I do not claim to know everything and count myself lucky when I know something. The following is a curiosity of mine and I welcome comments and corrections.

I here a lot and see a lot information about larger throttle bodies and wanted to start a post looking into the concept as it applies to the 63 motors (MB 156 AMG 6.2 liter).

First, I would like to drill down through the “tuning tree” as I know it to see where Bigger Throttle Bodies (BTB) fit in.

Two general tuning paths-
Increase Air Into Motor
Increase Torque Derived from a Given Quantity of Air (increased thermal efficiency)

BTBs seem to fit the Increase Air category.

Two paths for Increasing Air (normally aspirated engines)
Bigger Pump (increased engine displacement)
Improved ability to pump (increase Volumetric Efficiency or VE)

BTBs seem to fit the improved VE category.

If my logic above holds, then the question becomes-
Do BTBs improve VE for the 63 motor in stock and modified trims?

It is a simple matter to use the ME97 ECU to measure Mass AirFlow (MAF) and calculated torque. I would like to do these measurements before and after the addition of BTBs on a C63 to see what they really do. Do they help with a stock engine? Does the reduction of exhaust restriction brought about using long tube headers change the equation such that BTBs make a difference?

I am reasonably certain that BTBs will feel better on tip in and low throttle transitions. This feeling is based on the idea that a BTBs will flow more air at low throttle openings than their smaller brothers so, if the ECU commands 12% opening the BTBs will give you more air when they reach that set point and thus the car will feel more powerful. You can achieve the very same affect by making the throttle pedal (Driver Torque Demand Input) more sensitive so I am more interested in peak airflow for a certain RPM at maximum throttle opening (in the low 90% region as any more is useless because of the throttle shaft diameter).

I will toss in the data logging and related support for anyone interest in BTBs and getting answers I will also post all resluts in this thread.

Again, I do not begin to claim to know everything so please feel free to chime in and correct me.

 

Good info and assessment, lola. This modification certainly needs some data behind it. I really wish you were in the PNW.

 

I support stuff in Europe and the UAE so the PNW is no problem. If you are thinking about BTBs, I can pitch in with the tools to evaluate the work.

 

Doing a comparison on the C63 is more complicated than the usual car. Our T/B's do not open 100% when they have a stock tune. If fact it's less that 70% stock. Therefore the btb's will create more air flow because of the additional size and possibly not be too large. Not until you get a tune can you really do a real comparison.
We have to be careful not to create too much air too low which can loose torque. May pickup HP top end but sacrifice torque and drivability if you have a tune. The stock t/b's will flow enough air for a motor much larger than what we have.
I too would like to see the results on a modded car that can utilize the additional air flow with a tune that opens the t/b's closer to 100%.

 

i`ve read that the SLS has BTB`s and diff. camshafts,equal length headers(450mmand 500mm) beside other things,the HP on it went up to 570 ps(564 hp).i have`nt seen solid figuers on BTB from the tuner who`s offering it and still waiting for a forum member who has it.

 

TB's for all the 63 engine are the same, at least in north america, including the SLS

kleemann offers bigger TB's for the 63

 

I think kleemann should lower their price on their tbs.

 

I think someone should post some freakin data!

Kleeman where on earth are your c63 dyno charts for this product?

And i pose the question again from my other post, is it totally illogical to consider putting in a larger throttle body if you dont have LT headers (but hiflow cats and electric cutouts)

 

I stand corrected about the TB`s on sls.
quote( The newly developed magnesium intake manifold features precisely coordinated resonance tube lengths. Eight velocity stacks with a length of 290 millimetres and a diameter of 51.5 millimetres supply the combustion chambers with fresh air. Behind the new air filters with a volume of just under 9500 cubic centimetres there are two throttle flaps with a diameter of 74 millimetres. Their electronic adjustment is practically instantaneous: it takes only 150 milliseconds to open the two throttle flaps to their maximum. The result is exhilarating responsiveness. Two hot-film air mass sensors located behind the air filters supply the engine electronics with the necessary temperature and density data for the intake air.
source(http://www.topspeed.com/cars/mercede...g-ar78916.html)

 

I agree and am willing to do whatever work I can to support collecting that data including supplying the tools and technical support for the project. I am particularly interested in (somewhat more independent) customer generated/gathered data before and after only the BTB change (with or without other mods). If required, I can also ensure that the proper wide open throttle angles are achieved and this would be verified by the data as well. Ideally we could find a car or cars where we get/post stock data, ECU tune only, tune plus Long Tube Headers (LTH) then add BTBs to see exactly what they add to the mix.

