VVT logs showing lower values

Tuning discussion specific to 2006-2008 NC1 Miata MX-5 vehicles
Post Reply
reibes
Posts: 6
Joined: April 13th, 2025, 4:44 am

VVT logs showing lower values

Post by reibes »

Hello,
I am after some dyno tuning session.
And we have found out some hiccups during the tuning.
I have received a VVT table from camshaft manufacturer where he sent me timing set to 40 for those cams.
But during the dyno run we have seen logged only 36.
Is it because I did not allow entering unsafe values or is there any hard limit in ecu for this?
xbrandino
Posts: 34
Joined: August 15th, 2023, 1:08 pm

Re: VVT logs showing lower values

Post by xbrandino »

I may be wrong, but I believe the VVT cam phaser maxes at around 35-36 degrees. Meaning you physically can't go more then the 35-36 degrees of VVT advance, which you saw.

What does your VVT map look like? It shouldn't be set to 40 degrees across the board if that is what you are inferring. On naturally aspirated, it normally starts high at low RPMs and fades down by redline.
reibes
Posts: 6
Joined: April 13th, 2025, 4:44 am

Re: VVT logs showing lower values

Post by reibes »

No I don't have a setup for 40degrees in vvt across board. Tuner who was tuning the engine on the dyno pointed this out.
As I was sending him the VVT table suggested from the camshaft supplier.
This is the VVT table that I am using right now.
Screenshot From 2025-06-17 19-11-21.png
Screenshot From 2025-06-17 19-11-21.png (27.28 KiB) Viewed 494 times
xbrandino
Posts: 34
Joined: August 15th, 2023, 1:08 pm

Re: VVT logs showing lower values

Post by xbrandino »

I suppose if the supplier sent that, then that is what should be best. They are a bit higher than what I would've expected, especially 25-30 degrees by redline. What camshafts are they?

But as I stated, the cam phaser physically can't advance past 35-36 degrees of VVT advance, so anything greater than that will not make a change. So simply any value that is greater than 35, make it 35.
Post Reply