Nitrous Tuning

**JwMonE99** · 07-31-2009, 03:08 PM

Getting ready to install a nitrous kit and wideband so I can start tuning.
Right now it is set up for a 75 shot "wet"
I am going for a 13.8 WOT AFR but what exactly do I need to tune for the spray? I know I have to retard timing by 1 degree but I am also wondering how would that effect N/A DD tune?
Any help/tips would be great.

**karpetcm** · 07-31-2009, 11:17 PM

You will get many different answers as to how much timing you need to pull, without a doubt i would pull atleast 2 degrees and its 2 degress for every 50 hp and not one. This isnt something ive made up but asked a couple of shops that sell the nitrous and race there own cars running nitrous for years. I learned it the hard way through many months of testing and in the end i pulled 7 degrees for 150 shot on my past 2 Z's. If you pull 2 degrees for the 75 shot of nitrous you will feel the power loss up top as i did. If you meant 13.8 WOT on nitrous that is really lean, ive never ran a 75 shot so you can also ask about that, talk to Frost. I know on my 01 Z ive ordered something were only when you flip the switch for nitrous it will ONLY pull timing then but once the switch is off it will go back to N/A tune. I dont know if he has this option for LT1 cars you can ask him. Again i will say you will have many different answers in regards to this and even people telling you that they never pulled any timing what so ever and even say that they didnt get a tune, lol.

**JwMonE99** · 08-01-2009, 06:10 AM

Yea that would be perfect.
I meant a 13.8 WOT n/a, I have no idea what I am going to be looking at with the spray. Any ideas of what is optimum for a WOT AFR on a 75 shot?
What would happen if my normal tune was retarded degrees for N/A DD?

**jakesz28** · 08-01-2009, 08:56 AM

A car on nitrous wants about the same AFR as it does n/a. Also the pull two degrees per fifty is garbage.

My car likes 38* N/A and I spray it with 350hp. Now at 2 per 50 I would have to pull 16*. But I started with 12* total timing which is pulling 26*. Not trying to be harsh or a smart a## but timing and fuel are what hurts a nitrous motor. I would run the same AFR you do n/a on up to a 150 shot then start reading the plugs and skip the wideband after that. You will have to research reading plugs to learn what to look for but you want a clean plug that looks almost like it came out of the box.

I would pull extra timing at first and slowly add it back while looking for a timing mark on the strap. Or while watching the mph on the timeslip. If it didn't pick up mph it didn't want the timing.

**cuzimoto** · 08-01-2009, 01:27 PM

Spray & Pray

**jakesz28** · 08-02-2009, 10:06 AM

The only praying I do is that it drives straight and stays off the bumper

**Frost** · 08-02-2009, 12:17 PM

Originally Posted by JwMonE99

Yea that would be perfect.
I meant a 13.8 WOT n/a, I have no idea what I am going to be looking at with the spray. Any ideas of what is optimum for a WOT AFR on a 75 shot?
What would happen if my normal tune was retarded degrees for N/A DD?

Why so lean?

I tune for 12.6-12.8 N/A typically...

**JwMonE99** · 08-02-2009, 07:36 PM

Originally Posted by Frost

Why so lean?

I tune for 12.6-12.8 N/A typically...

I thought perfect AFR was 14.0 for n/a?

So what would you recommend I go for in my situation?

Do you sell that switch where when the nitrous is armed, it would retard my timing by 2 degrees that would work for an LT1 OBD2?

**karpetcm** · 08-02-2009, 07:44 PM

14.0 is very very lean, just be carefull. Ive had 5 camaro's and never ran that lean at all. Right now im about 12.8-13.0 and thats just about right for my car and frost did an excellent job on the tune. Look him up either way

**JwMonE99** · 08-03-2009, 06:23 AM

I did, but he only does LS1s

**karpetcm** · 08-03-2009, 08:49 AM

Look into others, PCMforLESS or MADZ28 as well they did good tunes on my past LT1 cars as well.

**JwMonE99** · 08-03-2009, 07:56 PM

Well I already have everything I need to tune myself, I just need to know what numbers to look for.

**karpetcm** · 08-03-2009, 08:17 PM

Just tune it for what Frost said as far as A/F, 13.8-14.0 is too lean. The timing and all i dont know really, i had my past Z's tuned with the timing i stated above and didnt have any issues at all and ran it that way for 4 years others may need more timing pulled or less.

**Frost** · 08-03-2009, 11:10 PM

Originally Posted by JwMonE99

Well I already have everything I need to tune myself, I just need to know what numbers to look for.

12.5-12.7 from your wideband in a front bung. The tailpipe units read 0.3-0.5 leaner than measuring up front, so people are used to seeing 12.8-13.1 on them.

That LT1 will likely be happy with 36-38deg @ WOT N/A with 1-deg removed for each 50ish HP of nitrous added. An 8deg retard is not out of the question for a 150 hit. Nitrous HP is not made with timing (well to an extent) like FI HP.

**JwMonE99** · 08-04-2009, 11:03 AM

Well for now its going to be a 75 shot till I get use to it, later on a 100.
So I should be ok with just a -1 degree right?

Yea I have an innovate LC-1 Wideband with the XD gauge.
How much of a difference am I looking at between a 12.5 and 12.7 WOT AFR?
Would should AFR be with the spray on a 75 shot?

BTW thanks for your help guys, I think I am almost ready with everything I need to know.

**jakesz28** · 08-04-2009, 02:11 PM

I would have to agree with frost that 14.0 could be lean. But do to placement and possible inaccuracy of the wideband reading the plug is the best indicater on nitrous. But small shots (less then 250hp) just about any tuneup can live. Timing is what kills a nitrous motor. If you run it lean on a safe amount of timing you lose power before you hurt parts. I have seen people run a nitrous motor with a AFR of 15 to 1 which leaves me to beleave ther could be problems with the readings. But tuning to specific AFR may not lead to the most power. Every combo wants a slightly different afr. What ever ratio gives you the most power n/a will most likely give you the best power on the bottle too.