l2r99gst

iTrader: (2)

Bez,

Thanks so much for coming here and letting us know about the disassembly. I really appreciate it. Just as I thought then, if the final load is used, the third load, it is incorporating baro and temperature.

One statement caught my eye, though:

MUT 28 is a 1 byte variable for air mass or air mass/rev? Is there a way that we can log the full resolution of this similar to the 2-byte load, etc?


Thanks,
Eric

C6C6CH3vo

iTrader: (9)

I've been asking questions searching for answers like these for about a year.

Now back to Eric's question

tkklemann

iTrader: (6)

So, not to stray to far off topic, according to your calculations of 270 load at 7500rpm being 46.9 lbs/min, and the stock turbo being rated at 44 lbs/min, does that mean I am maxing it out now?

Funny thing is that graph was with a small boost leak too.. He he...

In some non-boost leak logs, I have seen up to 280 loads by redline too.

Is this reasoning to get an FPGreen? I need an excuse....

l2r99gst

iTrader: (2)

Yes, that's right, if the rough approximation is close.

In the one log that you sent me for this, you had 238 load at 6900 RPM.

So that would be:

238*6900/(454*95)= 38.1 lbs/min

If you do have any logs with a 270-280 load at 7500, I would say your turbo is maxed out, for sure. Actually, before we get the answer from Bez about MUT 28, I would like to see logs with the highest loads with the stock turbo maxed out, to see how close my approximation really is.

I would venture to guess that we won't see many stock turbos in that load range at that high of an RPM. At 7500RPM, the stock turbo should struggle to hit over ~260 load.


Eric

gunzo

iTrader: (2)

Eric, I understand this G/rev measurement will be thrown out the window when you change the intake pipings ??

My experience with the intake piping when you changed to a hardpipe is your airflow frequencies changed quite significantly

l2r99gst

iTrader: (2)

Yes, anything that throws off your airflow metering will throw off the load and these calculations.

C6C6CH3vo

iTrader: (9)

+1

I see significant changes in load every time my intake is removed and reinstalled (I'm constantly dicking around with the car) just from small changes in the way the MAF is positioned. Also, with what Bez informed us about the temp and baro being part of the equation, load values will significantly change with the weather. Even though what your trying to accomplish is likely the same method used when studies are done on turbo's, and moreover your research has brought to surface many facts we all been wondering, there is one thing required to make your results valid, and that's about a million dollars worth of standardized test equipment including a pitot system.

l2r99gst

iTrader: (2)

I agree with you, but this is one more tool that we will have at our disposal to see changes, for example, with different intakes. If you have your standard logs before a change and are flowing 40 lb/min, then after the change you are flowing 60lb/min, then you know that change messed up your reading and you should compensate, whether it be with the MAF scaling, etc.

You're absolutely right that load would change with weather changes. Anything that changes the mass airflow will change the load. Higher temperatures will lower the load (mass airflow) and lower baro-higher elevations will lower the load. Actually, that shows how important a good intercooler is with a turbo vehicle or how cooler weather really helps with power. But, the point here is that you want to see the real load, or mass airflow, no matter what effects it. A load value that didn't incorporate baro and temp would be somewhat useless.

Anyway, I'm agreeing with you, I think. I didn't intend for this to be an exact calculation. But, I like seeing things in mass airflow, rather than an arbitrary load number. It's great that Bez confirmed what I thought all along....that load really is a mass airflow/rev. That helps me out tremendously, since I was spoiled for years with DSMLink and logging mass airflow all along. Knowing now that we were basically doing the same thing with load just gives me another tool in the tuning process. Everything is based off of a mass airflow, so that helps a ton.


Eric

JohnBradley

iTrader: (30)

Here is what 22psi at redline looks like with an attached log screenshot. Lucas has switched the hotside, made an interesting CAI and is now holding 24. As I recall from the last log of his I saw he is around 245 or so by redline, maybe 250?

https://www.evolutionm.net/forums/sh...light=E85+dyno

tkklemann

iTrader: (6)

I do have some logs that I can recall seeing over 260 load by redline. But, a big BUT, I have never rescaled my MAF with my Injen intake pipe because my fuel trims were never off enough for me to want to go through the effort. But, that might be making a difference now that I think about it at higher rev's.

I will be screwing around this weekend with the car, retuning because of the weather changes here in SC, and getting the car to hit the loads it used to. I am targeting around 310-315 loads at peak torque, and tapering to around 250/260 by redline. (I am pretty positive, with enough searching, I can send you a log hitting 320 with the stock turbo too around 3500/4000 rpm..) I am pretty positive I can hit it, as I have done it before. Once I do, I will send you the logs for poop's & giggles.

Hopefully this weekend I can get the car back to where it should be..

In the middle of October, things are going to get really interesting as the car will have a fully built head, ported TB/Intake manifold, ported exhaust manifold, ported compressor/exhaust side stock turbo and tons of other stuff. I have a feeling that I am going to to very quickly realize the stock turbo is what is going to keep the car from going any faster.

l2r99gst

iTrader: (2)

I think we can all safely agree that he has that turbo maxed out. Even though he wasn't logging 2-byte load, even his load at 7500 RPM was about 235.

235*7500/(454*95)= 41lbs/min

So, the math seems to hold pretty well. Looking at the compressor map for the EvoVIII 16g and plotting points at 7500RPM shows me about 42 lb/min to be maxed out. This will change slightly depending on volumetric efficiency, etc, but the calculations seem to hold pretty well.


Eric

l2r99gst

iTrader: (2)

Post a couple up...that would be great to see more data. Hitting in the 300's in middle RPMs isn't a problem. It's holding to redline that I'm saying isn't possible on the stock turbo. 250-260 load at 7500RPM would be very impressive, and I don't think possible, on the stock turbo. Of course, if the air metering is slightly off due to intake pipes, etc, it is possible, but you get my point.


Eric

JohnBradley

iTrader: (30)

Now instead of making Evoscan try to do a bunch of math like I did last time we discussed it (based on your Mitsulogger forumlas) I should be able to make this work pretty easily and log according to g/rev and then have it convert that math with this condensed formula. I am curious to see what the Green is actually doing. Especially since at the track I have logs of 2 byte load holding to 310 or so by 6500...cant remember what it dropped to by redline (8K). It was blowing out spark like a SOB though so its not 100% reliable data.

l2r99gst

iTrader: (2)

I would be interested in seeing that myself. The green, IIRC, has a 48lb/min compressor wheel. Something around there. So, if it was maxed out, you should be seeing somewhere around that value.

I remember one person from the DSMLink boards that is running DSMLink in his Evo ran the green with the wastegate disconnected, and he showed right around 48.7 lb/min max airflow. I think his name on here was kjewer or kjewer1.

So, seeing data from your setup would be good to see how close this approximation actually is.


Eric


EDIT: Here is Kevin's post: https://www.evolutionm.net/forums/sh...=green+dsmlink

Here is his graph showing the green maxing out at 48.7lb/min using DSMLink:

C6C6CH3vo

iTrader: (9)

At 24 psi and about 7080 RPM my MAF reads 1815hz and 223%. Readings are from 2byte Hz and load, the boost is tapped from diverter valve port.

The 10.5 HS modded stock turbo on the car really runs out of steam at about 6300RPM when viewing RPM slopes even though WHP may still increase on up, just not much. I do however enjoy the stockers response at 4000rpm and being pinned to the seat even though this won't help much on a dragstrip. Efficiency beyond 6500rpm with another turbo would be nice, but I don't have the time or tools to pull the head and replace the rod bolts so it's stock turbo taper for me