Whatever you want to do, we'd all appreciate a back-to-back test from one dyno to the other. I will pay for the Dynojet if that happens and send some shirts PM an address and shirt size.

Correct me if I am wrong and this might be more for Mike W. than you. Someone in one of these freaking threads I thought said the Dynapak on your car was set up for an 11 second run? Is that correct? If so how does that work? Does it take 11 seconds for the car to go from 2500-7500 rpm in 3rd gear?

 

 

Anyone have an answer on the Dynapak question?

 

I don't have a ton of experience with dynopaks FYI but I have been around them a few times.

You set the start and end RPM's of the pull in the software. You then tell the system how long you want it to take to get from point A to point B. Much like some engine dynos.

The dyno will then load the car to make the pull last that long. It has to recalculate how much load is needed constantly which is why a lot of dynopak dynos are wavy from the dyno changing the loading of the car during the pull.

Dynopaks are GREAT to tune on, they are very sensitive with steady state load holds ect but the numbers are not real comparable to other dynos from my experience. Dynojet or nothing when you want to compare dynos IMHO.

 

It's another way to set engine rev rate. Western's Engine Dyno is this way.

 

OK, hmmm, R/T, was it you that had said somewhere or maybe Mike was quoted to say the pull on the EFR turbo was 11 seconds in 3rd gear?

 

Mike states what his run duration was in the 7670 thread.

Don't quote me but I think it was 11 seconds in 3rd gear. The longer the pull, the better the spool up looks. The shorter the pull... the worse the spool looks like.

Changing the time duration of the pull is similar to running the car in 4th versus 3rd... it makes the power band look different.

 

OK, that is what I thought. Tell you what, since this thread is clean and nice I am going to quote you and respond over in the other thread we already wrecked! haha

 

Here was the setup

 

Ok, I don't know what that is or what it means. I am Dynapak stupid. Does the car actually take 11 seconds to do a 2500-8000 rpm pull in 3rd gear like that? That is a LONG time for a 3rd gear run. Think about it, your car at that power level should go through 1st, 2nd, 3rd and 4th in 10 seconds. Loading the car/turbo that hard would drastically change how the curve looks.

 

I think that is what a lot of people were getting at in this thread with the whole spool being off factor.

Peak power shouldn't be affected though. But the whole, this car spools insanely fast isn't accurate probably.

However, to be fair, Mike provided other setups with the same dyno settings. So the comparisons are still very valid I think.

 

Is the world ending today or something?

DB and RT have got along for over a page worth of this thread... haha

 

It controls the rate of acceleration. So yes the dyno slows the rate of acceleration to achieve a run duration of 11 seconds.

Now... to make this more clear Dave in my use of engine dyno's if you hold your run rate accleration the same and do the runs in different gears... you get a different power curve (same as experienced in chassis dyno's that you're familiar with)

I know the run time will have an effect on the shape of the curve, but I don't think it will change the curve to the extent that you're anticipating (or on the same order of magnitude as a gear change does) I say that because the engine dyno that uses a closed loop control system for engine run rate doesn't make that significant amount of change.

I really don't think an 11 second run time is exceptionally long either...

Take this video for example

640whp ER built engine on a 3586 on a Dynojet. Run starts at :29 and is finished at :41 approximately a 12 second run (2500 -8200)

http://vimeo.com/10250195

The high aggressive torque spike that you noted previously Dave I feel is completely associated with the super low MOI of the wheel and it's ability to accelerate much faster than it's Inco alternatives. I think the torque "spike" is completely realistic and is evident in the SSE dyno charts (sorry to bring that up again) as well.

just my 2cents

 

R/T, thanks for the best response I have ever got from you in any thread.

I do not agree though (you knew that was coming). Here is the reason, that is a 2.0 with an HTA86, it's laggy. If you watch that video and start counting as soon as it starts to make boost it take 4 seconds for the rest of the run. In the case of the car I dyno'd today the power came on fast because it was a smaller turbo of some type and in the case of this EFR the power obviously comes on very fast. There is a difference in a 12 second dyno run when you are waiting for the boost/power to come in and an 11 second run when the boost/power comes in instantly, agree?

He has agreed to go to a Dynojet, it will be very interesting to see the difference. I'd also like to see if he can print the dyno sheet by RPM and then by time. The MD has the ability to print the charts by time, I think DJ does too. I bet it takes less than 5 seconds to make a 3rd gear pull on a DJ.

 

yeah I see your point. I agree that the slow part of the run will be "fast forwarded" through and the normally "fast" part of the run will be slowed down. How much that affects the curve I don't know, but I don't think it's going to be shocking.

We should overlay a 2.0L FP Red setup against leet's old dyno chart. Or post one of a stock 2.0L with an FP Red ~ 450 MD hp... and I'll throw up a MS paint comparison. Should be telling of how it loads the engine. That is afterall what you're trying to accomplish by having him do the back to back test. It would give you a ball park

From 2500- 8000 RPMS I bet its right at 10-11 seconds. just my best guess.