chris2o2 Posted January 3, 2009 Share Posted January 3, 2009 Mine makes 0.9 on the first tubby and 1.0 on the second - Mines ecu i think . I have no boost controller plugged in . Quote Link to comment Share on other sites More sharing options...
Scott Posted January 3, 2009 Share Posted January 3, 2009 To be honest i havent looked for a while Maybe im just exagerating in my head . Yep the car is fully bpu. all apart from a boost controller. doesnt seem to need on as it tops out on boost at about 1.3 and then if you keep your foot in stops at 1.4. I remember hearing somewhere it was because its uk spec and something else limited it :S Its still strange because the wastegate on the UK's is big enough to control the boost. Whatever the actuator is set at it should flow enough through the wastegate to control it. UK's don't need restrictor rings because the wastegate can handle it, basically. If a UK is over boosting from stock levels without boost control i would have it looked at. Might be nothing, might be something. Better safe than sorry though Quote Link to comment Share on other sites More sharing options...
Guigsy Posted January 3, 2009 Share Posted January 3, 2009 nobody who has had the car when its been places has ever said anything about it. lol I plan on taking it to CW soon as i have a bit list of jobs that need doing Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted January 3, 2009 Share Posted January 3, 2009 In principle its a sound theory. Basically all you are doing is upping when the 1st turbo's "wastegate" opens the same way as you do the 2nd turbo for normal BPU. I think if you set the 1st turbo at 1bar and the 1st and 2nd turbo at 1.2 bar then you are evening up the work done by each turbo. By just increasing the 2nd turbo for BPU levels you are making it work much harder to reach the same level. My understanding of it was that by increasing boost on the first turbo you reduce the pre-spool of the second turbo, and depending on by how much you do this/bleed off, it can result in the second turbo coming on late or even causing damage to the shaft as it goes from 0-1.2bar all at once. Quote Link to comment Share on other sites More sharing options...
Scott Posted January 4, 2009 Share Posted January 4, 2009 My understanding of it was that by increasing boost on the first turbo you reduce the pre-spool of the second turbo, and depending on by how much you do this/bleed off, it can result in the second turbo coming on late or even causing damage to the shaft as it goes from 0-1.2bar all at once. I read it as the opposite of that. According to the description the tail off will have less of an impact as the boost required to spool the 2nd turbo won't change but instead of dropping from 0.8 to 0.4 then to 1.2 it will drop from 1.0 to 0.6 then back to 1.2. Obviously the difference in boost is still the same, 0.4, but more boost is being provided giving a bit more power during the transition. Guess there is only really one way to find out though Quote Link to comment Share on other sites More sharing options...
jaymdee Posted January 5, 2009 Share Posted January 5, 2009 I believe that at that boost the first turbo will be running so hot that the extra boost is negated by the increased intake temps, hence, as Alex said the 'seat of the pants' dyno feels little or no different. Also, it's massively shortening the life expectancy of the first turbo. Also, If you could run each at 1.2Bar, then surely you could run both at a combined 2.4Bar - not recommended!! Quote Link to comment Share on other sites More sharing options...
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