SonnyakaPig

E Money, we are in agreement once again today (*I agreed with one of your points in another thread), I also do not think there is enough air for our cars at the top of 5th gear. Frankly, it scares me at the top of 4th gear.

I've been to a few dyno shops and honestly I have not been impressed with their fan setups. What I kept telling myself was, "hey, there are much more expensive and powerful cars than yours that use this dyno, so it must be okay."

But, interestingly, at the last dyno shop I went to, which happened to be my third time going there (I took another car there as well), before doing the runs we were trying to find out which gear would provide a true 1:1, and although we incorrectly believed 4th was the correct gear, one of the regular patrons at the shop who came down to see my car dynod, openly questioned whether there was enough air to accomodate my car when it's going 150+ mph.

Do you know if the engine can be damaged if there is inadequate air supply for the car when it's on the dyno?

propain

Another OE...

http://www.youtube.com/watch?v=0UL9aZKUcPw


427 to the wheels.. no chart though..

Also shifting on the dyno at full throttle in the middle of the dyno...

SonnyakaPig

Mine did that too. I think it's because we didn't have my car in dyno mode.

Nice numbers.

propain

RPM is RPM. If you dont have enough air it can damage the engine in any gear. I dont understand the thought process behind this. Can anyone explain?

As shown on my charts the 5th pull generated more power (Barely) and much more torque. The more load the car is under the more power she seems to produce.

The fan setups do indeed need to be improved upon. The more air you get the better your cooling of course but also the better your dyno results will be.

SonnyakaPig

I understand your point about RPM being the important factor compared to vehicle speed. But it still seems like air supply increases in importance as the speed increases. I would love to understand this concept better.

My unsubstantiated fear of running out of air during a run involves thoughts of internal engine scoring, but, like any combustion, I would imagine the spark would lose some ignition potential, maybe full timing wouldn't be available.

I was told by Powerchip's tuner, Bill, that C63's lose intake manifold pressure (MAP), measured in kPa, in the last 400 rpms or so. That could account for the flattening out of the hp curve that is seen in stock cars. He didn't know what was causing it, but it is an interesting observation.

We talked about potential solutions, including a slightly revised air intake system.

BerBer63

Just some follow up to the custom box - I cut my box up into an improvised ROW - removed the charcoal lattice and cut a half inch semi-circle (D) off the flat part. Couldn't really tell the difference, but it was free. Noticed my exhaust was more robust, but maybe my brain was just playing tricks. Oh well...I wonder what TTM does.

SonnyakaPig

Very cool effort. It's a good idea.

Do you notice any new drone in the cabin as you're driving now?

AMS Performance

Run #1 is the only run that counts (real world conditions).

Very strong results, great job, good numbers.

(426@ wheels on dynojet = 519HP @ crank)

propain

All the runs "count" Its about how much power the car can make.


Run#1 is a im driving around on the street for an hour and someone races me.
Run#5 is at the track when I cool it down before my run.

TTMotorsports

For someone that just reads and "learns" from the internet and has absolutely no real world experience you are quite an expert!

Keyboard assassin that knows JACK!!

You know that guy that everyone talks about, tries to race everyone to prove his manhood, gives a bad name to other C63 owners, etc. BINGO!!!!!!!

He had his car tuned by Jeremy at TTM but he is definitely NOT MY CLIENT which I told him after all of his "expert" opinions garnered from the internet! NO TOOLS ALLOWED!

You will all understand eventually.

TTMotorsports

Dyno numbers are just that.......NUMBERS!
1)Pre and post mod to see what the difference is and to make sure you are going in the right direction
2)Getting a base file done on a total custom driveline set up on a race/track car.

Now the reasoning behind dynoing in the gear that is 1:1;

The first 4 gears in a 722.9 are know as reduction gear ratios. The output speed at the transmission tail is slower then the input side which is the flywheel.
5th gear is a 1:1 where as the input and output speed are the same.
6th and 7th are overdrive gears where as the output speed at the transmission tail is faster than the flywheel speed.

This is why "dyno tuning" can only be done correctly in a wind tunnel where you will have REAL WORLD and WIND conditions and not just fans trying to replicate the actual air velocity.

Hope this classifies as a good explanation!

TTMotorsports

If you are running out of air the car will start to run rich but the ME9.7 does an incredible job of correcting that issue. Don't be concerned.

The dual 74mm TB's are only open partially so that is why the MAP goes down in the higher rpm range. The 74mm can flow ~1400cfm and they are extremely restricted from the factory. While increasing velocity and smoothing out the air charge will always help, getting the TB's to open fully will correct your MAP issue!

SonnyakaPig

Thank you for the response.

Regarding the MAP issue, I think the TB's -- even though they are restricted -- are flowing enough air. These N/A cars can never suck in 1400 cfm.

That's why I don't understand making the air boxes tops any larger than the ROW airboxes. I would think the ROW airbox tops are as big as the M156 engines will ever need. Just to clarify, I'm questioning the utility of air box tops made by Carbonio.

