So I know when adding a cam you need to decrease the VE in the lower RPMs and increase in the upper RPMs. I do have it sorted out in the upper range but some questions in the lower idle areas.
Noticing the spark does bounce quite a bit and believe this is because the VE is not quite right yet but would like some input on this. Also, when rolling off the throttle it sometimes stalls. In the car world we would add IAC. Is there something I need to configure on this?
The spark bouncing at idle, is from idle control, idle moving at rpm is from spark efficiency/torque control
What is the best way to fix?Originally Posted by MRRPMBRP
What are you wanting to fix?
I think he means fixing the spark bouncing at idle.
Spark moving around at idle is normal, as it is in about all efi electronic tb cars.
Completly agree with you. This is one of the ways it keeps the RPMs where it needs to be. Just seemed to be more than it should be. Got my VE dialed in and the KPA is now around 65-70 and the idle is much better and timing does not seem to jump around as much.
Still have a small issue where if I let off the throttle, RPMs drop and sometimes it is not able to recover and stalls. In say a Ford, I would increase IAC.
Increase sc tq, or reserve tq, or both
Tom,
When you started, did you just add a percentage to the base VE in the higher RPM range, and pull some in the low? Say, 20% multiplier for the extra lift/duration at higher rpm and minus 5% for a stable enough idle to tune?
I was looking for a safe baseline so it's not too lean while doing the actual data logging to dial in the VE...
what cam are you using ?
Ruthless,
The way these were ranked in order of performance (dudes over on the FB group), which I take to mean the most aggressive duration/lift:
OEM 230
OEM 300
OEM past year supercharged skis
OEM 325
Calas Performance
I am going to go with the Calas and his springs/retainers. I know the easy way would be to use a 300 or even a 325 cam and then I'd have oem 300 tables to use as a starting point.
Your cam gets good reviews on the FB group as well, by the way, I assume it's up there at the top!
What are your thoughts on going in airflow/fuel?
The issue with the 230 cam is anything is a significant improvement, want to be safe when I start the tuning process!
I know I've said it before, but swampdonkey is the best forum handle ever.
Ha!
YUP, my new cams are made by Kelford Cams, and we use beehive springs and titanium retainers also by Kelford Cams for the best acceleration in an sc build.
the best part is our camshaft doesn't need special tunning to be stable in iddle like others with ibr error issues
Last edited by RUTHLESS; 01-21-2025 at 10:39 AM.
Its gonna have to be tuned once the mods start comin. Its nice that yours has a stable idle. Where does it fall in the line above in terms of torque across the curve?
I wish the powersports would post specs and dyno charts like the car guys do.
Thanks.
fueltech estimated power 690hp
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