scalbert

I went to a local meet at a dyno for the S4. My numbers were about what I expected on this car, ~250 WHP and 300 WTQ, on a Dyno Dynamics dyno with just the X-Chip. I did have a gallon of Toluene in the tank with a fresh fill so it was about 94.3 octane.

As you can see, the midrange torque is excellent. Combined with AWD I can really use the grunt in normal driving. But at the same time you can see what I have been stating; the top end pulls drops off quickly. It will take bigger turbos and a fueling kit to get it to maintain the torque at the high revs. I would be happy to not make any more torque but to hold that level until after 6k revs. That may be down the road though…

Having spent most of my dyno life on Dynojets I was curious what the power differences would be. So I went to an AWD Dynojet today to make a few pulls; the results were not what I expected.

The plots are below but I'll state my remarks first. I never expected them to be the same, different measurement technologies, different conditions (although the ambient conditions were similar, albeit a little worse today) all adds up to a different reading. But I was curious nonetheless. I also still had the same tank of fuel. For further tuning I will pick a single dyno and stay with it to eliminate all possible variables. Now on to the numbers...

On the Dynojet it made only 256 WHP, a change of about 8 WHP over the Dyno Dynamics unit. I had expected more of a difference but that is fine. The interesting part was the torque; 359 WTQ, a difference of about 58 WTQ. That was a big difference and one I have a hard time accepting and honestly do not believe.

Either it read wrong and/or the inertial type was way optimistic. Considering the Dyno Dynamics unit, when estimating crank power and torque, was right about where I should have been, I was comfortable with that reading. But there is no way that car made nearly 360 WTQ.

On the next pull the numbers came up to close to what the Dyno Dynamics stated; (forgot the exact figures and don't have the plots but I will pick them up tomorrow) they were in the 255 WHP and 315 WTQ. There was one difference; I accidentally left the ESP on for this run. Although I didn't think it would make a difference, with the lack of loading from any of the accelerometers but with engine load, the ECU might decide there is a problem and reduce power. I just about kicked myself when I noticed that.

The reason it was off for the second run was that I stalled the car when coasting down from the first run and forgot that it defaults to off. The first run definitely had it off. However, an interesting thing occurred with it on. As I finished the pull and pushed in the clutch taking it out of gear to coast down, the revs jumped up and stopped at 6000. I tapped the throttle and they then started dropping. I can only assume that this was some sort of reaction by the ECU with the ESP still enabled.

My only conclusion is that I will continue to use the Dyno Dynamics unit as I feel better about the type of dyno and measurement technology used. I am just curious if the Dyno Dynamics operator did disable the ESP for the runs.

Now it is on to porting the manifold and installing DPs and exhaust. I’ll get back on the rollers then for further test. I expect to pick up a little torque but WHP may go up as much as 30 WHP.

Dyno Dynamics Estimated Crank Power Plot:



Dyno Dynamics Wheel Power Plot:



Dynojet Wheel Power Plot:

darrinb

whats the dyno called that you take your wheels off for??

Joe5.0

Its looks like the DynoJet reading is false because of that spike. Also, why is the reading so much more jagged on the DynoJet, even with a good amount of smoothing?

DynoJets are not inaccurate, they are just different. If you just want a number they are fine, but in the real world a Mustang Dyno is the most accurate. It accounts for wind resistance & rolling resistance. And especially if you have a turbo car its better because you can load the dyno at any rpm, whereas the DynoJet is just a freewheeling drum. Do you know what model DynoJet it was, because that determines what size drum your car was spinning, which can also affect the numbers.

Anyways 250awhp is pretty damn good, but that tq curve sure does take a dive after 5k rpm.

And Darrin the DynoPack are the ones that read through the hub (I believe anyways, never been to one).

scalbert

To aid to the testing issue, the fan that was used wasn't sutiable. No air was hitting the ICs; just a little against the radiators.

scalbert

That spike is the ECU trying to control boost and is why it was cycling. The boost would fluctuate between 15 and 19 PSI and is obvious on the plot. I will be installing a MBC in parallel to the stock boost control solenoid to eliminate the spikes.

Yep, those K03 turbos can't keep up in the upper revs and boost drops to nearly 12 PSI by redline. With larger turbos and fueling, many are able to maintain nearly 20 PSI past 6000 RPM.

If I ever decide to really get into this car and work it over, I will shoot for 400/400 HP/TQ at the wheels. That is very doable, it just takes quite a bit of work. But not really any more $$ than what I put into the CL though.

Smitty

like I said on the tele..... nice numbers.....

where do you go from here?.... next performance mod------>

scalbert

The port and polish of the intake manifold is next along with a down pipe and exhaust. That should take it up another 30 WHP; maybe more and little torque as well.

After that the only thing I could do are turbo upgrades. Those plans are still out at this time.

Joe5.0

Does it spike like that in normal driving, or was it jus the ECU freaking out on the dyno?

You gonna get some track times before doing more mods to see what the gains equate to?

scalbert

Yep, it spikes on the road. The severity depends on the gear and ambient temps.

I doubt I'll get some times in before other mods are applied. But that really doesn't concern me too much as there are plenty of examples and times from various levels of modifications for the B5 S4.

darrinb

ya need some time slips now steve

Joe5.0

I concur, we all know what other people run how bout u?

scalbert

I will make it when they open (never understood why they close in the south). If If I can't take advantage of AWD to launch I will bow my head in shame.

I'm expecting mid-13's though.