Nitrous Help! [Archive] - GrandAmGT.com Forum

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OneFstGt
07-29-2009, 08:09 PM
Ok i have used the search button and sent Mp Racing an email and i cant seem to get an answer so my question is... Can i use nitrous with my tuned Pcm from mp racing if so how much? I guess you would say that i have a basic tune or the tune that is on the front page of there web site. Thanks for any help.

lone_wolf025
07-29-2009, 08:17 PM
Short answer: yes with a but.

Long answer: Unless you wanna destroy your engine DO NOT use nitrous without a tune.

OneFstGt
07-29-2009, 08:49 PM
I wonder what would be safe to use? 25-50-75

lone_wolf025
07-29-2009, 08:59 PM
Depends on if you go wet or dry. A dry shot typically 50 is safe 75 is iffy. Wet 75 is safe 100 is doable but is at the max end of safe. However, nitrous comes with the catch that if you're not careful you can blow up your engine really easy. Whatever you do, do it right and do it smart even if it takes 2x as much money and time.

burgett2103
07-29-2009, 09:53 PM
Depends on if you go wet or dry. A dry shot typically 50 is safe 75 is iffy. Wet 75 is safe 100 is doable but is at the max end of safe. However, nitrous comes with the catch that if you're not careful you can blow up your engine really easy. Whatever you do, do it right and do it smart even if it takes 2x as much money and time.

x2

OneFstGt
07-30-2009, 07:42 AM
Thanks guys for all the help.

iceman
07-30-2009, 09:37 AM
Dunno about MP racing but the other PCMs I know about advance timing.. not something you want to do w/ Nitrous. I wouldn't run it without a proper tune, not only for the safety fact but also you want to get all the benefits out of it and not just shoot in the dark.

<have seen motor explode on the dyno w/ improper tuning + nitrous

Silversmok3
07-30-2009, 12:07 PM
Ok i have used the search button and sent Mp Racing an email and i cant seem to get an answer so my question is... Can i use nitrous with my tuned Pcm from mp racing if so how much? I guess you would say that i have a basic tune or the tune that is on the front page of there web site. Thanks for any help.

Absolutely not!!

With nitrous you want to RETARD timing, not advance it. The tuned PCMs have the timing advanced with high octane fuel to yield power otherwise lost to the stock PCM's programming, which uses a more conservative timing map.

On a stock PCM youd achieve the same effect as retarding the timing by changing the spark plugs to two degrees colder for more than a 50 shot (wet or dry), or one heat range colder for 50 shot wet or dry.That plus the conservative stock timing map will safely work for shots less than 75.

Combining an advance timing PCM with any nitrous kit = tow truck and ruined motor.

Either downgrade back to stock ( cheaper) , or edit the mail order tune professionally ( Xpensive).

AaronGTR
07-30-2009, 02:41 PM
I'd say you could do it... IF... you install something that will let you decrease the timing when you are using the nitrous. Just as an example, the MSD DIS-4 ignition box will run unaltered timing (meaning whatever your pcm is programmed to command) OR there are some switches you can change on it to select two different curves of ignition retard, where the amount of retard goes up with rpm. One is less aggressive retard and one is more aggressive. You have to have all the other key things of course... the right plugs, right fuel octane, nitrous and fuel jetted properly... but the MSD may let you run the nitrous without changing the pcm. The key of course is scanning for detonation. Otherwise your only choice would be to have the pcm retuned with ignition timing that will work with the nitrous, in which case your timing will be compromised any time you aren't on the bottle (ie all your street driving).

Tupperware SC2
07-30-2009, 03:02 PM
another good tip is using colder plugs, like two heat ranges colder. that will help with predet.

with your tune do you also have a wideband? do you know your AF at WOT? if you are planning on running anything more than just a 50 dry shot then you are going to need to be real rich. rich is cold.

thirdly using a window switch will make your nitrous usage more reliable and will help you from blowing that beast up.

AleroB888
07-30-2009, 08:02 PM
.............the conservative stock timing map will safely work for shots less than 75.........

I consider the stock timing tables somewhat aggressive in some of the PCM calibrations I have used. .................

GrandAmGTTT
08-03-2009, 11:10 AM
i'm running 75 wet shot from zex and i've had no problems. whavever you do DON"T USE A DRY NITROUS KIT!! You will destroy your motor