Baseline Dyno Results

[VIP_MBZ]

Well I'm starting to accumulate all of the mods I plan on using, but I decided to start with a baseline dyno so I can see what I'm working with. Here's the graph:

http://suprablur.935motorsports.com/mbz/dyno_baseline.jpg

The results were 157 rwhp, 175 rwtq as a maximum. Subsequent runs resulted in slightly lower numbers, indicating the inefficiency of the intercooler over repeated pulls. Real world results would fare better given that you get more air flow than any dyno fan will give you.

a/f ratios hovered in the 13.5-13.8:1 area, which is a little leaner than I'd like, but given that the car is completely stock, I can probably attribute this to Mercedes wanting to maintain good fuel efficiency, even under boost. The graph shows no sign of pulling timing in response to the knock sensor(s), so I will assume that all is normal (unless someone here has other experience).

With the ratio in mind, I'm going to tread carefully during the next few mods, and maybe even dyno again after adding the exhaust alone. We'll see how it all goes; and whatever inconsistencies don't iron themselves out will be taken care of by Upsolute.

-Ray

[Pagz]

your graph ratios are alittle out maybe....this is what mine turned out like....sorry bout the poor picture,it shows boost(pink),torque(black),KW(red),and air/fuel(blue)....ill try get a better pic up

http://memimage.cardomain.net/member_images/3/web/735000-735999/735658_48_full.jpg

if for some reason this pic isnt showing,...right click show pic works....

[VIP_MBZ]

Wow yours looks like it is even leaner than mine (over 14:1 if I'm reading correctly). Makes me feel more "normal." The Japanese Denso ECU's (Toyota, Nissan, Honda) are closer to 12.5:1 under normal driving, and dip into the 10-11:1 ratio during WOT. So I was definitely not used to seeing a WOT ratio above 13:1.

You also have 174hp versus my 157hp -- was this on a stock C230k, or after mods? Automatic or manual? If all else is equal, I know I have some tuning up to do before proceeding.

Yeah the graph ratio sucks on my hp/torque, I'll have them make a better printout next time. In the meantime, I can stretch it with photoshop, ha.

-Ray

[MrSpace]

157whp for a stock W202 automatic and north american is a lot, good numbers

Etienne

[Pagz]

Originally posted by VIP_MBZ
Wow yours looks like it is even leaner than mine (over 14:1 if I'm reading correctly). Makes me feel more "normal." The Japanese Denso ECU's (Toyota, Nissan, Honda) are closer to 12.5:1 under normal driving, and dip into the 10-11:1 ratio during WOT. So I was definitely not used to seeing a WOT ratio above 13:1.

You also have 174hp versus my 157hp -- was this on a stock C230k, or after mods? Automatic or manual? If all else is equal, I know I have some tuning up to do before proceeding.

Yeah the graph ratio sucks on my hp/torque, I'll have them make a better printout next time. In the meantime, I can stretch it with photoshop, ha.

-Ray
the run was stock...although i found out when i did my exhaust,that there was no cat ever in my car...that would give gains too!
its actually 14.3!!
i was not to concered with it...and neither were the tuning shop...
but after seeing yours it might be worth a look!!...
I have a manual trans,with good lube they are usually more efficient than the auto....

i guess you already know this but....,although most dyno's can only be used to accurately measure performance after mods from a base run...as long as you use the same dyno again,i havent found many dynos that will produce the same results on the same car.....but there is so many factors like air temp,air pressure,fuel,humidity that effect performance on the day...
and then theres the condition of your wheel/drive/engine/pully bearings,CV's,Gearbox/diff/engine oils,fuel and ignition sytems and how well the engine has been looked after....these can easily add up to be +/- 25hp when compared with other 230k's

Regards,
Paul

[MrSpace]

ah, then your numbers are ok

an auto W202 should put out about 150whp, you don't have cat plus manual (on the SLK, manual gave 5more whp)

so then your results are good

Etienne

[Linh]

Originally posted by VIP_MBZ
Well I'm starting to accumulate all of the mods I plan on using, but I decided to start with a baseline dyno so I can see what I'm working with. Here's the graph:

http://suprablur.935motorsports.com/mbz/dyno_baseline.jpg

The results were 157 rwhp, 175 rwtq as a maximum. Subsequent runs resulted in slightly lower numbers, indicating the inefficiency of the intercooler over repeated pulls. Real world results would fare better given that you get more air flow than any dyno fan will give you.

a/f ratios hovered in the 13.5-13.8:1 area, which is a little leaner than I'd like, but given that the car is completely stock, I can probably attribute this to Mercedes wanting to maintain good fuel efficiency, even under boost. The graph shows no sign of pulling timing in response to the knock sensor(s), so I will assume that all is normal (unless someone here has other experience).

With the ratio in mind, I'm going to tread carefully during the next few mods, and maybe even dyno again after adding the exhaust alone. We'll see how it all goes; and whatever inconsistencies don't iron themselves out will be taken care of by Upsolute.

