1145 replies to this topic

[siztenboots]

is there cam overlap?

 

whats your idle vacuum?

 

stg1 zzp cams have a lsa of 109 the stg2 is 112

[CHILL Gone DUTCH]

Can a mod please change the title to the on going project

[Graeme Lambert]

is there cam overlap?

 

asking wrong person Steve

[Graeme Lambert]

Can a mod please change the title to the on going project

 

fcuk off   

[CHILL Gone DUTCH]

Can a mod please change the title to the on going project

  fcuk off   

Lol

[Graeme Lambert]

It's still project Once. I've not finished and gone back to sort things, this is just fine tuning in the middle!

[Exmantaa]

 

 

Regarding the scale on the graph, it isn't entirely accurate. It was set at the same ratio as when Sam mapped Bills car, to allow that comparison. So where it shows the peak power is made at approx 5,750rpm, it is actually making this around 4-500rpm later at 6,250-6,350rpm. The cut off, where it is revved too, is actually at 7,200rpm, not the 6,650rpm it shows on the plot. 7,200rpm was used simply because Sam felt there was no need to rev further since it was already dropping off.

 

Due to what Sam suspects is a geometry issue - I'm not sure if the car has ever been set up since the suspension etc has been bolted back on - he said it felt like the left wheel was wheelspinning slightly. He could hear a squeal when backing off, as if it was gripping again. The boost does tail off slightly towards the top-end, but not enough to warrant further investigation in his opinion, so while he agrees it could be belt slip, it wasn't his first thought.

 

I have confirmed that the dyno does measure in lb/ft, so this engine did make a peak of near 350lb/ft between around 4,000rpm to 4,700rpm (adjusted for the scale being out of sync). In new money that's 475Nm....

 

 

475Nm is unusually high for a 2.0 Harrop engine. Dyno measurement numbers are debatable, but that would be almost 50% more torque than our 325Nm measurement. (And only due to "better efficiency" of head/cams and exhaust...   )  

Vocky timed your cams, right? So he will have dialed them in to the prescribed Comp cam timing.

 

Still think you had wheel spin that skews the measurment. We normally see the Harrop boost rising (with 80mm pulley) till max rpms, as it's simply a fixed volume airpump pushing agains the engine's flow restrictions.

Edited by Exmantaa, 10 July 2015 - 02:37 PM.

[Graeme Lambert]

 

 

 

Regarding the scale on the graph, it isn't entirely accurate. It was set at the same ratio as when Sam mapped Bills car, to allow that comparison. So where it shows the peak power is made at approx 5,750rpm, it is actually making this around 4-500rpm later at 6,250-6,350rpm. The cut off, where it is revved too, is actually at 7,200rpm, not the 6,650rpm it shows on the plot. 7,200rpm was used simply because Sam felt there was no need to rev further since it was already dropping off.

 

Due to what Sam suspects is a geometry issue - I'm not sure if the car has ever been set up since the suspension etc has been bolted back on - he said it felt like the left wheel was wheelspinning slightly. He could hear a squeal when backing off, as if it was gripping again. The boost does tail off slightly towards the top-end, but not enough to warrant further investigation in his opinion, so while he agrees it could be belt slip, it wasn't his first thought.

 

I have confirmed that the dyno does measure in lb/ft, so this engine did make a peak of near 350lb/ft between around 4,000rpm to 4,700rpm (adjusted for the scale being out of sync). In new money that's 475Nm....

 

 

475Nm is unusually high for a 2.0 Harrop engine. Dyno measurement numbers are debatable, but that would be almost 50% more torque than our 325Nm measurement. (And only due to "better efficiency" of head/cams and exhaust...   )  

Vocky timed your cams, right? So he will have dialed them in to the prescribed Comp cam timing.

 

Still think you had wheel spin that skews the measurment. We normally see the Harrop boost rising (with 80m pulley) till max rpms, as it's simply a fixed volume airpump pushing agains the engine's flow restrictions.

 

 

Nope, cams dialled in by MBR, not Vocky.

 

Agreed the torque figure comes across as ridiculous...

[Matthew Bentley Racing Ltd]

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

[leevx2.2]

Just putting it out there, could we be noticing the top end lumps more because we're used to looking at CS graphs which don't cross over 5252rpm and is generally more stretched out?
 

I think Ray is right cs stretch it out proberly to look smoother lol

[CHILL Gone DUTCH]

Good spot ray I see it now But what's causing it

[The Batman]

they print graphes out for turbo owners on A3 paper

[Zoobeef]

they print graphes out for turbo owners on A3 paper

 

 Thought it was a seismograph roll.

[Bargi]

Good spot ray I see it now But what's causing it

you know, I think I get the same dips as well up top. Especially since I fixed the CC pump. Maybe the ZZP cams. What would be telling would be Lee or Nick, think they've got Blower cams?

[CHILL Gone DUTCH]

i could find one of nicks 

i have a very large collection of maps and power runs 

[CHILL Gone DUTCH]

i can confirm nick has a dip but its not as noticable as mine 

im not going to post it without nicks permission 

but its no where as noticeable as mine 

 

[Mangham54]

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.

[CHILL Gone DUTCH]

if i start the power run at 4 or 5 k rather than lower it still does it 

[CHILL Gone DUTCH]

i believe mine is so prominent because of my large pulley and its the resistance of the manifold and the boost having to push past it 

[Bargi]

You got Haggi or ChrisUK. They're blower as well I think. Anyway... perhaps we should over this to the Dutch thread and let the G and The Never Ending Story ahem... Project Once continue