1145 replies to this topic

[fezzasus]

Probably valve overlap if the cam type is consistent. 

[CHILL Gone DUTCH]

You do no silver will add 40 hp but will lose 28 ft lb

You're all torque Chris

I only have 300 ft lb 😜

[Graeme Lambert]

You do no silver will add 40 hp but will lose 28 ft lb

You're all torque Chris

I only have 300 ft lb �

Then we can't be friends anymore �

[oakmere]

As it is the harrop cars that really show this dip up I think it is flow issues with the inlet manifold.

[CHILL Gone DUTCH]

Afr will be 14's at idle. Late 13's low load running to late 12's on max boost.

 
 
Cock up alert, was just talking to someone about this and spotted my mistake. I meant Low 12's not late 12's at max boost. Sorry
 
But still not 11's

Don't think your running as lean as you first thought ( or I first thought ) after looking at the maps and various conversations
I've had with various people

Here is a more standard target AFR



And here is a MBR AFR on Bills car




Now on the face of it it looks like the settings on matts map his afr are running at 12.5 WOT depending on what pressure is running

But if you look at the correction numbers under the target AFR table it actually gives a different story
It only actual 12.5 of inlet temps are below 51 degrees
Where as a normally it's at 71 degrees before extra fuelling is added

So in effect if temps could be controlled on a RR than the 12.5 AFR would be being used for max powers but in reality on the road temps are very rare are below this temp

So matt has cleverly used the Tmap sensor on his calibration to control the power
At the same time keeping it safe enough on road/ track use when temps are likely to be higher

Edited by CHILL Gone DUTCH, 11 July 2015 - 09:28 AM.

[CHILL Gone DUTCH]

I posted the wrong graph at first But have now edited it

[CHILL Gone DUTCH]

As it is the harrop cars that really show this dip up I think it is flow issues with the inlet manifold.

That's my thoughts And because I run a bigger pulley my car finds it harder to push past it so looks like I suffer more

Edited by CHILL Gone DUTCH, 11 July 2015 - 09:43 AM.

[NickB787]

Blue by the way best colour...,, Chis can we move the either the Dutch ecu tread or yours so we don't annoy the owner of this one.

[CHILL Gone DUTCH]

Moved sorry GL http://www.vx220.org...79#entry1803335

[Bargi]

[quote data-cid='1803305' name='fezzasus' timestamp='1436602431' post='1803305']Probably valve overlap if

Insomuch as they are high lift cams. You've got blower and the zzp Stage 2.
What's common so far is they are all Harrop. Would be interesting to see the same with a M62 just to eliminate the SC.

My semi technical brain tells me cama should help those RPM. What I've learnt over the years that things are never straightforward

[CHILL Gone DUTCH]

Here is my stage 3
And it's still there
M62

Edited by CHILL Gone DUTCH, 11 July 2015 - 01:48 PM.

[CHILL Gone DUTCH]

And it's there on my stage 2



No cams

[Graeme Lambert]

And it's there on my stage 2 No cams

So inlet manifold. Which we know isn't ideal. So who's going to remove laminova to see if that helps (and cool it another way)

[The Batman]

I guess it's either you are lee who are running the sandwich plates

[Graeme Lambert]

Surely sandwich plates wouldn't be enough? Now, sandwich plate and water injection? Acidpopstar where are you?

[CHILL Gone DUTCH]

Oakmere had the dip on his NA on a CS map So maybe it's something else Didn't someone mention some kind of harmonics

Edited by CHILL Gone DUTCH, 11 July 2015 - 04:56 PM.

[CHILL Gone DUTCH]

So could it be a harmonic issue that is disturbing the flow? How does the graph look if you drop part throttle to say 4k and push back up? I presume it would be identical, but if it is different then something is indirectly affecting the results, rather than map/harrop/Mani rtf.

Here

[fezzasus]

Oakmere had the dip on his NA on a CS map So maybe it's something else Didn't someone mention some kind of harmonics

 

I still maintain it's valve overlap. Here's why:

 

At low RPM the valves close following the profile of the cam, as you go up in speed, the mass of the valve leads to a slight valve float. In other words, the closing of the valve doesn't follow the cam profile but instead is restricted by the speed the valve can accelerate at. This has been addressed somewhat by using stronger springs, but they add extra mass so really just delay the issue.

 

This dip appears to be at around the same RPM on engines with similar cams and springs. I would suggest that systems with original springs will see this dip lower down the rev range, however it would be very rare to find an engine with different cams but the same springs.

[CHILL Gone DUTCH]

Ok fez that's a new idea so now we need people to ID there cams and springs along with there graphs if possible

[Graeme Lambert]

Ok so I'm stage 2 ZZP cams, Supertech double valve springs