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Car is sorted, faulty CAS.... 385rwkw @ 22 dropping to 18psi.... very conservative tune due to the previous issues... should swing 400rwkw without a sweat.

To those who questioned pinging trust me i can pick it up well in advance i have over $2500 in knock monitoring gear (PLEX which is the best on the market and another which was originally designed for RBs during the gibson era)

Its a truly weird occurrence and is only the second RB in 10yrs i've had with this issue (different symptoms though).

  • Like 1

Ill copy paste from my build thread

So yeah. Still Internal gate standard manifold position:

Update:

Car issue all sorted

Ended up being a faulty CAS

22 psi down to 18 psi, conservative tune to make sure it is all ok.

Then will be coming back with 2-3 degrees more timing (~20rwkw) and up to 6 psi boost

Top line no airbox

2nd line airbox restriction

1622751_804351736245854_1333795786_n.jpg

Nice. thats a very high number for a bolton turbo setup. Dyno sheet?

Borrow a standard 600x300 core from someone and hook it up outside of the car. Yep just literally hang it out the bonnet with some long ass pipes.

I'll give you my EFT details when you're ready.

Lol

Car is sorted, faulty CAS.... 385rwkw @ 22 dropping to 18psi.... very conservative tune due to the previous issues... should swing 400rwkw without a sweat.

To those who questioned pinging trust me i can pick it up well in advance i have over $2500 in knock monitoring gear (PLEX which is the best on the market and another which was originally designed for RBs during the gibson era)

Its a truly weird occurrence and is only the second RB in 10yrs i've had with this issue (different symptoms though).

Wow - an actual faulty CAS, good to know this can happen - have had discussions about the possibility of this kind of thing when working through a similar issue and was told by people that this would never happen due to a CAS specific problem, at least without huge rpm being involved. I had picked up the tuning of a while ago, it would take SFA timing without pinging (exactly the same symptoms as this one it seems) its head off - in this particular instance it was actually a seriously buggered cam belt which had enough slop at mid rpm to cause the CAS to throw out erratic triggering signals. Just replacing the cambelt etc (left the original CAS) allowed a further 5+deg of timing to be put into it and the owner was beside himself at the final result.

I "only" use a G4 KnockBlock - but even with that I can tell dodgy combustion in cars which the owners are adamant the existing tune is fine, even when it has apparently been tuned with det cans of some sort - I sometimes wonder how much it is the user and how much it is the hardware where people aren't noticing knock. I won't personally won't tolerate the little static noise you can get before you even hear rattling.

Thanks for sharing the positive outcome, definitely duly noted

Also great to see a high nistune result.

580rwkw is my record but im sure there are higher ones out there.... even a 460rwkw Nistune SR has come through with flying colors.

Was that 580kw with an AFM ( I would presume so as I don't think you can have a MAP sensor with NIStune?) if so which one?

I'm assuming it would just be a standard sensor in a different diameter pipe recalibrated?

Was that 580kw with an AFM ( I would presume so as I don't think you can have a MAP sensor with NIStune?) if so which one?

I'm assuming it would just be a standard sensor in a different diameter pipe recalibrated?

Was that 580kw with an AFM ( I would presume so as I don't think you can have a MAP sensor with NIStune?) if so which one?

I'm assuming it would just be a standard sensor in a different diameter pipe recalibrated?

few tricks like

Lol

Wow - an actual faulty CAS, good to know this can happen - have had discussions about the possibility of this kind of thing when working through a similar issue and was told by people that this would never happen due to a CAS specific problem, at least without huge rpm being involved. I had picked up the tuning of a while ago, it would take SFA timing without pinging (exactly the same symptoms as this one it seems) its head off - in this particular instance it was actually a seriously buggered cam belt which had enough slop at mid rpm to cause the CAS to throw out erratic triggering signals. Just replacing the cambelt etc (left the original CAS) allowed a further 5+deg of timing to be put into it and the owner was beside himself at the final result.

I "only" use a G4 KnockBlock - but even with that I can tell dodgy combustion in cars which the owners are adamant the existing tune is fine, even when it has apparently been tuned with det cans of some sort - I sometimes wonder how much it is the user and how much it is the hardware where people aren't noticing knock. I won't personally won't tolerate the little static noise you can get before you even hear rattling.

Thanks for sharing the positive outcome, definitely duly noted

Worst part is the ignition trace is not scattered like you would assume. ( not sure why the above is not in qoute tags lol)

100kw from a CAS replacement is a great result. I wonder how common this issue is...

I had the same issue in 2010, it was a bastard to diagnose. Basically boosting up but then breaking down in the upper RPM range, exactly the same as with OP, although on a stock car.

Good to hear it's sorted - very tidy power figure too btw!

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