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Discussion Starter #1
i had a dyno today and the air to fuel ratio was 15:1. Not to mention that the dyno result were 328hp and 298 torque(yes it's an s2). there is no doubt that my torque number have gone way down since i got the s2. i dynoed one time at 352hp and 308 torque. but dynoed at 328 and 316 with just the s1. someone help me understand whats going on.
 

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i have a hard time beliving that. How does the car feel? Stronger than before? That afr is lean, dinan is typically conservative, which is rich at high load. The guys at powerchip can usually gain 8-12 hp on an s2 by leaning it out a bit, i believe. Is this the same dyno you ran on before?
 

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Discussion Starter #3 (Edited)
no it's not the same dyno. yes the car feels a little stronger but i can also feel the torque loss. it was also dynoed in 4th with no fuses pulled(not my fault). the new dinan clutch feels slippery. it doesnt sound right to me. these are two runs done on the same dyno. it doesnt matter what dyno i went to my car shouldnt lose torque.

run 1 328hp 316torque (S1)
run 2 347-352hp 298-308 torque (S2)

however the a/f ratio cant be good. can it be fixed? i know they dont really do anything but download the dinan overwrite program.

i was told that lean means that the motor is getting the right amount of fuel and cylinders could detonate and that running richer would increase horsepower.
 

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Go to Buford BMW and tell you want a refund.
 

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I had asked wayne at powerchip about the afr from the dyno shop after getting my car dyno'd after the headers. He said there are way too many variables to getting an acurate afr on a dyno, from the position of the tail pipe sniffer to basic maintanance of the dyno and afr analyzer, so i wouln't put too much weight on that. If the clutch is slipping, that could certainly be a factor. Not removing the fuses is also a problem, as most M5's that i've seen dynoed cut back on power at the top end as the dsc goes crazy with the rear wheels at 120+mph while the fronts are stationary.

According to all the dinan literature, your s2 should have more torque everywhere, not less. On my car, i lost about 10hp at 3k rpm with the headers, but i feel it's something i can barely feel, and the mid-top end gains more than make up for it. I wonder if there's something else not right on your car, like a mafs, cps or??

If I were you, first thing i'd do is go to another dyno shop, if you still get crappy numbers, go back to your dinan people.
Mike

bluestreak said:
no it's not the same dyno. yes the car feels a little stronger but i can also feel the torque loss. it was also dynoed in 4th with no fuses pulled(not my fault). the new dinan clutch feels slippery. it doesnt sound right to me. these are two runs done on the same dyno. it doesnt matter what dyno i went to my car shouldnt lose torque.

run 1 328hp 316torque (S1)
run 2 347-352hp 298-308 torque (S2)

however the a/f ratio cant be good. can it be fixed? i know they dont really do anything but download the dinan overwrite program.
 

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Discussion Starter #6 (Edited)
i considered getting rid of my m5 today for the first time because this is way to frustrating for the money being spent. i was going to get the dinan supercharger but at the rate im gaining power ill end up with maybe 400 at the rear wheels even with it.


we changed the position of the tailpipe sniffer and they even connected to the computer module that is used by emmisions, there cant be any error in that. the readings were the exact same. i will admit that the guys who dynoed my car had no clue about how to dyno and m5. they were used to dynoing 350z's but still i think those results are bad. the car feels like it want to accelerate like mad then it hits like an 85% sprint at wot. it doesnt feel or sound right to me.
 

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bluestreak said:
no it's not the same dyno. yes the car feels a little stronger but i can also feel the torque loss. it was also dynoed in 4th with no fuses pulled(not my fault). the new dinan clutch feels slippery. it doesnt sound right to me. these are two runs done on the same dyno. it doesnt matter what dyno i went to my car shouldnt lose torque.

run 1 328hp 316torque (S1)
run 2 347-352hp 298-308 torque (S2)

however the a/f ratio cant be good. can it be fixed? i know they dont really do anything but download the dinan overwrite program.
Assuming the dyno is measuring correctly, that is way lean at WOT. The S2 adds the Dinan headers. It is almost as if someone forgot to reprogram the ECU to account for the headers. At part throttle you may not be doing much harm, but at WOT you want to be in the 12's. Air leaks usually cause a rich condition, so have someone check your ECU.
Regards
Jerry
 

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bluestreak said:
i considered getting rid of my m5 today for the first time because this is way to frustrating for the money being spent. i was going to get the dinan supercharger but at the rate im gaining power ill end up with maybe 400 at the rear wheels even with it.
The real potential problem with the M5 is all of the little electronic sensors and obd2 stuff. If everything isn't working at 100% the car will be down on power. Do you have a code reader? Might be worth checking if there are any fault codes stored.
Mike
 

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Discussion Starter #9 (Edited)
i really just need to go to the track and see what it does. if my 1/4 mile times and traps are slow then ill be major league pissed. im only in the minors right now, AAA league. but thanks for the inpu guys and any further info is greatly appreciated.
 

