My Progress with Cipher (charts included)
Originally Posted by dovla
Silo, that dyno chart looks like from REV-UP engine!
And why the power fell below stock after 6k rpm - is that still an issue with the current MREV-xx version?
Hi Silo,
Yes, that is a REVUP engine in the link. It was the first generation MREV and yes, they lost a little on the top.
On a non-REVUP engine, MREV+ or MREV2 will produce good gains on the top end with no loss anywhwere on the curve.
On a REVUP engine, the MREV+ and MREV2 (with a 5/16" spacer) typically have no loss anywhere on the curve with very large upper midrange gains.
I hope this description isn't too confusing.
Yes, that is a REVUP engine in the link. It was the first generation MREV and yes, they lost a little on the top.
On a non-REVUP engine, MREV+ or MREV2 will produce good gains on the top end with no loss anywhwere on the curve.
On a REVUP engine, the MREV+ and MREV2 (with a 5/16" spacer) typically have no loss anywhere on the curve with very large upper midrange gains.
I hope this description isn't too confusing.
Last edited by Hydrazine; Sep 27, 2006 at 06:22 AM.
Tony... just wanted to ask you if you noticed in my first post, the difference between AFR bank 1 and 2. Do you typically see this with a stock Z, or do you think it might be due to the mrev2?
Not that its a big problem, but I'm curious.
If you address this it could help when designing mrev3
since if each cylinder is running how it should and getting the air it should, that equals much more power
Not that its a big problem, but I'm curious.
If you address this it could help when designing mrev3
since if each cylinder is running how it should and getting the air it should, that equals much more power
This is a common issue.
It has nothing to do with MREV2 or plenum mods. Bank one and bank two A/F often don't match. Totally stock, mild bolt ons, heavy bolt ons, or even FI. Bank one and two will often be biased to one side or the other.
Its frustrating to see because its difficult to say how/why they are different. Some cars will have bank one leaner. Some cars will have bank two leaner. Analysis of all the cipher data still doesn't give a clear answer as to why.
Bank one and two injector duty cycles can be identical but A/F's are still different.(this suggests its not ECU fuel flow control related)
Stock or modified plenums provide the same results. (this suggests its not plenum related)
It happens on revup and non revup engines. (this suggests its not engine class related)
Stock fuel rails can't be blamed because A/F trends are not consistant with expected pressure drop charecteristics of changing flow rates and A/F. And different cars will have different banks running leaner than the other. (this suggests its not fuel rail related)
Cam advance angles do not necessarily correspond the changes of bank A/F. Changes of cam angle do not follow changes of delta bank A/F. (This suggests it is not angle measurement related)
Bank sensors 1 and 2 were swapped over to the opposite bank to see if the sensors were causing the delta readings... but the results were the same. (This suggests its not sensor related)
The bank one/two difference's are real but its hard to say why.
The only thing left untested is the cam angle "sensor" variability but that won't be easy to test.
See Dovla's link to the related thread on G35driver.com for more information on the testing, discussions and analysis. Maybey you can take a hard look at your engine data and see if we missed anything.
It has nothing to do with MREV2 or plenum mods. Bank one and bank two A/F often don't match. Totally stock, mild bolt ons, heavy bolt ons, or even FI. Bank one and two will often be biased to one side or the other.
Its frustrating to see because its difficult to say how/why they are different. Some cars will have bank one leaner. Some cars will have bank two leaner. Analysis of all the cipher data still doesn't give a clear answer as to why.
Bank one and two injector duty cycles can be identical but A/F's are still different.(this suggests its not ECU fuel flow control related)
Stock or modified plenums provide the same results. (this suggests its not plenum related)
It happens on revup and non revup engines. (this suggests its not engine class related)
Stock fuel rails can't be blamed because A/F trends are not consistant with expected pressure drop charecteristics of changing flow rates and A/F. And different cars will have different banks running leaner than the other. (this suggests its not fuel rail related)
Cam advance angles do not necessarily correspond the changes of bank A/F. Changes of cam angle do not follow changes of delta bank A/F. (This suggests it is not angle measurement related)
Bank sensors 1 and 2 were swapped over to the opposite bank to see if the sensors were causing the delta readings... but the results were the same. (This suggests its not sensor related)
The bank one/two difference's are real but its hard to say why.
