I have an ebc that i am reading the boost from. BTW I got your message, im sorry i have not returned your call yet I've been working a lot. We should grab a beer and you can school me on tuning. In your opinion is 25psi alright on NM crap fuel?

 

No, VDR and Virtual Dyno both show uncorrected numbers. So if you are around 300awhp on the virtual ones you will be around 360 corrected, which is incorrect..... I hate correction factors.

 

Good stuff I didn't know that. So how would I get VDR or virtual dyno to reflect corrected numbers? I don't want to just have a higher number but I want a compairison from when the car was dynoed to now to see the gains. Is there a way to have corrected numbers displayed? We should get a beer and talk evos let me know man

 

Just add ~20%. I could help you out, check your pm box. What I would do if I were you is find out the cf that was used when you dynoed it and divide the cf and start from there. Who tuned you originally?

 

you should be able to run 13-14* at redline with ur setup no problem

 

Unfortunately, weather correction isn't going to help you make an apples-to-apples comparison with someone at sea level. With weather taken out of the equation and we ONLY compensate for elevation, you are looking at a correction of 1.283 using the current SAE weather correction and a correction factor of 1.343 using the older STD weather correction that is still used by quite a lot of Dynojet shops still. SAE states a maximum of +/-7% weather correction before inaccuracies begin to occur. Most dyno manufacturers will allow up to 10% though which is still fairly accurate.

Even though the actual corrected dyno #'s aren't 100% comparable to sea level results, the 'WEATHER' correction portion is still very reliable. So its still useful for people that get dyno'd at the same elevation each time even though the weather conditions were very different.

VDRv5.71 and VD don't have accurate weather correction sections so don't bother using them. When I first added the weather correction to VDR, I made some huge mathematical errors in my weather corrections....magically, VD uses the the EXACT same incorrect formulas that I made by mistake. Strange,I know. The weather correction section I have coming in v6 has 2 different weather correction standards to choose from and it uses the exact formulas used by the dyno manufacturers,to the tee. Don't disregard weather correction as a useful tool, it is very useful. Especially for DIY tuners who have to tune on different days under different weather conditions.

I live in New England where weather is all over the place, even during the same day. Here is an example for ya using JUST the air temp as an example. In the morning, you do a pull on the way to work and the sun isn't quite up yet and its 55*f outside and your car registers 308whp on a simulator without any weather correction. You then do a pull at lunch when the air temp is 85*f outside but your car only puts down 298whp now? This can send people on wild goose chases and if the temps were reversed you might have thought something you did gained you 10whp even though its still the same as before. Hot air temps,any humidity and higher altitudes all rob your car of power,naturally.

I'd love to see what the weather correction factor was on the original dyno session. I'm sure shops at those altitudes are forced to go past the +/-7 to 10% limit imposed by SAE so I'd expect it to be a very high correction factor unfortunately. They might enter a lower elevation into the dyno software to kind of even out the figures with Sea Level dyno's, that'd probably be my guess.

 

All of the shops cf are almost always between 19-24, way outside of the 7% accuracy range. It is so much simpler to just use the number that is produced and multiply by 20% or 1.2. It is exactly what the dynos in town do and it is what should be done if he wants to find out what his "corrected" numbers would be if he went to a local dyno.

I don't think a cf is needed, ever, if it is going to be incorrect. The only good thing is that it will be incorrect consistently. That is great to see what hp you actually picked up without having to factor in all of the conditions. In the summer, depending on fuel, you will have less hp, except with pump e85 due to the fact that it is e70 in the winter and most of the fall and spring. The bad thing is everyone seems to believe that these numbers are correct.

I was thinking about the bold part and that is also an incorrect way to figure gains and losses due to the fact that the cf should be lower in the winter. So the 1.2 isn't a fix all and JoT's WCF would work a lot better. Just don't use those numbers as correct numbers lol

 

Yeah, high elevation people have to basically dismiss WCF readings as being accurate "d**k measuring sticks" and just use them to help see gains/losses from previous sessions with weather changes. Like everyone says, the dyno is a tool. The WCF stuff still worlds up in the clouds,just don't get caught up on the actual HP/TQ values. Weather Correction systems weren't designed or intended for such extreme elevations. Basically, 1500-2500' is pushing the limits where 'accuracy compared to sea-level' starts taking a dive. Its best to use Uncorrected values as a reference point and use the corrected values just to compare different sessions.

 

So I seem to be headed in the right direction but think with my mods I should be putting down more power. This log is from a few days ago, air temp was about 65* and boost was about 22.3 psi. Input from you guys stated I sould be going for about 25 psi, but my log this morning(not posted, fighting with evoscan v2.7) was hitting 3 counts through almost the whole log. So sould I reduce timing and turn up boost or am I over looking something? VD is showing about 342hp just to throw that in there. Other thing is boost is holding strong so should I increase timing over 6000rpm so the curve won't fall off. Please let me know your thoughts guys, thanks.

 

Im just getting into tuning but the jump from the 100-120 coloumn after 2500 is too big I think. You might hit those cells in different gears or if you start the pull at a different rpm. Someone correct me if Im wrong.

 

You are correct but i want to get the peak numbers dialed in before I smooth the transition

 

I may be wrong, but knock at the start of a pull due to a rough transition could affect what timing the car runs up top on the same pull, so you might want to work on the transition if it's causing any knock.

 

You are correct sir. Once knock is registered (phantom or real) the ecu keeps the timing pulled until it sees the issue go away....THEN there is a decay time as it slowly ramps back up to normal.

If you get knock during spoolup (100 load and up), it will easily continue to affect your timing curve as you pass the peak torque area on a stock turbo since it spools ridiculously fast. The best way to tune is start with is the spoolup area, then peak torque, then midrange, and tune the top end last. That's the most extensive way of fine tuning your tune, IMO.

 

If the differences between the high and low octane ignition map is small than the ecu coud pull less timing ?

 

No - the low octane map is for "long term" timing adjustments. The ECU uses an"octane value" stored in the ECU to decide how much it interpolates between the high and low octane maps. The "octane value" starts at 100% - meaning that the car is running 100% on the high octane map and 0% on the low octane map. If the ECU detects enough knock, then the "octane value" gradually diminishes and the ECU starts interpolating the values in the high octane map with those in the low octane map.

As an example, let's say that at a given rpm/load, your high octane timing map calls for 10 degrees of advance, and your low octane map calls for 0 degrees. With the octane value at 100%, the ECU will attempt to run 10 degrees, but if the octane value comes down to 60% after prolonged and heavy knocking, then it will run 6 degrees.

That being said, even if your high and low timing are exactly the same, the ECU will still pull timing immediately after it detects knock, and gradually try adding it back when the knock clears up. After that pull though, if you do another one then it'll try running exactly the same timing as it tried before, it won't remember that the last pull knocked, unless you had enough knock to get it to interpolate between the 2 maps. Think of it as "short term" timing adjustments as opposed to the "long term" adjustment made by the octane value, which is stored in the ECU and that you can't just reset. As the car runs under boost knock-free, the octane value will gradually rise back up to 100%.

Hopefully that makes sense.

JoT, or anyone else for that matter, if I made any mistakes in my explanation, please correct me!