Notice to all my Vipec i88 and Link G4+ Customers
If you are an existing Link or Vipec customer or are thinking of buying one you need to read this. The following relates to Link G4+ and Vipec i88 model ECU.
For simplicity I will refer then them all as the Link G4+.
The Link G4+ traction
control does not work very well. It can make the car accelerate slower and
in some cases very badly. It can be setup to work correctly by experimenting
with the settings for a set road condition, temperature and humidity. If there
is a change in any of these conditions the settings are wrong and the car
will accelerate slower. If you setup the traction control for a dry road,
then on a wet road it is totally wrong. You may think this would be expected,
but it should still do a reasonable job of maintaining traction and acceleration.
The Autronic traction control does a very good job. Dry settings work well
on wet roads. I believe the Autronic targets wheel slip where the Link tries
to stop slip. To get maximum acceleration you need around 10% slip on dry
roads and 5% on wet. The Autronic has a slip control range and threshold tables.
The Link only has a threshold. I am sure this, plus the code logic are why
it does not work as it should.
Traction control is banned on many motorsports as it gives an unfair advantage when accelerating in a straight line or out of a corner. I could never see someone get caught using the Link traction control.
Closed Loop E-Throttle Idle Control:
This has a random bug
that causes the engine RPM to idle very fast. The only solution when this
happens, is to turn the ignition off and back on. A engineer at link has confirmed
the bug and said this,
We are suspicious that some of the idle control is limited by the ECU hardware as our in house testing gave mixed results as well. So will continue working on options but it might have to wait a hardware upgrade.
The cruise control works badly. Example:- When you select resume it badly overshoots the set speed. No amount of changing the settings will fix this. The cruise control needs to slow down acceleration as it gets close to the target speed. The Motec ECU has Cruise Speed Decrement Fast and Slow, Cruise Control Acceleration Time Constant Negative and Positive settings.
The Link G4+ has none
of this. The result is cruise control that uses a lot of fuel and jerking.
Also you get different results based on what gear you are using. The Link
Support said this from one of the Engineers.
Andrew agrees that a decay on the accel is going to be the best option without adding too much complexity and will get that in to the improvements list.
So why am I making this public ?
I have been trying to get this things fixed for more then two years. I have sent Link datalogs and done everything they asked to me to try, in an attempt to make things work better. I was told on the 06/06/2018 by their tech support people that the cruise control will not be fixed in the G4+ as they are winding down development on the G4+ and are concentrating on the new G5 ECU.
So if you are a current Vipec/Link customer with a i88/G4+ or are thinking of buying one you need to contact Link to get these fixed before the G5 is released.