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Just got my car dynoed at Midnight Performance in Sacramento, CA. Some interesting results…

My car is a Discovery Automotive Alien Tech III package. SS headers, stock cats, X-pipe , SS cans, AA CAI and Discovery Auto Velocity stacks…The other stuff on my car can be seen at the D/A web site under eye candy…J

So far after 1000 plus miles the car has been great…

I did not want the K&N filters in my stock air boxes so I asked Bill to keep the stock air filter…Apparently that turned out to be a big mistake…

My first two dyno runs were not good. Max RWHP 343 and Max Torque at 303. Both runs were +/- one HP…and the car was running slightly rich…

Warren the owner of the shop asked me what type of air filter was I running? I told him stock paper elements…He just shook his head and said that they were very restrictive…I said lets do some more runs with the paper filter elements out…Good recommendation…

With the stock paper out and nothing in the box the car pulled 358 RWHP and 314 Torque and these were on runs with out much cool down and the results were within less than one HP of each other…And that is not the best part…

Check out the HP and Torque difference…

RPM, Torque paper, (Torque open box), HP paper (HP open box)

2500rpm, 260, (315), 125, (150)
3000rpm, 283, (300), 165, (165)
3500rpm, 290, (300), 195, (197)
4000rpm, 290, (300), 223, (229)

Check out how the Torque increased by at least 55 ft/lbs at 2500rpm w/o the air filter.

Could this be how we lost our lost torque from 2000rpm to 3500rpm from the header install?

On top of all of this my A/F ratio increased by about a half of point leaner across the board…

RPM, A/F with paper, (A/F open box)

2.5K to 3.5K rpm, 14.8 to 13.1, (14.5 to 14.0)
4K to 5.5K rpm, 13.2 to 13.4, (13.7 to 13.8)
6K to 7K rpm, 13.4 to 12.6, (13.4 to 12.9)

I am going to stick some K&Ns in and re dyno in two weeks…

Thoughts?

Mark
 

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wow Mark, that is really surprising. I wouldn't have expected the filters to cause any measurable losses. really interesting.

We all seem to be in a similar range of 355-360whp. I have the dinan cai's, which i doubt add much hp, but are probably similar to k&n's in the stock boxes with the AA intake tubes. I'm still not seeing any major gains from the stacks, maybe 5hp, and perhaps a little torque loss.
Mike
 

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drallen said:
Just got my car dynoed at Midnight Performance in Sacramento, CA. Some interesting results…

My car is a Discovery Automotive Alien Tech III package. SS headers, stock cats, X-pipe , SS cans, AA CAI and Discovery Auto Velocity stacks…The other stuff on my car can be seen at the D/A web site under eye candy…J

So far after 1000 plus miles the car has been great…

I did not want the K&N filters in my stock air boxes so I asked Bill to keep the stock air filter…Apparently that turned out to be a big mistake…

My first two dyno runs were not good. Max RWHP 343 and Max Torque at 303. Both runs were +/- one HP…and the car was running slightly rich…

Warren the owner of the shop asked me what type of air filter was I running? I told him stock paper elements…He just shook his head and said that they were very restrictive…I said lets do some more runs with the paper filter elements out…Good recommendation…

With the stock paper out and nothing in the box the car pulled 358 RWHP and 314 Torque and these were on runs with out much cool down and the results were within less than one HP of each other…And that is not the best part…

Check out the HP and Torque difference…

RPM, Torque paper, (Torque open box), HP paper (HP open box)

2500rpm, 260, (315), 125, (150)
3000rpm, 283, (300), 165, (165)
3500rpm, 290, (300), 195, (197)
4000rpm, 290, (300), 223, (229)

Check out how the Torque increased by at least 55 ft/lbs at 2500rpm w/o the air filter.

Could this be how we lost our lost torque from 2000rpm to 3500rpm from the header install?

On top of all of this my A/F ratio increased by about a half of point leaner across the board…

RPM, A/F with paper, (A/F open box)

2.5K to 3.5K rpm, 14.8 to 13.1, (14.5 to 14.0)
4K to 5.5K rpm, 13.2 to 13.4, (13.7 to 13.8)
6K to 7K rpm, 13.4 to 12.6, (13.4 to 12.9)

I am going to stick some K&Ns in and re dyno in two weeks…

Thoughts?

