Just got back from getting a dyno tune! 02 z06, My mods are Vararam intake, b&b bullets axle back, and LG street series LT headers with catted x pipe.
The car made 389/376 on a Dynojet, just thought I’d share!

 

Baseline?

 

what do you mean? Sorry I’m new to this !

 

Did you have a dyno run before adding your power adders to see the results? Also it is better to maintain using the same dyno/shop to keep the comparison true

 

I thought a zo6 was 405 out of the box
I've got a base 01vert and am in the process of having the rear end swapped from a 273 to a 373
Installing Kooks Long Tube Headers and have the Vararam
Their supposed to Tune it and put it on the Dyno
am I getting ready to get my feelings hurt?

 

The 405 is BHP at the motor. The Dyno run is wheel HP. Am I right?

 

“Unlike bhp, whp is the power output measured at the wheels. This is the information a dyno run provides and usually reads around *15 per cent less than the power measured at the engine (bhp) - this is because power is lost in the driveline (including clutch and transmission)” . Stole that from google cuz it sounds better than I was gonna explain it haha. So ya the car has 405 hp stock to the engine but when dynod stock its usually around 350-360 to the wheels. So I’m happy with pulling 390 to the wheels!

 

oh haha I’m dumb, but no I never dynod it before this so not sure on exactly what i gained. But I’m guessing 35 whp around there

 

Congrats on the curve. If you are new to 'this' I will give you some pro tips to get on track quickly


experienced eye tells that the engine is healthy with respect to it's cam timing, ring seals, all eight cylinders are more or less even. I can pretty much assure you that a compression test would yield good results.
In a way the dyno curve can tell us things like this is we are able to notice certain things and draw general conclusions.


Most diagnostics are done using the torque curve only. The shape of the curve, how it peaks near midline, tells us that cylinder pressure also likely peaks in the mid-range. Which is what a 'mild cam' is supposed to do. truck cams peak early, performance engine peak mid-way and all out racing engines peak as far to the right as possible, they shoot for peak torque near max redline for highest hp. Which is frowned upon for street cars which spend most of their time near 3000 and 4000 rpm, so your curve is absolutely perfect for street vehicle performance the way it is.

While there are some minor things you can do to improve the VE (height of the peak at every point) it is more or less 'capped' or has a maximum around the peak torque the engine is capable.of because it is ;likely already near 100% Volumetric efficiency.
Let me put that another way, almost every engine produced since 02+ is capable of reaching close to 95% or 100% VE, as VE generally follows TORQUE we can look for peak torque and assign a peak VE value near those regions. Because of the way engines work(timing vs cylinder pressure vs peak pressure x connecting arm position stuff) this isn't an exact figure but you can safely assume that peak torque of any modern engine run at WOT under any circumstances (I mean all factory engines untouched from performance mods from all manufacturers i.e. nissan toyota chevrolet etc... ) is near 95% to 100% VE so we just say 100% to be simple.

So if peak 100% is near 375ft*lbs of torque this gives u alot of information. Especially if the engine is at atmospheric known pressure. The issue however with boost is that everybody's boost figure will be different because the pressure is actually a differential which is highest at the compressor outlet and lowest near the cylinder. So one person could be recording boost from near the compressor, the other person from the intake manifold, or from the cold pipe, etc... location matters when discussing boost, and so does temperature. Most successful gasoline engines need IAT manifold temps near 100*F or less. And this is often more difficult to achieve at higher outputs for full out racing vehicles (due to peak power = peak flow = needs huge intercooling) but not too bad for street cars which rely more on mid-range torque than peak power.

When I discuss boost the number I use will be manifold pressure and atmospheric is assumed to be sea level 14.5psi
There is a nearly linear relationship between 1 atmospheres and torque. For example if an engine made 200ft*lbs of torque at atmospheric pressure, then 14.5psi of additional boost should double that to 400ftt*lbs.
Japanese engines tend to be small displacement 2L 3L so they need alot more boost to produce the same torque as a V8. Conserquently their gauges often read in terms of atmopheres i.e. they got 1, 2, 3, 4, ... where every 1 is an additional atmosphere or doubling of torque. It depends on fuel quality and temperature (because of ignition timing) but more or less this holds to be true across all platforms.

So using this data we would work backwards psi of boost to get actual engine VE. For some reason I thought we had boost involved and was prepared to do a more complex question

Well this is great then, we don't need to worry about temp, density of air, pressure, none of that. We can clearly see 100% atmospheric (assuming sea level) is adjusted near 375ft*lbs of torque.
since 430*.88 = 378ft*lbs (assumed 12% drivetrain loss) the engine is making close to 430ft*lbs of torque (BHP) near peak region.

The dyno curve is nice but it lacks information. Next time:
1. Always use smooth=0 and show the smoothing factor on the dyno curve, smoothing is to make the curve pretty, but you do NOT want any smoothing for diagnostic value, the graph contains much more information without the smoothing.

2. Always get an Air fuel ratio curve. An engine will run remarkably similar at 11:1, 12:1, 13:1 air fuel ratios and the difference would be minimal on a dyno output,
but
air fuel of 13.2:1 can destroy a sensitive high compression performance engine and 11:1 in this case would be excessive, ruin torque, smell bad/foul plugs, accelerate carbon deposits, waste fuel etc...
it is arguably just as important as a torque curve with smoothing = 0

3. Always use a dynojet. I think that is a dynojet but always show the name of the dyno "DYNOJET" So we can accurately compare. dynojet uses a standard that we can always depend on to report accurate RWHP numbers, to compare to other vehicles. It cannot be fooled easily or much at all (I think you can dial up and down around 2 or 4% max)

hope its helpful insights and next time 123

 

[QUOTE=NickZ06_;1601492442]“Unlike bhp, whp is the power output measured at the wheels. This is the information a dyno run provides and usually reads around *15 per cent less than the power measured at the engine (bhp) - this is because power is lost in the driveline (including clutch and transmission)” . Stole that from google cuz it sounds better than I was gonna explain it haha. So ya the car has 405 hp stock to the engine but when dynod stock its usually around 350-360 to the wheels. So I’m happy with pulling 390 to for 30ish