Troubling Dyno results for Stock 2006???

[MuscleJunkie]

Went today for the first dyno pull on my 2006 Coupe (all stock - 5K miles)

One the 1st run I noticed that the power significantly dropped about 4500rpm for just a min (it felt like a hesitation) and then it returned back to normal. I guess they didn't have the A/F gauge in so the run was not recorded.

Did two more runs and this was the result

Run 2: Max Power = 422.8 Max Torque = 416.8
Run 3: Max Power = 428.6 Max Torque = 423.9

I do not have access to a scanner right now but will tomorrow and will post the graphs but did notice the following.

1. A/F on both runs from 2k rpm was just below 15 and then started dropping at 3100. At 3500 it was at 12 then at 4000 it was at 11. At 4500 it was at 10.5 and stayed there the rest of the runs (only run 2). Run 3 dropped below 10 at 4600rpm then came back up just above 10 about 5300rpm

2. On run 3 the torque was at 410+ at 4600rpm then DROPPED to about 380 then climbed back up about 5300rpm

3. On run 3 there was a drop in HP from 360 to 330 and then back up matching run 2 around 5300rpm

It seems I have some sort of problem but not even sure where or what to start with.

Run 2 was very even but runs 1 and 3 were pretty much the same sort of issue.???

Thanks for any advice. I'll post the graphs tomorrow.

Oh regarding the "weather question" I am not sure exactly but it was a bit hot. I did hear the dyno owner say something about a 26.50 or 26.5. Not sure what that means.

I have used this dyno for my 01 Z06 and had good and expected results during those runs.

 

[adamlotus]

hp look normal for a stock 06 torque a little low imo

 

[MuscleJunkie]

Thanks for the response. Yeah I thought that the torque seemed off. The A/F seems to be really PIG RICH. Not sure what would be going on with this car to be getting this sort of dyno result?\\

What is the "actual" driveline loss figure for an 06?

 

[pteam]

at 15% 428.6 = 504 hp 422.8 = 497

a little low for sure.

 

[Fast Too]

I had similar results on my base dyno before mods. Max power was like 417RWHP, I forget the TQ.

 

[dave6666]

+1 on low. My '01 GTS with tubes, K&N's & cat-back was 436 rwhp. You should be at that or greater I would think.

Check the weather here for what it was that day...

Weather History for RALEIGH DURHAM INTER, NC - The Old Farmer's Almanac

 

[MuscleJunkie]

So for that I am guessing that temperature was between 87 and 90 and pressure was 26.50 (based off what he said his meter showed??)

Does any of that have anything to do with the low numbers?

 

[Fast Too]

If it was humid you were trying to push some very thick air through which would drive your numbers down. It was in the 90's and very humid when I did a 417rwhp base dyno.

 

[MuscleJunkie]

What do you guys think about the really low figure on Torque and it seeming to really dump fuel at 4500Rpm, etc. I am getting ready to post the graph and you will see what I mean. Its not too pretty.

 

[Fast Too]

Not sure whats up on your torque, but most graphs I have seen, mine as well, the car starts pushing fuel around that RPM as you start building manifold pressure.

 

[MuscleJunkie]

Ok, here is my dyno graph on this.

 

[Fast Too]

Kind of hard to see what is going on the graph. Can your tuner e-mail you the actual dyno file so we can look at it in the winpep7 program. We can see other contributing factors to your dyno with that program such as conditions, your A/F through the pulls etc.

 

[MikeR]

What kind of dyno was it on? Numbers seem low, especailly torque. I would think you would be somewhere around 430 rwhp/ 460 rwtq

 

[Fast Too]

What kind of dyno was it on? Numbers seem low, especailly torque. I would think you would be somewhere around 430 rwhp/ 460 rwtq

Hopefully it was dynojet so we can look at the files if he can get them.

 

[Roadrunner]

Ouch... if the pressure was 26.5" Hg.... that's only 670torr... sea level would be 760torr. You were lacking nearly 13.4% of available air due to low density. Power should have fallen similarly. Don't know what correction factor was being used at your dyno though.

 

[Fast Too]

Ouch... if the pressure was 26.5" Hg.... that's only 670torr... sea level would be 760torr. You were lacking nearly 13.4% of available air due to low density. Power should have fallen similarly. Don't know what correction factor was being used at your dyno though.

Looked like SAE on the graph axis headers

 

[MuscleJunkie]

Here are the files from the two runs the dyno operator sent. If something else is needed - let me know and I'll ask him for it.

Thanks everyone for the help!

