saabin

So this weekend I decided to play with the Durametric software and log some data from my car. I, like several others here, took advantage of the sale pricing for the FVD tune and thought it would be interesting to see how the tune affected the data.

I’m entirely new to this so I did read up a bit on some of the previous posts on what data to collect, etc. I settled on the following variables:

o Time
o Engine speed
o Engine load
o Boost in psi (a calculated value I created = ((Pressure ahead of throttle plate- Ambient pressure)/1000)*14.5037738. The ambient pressure is actually a variable that changes slightly. Typically between 975 and 990.) It’s a hidden column on my data below.
o MAF (mass air flow)
o IAT (intake air temp) in deg C
o EGT – exhaust gas temp – I believe this is a modeled/calculated value as I don’t think there is a direct measurement from the sensor.
o Ignition angle – same as timing advance I think?
o Injection time – can be used to calculate duty cycle of injectors
o Throttle plate angle – should be at 100 at WOT.
o Vehicle speed (in kph)
o Speed (MPH) - is a calculated value I created = vehicle speed/1.609344
o Lambda banks 1 & 2 -
o Pressure (in millibars)

My car is completely stock, 2007 997TT w/ 35K miles. 93 octane fuel. I did some pulls before flashing the car with the FVD tune. For my pulls, I was in 4th at 60mph when I went WOT. I backed off when I was around 5900rpm at 110 mph. Yes, I realize I should probably have gone to redline but going to redline in 4th is a recipe for jail time as there aren’t many public roads where I could pull this off repeatedly. In hindsight I probably should have done them all in 3rd instead and taken it to redline. Maybe next time.

The data is very interesting to me as an (no longer practicing) engineer..

- I’m not completely sure what engine load is telling me and how it is helpful. Looks like the range is 0-200?
- IAT of 40C seems high to me, but I suppose the more you compress air the higher the temp goes.. At what point does it cause the engine to retard timing or boost?
- EGTs of 800+ when under high boost.. seriously hot temps, at what temp do you start having problems?
- Ignition timing (angle) – Not sure what would be considered “normal”
- Lambda 1 & 2 – I know that 1 is considered stoichiometric.. but here in TX our fuel in a lot of places is 10% ethanol, so it would be considered E90, which changes this a bit?

So here’s the stock data in normal mode. I picked the “average” of the runs, I had one that had a higher boost pressure but used the mid-range one:
(Sorry for the small font..not sure of the best way to post an xls table..)




Here’s the stock data in sport mode.






I then used the My Genius unit to flash the FVD tune and repeated my runs. The tune runs were done 1 day later when it was a little cooler (by about 6C)

Here’s the FVD tune in normal mode:




Here’s the FVD tune in sport mode:




Clearly you can see that the FVD tune keeps the boost higher for longer. Here’s a graph showing the 4 runs of rpm vs. boost pressure. (Special thanks to member ut_farhan for creating the graph for me!)





I’m curious as to what the camel hump at the first of the tuned curves is caused by.. is this something built into the tune itself? It seems to hit a setpoint and then allow the boost to build even more..

Any comments welcome.. I don’t think I’m going to be doing much more to the car other than possibly an exhaust – the EP is sweet sounding.. I probably won’t venture towards the next stage, e.g. new turbos, intercoolers, injectors, etc..

I have the full data of all my runs in an XML file is anyone is interested..

atcbi5

Wow very impressive data! I spoke to Rhonda about it doing the same thing you have done. I also have the Dura Pro version and wanted to do this but I started to disassemble my engine due to a small leak of coolant in the heat exchangers. Have to lower the engine to get to the rear exchanger. I could not floor my car since it is bleeding coolant. Envy you! I will be getting the FVD exhaust that they might be putting on sale soon!!!!

TT Surgeon

Decent numbers, which exhaust are you getting?

saabin

Thanks! good luck getting the car put back together..

Not completely sure yet, I love the EP but may it's hard to convince myself to fork over the cash.. and rumors of an fvd exhaust may be tempting, althoguh I'd like to hear it in person first..ah, first world problems.

TB993tt

Saabin

Thanks for sharing, there is not enough sharing of this type of data on tech forums, if there were then there would be a lot less BS arguing about which tune is good and which are crap as the data tells the story.

