Hey fellow members. About 4 months ago I dynoed after installing H/C/I package. The numbers where a little dissapointing.



After consulting Tony Mamo, who helped me choose my setup, I went back to my tuner and we did some adjustments. The results speak for themselves.



Anyhow, While i was there I thought we might as well tune for the N2O. We took out 6 degrees of timing, and with the help of NANO kept a constant bottle pressure of 1050PSI. Here are the results for the 100 shot.



Needless to say, I am extremelly pleased with the results. I want to thank Tony for all his help especially the porting of the 90/90. I would also like to thank Matt and Brian at RPM (lewisville) for having the patience to get the tune right. Altogether I think we made 6-7 NA pulls, and 4-5 N2O pulls to get everything perfect.

 

all I see is red X's

 

Any better now?

 

Can't see any numbers so what is the afr. Looks low. I am considering similiar setup maybe a different cam.

 

AFR was 12.6 on NA tune, and considerably more conservative on the N2O tune.

 

nice NA #'s

The nitrous tune needs some work by the looks of the A/F. The constant bottle pressure should have made a much more consistent A/F. The low rpm is very lean and higher rpm very rich which is unsafe IMO.

 

Thanks for the input. I thought being rich in the high RPMs was supposed to be safer???? I don't think the low RPMs were all that lean, but I will discuss it with my tuner.

 

maybe it's just the graph, but it looks both lean and rich & too much either way can cause big problem

 

If thats the right A/F ratio there is still a bunch left in this thing....

Better results are achieved leaning the engine out as it approaches peak power....the most fuel needed is usually around peak torque where the engines volumetric efficiency is the highest (I usually like to see 12.5 - 12.8 in that area for best results). As the engines starts heading towards its power peak (and its V/E starts falling off), it actually likes less fuel. I usually like to see it drift towards 13.0 - 13.1 approaching peak power and above and sometimes slightly leaner as every combination is a little different (if you want to get the most out of it and all of this is predicated on the fact we are discussing N/A engines of course).

If you want it "safer" keep it in the mid 12's across the board (you may only give up 3-5 RWHP there) but by the looks of your A/F curve you might be in the 11.0 range (or worse) approaching peak power. As LS1 Speed mentioned....too rich can be just as harmful as too lean.

Get some actual numbers....has your tuner worked much with these types of combinations? I find it strange that he would send you out the door with the A/F ratio diving pig rich like that as the engine RPM's higher unless thats what you specifically told him to do.

Barring that the numbers look a whole lot better and if there is any left on the table its even sweeter.

Tony M.

PS....Call me if you need some input....Im afraid to ask how much timing

 

why does that dyno always spike at the end of every pull? Is it a trick or an issue?

 

You are too rich. Looks like you are 11:1 or fatter? Whats up?
You might have 480+rwhp if you lean it out.

 

if you hit the limiter the graph will spike/bounce all crazy. its all how you start/stop recording the run oposed to when you let out of it or hit the limiter. its not a trick but not acurate data either. claiming that little spike at the end of a pull as peak power is not real honest power. tho it looks as if it had that in it by twisting it alittle farther. stock bottem end? i would think it has a little more up top by taking it alittle farther in rpm.

and i agree, that from peak tq to peak power would benifit by leaning out a tad. and its hard to say on that nitrous run, the afr heads south in a hurry like you would see with a low/cold bottle. but you said you had a nano?? look at some of the earlier runs and see if they are the same. maybe you were getting low on juice. if not then well. i would try to flatten that out. def some left on the table on the bottle. and 6 degrees for a 100 shot. that alot.

nice combo and power tho. alittle tweeking and should be a monster

 

Is that with 3.42's?

 

So what did you change to get the extra ponies?

 

Thanks for the constructive criticism guys. I will look into this, and hopefully post results soon.

 

Was running a little rich, so we leaned it out. Apparently though, it still has some left in it.

 

Nice gains. You may find that you can make more power with a little less fuel and a little less timing NA. Correct fueling seems to make a bigger swing on power production than timing with these LS1s.

 

Its through a 9" with 4.11s and a Nitrous ready DS. Was a dynojet dyno however.

 

I pull to the limiter quite regularly but don't get that spike that increases peak.

I only mentioned it because 3 out 4 people here will read the peak numbers posted, glance at the graph, and then read on without realizing that the numbers came from a spike, and they are not the true peaks recorded/observed/produced by this setup.

 

Ok, I have an appointment at 9:30AM tomorrow at another shop. Will make 3 pulls to check the current tune and go from there depending on whether or not adjustments need to be made. I Will be sure to get a better A/F graph. Personally, I would be suprised if it needs significant adjustments, but a 2nd opinion is never a bad thing.

So, tomorrow I should look for an A/F ratio (NA) of somewhere in the neighboorhood of 13.0 at 6400RPMs, Right?

What about for the N2O tune? The main thing I am looking for on this tune is "safety". I don't want to exceed 550rwhp, because i think that is about the limit for the stock bottom end. So what should my A/F be like on the nitrous tune.