Mark

What did you think of Midnight Performance? Warren is a good guy.
 

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drallen said:
Warren the owner of the shop asked me what type of air filter was I running? I told him stock paper elements…He just shook his head and said that they were very restrictive…I said lets do some more runs with the paper filter elements out…Good recommendation…

With the stock paper out and nothing in the box the car pulled 358 RWHP and 314 Torque and these were on runs with out much cool down and the results were within less than one HP of each other…And that is not the best part…

Check out the HP and Torque difference…



On top of all of this my A/F ratio increased by about a half of point leaner across the board…

RPM, A/F with paper, (A/F open box)

2.5K to 3.5K rpm, 14.8 to 13.1, (14.5 to 14.0)
4K to 5.5K rpm, 13.2 to 13.4, (13.7 to 13.8)
6K to 7K rpm, 13.4 to 12.6, (13.4 to 12.9)

I am going to stick some K&Ns in and re dyno in two weeks…

Thoughts?

Mark
Depending on the accuracy of the probe reading the AF, I think you are still a little lean. You want closer to low 12's at 6-7k rpm with a corresponding adjustment across the board. On the other hand, your numbers look good. If you can have another program run about .5 richer all the way across, you could compare.
Regards,
Jerry
 

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Humm, might run out and buy are pair of K&N filters (which I've run in all my prev. cars without issue).
 

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gsfent said:
Depending on the accuracy of the probe reading the AF, I think you are still a little lean. You want closer to low 12's at 6-7k rpm with a corresponding adjustment across the board. On the other hand, your numbers look good. If you can have another program run about .5 richer all the way across, you could compare.
Regards,
Jerry

Yes, but are those numbers being read from the tailpipe or the header (engine)? That will make a 1 point diffrence right there.

I thought that 13 was safe and almost perfect... 12 is a little rich...?

Right now my A/F at:

3000 - 5500rpm ~ approx 12.5:1
6000rpm ~ 12.25:1
6500rpm ~ 12:1
7000rpm ~ 11.75:1
7200rpm ~ 11.75:1
 

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drallen said:
I am going to stick some K&Ns in and re dyno in two weeks…

Thoughts?

Mark

Mark,

We're these NEW OEM filters, if not, how much millage on them? My OEM filters at 15K miles 'look' new, but I used new filters for my baseline dyno test.

Philip
 

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MPRESIV said:
Mark, which K&N filters do you use?

Where can I get them?
If I read the post correctly, he has not posted the results with K&N filters. Only the stock boxes with and without the stock filters. The jury is still out on if the K&N filter elements will make a significant difference. Sounds like those results are coming.
 

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Hey Mark,

I didn't put the K & N 's in for fear of fouling the mafs.

Semi Old stock filters flow badly because they WORK. They have caught everything.

The idea is to replace them REGULARLY.

Far more regularly then service intervals, especially if you are in a dusty area.

I would love to see the dyno comparison with a NEW Stock filter Vs A New K & N.

I would expect them to be the same. The difference being as the paper one gets older it rapidly looses its flow, but the K & N maintains its flow.

Of course the arguement is, at what cost? Meaning that the K & N allows more through, including dirt.

cherrsagai
 

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I found the same thing with the K&N and without. They did foul my MAFS, so I replaced the MAFS with new ones and I placed the K&N in but, I cleaned all the filter oil off the filter. I then ran a high pressure air hose through them to dry them and put them back in. That was by far the best thing I did. I agree, maybe they don't clean the air going in as well as they should, but then again I don't drive my M5 everyday.

The BMW stock filters lose their effectiveness after only 5000 miles in some cases. Here in our service dept. we see cars with 3500 miles and the stock fliters are shot. I would go with K&N and just remove the K&N oil.

Good thread! :byee55amg
 

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M5manny said:
I found the same thing with the K&N and without. They did foul my MAFS, so I replaced the MAFS with new ones and I placed the K&N in but, I cleaned all the filter oil off the filter. I then ran a high pressure air hose through them to dry them and put them back in. That was by far the best thing I did. I agree, maybe they don't clean the air going in as well as they should, but then again I don't drive my M5 everyday.

