Boost Cut

[PaulG]

N00B ALERT.. ha

is boost cut the stock limit of 5500rpm where it just dies ?? or something else ??

also is the ATP boost cut defender for eliminating this ?

annnd.. i notice they all say install at your own risk with purchase ?? is there high risk involved with KABOOMING your engine with to much boost once u install this ??

[EQ]

we were all noobs once.

5500 is boost cut - we all have it (or did have it)

Boost cut defender will fix it, but there are other systems which are better in the long run, tunes such as standback, piasini etc etc will allow you to dial in the boost you want. Things like intakes and even exhausts can extend boost - more through the fact that the turbo is alreadu spinning and "carries on a bit more"

Fit at your own risk is a standard disclaimer. Make friends with your local dealer and guage their opinion on things - lol - my service manager has changed my pod filter for me on my CAI...

Boost levels upto 19PSI (some would say 21PSI) are safe - I have been running 17 for the past 12 months, now going to 19.

MPSGarage run theirs at 21PSI, but they have upgraaded a heap of stuff on their cars.

Jim

[PaulG]

yea i knew a full tune would get rid of it all together as well as open doors to a lot more options.. just was reading into BCD on US forums and there wasnt alot of info on it... i think mainly because everyone gets a tune done eventually...

BUT.. us with little coin to splash around haha... thought this may be an option to keep the mod bug happy and also give me a little more go ??

has anyone found a how to install guide or done this on here??

oh and if one was to install the Boost Cut Defender... would this then raise issues with fuel cut ?

[Nuliaj]

I could be totally wrong, but here's how I understand things:
Boost cut is when the MAP reading exceeds 4.9~5v whereas fuel cut is when certain currently unknown engine criterias are met. Fuel cut seems to happen more often at lower temperatures. If you're getting boost cut, you can try a MAP clamp.

The engine falling flat on it's face after 5500rpm is nothing to do with boost cut, but turbine efficiency, throttle plate closing and boost mapping. Things to improve post 5500rpm performance include tuning, improved IC, aftermarket dump pipe and test pipe etc.

[MattMPS3]

The stock MAP on the MPS is a 2.5 bar unit, so it will take 36 psi to reach its 5v threshold.
Boost cut is when the ECU sees 18 psi, for more than 2 seconds (why 2 seconds ?,to avoid cutting on boost spikes), I would strongly advise against a boost cut killer this completely removes the boost cut, so if your waste gate were to fail and you suddenly boosted to 30 psi nothing would intervene to stop this (except maybe a rod escaping the block, and fragments of piston and valves ratting around in your sump).
A MAP clamp can, and has been used successfully, however you should have some tuning to support any boost increases.
I also wouldnt run more than 18psi on the stock TMIC, see my post in the intake section about intercooler pressure drop etc.
5500rpm is NOT boost cut, it feels flat because the little spinning wheel is at the top of its efficiency ceiling, unable to push much more air, the throttle plate closure is there to help protect the turbo, yes breathing mods help reduce the load on the compressor wheel at these revs.

Fuel cut on the other hand seems to occur at random times, for random reasons, with no definite parameters to pin point the cause, from what I have read, fuel cut wont necessarily save your engine from exploding either, CPE have recently added a fuel cut eliminator flash to their ensemble.

[Nuliaj]

I'm sure I read in the US forums of guys who are maxing out at 5v and are runnning nowhere near 36psi, are you sure that's correct?

[MattMPS3]

Yeah, the US guys are maxing out their MAF sensors, and have experimented with larger housings to compensate, however I believe this makes the car a pig to drive down low.

[Nuliaj]

You're right I'm confusing MAF reading with MAP reading. Some of the guys maxing the MAF at 5v are looking at 4" intake/inlets including bigger MAF housing.

I still don't think the fuel cut issue is random, though I do think we have no idea what the different parameters causing it are. IMO I think CP-e should've first worked out what causes the fuel cut and then tweaked the settings rather than disable fuel cuts altogether.

[PaulG]

cool that what i wanted to hear ... haha... thanks

oh well... dream on i will... thought i could wiggle 100 bucks away without the girlfriend knowing.. haha full tune is just out of the question for a LOOOOONG TIME ...

[MS3]

we were all noobs once.

5500 is boost cut - we all have it (or did have it)

Boost cut defender will fix it, but there are other systems which are better in the long run, tunes such as standback, piasini etc etc will allow you to dial in the boost you want. Things like intakes and even exhausts can extend boost - more through the fact that the turbo is alreadu spinning and "carries on a bit more"

Fit at your own risk is a standard disclaimer. Make friends with your local dealer and guage their opinion on things - lol - my service manager has changed my pod filter for me on my CAI...

Boost levels upto 19PSI (some would say 21PSI) are safe - I have been running 17 for the past 12 months, now going to 19.

MPSGarage run theirs at 21PSI, but they have upgraaded a heap of stuff on their cars.

Jim

Is there any evidence out there to state our turbos can run up to 21psi? I'm getting my car re-tuned very soon and would like to run 21psi if i know it can be done.

My car is currently on 19psi, only reason why i'm re-tuning is because i need to finish my other map. Since then i've added my Upgraded fuel pump and colder spark plugs. So it wouldn't hurt to tune my current map also.