M2 Engine, 2.5 liter

[irdave]

5 hours ago, ray_ said:

 

 

They breathe better

 

 

@jimk kindly pointed out to me that they only breathe better over 6k.  He couldn't see me because we were talking on the phone, but my smile was ear to ear.  Yes, please!  I'm shooting for the typical annual group buy in January...

 

Alberto, all, can enough information be gathered by just pulling the oil pan- to at least verify the rods and pistons?  I mean, tearing the engine down completely?

 

And I think you bought the manuals I was fishing for!

[ray_]

20 minutes ago, irdave said:

 

@jimk kindly pointed out to me that they only breathe better over 6k.  He couldn't see me because we were talking on the phone, but my smile was ear to ear.  Yes, please!  I'm shooting for the typical annual group buy in January...

 

Alberto, all, can enough information be gathered by just pulling the oil pan- to at least verify the rods and pistons?  I mean, tearing the engine down completely?

 

And I think you bought the manuals I was fishing for!

 

 

That's interesting. Jim should correspond with Ron to discuss the limiting factors of the AFM.

 

http://rongineer.com/maf.html

 

Anyway, 6k to 7500 is an interesting place to be

Edited May 10, 2020 by ray_

[jimk]

19 minutes ago, ray_ said:

That's interesting. 

I have direct comparison of air charge per cylinder with a car that is set up with one.  Unless the engine is rev'ed to high rpm, I cant see spending the money if the AFM is thrown into the neighbors pool.

Maybe with a 4.10 axle it't between 6-7.5k rpm all the time!

Edited May 10, 2020 by jimk

[irdave]

10 minutes ago, jimk said:

I have direct comparison of air charge per cylinder with a car that is set up with one.  Unless the engine is rev'ed to high rpm, I cant see spending the money if the AFM is thrown into the neighbors pool.

Maybe with a 4.10 axle it't between 6-7.5k rpm all the time!

 

For sure Jim is down for the MAF and ditching the AFM.  And apparently he doesn't have a 4.10, nor like to send it to 7, like, apparently you and me, Ray.

[ray_]

28 minutes ago, irdave said:

 

For sure Jim is down for the MAF and ditching the AFM.  And apparently he doesn't have a 4.10, nor like to send it to 7, like, apparently you and me, Ray.

 

 

I think there are a couple (allegedly almost) directly correlate-able dyno runs (not mine) floating around somewhere, thought I'm sure Jim is mostly right,

 

He was wrong once, as I recall, when he thought he was wrong but he was actually right

 

I'd still trade him straight across, his car for mine.

[Preyupy]

If it is a 2.5L they have to have put in a Evo crank with an 87mm stroke.  The piston pin to the top of the piston distance in that picture is way too big to be a  piston that would work with a 144mm con-rod and a 87mm stroke.  

[jimk]

14 hours ago, ray_ said:

I think there are a couple (allegedly almost) directly correlate-able dyno runs (not mine) floating around somewhere, thought I'm sure Jim is mostly right,

Mostly.

Here is a comparison of the OEM air box to a Carbon Fiber air box.  Both cars are engine controlled by Haltech Elite ECUs and info plotted directly from on road datalogs.

 

OEM was at 800-900 ft elev, CF car was in LA, CA (not Lower Alabama)

Both operated with coil per plug, sequential injection.

Both engines 2.3 L.  OEM box engine has Oregon regind cams, don't know what the CF box engine has but they are not OEM.

Both cars require injectors larger than OEM due to OEM injectors max out. (320 cc/min flow vs 240 cc/min OEM flow)

OEM air box car uses MAF, CF engine car uses MAP with proprietary sensing arrangement.

Plots are from 5K to 7K rpm WOT both cars.

 

OEM box plot shows a level ~0.7 grams/cyl air flow up to about 6K rpm where it begins to fall off. (Corrected air flow means the MAF curve was corrected internally by the ECU from the wideband sensor correction.)

 

CF box a level ~0.7 grams/cyl air flow flat out to 7k rpm.  (ECU calculates the air flow from the VE table with Wideband sensor correction.)

 

The OEM box is good enough for me.

 

The car with the CF box

Edited May 10, 2020 by jimk

[irdave]

But it's so sexy!

[ray_]

Wouldn't it take a bit of assumption to say the test correlates to 2.5L?

[swift53]

18 hours ago, irdave said:

 

@jimk kindly pointed out to me that they only breathe better over 6k.  He couldn't see me because we were talking on the phone, but my smile was ear to ear.  Yes, please!  I'm shooting for the typical annual group buy in January...

 

Alberto, all, can enough information be gathered by just pulling the oil pan- to at least verify the rods and pistons?  I mean, tearing the engine down completely?

 

And I think you bought the manuals I was fishing for!

 

Dave, no unfortunately got beaten by a day on the manuals, oh well.

On the engine topic, yes, good idea, will remove the oil pan and see what's there.

Will post pix.

 

Regards, Alberto

[jimk]

5 hours ago, ray_ said:

Wouldn't it take a bit of assumption to say the test correlates to 2.5L?

I wouldn't even guess.  You need to put in a modern ECU to get the data 

Edited May 10, 2020 by jimk

[ray_]

14 minutes ago, jimk said:

I wouldn't even guess.  You need to put in a modern ECU to get the data 

Good! So I can claim the cf box provides more benefit to the 2.5 and you can't specifically refute me.

 

??

[jimk]

8 minutes ago, ray_ said:

Good! So I can claim the cf box provides more benefit to the 2.5 and you can't specifically refute me.

 

??

On a 2.5 L the stock box would have more of a loss, at some lower rpm due to more air flow

[ray_]

1 hour ago, jimk said:

On a 2.5 L the stock box would have more of a loss, at some lower rpm due to more air flow

As you know, my final drive ratio mitigates that!