The BMW stock filters lose their effectiveness after only 5000 miles in some cases. Here in our service dept. we see cars with 3500 miles and the stock fliters are shot. I would go with K&N and just remove the K&N oil.

Good thread! :byee55amg
I thought removing the oil from a K&N filter pretty much renders it useless.
 

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Discussion Starter #13
Thanks for all the replys...I am dying here because I have to work and not reply... :crying:

The OEM filters only had about 3000 miles on them.

Chad...with the filters in I stayed pretty close to 13.4 A/F after 2750 rpm and only dipped below 13.0 after 6500 rpm. With the filters out, I hovered around 13.7 and again dropped below 13.0 at 6500 rpm. A tail pipe sniffer was used...so does that mean I am running richer and safer?

I'll tell you one thing...the car sure sounds cool, all spooled up on the dyno... :1:

I'll try to get in on Monday with a new OEM filter and a new K&N filter...I am now kind of curious to find out what happens...

So is it looking like I am lean?...Good thing I live at 5000 feet...
:wroom:

Mark
 

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SACM5 said:
I thought removing the oil from a K&N filter pretty much renders it useless.
They'll still keep the large gravel and random bird out of the engine!
Mike
 

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drallen said:
Thanks for all the replys...I am dying here because I have to work and not reply... :crying:

The OEM filters only had about 3000 miles on them.

Chad...with the filters in I stayed pretty close to 13.4 A/F after 2750 rpm and only dipped below 13.0 after 6500 rpm. With the filters out, I hovered around 13.7 and again dropped below 13.0 at 6500 rpm. A tail pipe sniffer was used...so does that mean I am running richer and safer?

I'll tell you one thing...the car sure sounds cool, all spooled up on the dyno... :1:

I'll try to get in on Monday with a new OEM filter and a new K&N filter...I am now kind of curious to find out what happens...

So is it looking like I am lean?...Good thing I live at 5000 feet...
:wroom:

Mark
My understanding is that when you measure the A/F at the tailpipe you can subtract 1 point from the reading because it is going to be reading 1 point leaner than it really is. So anotherwards if you are measuring at the tail pipe and get a 13 you are really at a 12. If you feel that 13:1 A/F is safe then you woudl want to be showing 14:1 across the board on that particular system (at the tailpipe). Hopefully that makes sense.

Warren told me they had two diffrent cars both had bungs in place to measure A/F from the header pipe. They did seperate runs with both cars and found it to be consistent that the readings at the engine were 1 point richer than the readings at the tail pipe. Warren said it is would be safe (in his opinion) to figure .5 to 1 point leaner at the tailpipe.
 

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mottati said:
They'll still keep the large gravel and random bird out of the engine!
Mike

LOL. This is true. Guess you are in good shape then. ouich
 

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mottati said:
They'll still keep the large gravel and random bird out of the engine!
Mike

What filters do they have fitted in our Dinan CAI's?
 

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SACM5 said:
I thought removing the oil from a K&N filter pretty much renders it useless.

My understanding and experience is that it does not. I have ben running them this way for about 8000 miles and no problem with the MAFS. There's no residue inside the MAFS which we have seen to be the cause of them going bad.
 

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M5manny said:
My understanding and experience is that it does not. I have ben running them this way for about 8000 miles and no problem with the MAFS. There's no residue inside the MAFS which we have seen to be the cause of them going bad.

Oh no, I understand that the oil residue from the K&N messes with the MAF's. I just meant that the oil treatment you are supposed to use to treat the K&N air filter is an important part of the equation in terms of how that filter is able to do a good job filtering junk out of the air.

When you clean the filter and dont reapply the oil it seems like the filter woudl not be doing its job. Yes you will get better flow, yes your MAF's will be okay, but I woudl think you are going to intake a bunch of crap into the motor. Hey it might re-bore the thing for you... Then all you need are some bigger forged pistons and you are in business.
 

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Well, without the oil nothing will collect tiny sand dust. I don´t think it is any good for the cylinder walls to get sanded...

David
 
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