The only thing left untested is the cam angle "sensor" variability but that won't be easy to test.
See Dovla's link to the related thread on G35driver.com for more information on the testing, discussions and analysis. Maybey you can take a hard look at your engine data and see if we missed anything.
Last edited by Hydrazine; Sep 28, 2006 at 04:58 AM.
The reason may be that the throttle body is to one side of the motor. Momentum of incoming air makes it more available to one of the banks compared to the other. 
Dual TB setup like the vq35hr will be sweet... dual MAF sensor I'd assume too.
Dual TB setup like the vq35hr will be sweet... dual MAF sensor I'd assume too.
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Joined: Sep 2005
Posts: 183
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From: NJ
Rumor is that ECU uses same table(s) for both banks, whatever this might mean.
On cams subject, I still don’t get it about crank spinning twice as cams and different angle of opening intake valves when seen from crank and when seen from cams. I mean angle is point in space. Can someone point me to a book, or post or simply explain it to me. Thanks
On cams subject, I still don’t get it about crank spinning twice as cams and different angle of opening intake valves when seen from crank and when seen from cams. I mean angle is point in space. Can someone point me to a book, or post or simply explain it to me. Thanks
Originally Posted by dovla
Rumor is that ECU uses same table(s) for both banks, whatever this might mean.
On cams subject, I still don’t get it about crank spinning twice as cams and different angle of opening intake valves when seen from crank and when seen from cams. I mean angle is point in space. Can someone point me to a book, or post or simply explain it to me. Thanks
On cams subject, I still don’t get it about crank spinning twice as cams and different angle of opening intake valves when seen from crank and when seen from cams. I mean angle is point in space. Can someone point me to a book, or post or simply explain it to me. Thanks
But when it comes down to variable cams, timing chains, ECU timing control, cam overlap, etc.... I think I just need to see this stuff in action or have someone break it down step by step, exactly what is happening, and why.
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Joined: Aug 2002
Posts: 467
Likes: 3
From: Australia
Originally Posted by dovla
Rumor is that ECU uses same table(s) for both banks, whatever this might mean.
On cams subject, I still don’t get it about crank spinning twice as cams and different angle of opening intake valves when seen from crank and when seen from cams. I mean angle is point in space. Can someone point me to a book, or post or simply explain it to me. Thanks
On cams subject, I still don’t get it about crank spinning twice as cams and different angle of opening intake valves when seen from crank and when seen from cams. I mean angle is point in space. Can someone point me to a book, or post or simply explain it to me. Thanks
In the animation you can see the cam turning once to the cranks twice.
In the center illistration the blue section (inlet) is the angle that moves around on the Z motor from 6 deg ATDC to 34 deg BTDC , a 40deg rotation
of the crankshaft which is 20 deg of cam rotation.
So if the Cam is at + 34 deg opening then the closing is close to BDC & a lot of degrees ABDC when the cam is at 6 ATDC
Originally Posted by Nathan
Check out www.howstufworks.com/camshafts.htm
In the animation you can see the cam turning once to the cranks twice.
In the center illistration the blue section (inlet) is the angle that moves around on the Z motor from 6 deg ATDC to 34 deg BTDC , a 40deg rotation
of the crankshaft which is 20 deg of cam rotation.
So if the Cam is at + 34 deg opening then the closing is close to BDC & a lot of degrees ABDC when the cam is at 6 ATDC
In the animation you can see the cam turning once to the cranks twice.
In the center illistration the blue section (inlet) is the angle that moves around on the Z motor from 6 deg ATDC to 34 deg BTDC , a 40deg rotation
of the crankshaft which is 20 deg of cam rotation.
So if the Cam is at + 34 deg opening then the closing is close to BDC & a lot of degrees ABDC when the cam is at 6 ATDC
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