I went to the dyno yesterday and they told me since I had Jethots and didn't have an extra o2 bung I could not get a reading on air/fuel, is this true?? This was my first time ever at a dyno so I don't know how they work. FWIW, mt first pull was 200rwhp, second was 199rwhp, third was 174rwhp . We then let it sit for 15 minutes or so and went back and dyno'd one more time, they found that they had the tire size wrong (there was a z06 on it right before I dyno'd and they were using his size), this time I dyno'd 370rwhp. I don't know what to think. These #'s mean nothing to me since they were so diferant. I do know one thing.....it makes WAYYYYY more than 200rwhp! I can show you half the graph since that's all I got and you can tell me what y'all think. I thought the horsepower curve was WAY off. One more thing I only made 330rwtq?? Is that even possible with 370rwhp?

http://img.photobucket.com/albums/v6...20800/scan.jpg


Edit.... the z06 put down 299rwhp.......yeah right. LOL When you look at the graph and see on the bottom it says stock with the exception of cut out, lid and something else, that was the vette. I don't know what that something else was.

 

Those guys sure does not sound like they now what they are doing. You don't have to have an extra O2 bung to get a reading. They could have got buy taking out one of the O2's and let the other one hang loose and plugged there O2 in it. Since the O2's are takeing out of the equation at WOT anyway. As for the false readings, yes tire size does matter. Not to sure what you have done to your car but the 370rwhp sounds pretty good, there is no way that you can be making 200, unless its a V6 or something like that.

 

I should also mention he told me this was NOT a dynojet. he said something about it being a land and sea dyno I don't know. He also told me it had lower #'s than a mustang dyno by 15%. I don't know jack about dyno as you can see so I don't know what to think.

 

yeah...dont go there again

 

Since the first pulls were with the wrong tire size, the numbers are just wrong, no need to worry about them. Hopefully on the last pull they had it right, it looks pretty decent. Sure your torque can be lower than your HP - if you look at the graph you posted, torque is the blue line, HP is red, and you can see that your HP was still climbing at 5800rpm or wherever you stopped, so you didn't get a reading of what the actual peak was.

I'm not sure what the horizontal "Avg-EGT" line represents, it seems to be drawn where HP and torque cross (5250rpm), but I don't know what they're trying to tell you there.

The DYNOmite dyno (http://www.land-and-sea.com/) looks similar to a Dynojet, but you may or may not know, you can't compare values between dynos. The 15% figure is BS (IMO) - if you want to compare to someone's Dynojet figures, you'll have to get your car on a Dynojet.

Dave

 

That's the one......... so is that a good dyno or not? He's suppose to give me the rest of my printout sometime this week. I pulled to 6500. He said it was still pulling when I let out. Also what about the curve, it looks REAL arched don't you think??

 

I've never heard of DYNOmite, but that doesn't mean it's not a good dyno...

You should look for other dynos of LT1 cars with cc306 cams, to get a feel for what the torque and hp curves should look like with this cam. The only thing that looks odd to me is the flat spot at 4500rpm.

Dave

 

The rwhp numbers are believeable with a good set of heads, but the rwtq does seem low.. I would recommend going to a reputable place with a Dynojet to answer all your questions.

Dan

 

One more thing, I think the reason the chart goes up so slow is becuase they had me start a 2000 RPM's in 3 gear and then slowly work my way to 70 MPH and the give it the gas. That's probly why it slowly goes up the goes straighter across. I was just expecting it to go up sharply, get flat, then slowly drop off.

 

They had a problem with the software and forgot to put me in as an automatic lol. They had a few problems that day (pretty busy) so they're gonna let me redyno for free. Maybe things will go a little better this time!

 

Hard to understand how the minor differences in tire size between a Z06 tire and a 4th Gen F-Body tire would account for the HP showing up as only 50% of the "true" results.... I think they are pulling your chain.