Being the nerd that I am, I would also love to see a colum on the spread sheet showing $s/hp gained. I've spent a mountain of cash getting a few more horsepower out of a legal 2L sports racer motor and yet I am very cheap when it comes to mods on a (unregulated) street car. I tend to go for the best bang for the buck provided quality is equal.

By the way, I have no horse in this race and do not build or support the building of BTBs. I just have my own ideas about the effectiveness of this (and other) mods and it seems as though there are enough members on this forum that we could actually collect and share data as a community. There are a lot of guys/gals here with project cars that would permit gathering this type of data and a broad sample pool would provide the best and least biased data.

 

Hi William ; nice to here from you again. I have not put a set of m-156 heads on the flow bench. Andy over to MHP has, & has the numbers. The post he made over on AMGperformance dot net make sense to me On larger T-bodies I'll paste it here.

M156s and Larger TBs...

--------------------------------------------------------------------------------

I have recently seen aftermarket throttle body's being produced for 63 AMGs. Aside from the rather shocking price it should be known that the OEM dual 74mm TBs flow over 1400cfm. On it's best day a stock longblock M156 will ingest 675cfm at redline, with H/C still under 800cfm. What this means is that the stock TB diameter is sufficient for bolt-on applications and far far beyond, and is far from a restriction--there are much greater corks in the system that need to be addressed before anyone thinks about larger TBs for these motors.

I see two possible ways for cars with larger TBs to gain HP/TQ on the dyno or for only the first hundred miles or so, until the ECU adapts to the slightly leaner A/F the larger TBs cause. It has been posted that the DbW electronics inside the aftermarket TBs have not been reflashed to compensate for the additional airflow. This fact alone usually equates to a tuners worst nightmare.

I've also read in a post by a comany rep that makes said aftermarket TBs that additional fuel doesn't need to be added to the engine file because the ECU can compensate by adding enough fuel on its own. Seeing that an engine is essentially a large air-pump, if you're flowing significantly more air (30HP is a lot of additional air, and again the stock TBs are far from inadequate), you're going to need significantly more fuel. Case in point, our LT heads/Mids require an extra point to point and a half of fuel across the board since they flow so much more air than the OEM manifolds. With a stock ECU in place with our LTs/Mids my dual band A/F meter showed WOT A/Fs in the 14.2 range--dangerously lean. The same dual band A/F meter read the stock tune to be 12.5-12.8:1 across the board at WOT with a 100% stock C63-less charcoal filters and K&Ns. So again, if you're flowing that much more air, you need to add extra fuel. It's a simple fact.

The other reason these TBs could initially show a gain in HP/TQ being a superior design/shape to the radiused TB inlets vs stock, but from what I've seen so far the aftermarket TBs look identical to the stockers aside from having larger blades/openings so I wouldn't count on this being the saving grace here.

I look forward to seeing track/VBox before/after testing, however based on everything posted above I'd be surprised to see a legit 5-6hp gain.

To clarify, this thread was not created to bash any specific vendor, it was posted to educate the consumer about the airflow requirements of both stock and highly modified M156/63 AMGs.


Thanks
__________________
'08 Audi RS4
MHP S1 (v3 ECU, BMC)

Thanks for reading _PTEngineering

 

I have no doubt that an argument can be made for BTBs doing absolutely no good on a 63. I have been absolutely certain in the past that one modification or another would simply just not work and should not be tried. I was also very wrong on some of those occasions so I have grown to appreciate the "throw spaghetti on the wall and see what sticks" approach that many in the industry take. Some get results and, for me, that speaks for itself.