 

[pteam]

ouch that big dip on hp and tq at 4500 seems very concerning. I think something is wrong with the car.

 

[MuscleJunkie]

Well if you look at the A/F there is a big dump in fuel at that point. I was told there was some knock for some reason at that point and the computer did that in reaction? Not too sure what that means.

Thanks!

 

[pteam]

Its an 06 so should be still under warranty, I would take it in.

 

[MuscleJunkie]

Funny you should say that as I took it in to the dealership today and they looked at it and really didn't know of much to say. They said I should talk to some other local Viper owners and get their opinions. They felt that Chrysler wouldn't do anything but that was just an initial thought. They said they could pull the plugs and take a look but that was it for the moment......

 

[pteam]

Funny how often the board will know more than a dealership

 

[Fast Too]

Here is another view of your graphs and a text file of the data. It looks like the operator started getting off the car at 5,600 rpm to me, or it peaked there rather than 6,000. I don't have an answer for the torque. Cat going bad maybe looking at the a/f? The humidity was around 20%. I also used STD correction instead of SAE.

 

[MuscleJunkie]

Here is another view of your graphs and a text file of the data. It looks like the operator started getting off the car at 5,600 rpm to me, or it peaked there rather than 6,000. I don't have an answer for the torque. Cat going bad maybe looking at the a/f? The humidity was around 20%. I also used STD correction instead of SAE.

Thank You VERY MUCH for taking the time to do this. I am not sure all what I am looking at completely but I appreciate your explanation. I have forwarded the info to the dyno operator and will consult with the dealership and others to see if I might be able to get to the bottom of this and perhaps a find a resolution.

Thank You again!

 

[MuscleJunkie]

Ok, I sent this info over to the dyno operator and this is what came back.

That feedback really doesn't make any sense.

I don't even know who pulled the car, but trust me, foot was on the floor unless they said something about it. No one uses STD correction anymore. And cat going bad on a new car that's stock? Maybe, I guess. Never seen that happen on any GM vehicle.

Here's what I see: a car that shows quite rich WOT, could be that the computer has added some fuel due to a sensor malfunction, I see that all the time, there's variations in the stock sensors. Also, the appears that the timing is being pulled back in the computer, could be (if it were a GM) a false knock sensor event, a cat overtemp protection event, even torque management (which I know the Dodge trucks have BAD)

What I don't see is any indication that someone lifted their foot (do you know how hard it is to only lift your foot that much, it's hard!) and I find it hard to believe that a cat is going bad. I see the standard stuff that tuning takes care of on these cars.

Crazy. Lifted foot at the same time on 2 runs so that the car peaks early. I've never heard that in 6 years of doing this. And the 03/04's I've dynoed peak a little earlier 5400/5500 than yours at 5600/5700, not later as suggested. Even checked a couple of SRT10 trucks.

So, are the numbers ok? The 03/04 cars seemed to all be a good bit higher, maybe the 06 is supposed to be weaker??

Keep me posted, I'm just buying lifting throttle and bad cat.....

FYI - I was the one who was in the car and I kept my foot in it all the way to redline

 

[Roadrunner]

If it's the knock system.... run the tank down and get some better fuel. The 2005 and 2006 cars have an active knock system, and will pull up to 8 degrees to prevent knock and engine damage if the fuel is less than real 91 octane.

 

[Fast Too]

Ok, I sent this info over to the dyno operator and this is what came back.



FYI - I was the one who was in the car and I kept my foot in it all the way to redline

okay good you kept in it up to red line, but if you look at the data in the text file the car peaks at 5600 and drops off. No matter, something is wrong. You might want to send a pm to Joe Dell (a member here) or Dan Cragin (DC Performance) and send the dyno files in the zip file from your tuner which you posted up for us and get their opinions. They have forgotten more about tuning these cars than we will ever know. Your tuner knows GM cars, but what is his experience with Vipers? Also thought it was funny he didn't know who's foot was on the pedal since it was yours. Anyway good luck. I hope you get it worked out before something bad happens to the car.

 

[Fast Too]

MuscleJunkie - one other thing, and perhaps this an apple to orange comparison since I am modified but my HP peaks at 6,100 rpm not in the mid 5K's and TQ peaks around 5,300. My car is an 06 coupe.

 

[adamlotus]

on my 06 above 5000 rpms it felt like it was loosing power like it was it at 5000 rpms.where my 08 just keeps going above 5000 rpms

 

[MuscleJunkie]

Thanks everyone. I'll send a message to both Joe and Dan and see if they might be able to give some input here.

Thanks again and if anyone else can add anything it is much appreciated.!