Garage19

Whilst at the Autosport show I had a conversation with someone who makes their living in the engine tuning trade and claims to be an expert in the engine mapping field. Whilst explaining the virtues of a rolling road they made the following statement:

“The car made more power at 4 degrees ign advance than any other setting and as we upped the ign advance the power tailed off right until we hit det at 26 degrees.”

The car in question was an RS500 and after quizzing him about this statement he confirmed that it was max power he was talking about not just at a specific load/speed site.

I personally don’t believe this statement and can only see one mistake that would cause these results but would have thought a pro would know better.

What does anyone else think of this comment? Would love a comment from Stu or Karl.

From experience of mapping turbo cars and theoretical knowledge, I can’t see that a tuned YB will get anywhere near peak cylinder pressure at 16ish degrees ATDC with out det. So there will always be a compromise but the more advance you can run (with correct afr) and no det, the closer you will get to the max torque PCP and the better.

Jay,

iTrader: (4)

grant at gbe said the same he gave me a example when he mapped a evo 8 . He found det at 12 degree at peak power then back it off in 2 degree stages to 4 degrees and found a power gain of 15 bhp , To me goes all against all the principles that ourself chip ,stu and gareth has taught me and what ive read in Dave Walkers ecu manual

GARETH T

someone fitted there crank position sensor in the wrong place

Jay,

iTrader: (4)

bollox

Garage19

Up for the evening discussion.

rapidcossie

dont really understand what you are saying?

GARETH T

i dont understand what hes trying to get at! sometimes you can make peak power at 14 degrees but it wont det till 16,,, but not as wide as 4-26 degrees with no again of power!

rapidcossie

amount of igntion adv and how it effects power depends on alot differnt things..you cant apply one rule to all engines.

GARETH T

i agree,,, but i cant see an turbo yb making peak power at 4 degrees and not detting till 20 odd

rapidcossie

if that was the case i think there is something a miss with the engine...

i saw the results on my car as we adv and adv ign and cam timing....

power always increased but by diff amounts until a point where you no longer get increases or you start to approch det.

DazC

iTrader: (1)

I am inclined to agree with Gareth!

GARETH T

like the front crank pully/sensor is set wrong

AlexF

That was my 1st thought too!

jammy86

Surely getting it upto 6 deg would only be an issue of compression ratio and fuel octane level. Which could be effected by the cam timing (dynamic CR not static)

I would have thought that you cant tar all engines with the same brush, and would need to know alot more about it to be able to make such conclusions.

JAmes.

GARETH T

but making peak power at 6 degrees and not detting till 20 odd isnt like any YB ive seen heard about