Hey everyone! I know there's been a lot of discussion about the differences in Dyno Dynamics vs. Dynojet power numbers. Well here's a little comparison for everyone. I'm hope this sheds some light on some of the misconceptions that pop up when comparing different dyno types. This EVO X was tuned on a Dynojet at another local shop on Monday. The owner of the EVO, a mutual customer of ours, stopped by yesterday night and we threw his car on our Dyno Dynamics to see how the numbers would compare. Although, there are a few factors that would cause a variance in the % difference, this particular example shows that the Dyno Dynamics dyno reads ~12% lower in peak power than the Dynojet dyno. It's not called the 'Heart Breaker' dyno for nothing ----- Dynojet Graph: Dyno Dynamics Graph: Thanks for looking! Decker
How many times do we have to say that it doesnt matter if one dyno reads higher/lower. A dyno is a tuning tool, and all that matters is the improvement under the curve during a tune...
Good to know. Maybe you all can help me think through this one: I've never really understood why having a dyno that reads lower than most is a good decision for business. I am not implying that you want your customers to receive numbers that are higher than what they actually are, it just continues to strike me as odd. Sort of along the lines of, "Well I just paid a lot of money and I want to be impressed...not disappointed." And ultimately, yes, I agree that the machine is to be used as a tool for tuning a customer's vehicle. However, I believe that its numbers should reflect some sort of consistent metric that will allow for comparison.
Doug, you should be careful before making accusations like that. The entire tuning industry recogonizes that the Dyno Dynamics reads lower than a Dyno Jet except for you. To suggest that I would manipulate a dyno number is rediculous. We've posted comparos like this before for informational purposes only and never had this type of reaction. Your tune was actually very good and I told this to the customer. I did not critize the tune at all. We simply want people to understand, that the leading tuners in the country all generate comparable numbers, and a higher reading dyno can give the impression that one tuner is generating significantly higher power...which is oftentimes not the case. We set the load at 140 on this car, just like all the others. The dyno chart we printed off shows the load, so there can be no "manipulation" as you called it. And for reference, here is another EvoX I tuned last week. This one had exhaust, high flows, and an intake only. Notice the spool is the same. Guys, these are stock EvoX turbos...they spool instantly!
Cicio@TopSpeed, 2pt5RS, Alex, AtlxPat, Decker@Forged, Matt@Topspeed, nsvwrx, Ryan@Forged, sharif@forged, Tray@Forged ↑↑↑ based on this....I think we should just close this thread now
The reason we chose the Dyno Dynamics is not because it reads low. We chose it because we feel it's the best tuning tool, which is the primary purpose of the dyno. Load based dynos with precise control and data mechanisms allow us to do things that the DynoJet cannot do, or doesn't do as well. If we are simply looking to measure power, than I suppose any dyno would do. With the DD, we can accurarely hold loads on the car for real-time steady state tuning, graph in realtime, map an infinate number of engine inputs. We can also adjust the ramp rate (or load) on the rollers to compensate for lower and higher powered cars. It's a terrific diag tool as well. For instance, if a customer comes in with a hesitation at 2500rpm and 3psi boost, that is very difficult to duplicate on the road for any period of time. It's a snap on our dyno. I can hold it there all day long while reviewing data in realtime. We can also do a true steady-state engine break-in...just like would be done on an engine dyno. No road break in's required, which saves time, and allows for a much more complete and methodical engine break-in process. About 15% of our dyno time is utilized for engine break-in or diag work...oftentimes by other shops renting it out. Hope that helps shed some light on things. As for the numbers, Dyno Dynamics and Mustang (unadjusted) tend to read lower than Dyno Jet. Dyno Pack reads higher than all of them.
why does the graph have the nipple looking things at peak boost? is this some sort of overboost before the wastegate kicks in or something? Never noticed that before
Sometimes the trq spike is so sudden, our dyno has trouble keeping the load and it causes a little measurement spike. Some cars do it, and some don't.
For sanity sake.....why do you guys keep stating that the DD loads differently which causes your dyno charts to appear that the car spools very slow? For instance the 750r AMS turbo kit 08 STi? http://wrxatlanta.com/forums/showthread.php?t=28190 Statements are made that the loads on this dyno are misleading yet I'm seeing nearly identical spool response and such. It's really confusing.
For clarification, the load we put on the dyno does not change the peak power numbers, only the rate at which the turbo will spool up. You are comparing a big 750R with a very small stock EvoX turbo. Of course they will spool differently. The smaller turbo doesn't' require as much load to spool quickly, so it's much closer to the DJ in terms of spool. I posted two stock turbo EvoX plots from our dyno, and both spool the same. So take it for what's it's worth.
In bold above.....I was actually comparing a Forged tuned 750R kit on sti vs same EXACT car and kit Topspeed tuned car. Spool was significantly better on the TS tune and Forged defense was you can't compare the spool between the two dynos. Again not making a TS vs Forged debate but more of a why is the load/spool statement always being made on cars that are retuned by another tuner yet here they read the same. That's what is confusing.
I have stayed out of these threads, but doesn't just come down to if the customer is happy with the services provided by whatever shop. This is our hobby. A number is only a number. If you want to make it bigger spend more money.
Oh, I see what you mean. Well that's an easier question to answer. A large turbo needs more load to spool up. Launching those big 2000lb DJ rollers from 2500 rpm puts a crap load of load on the engine on the initial ramp. If you watch our dyno videos vs. a DJ, you can see that the first second or two of a DJ run it almost looks like nothing is happening. Getting those heavy rollers moving is what creates that load that helps the turbos spool. On our dyno, the ramp rate (load) is linear and constant through the run. Again, it makes no difference in measured power once peak boost is reached. Our dyno still reads lower.
Thanks for the explanation Shariff. Never thought about the size of the rollers vs the tiny ones the DD has.
Yes it is! The customer couldn't be happier...I have gotten 3 emails from him in two days telling me how amazing the tune is and how he was blown away by the customer service....thanks for pointing that out, in the end that absolutely is all that matters.
Very smooth tune on that car. The before and after speaks for itself. Interesting comparison though. I still would like to see a big hp car comparison....something in the 500+ range. I wonder how much the numbers vary as the hp goes up...if it holds at 12% or changes any. I would chip in $5 to pay for a run on a big hp car
It was a very clean tune, and I told that to the customer as well. The customer was happy with the tune and had nice things to say about TS. But we aren't comparing tunes/tuners, we are comparing dynos in this discussion. From what we've seen, the percentage increases as the power levels go up. Here is a same day comparo from a couple years ago. Twin turbo setup on a 350Z.
Were these same car, same day? Same area? I would think that it would go a long way to answering the questions people have. Why not pony up one of the GTR's or something?
Having a dyno that reads low could allow you some extra power if you're getting close to the HP limit in your class for time attack