1145 replies to this topic

[smiley]

imagine what a harrop with a 2.8 pully on a 2.4 could do

[Graeme Lambert]

Graph is in...

 

I'll await the comments 

 

 

Sam did mention he had some wheelspin at the top-end, and that their dyno doesn't read as high as the other one Matt uses (Which I take to be 1320 MINI)

[Rosssco]

340 lb/ft seems very high / impressive, especially for a 2.0

 

340 Nm = 250 lb/ft, which seems more realistic given the spec?

[techieboy]

Torque line doesn't follow the "usual" SC flat line. Weird.

[Graeme Lambert]

Torque line doesn't follow the "usual" SC flat line. Weird.

Wasn't just me that thought that then. To my (untrained) eyes it looks more like a turbo graph with the torque plot like that?

[CocoPops]

Does seem quite a drop off in torque, I was trying to find some other graphs to compare. But your sig link demonstrates other curves Matt.

[techieboy]

I think this was Nick's original Harrop dyno run at Courtenay's before they de-tuned it and shows the more classic torque line that we're used to and a ~40ftlb loss from peak across the range



Did you end up using that shonky Lotus specific Harrop? Wonder if there is any difference there? What needed to be done to get it to fit your engine/inlet?

[leevx2.2]

I wouldn't say that was a supercharged graph doesn't look right to me

[Graeme Lambert]

Cam timing issue? And yes Matt it's the lotus harrop. There was problems with the actuator being a bit on/off

[siztenboots]

seems to reach its peak breathing, then efficiency drops off, looks fine

 

what camshaft spec / SC pulley?

 

got at least 40 / 50 torque better than Nick's

[Graeme Lambert]

Zzp stg2 cams and a 2.9/2.95 pulley

[techieboy]

I wouldn't say that was a supercharged graph doesn't look right to me

Yeah, the more I look at it, the odder it looks. Ross is right, that's mega torque but neither the bhp or torque lines follow the usual SC pattern in that graph. I guess if the tyres did start slipping at ~5700rpm and he backed off, that would bugger the usual continually increasing bhp line to the rev limit and make the top end numbers worthless.

[CocoPops]

Even if you ignore 5,700+ figures, the torque still has too much of a curve though?

[NickB787]

Must admit does look a bit unusual for a Harrow s/c graph, are they adjustable cams or Luger cams

[techieboy]

Even if you ignore 5,700+ figures, the torque still has too much of a curve though?

Agreed. Need one of the Dutch or German guys with a Harroped 2.0 litre to post up a graph or two.

[NickB787]

I was looking for my z20let ecu dyno run, seem to remember it looked not too dissimilar.

[CocoPops]

http://www.vx220.org...ions/?p=1618207

[Nev]

Your torque curve is dropping off due to VE % dropping off. This is most likely due to a flow restriction of either the inlet charge or the exhaust gas. Anything from poorly flowing head, poor swirl, poor scavenging, CC causing turbulence etc etc. Quite hard to pin down most probably, as it could be loads of things. The easier things to eliminate might be to do the follow, do a dyno pull and see if the problem is alleviated: 1. Remove exhaust + manifold. 2. Remove airbox + inlet pipework. 3. Remove the laminovas or whatever CC restriction you have.

Edited by Nev, 08 July 2015 - 11:03 AM.

[siztenboots]

or air filter choking

[Rosssco]

Your torque curve is dropping off due to VE % dropping off. This is most likely due to a flow restriction of either the inlet charge or the exhaust gas. Anything from poorly flowing head, poor swirl, poor scavenging, CC causing turbulence etc etc. Quite hard to pin down most probably, as it could be loads of things. The easier things to eliminate might be to do the follow, do a dyno pull and see if the problem is alleviated: 1. Remove exhaust + manifold. 2. Remove airbox + inlet pipework. 3. Remove the laminovas or whatever CC restriction you have.

 

Out with practical considerations, won't removing the exhaust manifold have a detrimental effect on engine efficiency? Plus, where do you mount any lambda sensors?

 

Removing laminovas would result in the whole thing becoming completely heatsoaked in short order. Those that have run without them only temporarily have reported this.