I also get the feeling that there are people out there (and hopefully some on this forum) that will buy them and give them a go. For my part, I would like to see ECU data from them installed in a car and on the street. It seems the best way to get the most unbiased non-opinion based input on the subject.

With respect to the ECU correcting for air fuel, the ME97 runs closed loop most (if not all) the time, even at high loads or wide open throttle. I have seen one application were 50 hp was "applied" to the car while it was in the middle of a dyno pull and the ME97 adjusted perfectly and maintained the A/F target. Given that the ME97 is a target based system, it will accommodate BTBs without issue. In addition, I suspect the torque based control theory of the ECU will have it use smaller throttle openings with the BTBs for a given less than maximum available driver torque demand such that the proper amount of torque is generated.

 

lola
if i understand you correctly you`r cotradicting PTE`s quote from MHP ( Case in point, our LT heads/Mids require an extra point to point and a half of fuel across the board since they flow so much more air than the OEM manifolds. With a stock ECU in place with our LTs/Mids my dual band A/F meter showed WOT A/Fs in the 14.2 range--dangerously lean. The same dual band A/F meter read the stock tune to be 12.5-12.8:1 across the board at WOT with a 100% stock C63-less charcoal filters and K&Ns. So again, if you're flowing that much more air, you need to add extra fuel. It's a simple fact.)
please explain.

 

Open a Nitrous bottle in front of a 63 the next time you have one on the dyno and watch the A/F and hp curves. Horsepower will go up (function of inlet air temperature drop and increased oxygen content) while A/F stays spot on. This confirms for me what I know from the ECU firmware; the ME97 runs closed loop and can quickly correct mixture, probably on a cycle by cycle bases but I am just guessing on that one. In short, I am just passing along my perspective and personal observations not trying to contradict anyone. I have no desire to get into a pissing contest over anything and those contests can start for the silliest reasons.

Also, I know the tuner that does the files you are talking about. He is one of the best in the business and has probably forgotten more about MB tuning then I will ever know He is responsible for a lot of my understanding of the ME97.

 

I notice the TB mod is popular in the MB scene but not so much in the BMW scene. I think the only aftermarket TB I can get is the Dinan ones and I heard they don't work too well.

from what I know TB if not made properly it can cause lots of headaches, its this true?

but of course a Custom tune is needed.

Eugene

 

Here is a pic of both stock and the Kleemann unit. We installed in the C63 with MBH LT headers, no cats and stock resonator and mufflers, and Renntech tune. The work like a charm!

 

How much power does the car make?

was the car custom tuned or was their a tune make for the TB already?

 

lola
please don`t let the thread die.i want to know what the hype is all about.
thank you

 

I will try my best but it really comes down to someone interested in doing BTBs stepping up to the plate and doing so in a step by step or mod by mod way such that we can document the process with data. The very best would be to post data from stock through ECU tune then long tubes and finally doing BTBs.

If someone out there is game, I will pitch in with the data acquisition stuff.

 

a fellow member here (rarfinancial)has them on his cls63,waiting for him to tell how is the out come.

 

that`s what rar said about the BTB:
(So yes I do have the Kleeman TB's installed. As you guys know I have done just about all there is to do to a 63, mod wise, so the TB's for me was a must. I will be doing a few dyno runs soon and with all the dyno time I have I feel I'll have enough data to report back. As for what I think about the mod, well I can say for sure that the yellow triangle comes on a whole lot more The shifting feels harder and the response of the car is much quicker. The car really seems to pull much harder. I drive the car like I just got a new car, remember the first few days of driving the AMG when you first biught it? Well, that's how it feels after the install .. If I had the choice to do it again, I would. It is like the icing on the cake. More hp? but car feels and pulls much better. I'll give full report after dyno runs in about a week or two.. I hope this helps
DO IT! )

 

lola
any progress.

 

Nope!
I have not heard from anyone interested in doing this work (that is interested in publishing results).

 

can you fly to kuwait?i`ll do it.

 

I'm interested . . . just not at the $4K price Kleemann is asking for the TBs.