Looking at numerous dyno graphs representing tuned C63's, I have noticed that some tunes produce a hp curve that still shows a tendency to flatten out, even though the the hp curve has risen over stock.

Other tunes actually remove that flattening out and show a hp curve that pretty much climbs all the way to redline.

We can assume that every tune for the C63 involves opening up the TB's to some degree. So, I'm not sure why some tunes that open the TB's still have a hp curve that flattens out above 5000 rpms while others show a linear, steep hp curve all the way to redline.

Bill even mentioned an idea he had where you could somehow program one TB to close shut around the rpm where the MAP begins to drop, so that pressure would build in the intake manifold as air was being sucked in through one TB.

Of course, it's just a theory, but it would be good to know how much cfm C63's actually flow during WOT at the top of a run to see if one TB can sustain enough flow for the engine.

Just thought I would share some of this and see what you think.

Jons95c36amg

So Mr know it all. Explain why the CEL went away after I put the charcoals back? Waiting....

obsidian05e55

Any info on this "Air Box mod", or the price to perform it?

-Walter

BerBer63

BTW here is what I did. Didn't cut too much because these were my only set of air boxes. So I did a conservative taper, but I don't see much use of doing anymore since in the end the bottom is still flat. The next step would be ROW boxes or aftermarket, but for now this was free and easy and I don't like pointless emission differences with the rest of the world.

Used a dremel to remove about 5/8" from the center of the flat part [ -->( ] and did a taper to the edges. Smoothed it out and that was it. I also removed the charcoal lattice that crossed over mostly by hand you can twist and break them off or use a dremel. The rest of the black charcoal filter frame that goes around the airbox is silicone-glued in and I would advise just leaving those as is or you might break more than you intended and bc it's a PITA, so I gave up.

Anyone know how to clean the MAFs they look pretty straight forward, but I don't know if I gummed them up, while handling them. I know you can get poor air readings. What should I use?

Even Money

You can buy MAF cleaner at any auto parts store. Just spray it directly on the MAF sensor from both sides, let dry a bit, fairly easy.

BerBer63

so money....MAF cleaner

TTMotorsports

It is called ADAPTION but you already knew that Google Master!

themyst

@TTMotorsports - I understand Jon has issues and perhaps not the most agreeable or likable person on the planet, however demeaning a customer does not bode well for the image of the company as a whole. I think you guys would flip your lid with some of the retards in the N54 world, but the tuners of the said companies keep their trap shut and remain professional.

Did he do anything to provoke such a strong response from your company?

-edit- Never mind. Did some searching; I see that OE Tuning was taking appointments at your location, and you guys were not the ones servicing him.

Jons95c36amg

Yeah Ben I was nice to Bruce from the day I met him at TTmotorsports. But was rude and said "I dont know why your here"because I didnt want the airbox mod Its my freaking car dude Bruces arrogant attitude just left a sour taste in my mouth. Not a smart way to run a business. The last time I was treated like this the company went out of business

TTMotorsports

Demeaning a person by describing him to a "T"? That is more of a warning!

It seems that Jon has already made a name for himself on the BMW forums after racing a 135 and winning!

Jeremy and JJ of OE Tuning totally agreed with my assessment of Jon. They met probably 20-30 of my client's and they enjoyed all of them except for one! That is why I told him he would never be a client of mine.

TTMotorsports

It had nothing to do with an air box mod. There are so many members that call me from around the world regularly and they will all tell you that I spend as much time as is needed to answer questions and give real world, hands on advice. Maybe you guys should start pming Jon questions?

You asked me how many questions and you kept referring to "what you read on the internet" as your basis on your opinion. So why did you keep asking me then? He also doesn't believe in K&N or BMC filters. He likes the paper ones.

Gnat on a hot summer night!

c32AMG-DTM

Agreed.

It would, but I think you're perhaps missing an important aspect of this: when your vehicle is sitting on a dyno, it's true speed is zero. The only differences between a 3rd, 4th, or 5th gear run are the gear ratios and corresponding drivetrain speeds (tranny output, driveshaft, axles, wheels, etc.). So, if the engine's getting sufficient airflow during a 4th gear run - it's not like it's magically going to be running short of airflow during a 5th gear run. The only caveat to this that I can think of, is that a higher numerical gear run takes relatively longer to complete, therefore more heat is likely generated in the drivetrain.

EDIT: Thinking this through further, a higher numerical gear dyno run probably stresses the engine less. The fans used at dyno shops (at least, that I've been to) aren't variable speed fans - they're constant. So, during a higher-gear dyno run, the engine revs more slowly, therefore has more airflow volume from the constant velocity fans to work with, over that longer duration of time. Hmmm... interesting, hadn't thought of that before.

Jons95c36amg

Stay with the topic your running a business Yeah do you think I would come back after your treatment? Thank God Jeremy was a nice fellow and OE-tuning is not connected to TTmotorsports.