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Big thanks to Martin Kirk, BPU is awesome...!!


Havard

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Martin has had my car for just under a week and given it the once over. We have now got into a routing of me giving the car to him, he tells me what is wrong and I get him to fix it.

 

The car was due an MOT and I had been collecting decats, FCD etc to go BPU so I thought about doing the whole lot in one go.

 

The car is now louder but boy does it shift. I can see now how people get used to power and the thirst for more.

 

Cheers

 

H.

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Martin has had my car for just under a week and given it the once over. We have now got into a routing of me giving the car to him, he tells me what is wrong and I get him to fix it.

 

The car was due an MOT and I had been collecting decats, FCD etc to go BPU so I thought about doing the whole lot in one go.

 

The car is now louder but boy does it shift. I can see now how people get used to power and the thirst for more.

 

Cheers

 

H.

 

I'm very jealous. BPU & auto kickdown is an amazing, giggle inducing experience.

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Good to hear H! How do the brakes feel now hes prodded and probed them?

 

There is a bit of travel in the pedal and then it bites like a snake. I may replace the pads, but they are only half worn.

 

I'm very jealous. BPU & auto kickdown is an amazing, giggle inducing experience.

 

This has taken 30 years off my life and being 38, you can understand why I was bouncing up and down all the way home.

 

H.

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When you going proper power, get that single kit ordered lol.

 

My plans are to seriously move house so I can't see me going single for a while. It will be BPU, then get a boost controller and take the RR out. Then maybe single.

 

I called into my local body shop and arranged for a bit of paintwork to be done over the winter while she is off the road. Got the love back for the car again.

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My plans are to seriously move house so I can't see me going single for a while. It will be BPU, then get a boost controller and take the RR out. Then maybe single.

 

I called into my local body shop and arranged for a bit of paintwork to be done over the winter while she is off the road. Got the love back for the car again.

 

Restrictor ring needs to stay in ;)

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Restrictor ring needs to stay in ;)

 

How does it increase the boost then? I thought the restrictor ring was just a mechanical way of controlling the airflow out of the exhaust.

 

I really don't understand these things once we get beyond a certain point. I nearly forgot the FCD last week.

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How does it increase the boost then? I thought the restrictor ring was just a mechanical way of controlling the airflow out of the exhaust.

 

I really don't understand these things once we get beyond a certain point. I nearly forgot the FCD last week.

 

 

Restrictor ring stops the turbos from overboosting on their own. Without that restriction there would be no control as the wastegate on the jspecs is crap. The boost controller increases boost only, if you are seeing 1.0bar of boost just now then the only way to lower that boost is to increase the restriction... ie make the restrictor ring smaller.

 

The boost controller opens/closes the wastegate at a certain pressure. Even with the wastegate fully open the boost will increase past the safe limit if you don't have a restrictor ring in place. Here's a way of getting your head around it....

 

Boost controller set for 1.2 bar - Boost hits 1.21 bar - Boost controller opens wastegate and some of the exhaust gas is bypassed out of it - turbos slow down - boost pressure decreases.

 

The above rings true for setups with adequate wastegates. On the Jspec it goes something like the following....

 

Boost controller set for 1.2bar - Boost hits 1.21 bar - Boost controller opens wastegate and some of the exhaust gas is bypassed out of it (just not enough) - turbos slow down (just not enough) - boost pressure continues to rise.

 

The way to get around this is to fit a restrictor ring in order to FORCE the exhaust gas through the wastegate (easiest path with the least resistance). This means that more of the exhaust gas is bypassed and the turbos slow down MORE thus generating less pressure.

 

Simple rule of thumb... whatever boost your car makes with the boost controller disabled is the least amount of boost your car will ever make when running as it is. A boost controller can only increase the boost levels of any given setup.

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How does it increase the boost then? I thought the restrictor ring was just a mechanical way of controlling the airflow out of the exhaust.

 

I really don't understand these things once we get beyond a certain point. I nearly forgot the FCD last week.

 

The boost controller up's the boost H. The RR is there to stop overboosting which would destroy the ceramic internals of the Jspec turbo. Uk spec's don't need a RR as the turbos have steel internals.

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