Firstly, you don't mention the ambient temp, as you are in Texas I guess it is over 20C ?

You don't mention any acceleration times ? You can use the data to measure these, just work out say 60-100mph from the timings on the far left (as long as you were at full throttle) this will tell you (obviously) how much faster your tune is making the car.

You mention about not being able to go over ~100mph, I seriously am begininng to think that tuners are writing "tunes" which only work up to ~125mph since the US market (for street cars) seems to want these tyoes of very over aggressive tunes which give the best possible acceleration up to this speed and forget what happens at Autobahn speeds.

All your data numbers look fine except the last set where you ar ein FVD tune and sport mode and at the top end at ~6000rpm you ECU is richening the mixture , can I see lambda 0.68 ? that is 10:1 AFR, this is very rich and indicates an unbalanced tune to me.

EGT at anything up to 980C is OK but VTGs have temperature sensor on the turbos themselves (not readable by Durametric AFAIK) which will trigger ignition retard and rich mixtures if they get too critical.

You asked about the temp where ECU starts reducing timing and boost from optimum, it is around 43C IAT and happens in stages as it gets hotter.

Your IAT based on those logs would be over 50C by the end of 4th gear and up at 70C at max speed.

If you wanted to be purist about this you need to run a log up to 185mph, this will give you warts and all data about your tune compared with how the factory tuned it but like I said at the start, the US market street tunes seem to generally only work at lower speeds.

I posted some data below of what I tend to log

saabin

Yeah, makes sense. I just wanted to see a more detailed look at what the engine is doing..

OAT was about 25C during the stock run and about 20C during the tuned run.


Here's a graph my buddy ut_frahan did of the times after I sent him the raw data. I need to collect more data so as to have a larger sample size..



All this makes sense, and I'll collect some more data this weekend. The car certainly *feels* faster, but it would make sense for a tuner to concentrate more on where the car spends more of it's time. I'll also try some different gas like another member suggested.

All of this is very interesting and I'm learning a lot about these cars! Thanks for the feedback!

TRFALK

Great data! Thank you for sharing. My FVD tune is on the way. I have EP1 on my car and love it. Can't wait to get the tune installed.

earl3

Timing is alarming to me on the flashed sport mode pull. Its gone at 4200 rpm and never really recovers. Not only is it low, its also inconsistent - indicative of riding on the knock sensors. The DME ends the fun starting at 5700rpm with a flood of fuel. Add a splash of 100 octane and watch what happens to timing and EGT.

saabin

Is there a way to see if the engine is detecting knock w/ the Durametric? I seem to recall there being some values in Durametric that shows engine misfire or knock?

TT Surgeon

When I data logged mine last yr, my ign timing was a lot more constant, similar to Toby's.
For some reason, your ecu is pulling timing,,since I have a similar fvd tune and didn't pull timing, I'd say it might be your fuel, ambiant temp or both. If I can find it, I'll post it.

speed21

Decent numbers alright. Very telling indeed.

saabin

Ok Gents, I collected some more logs today after I filled up with a fresh tank of 93 from QT. I honestly don’t remember where I got my last tank from, although I *do* always only get 93.

Have a look and let me know your thoughts:

A few observations:

- It was cooler this morning when I went out, about 9C when I left the house and 13C when I got back. My IAT never got above 34C.
- I did the pulls in 3rd and took them to about redline. There are 2 pulls in sport mode and one in normal mode.
- I think the timing looks better, at least it’s smoother and doesn’t jump around as much as the last logs.
- The AFR looks better (?) to me in that it seems to stay in the .81 - .83 range at the upper RPMs and doesn’t go overly rich.
-
Assuming you guys agree these do look better, any idea on what would be the reason? Cooler IATs? Better gas? Both?

Looking back again, the IATs were only 10C different in the extremes (34 vs 44) between the two so could that alone be responsible?

Thanks for any feedback..

TT Surgeon

Could be anything, a lot of variables. You have a good tune, don't worry. I have the same tune with zero issues, my last car had it too.
Stock cats/exhaust might be an issue with a tune as well.

saabin

Not too worried about the tune per se, just wnated to make sure the car was running as good as it can. Thanks for the input.