706 replies to this topic

[ArticMonkey]

What's your rev limit on the car Martin?

[vocky]

also worth mentioning that the vx220 dash rev counter stops dead at 7000rpm, so how are you working out the max rpm of the engine ?

[CHILL Gone DUTCH]

Unsure what my inlet temps were I'm afraid, but something is stopping my engine hard at 7000, so even if I have a weird mix of oil and fuel going (people who followed me said my car really smelt fuelly)of fuel and oil) it wouldnt be that hard a stop, so think mine must be ignition related as it behaves like a rev limiter.   Martin S (Am right out of my depth in these conversations now!!!)    

It's not just heat which pulls ignition back It's also knock Up to you Martin but I was not convinced you got the knock the learn mode in to the ecu Artic monkeys (Harrop) ran a lot better yesterday in cooker differences but we did make some minor adjustments Lowered the rpm ( we did this due to blow by on his small pulley the piston rings are not so good when things are hot ) static compression test would not show this , this is also linked to the combustion chamber temps, amount of boost and any other restriction. We also used she'll optimax and used lower gapped plugs and lower temp number to cope with higher temps The temp range I think has been overlooked a lot But she'll IMO is a lot better fuel for temp control These are minor things but when brought together make large gains Which makes a bit of sense if you are getting raw fuel out of the rear of the car

Edited by CHILL Gone DUTCH, 11 October 2015 - 11:10 AM.

[ArticMonkey]

I also think my knock learn session applied to the map has made a very big difference. Maybe that's what was creating the rush of heat and putting the temps up quick.

[CHILL Gone DUTCH]

I also think my knock learn session applied to the map has made a very big difference. Maybe that's what was creating the rush of heat and putting the temps up quick.

I actual thing the BiGGesT difference was the cooler temps outside

[Exmantaa]

also worth mentioning that the vx220 dash rev counter stops dead at 7000rpm, so how are you working out the max rpm of the engine ?

 

The problem with the dropping BHP at high rpms show clearly in his OBD power logs... 

[Bargi]

also worth mentioning that the vx220 dash rev counter stops dead at 7000rpm, so how are you working out the max rpm of the engine ?

  The problem with the dropping BHP at high rpms show clearly in his OBD power logs... 

And it's not the ECU backing off power because of IATs?

[Exmantaa]

For sure Martin does not mind posting a pic of his problem:

 

 

OBD Tuner powerrun, showing a sharp torque and power drop from 7K onwards to the rev limiter.
Boostpressure stays fairly flat; ~200KPa (although a bit highish for an M62)
Ignition also steady up top with ~17-18 degrees.

This log does however show about 3 degrees knock retard from 5K on.... Maybe that causes some internal ecu function that limits power up top? (=> retard ignition map a bit from 5K onwards)

Edited by Exmantaa, 11 October 2015 - 06:47 PM.

[siztenboots]

remove air filter and try again

[Matthew Bentley Racing Ltd]

Iat?

[ArticMonkey]

Iat?

51.5 and 54.9 it says in the left hand table.

[CHILL Gone DUTCH]

I would imagine if there was constant WOT IAT would be higher @ 60 degrees there will be retardation

[Matthew Bentley Racing Ltd]

That reading temp from the inlet manifold yeah?

[The Batman]

Yeah

[ArticMonkey]

That reading temp from the inlet manifold yeah?

Yep from the Tmap.

[Exmantaa]

remove air filter and try again

 

Was one of my thought too and Martin said he changed that out for his old cone filter and tried another run (also with different plugs) with the same result.

Still no guarantee that his filter is not restrictive, but his boost pressure (MAP) is constant up top and that should show a drop if there was an inlet restriction.

Same with excessive exhaust pressure; that normally show a rise in MAP pressure. (We once saw 258KPa MAP with a blocked Tullettt cat on our Harrop... )

Edited by Exmantaa, 11 October 2015 - 07:43 PM.

[The Batman]

Knowing Martin he probably has a gearbox breather as a air filter

[Matthew Bentley Racing Ltd]

I think 54 deg is optimistic. I think that is probably from a single run after the system temps have dropped. I think after 3-4 gear changes that would be higher. A data run from a track session or few pulls on the dyno would be better. 

 

 

[Exmantaa]

It is optimistic and from a single run, but not the source of his poblem now; the power drop @ 7K.

And that was with those measured IAT's. (Although the TMAP is a bit slow at measuring air temps...)

[The Batman]

if it was a restriction like exhaust or intake, shouldnt it maintain the same power from 7k to 7.5k?

 

as that drops of then surely its a mechanical/ecu problem