Jaideep Singh

Hello All,

This question is directed towards all of my fellow W204 C63 NA owners those who love to log drive data and look at it. I would like to know the following

1. What is the maximum MAF value in g/s have you observed? and at what RPM? It would be closer to red-line but what exact RPM? What was the IAT? and Ambient temp?
2. I understand for those of us who are tuned the commanded throttle at WOT is 100% but have you seen what is the maximum actual throttle opening percentage at WOT?
3. What is your location's nominal atmospheric pressure in KPa? and what is the MAP value at WOT closer to 6000 to 7000 RPM? If it drops, by how much?

Please when reply can you mention your MODS as well if it is not in your signature? I am specifically looking to compare data from people with bigger throttle bodies vs stock? and also between tuners.

Thank you for looking into this. Have a great day and stay safe y'all.

Regards
Jay

BLKROKT

@skratch77 has a ton of airflow data

skratch77

Lol last time I was logging i hit a deer.

Jaideep Singh

Damn that's unfortunate. I saw your advice on putting the E63 Y pipe. were you ever able to log some data with it? Do you have any older data files which you can dig?

skratch77

I'll look but unfortunately I have a new cell phone and had those files on it.

Basically just start logging your car and see what you get..

I remember that night i was about to hit 400 g/s when I hit the deer. Crazy I was looking at the log right after lol.

Maybe saw like 6500 rpms so had a little more to go.

Jaideep Singh

I have a bunch of data files. I just want to compare it with others. The biggest concern is air charge per cylinder per liter for a 5.7L Hemi which has single overhead cam is higher than our dual over head cam 6.2L which doesn't seem right to me on my car. What data logger were you using? 400g/s seems like a very high airflow which is good. Let me know if you are able to locate those files. Thanks.

skratch77

Here is a few I found and the last one is on a race file with 30d timing (the pull i hit the deer)

So the best my car was doing was 305g/s at 4800 rpms compared to 260g/s at 4800 rpms on 93 Oct file. If I could of made the last pull all the way I would of broke 400 easily.

Jaideep Singh

Is this data file after the Y Pipe change? Do you have throttle opening percentage and MAP in the file too?

skratch77

This was 100% throttle and I dont have it after the y pipe as I've changed to many things on the car.

Jaideep Singh

Thank you for sharing. What I noticed was at WOT my commanded throttle is 100% but actual throttle feedback is 88%.

skratch77

Dont worry they open 100% I tested that with my throttle bodies outside the intake manifold

Jaideep Singh

Okay that is good to know. Thank you for the information. I appreciate it.

My vehicle’s max air flow is closer to 360g/sec. I am just trying to figure out what might be wrong.

BLKROKT

355g/s is the best I saw with 82’s on a standard EC V5 tune. And my car is known as a strong example.

If you just have an off-the-shelf tune, I’d say you’re spot on.

My EC dyno tune in Oct 2018 changed the power band significantly, and picked up a ton of peak tq/hp. I wouldn’t be surprised if I’m over 400g/s on my race gas file now.

Jaideep Singh

That’s what my worry is. This 360g/s max is with EC dyno tune on E85. I am just worried why it is so low.

skratch77

I also tested in the middle of winter with super cold dense air and no cats.

I had fi headers that are like mbh to 3 in mid section and 3in remus exhaust.

Here is the video showing our tbs open all the way even though it says 87%

skratch77

Are you catless?

hachiroku

at full sing i'm seeing around 363g/s plus or minus at redline. at times i've hit 379g/s and that region as well.

skratch77

Now you guys know i was so interested in the velocity stacks. I was trying to hit that 415gs/s

hachiroku

i'm on 91 octane

Jaideep Singh

Yes catless with X pipe stock resonator and mufflers

roadtalontsi

I'm not really sure what the point of this is but maybe i'll log mine lol. What airboxes are you running i'm sure that has an impact. Header design on a N/A motor will also have an impact aswell. Fuel should really make no difference on air. If the throttle is fully open it shouldn't really play a roll. Fuel changes ignition timing, it's not forced induction so you wont see any increase in boost etc...

Jaideep Singh

My objective is to understand if my cam timing is set right and VEs are good. My plan is to understand the bottle neck of air path and work on improving it. My car’s peak I saw today was closer to 366g/s. I never thought 400+ would be possible but people are getting it. I am using ROW Air box and LTH. What Kind of MAF you see up today and what MAP drop?

hachiroku

i wouldn't get too caught up in what another brands engine is registering on MAF g/s. i'm sure there is some variation as well as difference as we have 2 MAF's versus 1. also, these aren't lab grade testing devices either.

Jaideep Singh

Can you share some of your data files if it is okay? What kind of MAP drop do you see closer to redline? I think a DOHC engine should be able to have a higher GF Charge (per intake stroke per cylinder) as compared to a SOHC engine. This is just my thought. I have used GF Charge while we benchmarked engines back in the OEM I was working for. Anyways I would love to see your data as well if possible. Thank you for sharing all the good info on these forums.

hachiroku

DOHC and SOHC will not matter if the camshaft is comparable in terms of powerband.