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Old 06-11-2011, 04:39 PM   #51
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^ And no, I'm not being a smartass. I'm glad stealthfi gave a comprehensive explanation of the differences between AMM/MAF & MAP.
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Old 06-12-2011, 04:11 AM   #52
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If you know the density then you know the oxy content. If the air is less dense from humidity, temp or altitude an amm will see it.
Why have most if not all OEMs gone to amm/maf if map/speed density is so good?
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Old 06-12-2011, 12:42 PM   #53
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If you know the density then you know the oxy content.
incorrect. The 'density' of the air is affected and determined by its temperature, the ambient altitude, as well as the relative humidity. An AMM or MAF sensor does not and cannot precisely determine which of those three factors are making the air be the density it is that the AMM/MAF is reading. The AMM/MAF is only taking a calculated reading based on a 'temp gradient/energy used to maintain a certain temp at the hot wire/hot film' to come up with a air flow volume number that the ECU can use to determine fuel metering decisions.

NONE of that can be construed as an actual reading of the oxygen content. The AMM/MAF is ONLY trying to measure the total amount of air that is passing past its sensor. Any supposed calculation of actual OXYGEN being passed through is done via guessing that the air passing through contains XX% of oxygen.



....PLEASE!......get over the delusion that an air mass meter or a mass air flow sensor reads oxygen content. They DON'T!!!!!! An AMM/MAF has no way to measure oxygen content. period. end. of. story.


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If the air is less dense from humidity, temp or altitude an amm will see it.
hmmm: with higher relative humidity, the air is denser. With higher ambient temperatures, the air is less dense. With higher altitudes, the air is less dense.

Kinda hard for a sensor that uses an 'energy required to keep a wire or section of film at a certain temperature as air flows over it' reading to come up with the determination as the WHICH of the three factors affecting density is causing the reading the sensor is producing.

Actually it doesn't. What it DOES do, is this: the AMM/MAF gets its reading, then sends that data to the ECU. The ECU uses that info, along with its other input signals, to compare all those data signals to the stored look up tables of data from lab work measurements on running motors....or simulator runs....and THEN, make fuel metering decisions.

What the AMM/MAF sends to the ECU is only one of the inputs the ECU uses to determine fuel metering.

Sensor readings do not represent exact, precise measurements. They are close approximations. What the sensor readings do is give the ECU info to compare to the look up tables, and then decide what to do. It's the man-months or man-years of data acquisition and look up table compilation that makes it possible for the ECU to be able to decide certain things based on the input data signals it gets.

The lab work/sim work narrows down the parameters to sizes that the ECU can then use to make fairly accurate decisions.

WHICH, is why, when people start modifying their motors, they have changed the overall parameters of the engine's performance envelope, thusly affecting and possibly reducing the accuracy of the decisions the ECU makes.

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Why have most if not all OEMs gone to amm/maf if map/speed density is so good?
good or bad; better or worse; not always the why. Cost is one factor. Objectives for a particular system/ motor being used on are other reasons for the choices the MFR makes.

Luft and Druck are the two approaches to EFI the MFRs have. They have their own reasons for which one they choose.

Both have advantages; both have shortcomings.
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Old 06-12-2011, 01:25 PM   #54
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Most modern engines have MAF's AND intake air temp and manifold pressure sensors. OEM's will stick every sensor they can on there because OE applications see a HUGE range of conditions and the system needs to be able to compensate and meet strict emissions requirements.
Completely different approach to some ancient LH.

Let me know when Motec, Pectel, ProEFI, Wolf, Haltech, AEM, Link or Vipec release a system dedicated for use with a MAF.
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Old 06-12-2011, 03:57 PM   #55
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The IPD cam is more aggressive/larger than the V cam... That should make you think it will NOT improve low rpm performance.
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Old 06-12-2011, 04:40 PM   #56
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I never said an amm could tell you WHY air is more or less dense. It measures density, not the factors that change it. If you think a maf will not altitude compensate you are nuts.
Sorry this has gone of track
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Old 06-13-2011, 02:57 PM   #57
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The IPD cam is more aggressive/larger than the V cam... That should make you think it will NOT improve low rpm performance.
I think about LSA and the IPD is more large... ( 112 deg vs 109 ), so I think it'll be a little bit more "full" at low-end...
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Old 06-13-2011, 03:06 PM   #58
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I just try today the +3 ignition timing, and it feel better... I'll see what's happen after more driving...!
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Old 06-28-2011, 10:01 AM   #59
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So, update time :

I've installed the IPD Turbo cam and drove it 1200kms. My setup is exactly the same as with the "V" cam. What's happend?