-Ray

The baseline dyno hp and tq is normal. The a/f ratio is is concern. It should be alot richer at WOT. This is a major problem if you do the pulley upgrade wihtout chip or fuel pressure regulator. My Slk 230 with pulley a/f ratio max at 13.4:1 but drop down to 12.5:1 at WOT. I know that our car run very lean at idle due to the switch valve closed the fresh air side inlet and recirculated the exhaust gas. Btw, where did they measure the a/f ratio? Before or after the CAT? The right place to measure it is before the CAT.

[Pagz]

LOL mine must be alittle to lean!!....it was taken from the exhaust tip with no cat...

Rgrds,
Paul

[J Irwan]

Baseline dyno

doesn't mean anything to measure any performance gain, especially when it's done on different day, different machine, etc..etc..


the best way to measure any performance gain is to do run prior and right after upgrade.



Running dyno on the same car on different day of the week can yield different results.


Regardz,

[VIP_MBZ]

Unfortunately the a/f ratio was taken at the exhaust tip. I realize that this isn't a proper wideband reading, but it's all that we could do for the time being.

It seems to indicate to me that a post-cat reading would be deceivingly lean, since it has already been catalyzed.

BTW, how many cats are in the stock setup?

-Ray

[Linh]

Originally posted by VIP_MBZ
Unfortunately the a/f ratio was taken at the exhaust tip. I realize that this isn't a proper wideband reading, but it's all that we could do for the time being.

It seems to indicate to me that a post-cat reading would be deceivingly lean, since it has already been catalyzed.

BTW, how many cats are in the stock setup?

-Ray


Exactly. Only one CAT on my Slk 230.

[MrSpace]

Two side by side cats in my C230k

Etienne

[coolcarlskic43]

Originally posted by VIP_MBZ
Unfortunately the a/f ratio was taken at the exhaust tip. I realize that this isn't a proper wideband reading, but it's all that we could do for the time being.

It seems to indicate to me that a post-cat reading would be deceivingly lean, since it has already been catalyzed.

BTW, how many cats are in the stock setup?

-Ray You know,I think I might have to agree. I got my car dynoed and A/F was over 14 running close too high 15's with the guy holding the probe on the tail pipe.I didnt get the #'s I was expecting.(275whp/286ft lbs of TQ on Dynojet). I expected to be in the neighborhood of 285-294 whp/298-301 ft lb TQ. I 'm wondering if the car is really running lean or if the A/F reading is high because of the cats.If it's lean iIm suspecting that this is why I didnt get the 285-294#'s.I'm a little dissappointed.

[VIP_MBZ]

Unless it's pulling timing (which should be apparent on the curve by sudden dips), you'll make more power if it's lean.

-Ray

[Pagz]

well,it sounds like my system is running alittle lean,so...
would it be wise to take it to MB for a plug in and sensor check?

Paul

[Linh]

Originally posted by VIP_MBZ
Unless it's pulling timing (which should be apparent on the curve by sudden dips), you'll make more power if it's lean.

-Ray


So true on Mercedes engine. My Slk with Kleemann pulley dyno at 192 rwhp with a/f ratio went at high at 15.6:1. But with fuel pressure regulator, i only get 184 rwhp with an a/f ratio of 13.4:1.

[coolcarlskic43]

Originally posted by Linh
So true on Mercedes engine. My Slk with Kleemann pulley dyno at 192 rwhp with a/f ratio went at high at 15.6:1. But with fuel pressure regulator, i only get 184 rwhp with an a/f ratio of 13.4:1. Do you have cats on the car ?

Originally posted by VIP_MBZ
Unless it's pulling timing (which should be apparent on the curve by sudden dips), you'll make more power if it's lean.

-Ray Too lean and you can lose power. A/F anywhere in the 12's and mid 13's is considered optimal for a N/A motor performance wise.

[coolcarlskic43]

Here are my results.I'm dissappointed.

http://img155.echo.cx/img155/8629/icsdynoc558tq.jpg (http://www.imageshack.us) Best was 275.91whp and 287.72 ftlbs TQ hard to see.

Now don't get me wrng.The car does have a tremendous amt of pwr but my concern is the AF.I do have 4 cats on the car but the butt dyno tells me that it's possible that the A/F are inaccurate when done behind the cats.I'm still trying to figure out why the whp #'s are lower than the 284 -294 whp I expected.My friends 1999 E55 did 294whp and 301ftlbs TQ.It's a dilemna for me right now.Anybody have any thoughts?

[Linh]

Wow, your bottom end is running too lean. Based on the dyno chart, it look like misfired bottom end then smooth out nicely on top end due to richer.

[coolcarlskic43]

Originally posted by Linh
Wow, your bottom end is running too lean. Based on the dyno chart, it look like misfired bottom end then smooth out nicely on top end due to richer. I'm wondering if new plugs and wires would make a difference? And the Dyno indicates that the car is running lean but i don't know if that's accurate based on the fact that I have the probe in behind the 4 cats.You can see it's hitting 16 but there is no knock and no indication that the timing is being pulled back.Yes No?

