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Low Vacuum with big cams


purxr6t

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  • Member For: 4y 7m 16d

Hi recently purchased a 700+Rwkw Barra,

It is supposed to have Atomic stage 4.5 cams possibly stage 5,

And possibly locked timing gears.

 

It has low vacuum and very heavy brake pedal at idle or in heavy traffic,

Is this normal?

 

Has anyone found a solution?

 

Whether it be less overlap,

Or vacuum pump etc?

 

As it is in heavy traffic the brake pedal is like a rock,

And it's would be good to sort it out.

 

Cheers.

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  • Member For: 9y 10m 22d
  • Gender: Male
  • Location: South Australia

That's what happens with big cams. The brake booster will store vacuum on decel and a little bit at idle, you can drive around it like this. I never bothered with trying to fix it, I just press the pedal harder, you get used to it.

 

I'm sure you could fit a vacuum pump and it would be sweet. If the cams are locked, there's fark all you can do about it without changing your power band and needing a retune.

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  • Member For: 4y 7m 16d

Any good tuners you would recommend in Brisbane?

Who can also do a good ZF tune so it drives normally in "D"?

 

It can be a bit rough and erratic at some speeds,

For example either shifts up and down,

Or convertor lock up engages / disengages at some speeds,

40 kmh is one of those, and it gets annoying manually shifting all the time.

 

The power is there it could just do with some refining here and there.

 

Has a Haltech plug in,

With flex fuel mainly on E85 at the moment.

 

I think the idle could be better,

And for sure the ZF could be tuned a lot nicer !!!!

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  • Puff
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  • Member For: 9y 10m 22d
  • Gender: Male
  • Location: South Australia

Same as your other post, I'm not from there and don't really take note of who does what, you'd have to ring around or whatever. Again same as the other post, can you pull the tcm file and reflash it?

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  • Member For: 4y 7m 16d

Yeah will get PCM Tech if needed,

Otherwise if there's any places people from Brisbane can recommend,

That have done some big power ZF tunes that would be great !!!!

I mean they should already have PCM Tech and a near off the shelf tune ready to go.

 

Weird that there's only a fault after half an hour or so of driving in "D" though.

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  • Member For: 5y 5m 21d

You might have to look at Force Performance in Toowoomba man.

 

When I was in Brisbane, East Coast Customs did a lot of work on my car, and they deal with barras a lot. Not sure if they have a ZF transmission specialist though.

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  • Member For: 10y 4m 14d

They put a vacuum canister in for my stage 5 crow cams...did the job and a very simple fix.

 

Before that when the idle was low, pulling up to a car Infront of me was dangerous, braking suffered under the right conditions.

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