- Joined
- May 28, 2001
- Messages
- 16,458
Anyone looking at such?
Seems to be fairly involved.
User has hi rpm V sicks Ford, and has eaten the end off of a plug/blew a gasket, etc.
First thing that comes to mind when dealing with high rpm stuff is this
To shift the timing 5 degrees at 9,000 rpm for example
The spark only needs to arrive early by .0000194 seconds or 19.4uS which is .0194milliseconds. Two hundredths of a millisecond is all it takes to cause excessive cylinder pressure and damage parts.
There are inductive delay, microcontroller delay, frequency response (phase), physical materials delay, these must be empirically set at the crank, do not assume when using hardware originally intended to support only 7k 8k rpm that it will correctly align the timing values at 9k 10k as well.
Before tuning rapid acceleration high rpm event, always perform a complete trigger and ignition overhaul.
-Research the trigger and confirm compatibility with the resolution you are asking for
-Modify the trigger as needed to prevent warpage, slipping, bending, etc... at high rpm
-High quality crank sensor. shielded, tight, set tighter air gap to trigger, etc... factory gap and deflection may not be sufficient!
-High quality plug ends, I like to source OEM plugs from quality vehicles if possible
-Replace cable insulation with high quality
-Add shielding from EMI and re-route the trigger and coil wires far from all other wires, they get their own special pathways through the vehicle, dedicated trigger and ignition paths.
Tuning Advice: Ensure your timing maps are not FLAT at high rpm which leads to error +/- for each event, causing oscillating output and engine instability. Always use an incremental timing map sweeping from left to right from some point, for example peak torque is generally a low spot valley and the timing increases to the right all the way up
Generally end user will prefer high quality aftermarket crank trigger external to the engine for diagnostics and maintenance as part of high resolution timing control.
Not saying this is your problem! Just a psa, I tune alot of small displacement high RPM turbo engines and these are often critically overlooked aspects of preventing spark scatter and oscillation at high rpm.
Seems to be fairly involved.
User has hi rpm V sicks Ford, and has eaten the end off of a plug/blew a gasket, etc.
First thing that comes to mind when dealing with high rpm stuff is this
To shift the timing 5 degrees at 9,000 rpm for example
The spark only needs to arrive early by .0000194 seconds or 19.4uS which is .0194milliseconds. Two hundredths of a millisecond is all it takes to cause excessive cylinder pressure and damage parts.
There are inductive delay, microcontroller delay, frequency response (phase), physical materials delay, these must be empirically set at the crank, do not assume when using hardware originally intended to support only 7k 8k rpm that it will correctly align the timing values at 9k 10k as well.
Before tuning rapid acceleration high rpm event, always perform a complete trigger and ignition overhaul.
-Research the trigger and confirm compatibility with the resolution you are asking for
-Modify the trigger as needed to prevent warpage, slipping, bending, etc... at high rpm
-High quality crank sensor. shielded, tight, set tighter air gap to trigger, etc... factory gap and deflection may not be sufficient!
-High quality plug ends, I like to source OEM plugs from quality vehicles if possible
-Replace cable insulation with high quality
-Add shielding from EMI and re-route the trigger and coil wires far from all other wires, they get their own special pathways through the vehicle, dedicated trigger and ignition paths.
Tuning Advice: Ensure your timing maps are not FLAT at high rpm which leads to error +/- for each event, causing oscillating output and engine instability. Always use an incremental timing map sweeping from left to right from some point, for example peak torque is generally a low spot valley and the timing increases to the right all the way up
Generally end user will prefer high quality aftermarket crank trigger external to the engine for diagnostics and maintenance as part of high resolution timing control.
Not saying this is your problem! Just a psa, I tune alot of small displacement high RPM turbo engines and these are often critically overlooked aspects of preventing spark scatter and oscillation at high rpm.
