at all cause people here can´t tell a carbed LS or LQ from a smallblock cause it looks like a v8 a procharger can be used legal as "historic tuning" but i need to be able to keep the power level down if i get into those police checkstations. the toggle switch using the IAT is exactly what i´m looking into and sounds good and also keeping the rev limiter at 4k is no problem cause nobody here expects an american engine to rev like a new BMW or Mercedes AMG do i have to use the IAT sensor? i used one of the global folders from holley and the timing chart is at 20° idle and up to 44° all in. so if i set a timing retard that won´t get timing over 25° with all the boost is there a possibility that i damage something in the engine or is just a lot of fuel and air unburned leaving through the exhaust?
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04-19-2014, 01:48 PM
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that was the timing map for the 350-383 cui supercharged 14psi global folder which is one of the preprogrammed folders that comes with the holley software to make it a bit easier for newbies like me. damn that whole boosted LQ deal is gonna get a nightmare. i´m here on my own with nobody around.
04-19-2014, 02:09 PM
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did read the timing map wrong. it´s 25° idle without boost and 20° under full boost in the 383 supercharged.....yeah need to read me way more into boosted LS. but still if i pull for example another 10° or even 15° out could i do damage to the engine?
04-19-2014, 02:18 PM
#12
I was trying to think of a way to trigger something in the Holley setup to kill the power
my thinking is if he got stopped, and didn't have a laptop with him to swap tunes, he would need something
not sure what the deal is when he gets stopped, but if they actually have a mobil dyno, and its not tuned yet for boost, by by engine
prob best to take out a whole block in the timing section and kick it down to around 16
my thinking is if he got stopped, and didn't have a laptop with him to swap tunes, he would need something
not sure what the deal is when he gets stopped, but if they actually have a mobil dyno, and its not tuned yet for boost, by by engine
prob best to take out a whole block in the timing section and kick it down to around 16
04-19-2014, 03:21 PM
#14
austria is in europe haha that´s where the kangaroos go skiing and a weird former californian governor is from but seems he´s better acting in terminator movies than politics yeah it´s kinda tough here. the only way to get a old car registrated is a historic liscence plate but that means the car needs to be older than 25 years and there is a list of "rare and valuable cars" and it needs to be bone stock. so i´m doing pro-touring and i need to "hide" as much as possible. engine is no problem at all cause people here can´t tell a carbed LS or LQ from a smallblock cause it looks like a v8 a procharger can be used legal as "historic tuning" but i need to be able to keep the power level down if i get into those police checkstations. the toggle switch using the IAT is exactly what i´m looking into and sounds good and also keeping the rev limiter at 4k is no problem cause nobody here expects an american engine to rev like a new BMW or Mercedes AMG do i have to use the IAT sensor? i used one of the global folders from holley and the timing chart is at 20° idle and up to 44° all in. so if i set a timing retard that won´t get timing over 25° with all the boost is there a possibility that i damage something in the engine or is just a lot of fuel and air unburned leaving through the exhaust?
yeah it´s kinda tough here. the only way to get a old car registrated is a historic liscence plate but that means the car needs to be older than 25 years and there is a list of "rare and valuable cars" and it needs to be bone stock. so i´m doing pro-touring and i need to "hide" as much as possible. engine is no problem at all cause people here can´t tell a carbed LS or LQ from a smallblock cause it looks like a v8 a procharger can be used legal as "historic tuning" but i need to be able to keep the power level down if i get into those police checkstations. the toggle switch using the IAT is exactly what i´m looking into and sounds good and also keeping the rev limiter at 4k is no problem cause nobody here expects an american engine to rev like a new BMW or Mercedes AMG do i have to use the IAT sensor? i used one of the global folders from holley and the timing chart is at 20° idle and up to 44° all in. so if i set a timing retard that won´t get timing over 25° with all the boost is there a possibility that i damage something in the engine or is just a lot of fuel and air unburned leaving through the exhaust?
04-19-2014, 03:25 PM
#15
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It's easy, and there are several ways. It's actually a query that's been asked before by another user a few yeas back.
Retarding timing would be a bad idea...at least excessively anyway.
It would be very easy to install a BOV or w/g and configure it to blow open and vent almost all boost during any dyno test.
You could install a water injection system, inject pure water only and excessive amounts. Again this will cause a huge reduction in power. Youd need to test to see what works well without causing any major misfire or running problems they might get suspicious of.
You could probably install a cutout type device in the exhaust to cause a major restriction in the exhaust which again would cause a power reduction, Again you'd need to do some testing to see what works best for you. For a few dyno pulls this wouldnt post any problems.
Not a total block, just a substantial one.
Now if you really dont want to go down that route. I guess you could seriously over fuel the engine, and run lower reduced timing. Again you'd need to play with this on the dyno to see how effective it would be, and keep an eye on EGT's to make sure the low timing isnt going to hurt anything.
But running excessively rich isnt a great idea either. Although for one or two dyno pulls...should be ok.
Retarding timing would be a bad idea...at least excessively anyway.
It would be very easy to install a BOV or w/g and configure it to blow open and vent almost all boost during any dyno test.
You could install a water injection system, inject pure water only and excessive amounts. Again this will cause a huge reduction in power. Youd need to test to see what works well without causing any major misfire or running problems they might get suspicious of.
You could probably install a cutout type device in the exhaust to cause a major restriction in the exhaust which again would cause a power reduction, Again you'd need to do some testing to see what works best for you. For a few dyno pulls this wouldnt post any problems.
Not a total block, just a substantial one.
Now if you really dont want to go down that route. I guess you could seriously over fuel the engine, and run lower reduced timing. Again you'd need to play with this on the dyno to see how effective it would be, and keep an eye on EGT's to make sure the low timing isnt going to hurt anything.
But running excessively rich isnt a great idea either. Although for one or two dyno pulls...should be ok.
04-19-2014, 04:33 PM
#16
2 degrees up top. My car didn't have any power up top i though i missed my engine up, it loss so much power. Before i figured it out why i though it was pulling timing but i actually inputed the wrong value. I did many WOT runs to finale figure out what happened, so on the end of my mistake everything worked out find no damage to engine and a lesson learned. Double check ur input so ur not chasing ur tail like me. so i dont see a problem taking out timing to low single digits.
Last edited by helga203; 04-19-2014 at 05:44 PM.
04-19-2014, 05:20 PM
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you need a tune to kill the rpm and would kill timing or even retard the timing a bunch . It could be done . Make the iat sensor read really hot and when that happens it triggers the timing to be killed and only rev to say 5250 .
