Nitrous BASICS (It'll be like talking to a 3 year old)

[JesseB4533]

Hi, new to the forum (first post) and super green to tuning. Im looking for some help with adjusting my current tune to run some nitrous. The engine is an LQ4 based build and has already had dyno tuning by a pro and has been in our race truck for about 6 seasons with lots of success. I got sponsored by nitrous express and set the truck up to run a 75 shot for our smaller races and want to run up to a 150 shot for larger national type races as i get more experienced with tuning and monitoring whats going on. The system is a 90mm wet throttle body plate, tune is speed density only, it has a window switch that limits operation between 3000-6000 rpm and a progressive relay. The current tune is dialed in for 91 octance but i often mix a little 110 in for safety as we race in some extreme temperatures (mixing to roughly 96 octane).

My question is im not sure what the best way to dial back the timing is, i know because of the interwebs that i want to pull 2* per 50 shot as a starting point but i only want to pull it at WOT since the system is setup with a WOT switch. How do i go about doing that? Do i go into the retard (me :-) ) area and pull it out at 0kpa (which would represent WOT???). or do i have to pull it out across the full RPM range even when not under WOT? Like i said super new to tuning, going to roll into it slowly and trying to watch as many videos and what not that i can but ive searched a lot for this specific info and for some reason cant find a clear (clear to me) answer. Thanks in advance!!!

[2xLS1]

Do you have HP Tuners and know how to datalog a WOT run?

[JesseB4533]

Yes and yes*
Do you mean a run that only logs WOT aka set the logging trigger to be at TPS at 100%

[2xLS1]

If you log a WOT run and look at the timing histogram you will see where in the main timing table in the calibration where you would need to pull timing. And a hint, it's not at 0 kPa.

[JesseB4533]

I realized after I wrote the post that kpa is not correct. What am I looking for specifically? I?m going to the track this weekend for a shake down run, would it be worthwhile to just log it, take some screen shots and post them up? It?s an off road race truck, not a track car.

[kevin87turbot]

I realized after I wrote the post that kpa is not correct. What am I looking for specifically? I?m going to the track this weekend for a shake down run, would it be worthwhile to just log it, take some screen shots and post them up? It?s an off road race truck, not a track car.

The best way to retard the timing when the nitrous is activated is to buy a Lingenfelter LNC 2000 timing retard box. It doesn't retard the timing until the nitrous solenoids are activated. This works great on an application like yours.

[Alvin]

I realized after I wrote the post that kpa is not correct. What am I looking for specifically? I?m going to the track this weekend for a shake down run, would it be worthwhile to just log it, take some screen shots and post them up? It?s an off road race truck, not a track car.

In the timing table.. above 0.60 g/cyc is roughly about 80% throttle and up on most things like this.

[JesseB4533]

thanks guys, thats the info im looking for! I looked and the lnc2000, it seemed like the way to go but i figured HP Tuners could do it as well. Im thinking the LNC is the easy way to get there and HP isnt so straight forward for what im trying to do. I will still use HP to monitor it and adjust as needed as i learn it.

[RDF1]

The LNC2000 would be the easiest option.

or You can do the IAT sensor grounding trick with a 5 pin relay if you wanted to save some money.

[JesseB4533]

i like the quick external adjustability of the LNC and with the small shots im running i think the tune will always be close enough. These are super short burst of nitrous for short course off road, just out of the corners for 1-3 seconds. I will data log and adjust the tune if needed as time goes on maybe jump up the nitrous to around 100-150 shot as i learn about the tuning. Plus i got excited and already ordered it :-)

if you all do the "gram" check out balterbuiltracing and you can see the jalopy this is for, nothing terribly exciting.