[MrSpace]

you can plug an OBD2 scanner to check what the engine is reading

Etienne

[Linh]

Misfired could be alot of thing. Like Bad wire, plugs, injection....etc. In my opinion based on your dyno chart A/F ratio, the misfired is due to pre-detonation (too lean). You can see it on your dyno chart, the line is smoother as the engine run richer.

[coolcarlskic43]

Originally posted by Linh
Misfired could be alot of thing. Like Bad wire, plugs, injection....etc. In my opinion based on your dyno chart A/F ratio, the misfired is due to pre-detonation (too lean). You can see it on your dyno chart, the line is smoother as the engine run richer. I would think that a knock would have a harder dip than that.But you could be right.

[VIP_MBZ]

You're typically not going to ping on the bottom end. Not saying it's impossible, but just improbable.

Your difference in power versus your friend's E55 could be due to a lot of things. I'm not positive which 5.5L components were used in your swap, but most likely you're still using your stock transmission, driveshaft, and differential, which could be more lossy than the E55 setup. Cats also go bad over time.

The ratio can't be accurately read unless you're using a wideband O2 sensor that is tapped directly onto one of your exhaust runners. The dyno a/f graph is good for monitoring trends and consistency, but nothing really more than that.

-Ray

[coolcarlskic43]

Originally posted by VIP_MBZ
You're typically not going to ping on the bottom end. Not saying it's impossible, but just improbable.

Your difference in power versus your friend's E55 could be due to a lot of things. I'm not positive which 5.5L components were used in your swap, but most likely you're still using your stock transmission, driveshaft, and differential, which could be more lossy than the E55 setup. Cats also go bad over time.

The ratio can't be accurately read unless you're using a wideband O2 sensor that is tapped directly onto one of your exhaust runners. The dyno a/f graph is good for monitoring trends and consistency, but nothing really more than that.

-Ray Yes as far as pinging I can agree with you.Improbable but not impossible.I'm also using a E55 ECU.
The trannies are basically the same.The C43,C55(new) have 3.06 gears in the rear.I have 2 brand new high flow secondary cats on my car.

Yes I definitely agree with you on the A/F facts. I 'd like to put a bung in the down pipe but it's location makes it very very difficult.

[Linh]

I 'd like to put a bung in the down pipe but it's location makes it very very difficult.


How is it difficult ? Just drill and weld a flange onto your exhaust pipe just before the first CAT. Don't weld it to the exhaust runner because you want to record a/f ratio from all cylinders.

[coolcarlskic43]

Originally posted by Linh
How is it difficult ? Just drill and weld a flange onto your exhaust pipe just before the first CAT. Don't weld it to the exhaust runner because you want to record a/f ratio from all cylinders. Trust me!There's no room to get a drill in the space between the firewall and the cat,I'd have to take down the downpipe to do it for easy access which I guess is no big deal.

[Josh R]

I've found that on supercharged cars that an A/F ratio of 11.8.1 to no higher than 12.5.1 is the range needed. I like to see the A/F ratio go richer during the last 800 RPM's to redline as a safety measure.

I've also found that NA cars like to run 13.5.1 to no higher than 14.1 for a A/F ratio. The rule of thumb for NA cars is "Leaner is Meaner" For chip tuners this means add timing and pull fuel for NA cars. For SC cars its the exact opposite add fuel pull timing. If any of you are running a pulley that is effectively overdriving the supercharger and your AFR is in the teens you need to seriously get the chip reworked for more fuel, your in danger of catastrophic failure.

[Pagz]

mine runs 13.5 - 14.3.......this is looking alittle high for the 23K then?????,my car was standard when i had this run,(with no cat)so im guessing there is an engine sensor fault or somthing!?!?
maybe mass or O2 sensor....

i hope not cos iv just replaced almost every part on the car in the last 4 months LOL..... :p

[Josh R]

How did you measure the AFR? If you are measuring the AFR while cruising then yes your car will show stoichiometric readings. Now under full throttle conditions your car should be in the low 12's.

[coolcarlskic43]

Originally posted by coolcarlskic43
Here are my results.I'm dissappointed.

http://img155.echo.cx/img155/8629/icsdynoc558tq.jpg (http://www.imageshack.us) Best was 275.91whp and 287.72 ftlbs TQ hard to see.

Now don't get me wrng.The car does have a tremendous amt of pwr but my concern is the AF.I do have 4 cats on the car but the butt dyno tells me that it's possible that the A/F are inaccurate when done behind the cats.I'm still trying to figure out why the whp #'s are lower than the 284 -294 whp I expected.My friends 1999 E55 did 294whp and 301ftlbs TQ.It's a dilemna for me right now.Anybody have any thoughts? here are the new #'s Here it is:
http://img93.echo.cx/img93/8250/scan00068fc.jpg (http://www.imageshack.us)
http://img93.echo.cx/img93/5288/scan00070gt.jpg (http://www.imageshack.us) 293whp 307TQ