Just wondering how much HP you lose per degree of timing pulled for nitrous? I've heard you should pull about 2 degrees per 50hp shot of nitrous. If you are running a 150 shot or less, is it even worth it to get a timing tuner? How much hp would you be leaving on the table without the timing tuner?

 

You'll loose minimal amopunt of power, not enough you would ever notice. that's why i never understand the fear of removing a few degrees of timing. Most vendors will tell ya that a 150 and below, no timing pull is needed, given your a/f is correct and plugs etc. Now with that said, nitrous actually works better, or more efficantly with less timing, and along with the added safety feature, well only you can judge to pull or not to pull.
Robert

 

FWIW,
I pulled 6* for a 2 stage 250(total) shot and I lost 5rwhp.

 

Great! thats what I needed to know!

 

so the n20 hightimers don't make it a practice to come up to traces of kr and then back off , say like 2degrees?

 

Correct, the only real way to set timing is for n/a, you add timing until peak HP, not kr. then on the spray, the 2 degrees removed per 50 shot comes into play, and this rule really needs to be followed when going past a 150 shot. Currentlly I have my 200 shot set to pull timing down to 18 degrees, and will pull more as I go up in hp size. N/a timing is about 24/25*, which produced the highest rwhp, and no need to go any higher like most would think.
Robert

 

thats makes good sense, but a dyno is needed, and i noticed that on wet sys. the jet sizes are set so that you end up somewhat rich, so to lean it out to 11.8afr, dereasing the fuel jet size in small increments is the way to go, right
?

 

The last thing you need to use is a dyno as it doesn't simulate true load or account for the forced air entering the intake tract and effecting how the air is distributed into the runners. This needs to be done at the track or on the street to truly see where things lie with a wideband to a point. Then you need to make a pass and learn how to read plugs. Everything can look perfect on the KR and on the wideband but that damn LS1 # 7 hole can sneak up on you and get destroyed. Reading plugs is the true way to measure any nitrous system. Tune the system to the leanest cylinder, which on almost every ls1 setup will be # 7.
Many people live by old rules and myths and are generally lucky but you must learn how to read a plug to play in the big leagues of nitrous. Look at all of your pro level NMCA/NMRA cars who run N2O, they monitor each cylinder separately and they do it for the reason I mentioned above. Every design has 1 hole that inevitably leans out and you must tune accordingly.

I don't claim to be an expert but anyone who tells you anything drastically different is full of it.

 

Good input, however, he is not going pro levels, but asked about 150 and below. this still can be applied though. For those not going big and not knowing how to read plugs, the dyno and/or wide band are still the hobbiest's best friends. We have been waiting on a good/correct write up on reading plugs for the n2o users, it's somewhat of a science and most do not have the back ground experiance to do it correctly.
Robert

 

I luv this forum, awesome info!! Thanks to everyone!!

 

I agree. THis is an informative thread for me as well

 

Good point Robert,
I may have gotten a little carried away there. LOL There are some good color diagrams out there for reading plugs which can be a huge help even for maximizing a smaller system.

 

good thread...I'm savin' it.

 

Where would these color diagrams be found?

 

thanks for getting carried away man , it's good info, but isn't the proper way of testing the plugs, to imediately shut the motor down after a wot run? and if so where on the track do you do it? and also the dyno would be a good reference point to go from at the track, no?

 

From what Ive been told you should shut down right after your spray run and start pulling plugs. Probably works best out on some country roads, because I dont think youre allowed to kill the motor on the track because they're afraid of power brake failure.

 

so on a 150 shot what would you recomend to have pulled???would 3-4* be safe....

 

i'll take the dyno instead, but if you got wideband readout coupled with o2 sensor readout as a crosscheck, timing seems to be the more deceiving of the two. what you guys are saying is that when on the spray, peak hp timing is not necessarily a degree or two away from trace knock but instead it could be 4 or 6 or maybe 10 degs. on a 100 to 200 shot respectively! h/c and compression combos will also play a part where optimun timing is on the spray. dyno results should only be a reference point since the lack of cooling ram air will not give the same resulst as on the track, tuning a point or two richer is probably the way to go. who know maybe i'm off with this train of thought. but i definitely want to get the most out of my nos shots with a good safety margin.