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"I had asked wayne at powerchip about the afr from the dyno shop after getting my car dyno'd after the headers. He said there are way too many variables to getting an acurate afr on a dyno, from the position of the tail pipe sniffer to basic maintanance of the dyno and afr analyzer, so i wouln't put too much weight on"

In all reality,I just don't and cannot accept this statement.
 

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bluestreak said:
i really just need to go to the track and see what it does. if my 1/4 mile times and traps are slow then ill be major league pissed. im only in the minors right now, AAA league. but thanks for the inpu guys and any further info is greatly appreciated.
I would NOT run the car at the drag strip with 15:1 AFR. You stand a good chance of burning/holing a piston. Major league bucks (not AAA) to rebuild and S62. Confirm the car is runing correctly before tracking it. Just IMHO.
Regards,
Jerry
 

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Discussion Starter #12
gsfent said:
I would NOT run the car at the drag strip with 15:1 AFR. You stand a good chance of burning/holing a piston. Major league bucks (not AAA) to rebuild and S62. Confirm the car is runing correctly before tracking it. Just IMHO.
Regards,
Jerry

will do/ thanks
 

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Depending on calorific value of the fuel and some other detailed factors stoichiometric is around 14.75:1, you should only see stoi on light throttle openings when in closed loop mode. 15:1 is leaner than stoi and frankly at WOT is way way too lean, dangerously so. At WOT you should be around 13:1 maybe 13.5:1 depending on fuel and burn characteristics. A quick kludge might be to increase fuel pressure a little which will cover the lean areas, it's a bit of blkunt instrument because it will increase the fuel delivery everywhere. Really the map needs revision. Remember that fuel delivery increases by the quare root of increased pressure...

You chould consider feedback from a wide band Lambda rather than a CO meter.

Dave
 

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These cars run in the 14.5 AF range while idling and cruising in closed loop however as all have stated when the car is under load, particularly heavy load such as on the dyno you should be able to see the car go out of closed loop into open loop and the AF ratios depending on the tuner should fall immediately into the mid to low 12’s…..

In the case of moderate Supercharged applications I target 12.0 AF and the case of the more extreme Supercharged cars I target 11.8 AF……. I play a more conservative game of chess…..but then we drive home every night too

Now back to your car. I would immediately look in to it…. If the car had been on a dyno with me present the dyno would have been “TERMINATED” before the pull was completed.; far too lean for my comfort level.

Now the question is why……did they fail to reprogram the DME…maybe……. is the tuning they installed simply not up to the demands of the modifications…..very possible. Recent history has shown that those with the conversions you discuss found their cars to be very lean too. As the result PowerChip worked on these cars and brought them back to life and help to insure that they would have a long one.

I too highly recommend that you do not fail to correct this situation and furthermore I suggest that if you go through another dyno pull that you become the “PuppetMaster” of the process. You tell them when to begin sampling…meaning at what RPM…… typically I like to see at least one low RPM sampling 2000 RPM up to lets say 6500 RPM and then the remaining beginning around 2800-3000 RPM. With a final RPM between 6500 and 7000 depending on whether she is still making power. This is why one needs to be aware of what is going on during the dyno pull……. Lets say you request a 3000-7000 RPM sampling but the operator sees that at 6500 RPM she is falling on her face….there is NO sense in simply twisting her tighter……it is most important to know and share what are the points that the pull should be terminated…for example…..loss of tach signal…….AF ratios out of range….. power loss….etc…..the dyno is simply a data collection tool….not a miracle worker….

Remember that it all happens very fast and the person tossing the hammer down can be overcome by the moment and simply “Let Her Rip”……. I have seen some terrible results…… I love and hate dynos……… however if used correctly they are what they are….. a wonderful place to tune and to confirm condition….. a terrible place to leave parts on the ground.

Shadowman
 

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Discussion Starter #15 (Edited)
OK so I call my Dinan guy today to ask about the A/F ratio.
Before I tell you what he said let me first say this.

