Dyno sheet Whipple Stage 2

[DrDing.Muscle]

So I just came from dynoing my car. Considering the temperature outside and the fact that I have stock headers I am pretty happy with the numbers as it is a pretty healthy street car. The actual thing I am posting about is the AFR. The owner of the shop told me that his W/B for the dyno always reads leaner than any other wideband that is installed in the car but he did say it is consistent. In my case my dyno graph is showing that around 5500 the Air Fuel leans out slightly and then in the power graph right around that same spot you can see some hills and peaks. The guy at the dyno shop said it was probably pulling some timing right there because of the leaner condition and that is what caused the valleys. Has anybody else seen anything like this from their Whipple tune?

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[Dolsvt00]

Sniffer's in the tailpipe are usually about 1/2 a point leaner than up front where your sensors are that command WOT lambda. if you have cats it also skew's it more. That graph doesn't look bad to me.

 

[DrDing.Muscle]

Sniffer's in the tailpipe are usually about 1/2 a point leaner than up front where your sensors are that command WOT lambda. if you have cats it also skew's it more. That graph doesn't look bad to me.

Yeah I am not concerned with the overall AFR but why around 5500 does it lean out for a period and then richen up again?

 

[Dolsvt00]

Yeah I am not concerned with the overall AFR but why around 5500 does it lean out for a period and then richen up again?

I would imagine that it has to do with vct all things being equal ie fuel pressure,commanded wot fuel, timing ect. Im not familiar with their calibrations. Ive loooked at a ton of dyno sheets on here and some are worse, some are smooth as glass, tach signal and smoothing have alot to do with it. if you could get that graph with the x axis being mph vs rpm it would even give more insight into the bumps around the same area.

 

[Jmeo]

It could be so many different thing, I wish I could help you with an answer. Perhaps its your Avatar that keeps disrupting my thoughts by shunting blood away from my brain?????

 

[beefcake]

i would pay no attention to that, and hook up something to log the factory wide bands with.

#s look good!!!

 

[Excelerater]

My Whipple did within 5HP of yours before I added a pulley and headers.
so yuor right on target from what they promised

 

[Bartly]

For some reason I remember 700whp whenever I think of previous Whipple threads I've read.

 

[Roh92cp]

For some reason I remember 700whp whenever I think of previous Whipple threads I've read.

Many factors involved with Dyno numbers, like Dyno's read different, Dyno operator operation, RPM it was taken to, 4th or 5th gear nets different results, weather, fuel ext. I bet if you put 93 or Octanium in your fuel and revved to 7500 rpm you would see close to 700whp.

 

[Whipple SC]

I can guarantee air fuel is not correct reading. Tailpipe sniffer is almost worthless, it's rarely accurate, especially with cats.

Power in general is down, not sure what gear and how many pulls you made as power is best on 2nd and 3rd pulls.

Octane is critical, Shell, Chevron, Sunoco.....

Always turn knock limiting off in flight control.

Did somebody flip the octane switch to on? A few do that but it's surely not needed, especially with 93.

 

[DAVECS1]

Is it the stock fuel pump? I imagine there is some things that need to adjust once it hits its max flow rate.

 

[Whipple SC]

Is it the stock fuel pump? I imagine there is some things that need to adjust once it hits its max flow rate.

Yes and no, cal is 100% dialed in. Tailpipe sniffers should never be used for any testing unless it's just comparative, back to back and only used as reference. They are not accurate in anyway.

S550 have dual wide bands, they don't go lean, they run target.

 

[smokinzx14r]

Why are the TQ numbers so low ?

 

[DAVECS1]

Yes and no, cal is 100% dialed in. Tailpipe sniffers should never be used for any testing unless it's just comparative, back to back and only used as reference. They are not accurate in anyway.

S550 have dual wide bands, they don't go lean, they run target.

I was not trying to imply the calibration was off. I was simply offering a possible reason for the noise he pointed out in his graph. I personally do not see an issue with that much movement. It could be a number of things.

On other models of sc cars I tune on the dyno. I see that type of wiggle when they are using a boost a pump. It takes a bit for that thing to get up to full tilt.

 

[Whipple SC]

I was not trying to imply the calibration was off. I was simply offering a possible reason for the noise he pointed out in his graph. I personally do not see an issue with that much movement. It could be a number of things.

On other models of sc cars I tune on the dyno. I see that type of wiggle when they are using a boost a pump. It takes a bit for that thing to get up to full tilt.

I understand but this is controlled by wide bands therefore it does not very like this. Therefore the reading is inaccurate. He has more than enough fuel. Issue is either airflow or spark. My guess is spark as the curve looks like the octane switch is toggled on.

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