Vcm Cam Tuning For A Ba/bf

[riptide]

Have been learning a little about tuning and have been involved with tuning my BA motor and a couple of other BA's.

I noticed one that has the same hardware as me but makes about 100rwkw less but makes more torque lower down.

I did a 'compare' with the two vehicles in the cam angle and noticed he has a much higher number at between 0.8 and 1.0 load peaking around 2500rpm and then dropping off but mine tapers right off in the heavier loading and rises toward the higher rev range. He makes about 100nm more than me in the lower rev range.

I was wondering if the cam angle settings might have been changed to save his 4spd auto?

Is there some info on tuning these cams anywhere?

[Mr_4.0]

So what I'm reading it would cause his car to maybe make a little more boost down low as a result? Is that correct? His sounds like it retards timing earlier.

Are you comparing a ba with a ba?

[riptide]

We can make plenty of boost no problem and low down torque but no serious power.

Yes they are both BA motors but mine is on a ZF and his on a 4spd auto.

We are trying to get a handle on tuning the cam angle.

I have taken the early part of his table and added it to the back half of my table and will be testing it later in the week to see if we get good all round torque and power.

[IH8TOADS]

There is a cam table missing in HP and may also affect what you are trying to do. Chief Wigs may have got HP to add it by now? There is also a max retard table which is editable via HP so dont ignore that. Cam angle is a personal thing and the lower load areas will affect fuel economy and response.

Here's a tip...you can use the speed density tables to reverse engineer the stock engines airflow and VE at each cam angle and RPM.

Avoid 'trial and error'!!!

[rob82]

Are you comparing a ba ECM vs a bf ECM? If so the bf independently phase the cams which means you can run varying overlap to gain bottom end power.

[Mr_4.0]

He said both cars are ba.

Advancing and retarding cams is a good way to pick up power and spool bit there's always a down side when changing from factory settings.. Fuel economy and throttle response.

From memory the ba advances the cam again at the very end of the rev range to help soften the blow of hitting the limiter. If you keep it retarded in the area you will peak up a few extra peak kw.

[Mr_4.0]

Also keep in mind p/v clearance. Especially with aftermarket cams!

[riptide]

Thanks for the info guys, definitely more to it than meets the eye.

The car is a BF but the engine is BA....but that's another story.

I will look at the latest beta of VCM and see what's there.

[riptide]

Would I be correct in assuming the dyno printout figures are mostly in the 0.8 to 1.0 loading range?

[IH8TOADS]

NA yes. Forced induction no.