New to nitrous with 685 questions.
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New to nitrous with 685 questions. I am new to the nitrous game and have a few questions regarding my Mallory 685 box. Before I permanetly mount it, I want to get all the settings correct. I have a PCMForLess tune (not tuned for the nitrous), Tr-6 plugs and a Harris Speed Works Wet kit in which I will be spraying a 100 shot. My car is a 95 Camaro Z28. Here are my three questions:
1) What should I set the main rev limiter at? What is the factory limiter set at?
2) Being extra cautious, what should I set my window switch at? Opening RPM and Closing RPM.
3) What is the best way to hook up the timing retard function? How many degrees should I retard the timing with my PCM performance tune?
Any other advice would be appreciated as well.
1) What should I set the main rev limiter at? What is the factory limiter set at?
2) Being extra cautious, what should I set my window switch at? Opening RPM and Closing RPM.
3) What is the best way to hook up the timing retard function? How many degrees should I retard the timing with my PCM performance tune?
Any other advice would be appreciated as well.
Originally Posted by Gentner_Z28
I am new to the nitrous game and have a few questions regarding my Mallory 685 box. Before I permanetly mount it, I want to get all the settings correct. I have a PCMForLess tune (not tuned for the nitrous), Tr-6 plugs and a Harris Speed Works Wet kit in which I will be spraying a 100 shot. My car is a 95 Camaro Z28. Here are my three questions:
1) What should I set the main rev limiter at? What is the factory limiter set at?
You should set it for 200-400rpms BEFORE your shift point/rev limiter, whichever is lower.
2) Being extra cautious, what should I set my window switch at? Opening RPM and Closing RPM.
No earlier than 3000rpms for opening, and close mentioned piror.
3) What is the best way to hook up the timing retard function? How many degrees should I retard the timing with my PCM performance tune?
What size shot? If its 100 or less you dont need retard unless your tune is on the NA Edge. If you dont know what your tuning is, you could get ahold of PCM4ess and see if they can get that info. Then, report back we can go from there. Also, R.O.T. is 2* per 50 shot, that's just a rule of thumb though.
Any other advice would be appreciated as well.
1) What should I set the main rev limiter at? What is the factory limiter set at?
You should set it for 200-400rpms BEFORE your shift point/rev limiter, whichever is lower.
2) Being extra cautious, what should I set my window switch at? Opening RPM and Closing RPM.
No earlier than 3000rpms for opening, and close mentioned piror.
3) What is the best way to hook up the timing retard function? How many degrees should I retard the timing with my PCM performance tune?
What size shot? If its 100 or less you dont need retard unless your tune is on the NA Edge. If you dont know what your tuning is, you could get ahold of PCM4ess and see if they can get that info. Then, report back we can go from there. Also, R.O.T. is 2* per 50 shot, that's just a rule of thumb though.
Any other advice would be appreciated as well.
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Originally Posted by Gentner_Z28
1) What should I set the main rev limiter at? What is the factory limiter set at?.
Correct me if I am wrong but I think the factory rev limiter is set at 5800.
Originally Posted by Gentner_Z28
2) Being extra cautious, what should I set my window switch at? Opening RPM and Closing RPM.
Open RPM should never be below 3000rpm, that is to ensure you have enough velocity through the intake to prevent puddling.
Close rpm should be 1-300rpm before the rev limiter on a M6 or befoere the shift point if an auto and you do not want to spray through the shift.
Spraying through the shift will net a faster ET but will be harder on the tranny.
For my personal car my window is 3000-6900 w/a 7000rpm rev limiter
My current shift point is 6500 w/a full manual 700r4.
I am spraying from green light to win light.
Originally Posted by Gentner_Z28
3) What is the best way to hook up the timing retard function? How many degrees should I retard the timing with my PCM performance tune?
Hope this helps...let me know if you have any other questions.
P.S. try to keep a straight face the first time you spray it....I didn't stop smiling for a week
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From: Bullhead City, AZ
My car is a M6 and I have used the search function many times. I know through reading the stickies that it is not safe to spray below 3000 RPM's. I just wanted to know what would be the safest recommended RPM for a daily driver with the occasional street race. I do not know what the exact factory rev limiter is on my LT1, is it exactly 5800 as stated before?
The timing retard question was mainly directed towards wiring. Where does the yellow wire coming out of the 685 connect to? All it says in the instructions is that 12 volts activates. I looked for a wiring sticky with that info and came up with nothing. Does anybody know of a wiring diagram for a Wet kit/Mallory 685/FPSS/Purge ??
I guess what would make my questions a little more clear is this: If this were your car, how would you set the 685 settings?
The timing retard question was mainly directed towards wiring. Where does the yellow wire coming out of the 685 connect to? All it says in the instructions is that 12 volts activates. I looked for a wiring sticky with that info and came up with nothing. Does anybody know of a wiring diagram for a Wet kit/Mallory 685/FPSS/Purge ??
I guess what would make my questions a little more clear is this: If this were your car, how would you set the 685 settings?
Staging Lane
Joined: Jul 2004
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From: Central cali.
Originally Posted by Gentner_Z28
The timing retard question was mainly directed towards wiring. Where does the yellow wire coming out of the 685 connect to? All it says in the instructions is that 12 volts activates. I looked for a wiring sticky with that info and came up with nothing. Does anybody know of a wiring diagram for a Wet kit/Mallory 685/FPSS/Purge ??
I guess what would make my questions a little more clear is this: If this were your car, how would you set the 685 settings?
I guess what would make my questions a little more clear is this: If this were your car, how would you set the 685 settings?
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From: Bullhead City, AZ
I'll run what I am thinking about doing by you guys and see what you think. Please critique:
Main RPM limiter: 5800 RPM's
Window Switch Start: 3200 RPM's
Window Switch Finish: 5600 RPM's
Timing retard when Nitrous is active: 4 Degrees
Since I have the PCMforless tuning, I figure this would put me at about 2 degrees retarded. (Counting the advance of the tune)
If I ever disconnect my battery, will the 685 keep my settings stored or will I have to reset them every time?
Main RPM limiter: 5800 RPM's
Window Switch Start: 3200 RPM's
Window Switch Finish: 5600 RPM's
Timing retard when Nitrous is active: 4 Degrees
Since I have the PCMforless tuning, I figure this would put me at about 2 degrees retarded. (Counting the advance of the tune)
If I ever disconnect my battery, will the 685 keep my settings stored or will I have to reset them every time?
