01 Creampuff Dyno Results (and a few questions)...

[gozer]

I had three runs today and the best was:

418 RWHP 455 RWTQ

The average of the three runs was: 416.9 RWHP 453.9 RWTQ

These numbers are on a Stock 2001 GTS (ie does not have K&Ns or smooth tubes). The car had 7269 mi on it. I'm planning on installing the K&Ns & tubes this weekend.

Here is the printout: http://members.cox.net/gozer/dyno.htm

Questions:

1. Do the curves look "normal"?

2. Is there a calc to determine the HP & TQ at the motor?

3. Why does a stock 450HP motor from '97 make more RWHP than a stock 450HP motor from '01? Did the efficiency on the driveline go down that much or do the "lumpy" motors make more HP than advertised?

Any observations, comments or recommendations are welcome.

Thanks,
Gozer

 

[THEMASH]

That is a high number for a '01 viper, make sure those numbers are corrected.

1) The curve looks normal to me
2) 418/.85 = 492 Hp at motor
455/.85 = 535 Tq at motor

3) There are tons of detailed info on that if you search. i believe it has to do with the different cam, pistons and ECU.

You should gain 5-7 RWHP with the intake and smooth tubes.

 

[gozer]

They are corrected numbers. I think the correction factor was somewhere around .95.

From what I remember the temp was approx 69F and the pressure was around 29.98. I didnt think to get a print out of the info from the Dyno.

The weather from Accuweather.com for that area at the time of the run was:

Temp: 62F Rel Hum: 33% Press: 29.94

Thanks,

Gozer

 

[Bill/APEX Motorsports]

The curves look normal, but what really tells all is the air/fuel ratio. Since the dynos were done on a Dynojet, get the AFR printout and post that as well. Also, within the Dynojet software, you can see the weather conditions of the run by just right-clicking on the hp/torque graph, going to "Graph Options," then going to "Conditions." This will display the same hp/torque/AFR/etc. graph but with the temperature, barometric pressure, and correction factor.
Have your dyno shop print that out for you as well. It's helpful to have that info handy when comparing runs.

 

[MES]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>I had three runs today and the best was:

418 RWHP 455 RWTQ<HR></BLOCKQUOTE>

Seems abnormally high by 10-15hp


<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>They are corrected numbers. I think the correction factor was somewhere around .95

From what I remember the temp was approx 69F and the pressure was around 29.98. I didnt think to get a print out of the info from the Dyno.<HR></BLOCKQUOTE>

What was the un-corrected numbers? with a .95 correction factor you were actually making 440 rwhp? Don't think so. You should try a different dyno if you want a good baseline to measure gains from for your future mods. I wouldn't trust that one.

I have stock dyno numbers for various years in my Viper page below.

 

[John H]

MES, his average #s seem about right for a good running Gen 2. Being "abnormally high by 10-15" isn't anything to speak of because dyno runs can fluctuate that much on the same car between runs. If anything, your dyno numbers (off nitrous) seem rather low for the amount of mods you have - especially being a '97. Belanger headers, no cats, Corsa catback, smooth tubes, filters, and a tuned VEC 1 should yield more than your 436rwhp. Something seems wrong with your car. Do you have a timeslip to show your trap speed?

John H

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by MES:

Seems abnormally high by 10-15hp
What was the un-corrected numbers? with a .95 correction factor you were actually making 440 rwhp? Don't think so. You should try a different dyno if you want a good baseline to measure gains from for your future mods. I wouldn't trust that one.

I have stock dyno numbers for various years in my Viper page below.


<HR></BLOCKQUOTE>

 

[Joseph Dell]

2 of the 3 stock 2000's at the dyno-day yesterday pulled consistent numbers of that sort. (within 1 or 2 hp).

Maybe Dodge put out a _strong_ batch of creampuffs...

JD

 

[gozer]

Thanks for your comments.

Its good to know that other "Creampuffs" are running in the same range. Although it is always possible that there were problems with the dyno, the particular shop I went to is good enough for Hot Rod Magazine. As a matter of fact, they were running a subject truck on the dyno just prior to my runs. The shop is owned by Joe Jill. I'm not sure who he is, but the Hot Rod Magazine guys thought pretty highly of him. Not that this means the dyno is above reproach, but if this guy (Joe) has a rep to maintain, he may less incline to let his test equipment go out of calibration.

While none of this really means all that much, it is all I have to go on for now. I do plan on running my car on another dyno this week. Unfortunately, I installed the K&Ns and smooth tubes on Saturday and I dont feel like removing them for another baseline dyno. Most say that K&Ns and tubes are good for +5 to +10HP, therefore, if this other dyno is within 5 or 10 HP of the original, then the original numbers will be fairly accurate. Remember if the original numbers are correct (418HP), then a 10 HP difference will only be a variation of approx 2%. I'm not sure what the accuracy of the DynoJet is, but given all the variables, I would think 2% is acceptable. Any thoughts?

My main purpose of dynoing the car in the first place was to determine a baseline number. Of course I would like that number to be as accurate as possible. My desire for a baseline is to see what each modification yields.

I'll keep you posted.

Thanks,

Gozer