[email protected]#@[email protected]#%&%&*%#[email protected][email protected]!$!$^%#$^

Ok now that I have vented my frustration let me tell you waht he said. "Did you do it (test the A/F) on the road or on the dyno" "Those things cant dyno your car" (second time I've heard that exact same thing for two different subjects) "15:1 is fine and actually is a little bit RICH, 14:1 is perfect and you'll never get perfect, those little fans they have blowing into you engine arent enough, you shouold see Dinan's dyno he has this gargatuan turbine that give the real affect of driving on the road. M5's have a special sensor on the front that measures the air flow and if your on the dyno with those little fans then the air cant be flowing right and the car thinks it's about to blow up"


Once again I say [email protected]#$!%%@@$^@$!#[email protected]!#%^

So if the car thought it was about to blow up and therefore the ratio was 15: the why is that a good A/F ratio? It just doesnt add up. Luckily we have two Dinan dealers here in the ATL and I guess the other one will be the one I go to from now on. Im so pissed right now.

On the positive side I did stay even with a Z06 on saturday right before the dyno. was going to a 350Z meet in a town I had never been to so wasnt too willing to go busting around everywhere. We only got up to about 90 but I was catching up slowly (might be wishful thinking but was not losing ground for sure).
 

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As I shared 14.1 is fine when in closed loop cruising..in fact a bit rich because typically it will be closer to 14.5......however not under WOT when the gal goes in to open loop....... they know this.....however maybe the person you chatted with did not....... I would have been saying ^%%%&9HYFFCKCKCFCCNMIJ"OIH:YFD....too because I would have felt like my chain was being pulled........

Sooner or later you will have to decide who to listen to and follow the direction to it's end....... all I can say is that if I were told that 15.1 was fine when pulling on a dyno this is not who I would be listening too..... just my opinion.....as for super fans........ he shared the brand......did not sound like Dinan so I would assume that others have similar fans too....... remember that Dinan no different than www.Discovery-Automotive.com is simply another tuner facility........ and all of our opinions are not the same.

Take care

Shadowman

bluestreak said:
OK so I call my Dinan guy today to ask about the A/F ratio.
Before I tell you what he said let me first say this.

[email protected]#@[email protected]#%&%&*%#[email protected][email protected]!$!$^%#$^

Ok now that I have vented my frustration let me tell you waht he said. "Did you do it (test the A/F) on the road or on the dyno" "Those things cant dyno your car" (second time I've heard that exact same thing for two different subjects) "15:1 is fine and actually is a little bit RICH, 14:1 is perfect and you'll never get perfect, those little fans they have blowing into you engine arent enough, you shouold see Dinan's dyno he has this gargatuan turbine that give the real affect of driving on the road. M5's have a special sensor on the front that measures the air flow and if your on the dyno with those little fans then the air cant be flowing right and the car thinks it's about to blow up"


Once again I say [email protected]#$!%%@@$^@$!#[email protected]!#%^

So if the car thought it was about to blow up and therefore the ratio was 15: the why is that a good A/F ratio? It just doesnt add up. Luckily we have two Dinan dealers here in the ATL and I guess the other one will be the one I go to from now on. Im so pissed right now.

On the positive side I did stay even with a Z06 on saturday right before the dyno. was going to a 350Z meet in a town I had never been to so wasnt too willing to go busting around everywhere. We only got up to about 90 but I was catching up slowly (might be wishful thinking but was not losing ground for sure).
 

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bluestreak said:
OK so I call my Dinan guy today to ask about the A/F ratio.
Before I tell you what he said let me first say this.

[email protected]#@[email protected]#%&%&*%#[email protected][email protected]!$!$^%#$^

Ok now that I have vented my frustration let me tell you waht he said. "Did you do it (test the A/F) on the road or on the dyno" "Those things cant dyno your car" (second time I've heard that exact same thing for two different subjects) "15:1 is fine and actually is a little bit RICH, 14:1 is perfect and you'll never get perfect, those little fans they have blowing into you engine arent enough, you shouold see Dinan's dyno he has this gargatuan turbine that give the real affect of driving on the road. M5's have a special sensor on the front that measures the air flow and if your on the dyno with those little fans then the air cant be flowing right and the car thinks it's about to blow up"


Once again I say [email protected]#$!%%@@$^@$!#[email protected]!#%^

So if the car thought it was about to blow up and therefore the ratio was 15: the why is that a good A/F ratio? It just doesnt add up. Luckily we have two Dinan dealers here in the ATL and I guess the other one will be the one I go to from now on. Im so pissed right now.

On the positive side I did stay even with a Z06 on saturday right before the dyno. was going to a 350Z meet in a town I had never been to so wasnt too willing to go busting around everywhere. We only got up to about 90 but I was catching up slowly (might be wishful thinking but was not losing ground for sure).
Your Dinan guy is a moron. If you listen to him, your motor will look like it was sent to RMS for service :confused3 . Listen to Shadowman, he builds fast cars as a living/hobby.