My car have now a very nice torque from 1200 to 2500 RPM, and after that, pulls like hell to 6000+ RPM !!! I can drive it in 5th gear in the city without any hesitation, and I feel my motor is ok. And also in the mid-range, it revs very happily and fast!

It's a very huge improvment!!!

Don't spend your time and money, buy the IPD Turbo cam!
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Old 06-28-2011, 11:27 AM   #60
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Old 06-28-2011, 12:34 PM   #61
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for sure!!!
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Old 08-08-2011, 03:48 PM   #62
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Hi,

I am testing the M cam from a b230f in my 230FT with 531 head... and TLAO Chips. (the small dual pattern cam known in US as f cam I think)

The intention is to create a well driveable car with very moderate mods and use a volvo cam with a dual pattern disign with the strong side at the exhaust. The t cam i have never driven in my system with the 531 head and T3 charger.
Well...so far I think compared to the V-cam I lost some torgue at low end (over 2000 rpm). But some people are different opinion about the m cam. I think I am the first one who drives it in a combination with 531 and t3 charger? The V cam is a beast behind 3200 rpm no doubt with the right setup over 6000 and more...

So far I have to play a little bit with other mods and then I can say more about the M-Cam.

I think pretty low end depends on more than only cam specs...or advancing a cam and so on...
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Old 08-08-2011, 04:06 PM   #63
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I've used the "M" cam also. For me, it was far better then the "T". But I've had the stock 13c turbo and a ported 530 head...
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Old 08-08-2011, 06:30 PM   #64
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That's great Roy! Glad you are enjoying the cam. I am using the enem V15 turbo cam with my B21FT. The powerband you describe is how my 82 turbo runs as well. It has plenty of useful low rpm power. The boost is useful but not powerful around 2500 rpm. Then all hell breaks loose from 3300-3500rpm to 6800rpm redline.

I think what people forget is that the IPD cam is based on the Unitek Phase One which is based on the enem V15. This is a first level street performance cam thus the phase one name. It runs smooth at idle and you can easily pass emissions. The 256 duration is the same as the Volvo B cam so it's not anything radical at all.
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Old 08-08-2011, 09:15 PM   #65
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For what it's worth, my 1990 745T runs an IPD Turbo cam, and the 530 head has been shaved .020 so the compression ratio should be around 9.1:1. I also live at 3000ft. I did notice a loss of low end torque compared to the T cam and the head with nothing taken off. I have an adjustable cam gear though, I still need to play around with the advance, hopefully I can get some of that low end back.

Also with my K-Jet B23E H cam 244, I can get away with a huge amount of ignition advance with 98 octane fuel at this altitude. When I head down towards sea level I have to be careful to avoid giving it much throttle below 3000 rpm or it will ping.
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Old 08-08-2011, 09:15 PM   #66
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Old 10-05-2011, 03:47 PM   #67
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Quote:
Originally Posted by Roy 940 View Post
So, update time :

I've installed the IPD Turbo cam and drove it 1200kms. My setup is exactly the same as with the "V" cam. What's happend?

My car have now a very nice torque from 1200 to 2500 RPM, and after that, pulls like hell to 6000+ RPM !!! I can drive it in 5th gear in the city without any hesitation, and I feel my motor is ok. And also in the mid-range, it revs very happily and fast!

It's a very huge improvment!!!

Don't spend your time and money, buy the IPD Turbo cam!
Sounds good to me.
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Old 10-07-2011, 02:27 AM   #68
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And I've tried also the different timing setup, and now when the cam is retarded 4 deg, my car have a lot of low end torque, and pulls far better from mid to high revs!!! I'm sure now with the Nathan Intake and it's shorter runners, I've find the best setup! So I'll let the IPD T cam for a while in my car!
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Old 02-25-2014, 04:43 AM   #69
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Quote:
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And I've tried also the different timing setup, and now when the cam is retarded 4 deg, my car have a lot of low end torque, and pulls far better from mid to high revs!!! I'm sure now with the Nathan Intake and it's shorter runners, I've find the best setup! So I'll let the IPD T cam for a while in my car!

Roy why you change the IPD to RSI? I drive V now with -4 regresed and it pulls good but after 3000, when i put IPD it will be better?
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Old 02-25-2014, 01:41 PM   #70
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The RSI Stage 2 is a far more aggressive cam over the IPD, but with a nice power band also. It's for me the best combo with my setup...

In my car, the IPD cam was better as the V, so I think you'll have a nice upgrade if you install it...
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Old 02-26-2014, 05:38 PM   #71
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This is so beautiful about turbobricks....

Someone responds on a three year old discussion and within a day he gets an answer from the same guy who posted the last post three years ago...as if it was yesterday!
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