The guy at the dyno shop sent me winpep 7 along with my runs from 2 springs and today. I guess I should have expected the numbers based on my 115.5 trap speed black bumper.

I don't know if you guys prefer uncorrected or SAE numbers, but I'll post the higher one to feel good about myself. (uncorrected)

ALL motor:
269.62hp
242.11tq

Spray (950psi bottle pressure):
362.04hp
374.31tq

AFR hit 12.0 @ 4200rpm and dropped from there. It bottomed out @ 5800. I'm leaving a lot of power on the table.

All runs made on pump gas with 2 degrees of timing pulled across the board and LFR6a coppers installed. I've attached the 2 runs for dissection.

 

what are you doing to pull the timing ?

 

What is the story on the torque? Sudden drop at 5,000 RPM?

 

Too much fuel......damn near washing the motor out with a/f like that.

 

Ratio of Nitrous to fuel decreases as RPM goes up (more fuel added per unit time) so there is less oxygen for the reaction. Thus, with most linear nitrous setups, you get a big torque loss as RPMs go up.

 

Factory retard. Just the opposite of having them add more. My understanding is that they can go 2* in either direction. It gives me a warm fuzzy feeling.

 

Hella fuel. I'm running .002 sized larger jets than recommended. I'm really thinking about adjusting that. I'm just about done with the "more with less" path. I just want one 11.9 pass on an open diff with no tune other than reading plugs and the occasional dyno.

 

That begs the question. Do I dial back the fuel and risk an even bigger lean spike at activation, or add a 35hp 2nd stage and get up around 400rwhp?

 

I am guessing that you are getting the uneven mixture due to nitrous pressure drop with consistent use throughout the run?

 

Yeah, thats always been my thought... people are saying that the Z will handle a 125hp shot fine, and usually, the danger with nitrous is at lower rpm's, due to massive torque increase.

Therefore, people should run a 175hp progressive shot :-D.

 

OP try 200 shot to lean it out.. Get a little over 400whp safely.

 

200 shot and safely don't belong in the same reply. He just needs a real tune on the shot he has (along with properly sized fuel jets), and he will be on his way.

 

You would pull timing in the early phases of nitrous introduction and get more aggressive as the ratio of nitrous to fuel per time decreases. I dont have any expierience in tuning cars, but from what I understand in motor tuning and control theory in general, thats what I would try.

 

What size jets are you running? I think a progressive 175 shot sounds like a great idea! You should try that and let me know how it goes.

 

I run .061n .036f. This is my last season of experimentation. Next is suspension.

 

Wow, that is a big shot for -2* and pump gas. So I guess a 34 fuel jet would probably work a little better up high but that will be pretty scary right at the hit. I got the progressive controller/window switch from Dynotune not really planning on using the progressive part of it, but if my dyno sheet looks anything like this one I will most likely run it progressive.

 

get a used utec and pull fuel on the top end

 

what a/f are you wanting to be at on spray?

 

bump

 

by the sound of it you have no tuning software and aren't tuning the ecu then.

Here's the kicker, your tip in (lean spot) will always occur when you jam the gas unless you tune the ecu to fix that. So here's the smart thing, set your window switch on the nitrous to engage AFTER your initial tip in. So your tip in will happen at 3k rpms and nitrous hits at 3.5k therefore giving your engine 500 rpms to adjust for the big rush of air before you blast it with nitrous That will help the tip in lean condition.

because of that, i would also pull back the jetting big time.

if you are drag racing the question is why have your nitrous engage so low? when you shift you aren't going to be anywhere near 3k range so just move the window switch up and you can pull more fuel since you're leaner down lower rpms.