I did my dyno pulls on a dynojet dyno, and I can assure you there was nothing close to 15:1 on any pull. Pulls started at 2000rpm. I will have to dig out the runs, but I suspect that I started low 14's or high 13's and got down to low 12s/very high 11's on various pulls. Is the AF exact? Probably not, they use a sniffer in the tailpipe, but it should be pretty close. If anything, you want to run a little rich for safety and to compensate for the lack of air you will get at speed on the highway.

If you have a choice of Dinan dealers, try the other. Or better yet, call out to Morgan Hills, Ca. and ask to talk to someone about software for your car. I bet they tell you 15:1 is NOT the recommended AF for WOT.

There is something wrong with your setup. You have an S2 and have 328 hp at the wheels? My car, with only CAI, IATS and PC software pulled 323 at the wheels!! and with headers, I have 353 at the wheels. Your S2 has all that I have, plus bigger throttle bodies and bigger MAFS. No way you should only pull 328 hp.
Regards,
Jerry
 

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I just had a couple communications with PowerChip and like myself they have been watching this thread.

As I have shared before we do work closely together and they (PowerChip) has offered to ship you a portable AF meter that you can collect some real time data with and then forward it back so the tuning of your car can be determined. This is being offered to you at no cost....... let's call this a joint venture between PowerChip......BlueStreak......and Discovery Automotive.

I think that this would be a wonderful thing for you and could turn your gal in to the car you have been expecting through this process.

There is NO doubt that your HP and torque are being reduced with the AF's that you have shared.

Let me know directly or contact PowerChip (800) 495-0777 and ask for Joel and then between us we will assist with this situation.

Chat soon.

Shadowman


bluestreak said:
OK so I call my Dinan guy today to ask about the A/F ratio.
Before I tell you what he said let me first say this.

[email protected]#@[email protected]#%&%&*%#[email protected][email protected]!$!$^%#$^

Ok now that I have vented my frustration let me tell you waht he said. "Did you do it (test the A/F) on the road or on the dyno" "Those things cant dyno your car" (second time I've heard that exact same thing for two different subjects) "15:1 is fine and actually is a little bit RICH, 14:1 is perfect and you'll never get perfect, those little fans they have blowing into you engine arent enough, you shouold see Dinan's dyno he has this gargatuan turbine that give the real affect of driving on the road. M5's have a special sensor on the front that measures the air flow and if your on the dyno with those little fans then the air cant be flowing right and the car thinks it's about to blow up"


Once again I say [email protected]#$!%%@@$^@$!#[email protected]!#%^

So if the car thought it was about to blow up and therefore the ratio was 15: the why is that a good A/F ratio? It just doesnt add up. Luckily we have two Dinan dealers here in the ATL and I guess the other one will be the one I go to from now on. Im so pissed right now.

On the positive side I did stay even with a Z06 on saturday right before the dyno. was going to a 350Z meet in a town I had never been to so wasnt too willing to go busting around everywhere. We only got up to about 90 but I was catching up slowly (might be wishful thinking but was not losing ground for sure).
 

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shadowman said:
As I have shared before we do work closely together and they (PowerChip) has offered to ship you a portable AF meter that you can collect some real time data with and then forward it back so the tuning of your car can be determined. This is being offered to you at no cost....... let's call this a joint venture between PowerChip......BlueStreak......and Discovery Automotive.



Let me know directly or contact PowerChip (800) 495-0777 and ask for Joel and then between us we will assist with this situation.

Chat soon.

Shadowman
bluestreak

That is more than generous. As you can see in my sig, I have Powerchip software. What it does not say is that when I acquired my car it had Dinan software!!! Difference was night and day. And PC redid my ECU when I got my SS headers (from Bill). Dinan does a lot of things well, but this is one area where Powerchip is noticably better. Knowing what I know now, I would talk to Joel or Wayne about doing the Powerchip ECU upgrade with their money back guarantee and not even fool around with the Dinan setup. In over 4 years on this board, I think only ONE person ever returned the PC software. 'Nuff said.
Regards,
Jerry
 

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15:1 ratio is very lean, especially for a high compression motor. I wouldn't worry too much about damaging the engine as the sophisticated electronics seem to be so far doing a great job, hence your "feeling" of low power.

Just to show you how the ratios can get affected here's a plot of a/f on a baseline then with a CAI install, no software addition, straight air box swap. See the difference it creates, so I feel very positive you do not have the correct programming on your car and should get it re-flashed, that plus the fact that I pulled a 308 lb/ft as well on my 540.
 

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