Dyno results...hmmmm...

[Z Ya Later]

Well, I'll let the sheet speak for itself...

http://home.comcast.net/~budlopez/pictures/dyno.jpg

Something just doesn't seem right. With the other cars I've run with (esp. against LS1s), this just doesn't seem right to me. After talking with Kev, could it be the car wasn't centered properly on the rollers? Also, they told me I'm running too lean. Is that the case? Thanks guys.

***EDIT***

Almost forgot, I was running Datamaster and saved the scan. I did get a little bit of knock retard, but nothing over ~1 deg. and that was near the top of the band. Would this point to bad plugs and wires? I've got the .uni file if anyone wants to look at it.

[darkz711]

Well, I'll let the sheet speak for itself...

http://home.comcast.net/~budlopez/pictures/dyno.jpg

Something just doesn't seem right. With the other cars I've run with (esp. against LS1s), this just doesn't seem right to me. After talking with Kev, could it be the car wasn't centered properly on the rollers? Also, they told me I'm running too lean. Is that the case? Thanks guys.

***EDIT***

Almost forgot, I was running Datamaster and saved the scan. I did get a little bit of knock retard, but nothing over ~1 deg. and that was near the top of the band. Would this point to bad plugs and wires? I've got the .uni file if anyone wants to look at it.

your mods arent all that power inducing... i think you are around what you should be at

[Craig 94 TA GT]

I don't think that's where he should be. That equates to only 307 FWHP using the 15% drivetrain loss figure. And near 14 AFR seems dangerously lean. I started another thread because I'm having similar problems, but have a previous dyno to prove something is going on here.

[wolfdogs]

is this that "dyojet" portable dyno thing? if so..those things are so off its not funny.....?

[Joe 1320]

I dunno..... 260HP and 300 TQ at the wheels is reasonable. What coolant temp, ambient air temps and elevation were you testing at? I've seen stock cars dyno as little as 235 hp at the wheels, so 25 hp with your mods seems about in the right ballpark. deleting the cat might give you 5 more, a better Y pipe maybe another 5. Headers would be a big help too.

[JeffM]

I made 258hp/309tq with my 94 Formula A4 with 2.73's - had a K&N and a catback. Just for comparison..

[raroZ28]

that car is barely modified. what did you expect?

[Z Ya Later]

Coolant temp was at ~180 deg., outside temp was around 70 deg. with the barometer at 30 in. Hg. It was pretty close to perfect SAE temp.

And yes, it was one of the portable dynos. I remember you saying they are off Ken. And there's rumor that theirs is off as well. I'll give Alvin a call and see what he says about the A/F ratio.

[Craig 94 TA GT]

The temperature was 81.3 degrees, humidity 35.7, baro pressure 30.1 according to the video.

I don't think their dyno is far off if any at all. The stock auto LS1s were at 290-300 RWHP, right where they should be. And the stock new GTs are at 260, just as many other dynojets read. I still think we need to take a closer look at the tune, and the reason why we say 1 degree of knock retard above 4400 RPM.

[Injuneer]

If you convert the Datamaster file to .csv format, I'll take a look at it.

[Craig 94 TA GT]

Here is his csv. He scanned it in my laptop and I'm having trouble emailing it to him. http://s94938520.onlinehome.us/dyno_Z.csv

[fastTa]

There are basically 2 benchmarks by which dyno operators will correct your actual HP numbers. There is what they call the SAE Standard Correction which uses the following weather data as it’s benchmark: 60° F, 29.92 InHg, and 0% relative humidity. Then there is what they call the SAE J1349 Revision JUN90 which uses the following weather data as it’s benchmark: 77°F, 29.235 InHg, and 0% relative humidity.

Normally tuners will use the standard correction which will obviously generate higher corrected numbers, but sometimes they will use the June 1990 Revision guidelines by which to correct. This will cause you numbers to be about 4% lower than the "SAE Standard" correction.

It may be beneficial to find out which method they used. But other than that, like I said, those numbers ain't too bad at all given your mods and given the fact that the 93's were 275 HP stock.

[Kevin - Blown 95 TA]

How did they measure the AFR? If they stuck it in the tailpipe of a car with a cat, they should know better - it won't be accurate, no way. It needs to be before the cat in a welded in bung for an accurate reading. No way a LT1 car should be reading 14.xx AFR at WOT.

[Craig 94 TA GT]

I contacted the dyno shop and this was their respose to Kevin's (fastTA) question:

"SAE J1349 Revision JUN90 or SAE is what dynojet uses in thier formula I beleive.

check out this website.

http://wahiduddin.net/calc/calc_cf.htm"

It seems like he uses the "lower number" correction factor, but then again, it seems that he thinks all dynojets use this

[Z Ya Later]

How did they measure the AFR? If they stuck it in the tailpipe of a car with a cat, they should know better - it won't be accurate, no way. It needs to be before the cat in a welded in bung for an accurate reading. No way a LT1 car should be reading 14.xx AFR at WOT.

Ya know Kevin, that's a good question. The first shop we went to when Craig got his dyno done did the tailpipe sensor, but I have no idea how they did it at this shop. Might be worth finding out.

Also, Fred, if you have problems with that CSV file, I did finally manage to get it right on my computer. Just let me know if you need it and I can e-mail it to you.