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Rolls

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Everything posted by Rolls

  1. Rolls
    Well if Motec and Ford seemed to think it was enough of an issue to measure it and adjust their tuning to suit, then I'm going to guess it isn't ridiculous.
  2. Rolls
    Lol why is that nismoid
  3. Rolls
    Would be curious to hear STATUS' opinion on this.
  4. Rolls
    It is a factor of load as well adriano, eg if you are dynoing full load in 4th gear then it is going to be almost 1 second between load cells anyway. I'm guessing but I would say if it is an issue, it would be at low load levels when road tuning eg 1st and 2nd gear.
  5. Rolls
    Would definitely be of great benefit to the at home tuning community on here with to see what kind of difference is to be expected in both AFR and lag time. Can't beat real world results at the end of the day. Thanks!
  6. Rolls
    That would be a fantastic test gotrice! would love to see the difference in both AFR measured and lag. Please do it. A graph with all 3 overlayed at idle and say reving out 1st or 2nd gear would be the most interesting, higher gears would be slower so any lag would be compensated for by being closer to steady state.
  7. Rolls
    Well lets prove him wrong then, who has a wideband here?
  8. Rolls
    Well it was someone from motec so that gives it some merit. I personally haven't ever experimented eg running real rich then normal and looking at the graphs to see the lag. I imagine there would be some lag, how much I guess you'd have to try and see. Anyone want to test this out? I'm curious how close it is.
  9. Rolls
    So I heard this through the grape vine from someone at motec, it makes sense now that I think about it but I wonder how often it is overlooked. The exhaust gases in your exhaust take about 3 seconds to reach the muffler from the turbo outlet. It is obviously a function of exhaust gas pressure, exhaust size etc, but on the race car they were talking about it would take roughly this long. That means you really need to calibrate your tuning software for this lag as it is going to mess with your maps if aren't aware.
  10. Rolls
    What does a setup like that cost and how easily can you hook it into most tuning packages?
  11. Rolls
    I find if you have a bit of a relationship with them, eg have been there many times in the past and they know you on a first name basis they are far more likely to give it 100% of their energy, even better if you are a friend of a friend as they feel more accountable that way.
  12. Rolls
    Luckily Ive found a tuner where tuning is his hobbie and he also has bucket loads of experience to go with it. He doesn't really tune for money (thought he does charge of course) but more because he enjoys it, lets you sit in the car and explains everything he is doing and won't finish until you are happy with the result. If you just want to give him money and pick it up he isn't really interested in tuning as he doesn't get much of a kick out of generic jobs if you aren't actually interested in what is going on.
  13. Rolls
    This is more the issue, I found good tuners but they were lazy and rushed as they had too many customers half the time and I couldn't trust they had put 100% into it. When they had no cars they did a top job.
  14. Rolls
    Moral of the story, most tuners are rubbish.
  15. Rolls
    it is like how he is obsessed with rb20s for some reason, makes no sense.
  16. Rolls
    This is a bit misleading because the gear will be over quicker, hence you'll be in the taller gear sooner. If you were to graph the acceleration of both diffs overlapping you'd see on average the acceleration isn't improved greatly when looking at a large spread of kph. In just first gear etc it will be a large increase though.
  17. Rolls
    yes higher temperature = less air for the same pressure hence smaller bang/combustion pressure. So technically higher temperatures lower combustion pressure but it means a smaller increase in temperature is needed to reach autoignition temp though hence why higher intake temp charges can result in detonation.
  18. Rolls
    intake temperature would have no effect on combustion pressure surely?
  19. Rolls
    Yeah empirical evidence suggests that intake temperature are definitely the dominating factor, hence ironically it might be generally safer to make 300kw+ with a big turbo than pushing these HG turbos to the max to make 280kw (with obviously far better response).
  20. Rolls
    I guess what I am asking, which setup is more likely to induce detonation out of these two hypothetical setups running a street fuel like BP98: Hypergear turbo 24psi 250kw out of efficiency zone, cooking the air lower combustion pressure, greater temperature big GT42 or larger 15psi 400kw barely pushing the turbo, very efficiency and low temps greater combustion pressure, lower temperature. eg what is the dominating factor for detonation in an RB engine at these power levels, intake temperature, or combustion pressure? edit: or have I gotten this wrong, and with the greater temperature the combustion pressure is similar between the two setups?
  21. Rolls
    Yeah I understand how efficiency works, what I am asking is what is the main cause of detonation with everything being held constant, increasing intake temps, or increase combustion pressure (more air+fuel due to more boost).
  22. Rolls
    The chance of detonation does go up exponentially with more boost, but I am of the opinion if you tune badly enough to blow it up at 22psi, then the motor has no chance at 18psi. The same level of care is required in both situations, the same safety margins are required. What is the biggest factor for detonation at these sort of power levels, is it combustion pressure? Or is it intake temperature, I know both are major factors but combustion pressure is related to power/torque, and the smaller the turbo generally the higher the intake temp for any given power level. If it is combustion pressure then people should be more worried about power level being the factor that makes you stop due to fear of detonation, eg a a gt35 running 15psi etc. I am not sure as I don't have first hand experience tuning motors. Are engines more likely to det due to intake heat from being out of efficiency range, or more likely to det because of pure combustion pressure? An example if tuning on BP98 is it just simply hard to get over xkw due to detonation? or is it a matter of temp, so you can make 1000hp on an rb25 on bp98 as long as you get a turbo that is efficient and cool at that power level? Bit of a ramble but does that make sense?
  23. Rolls
    It will just be a touch up tune, not like he will have to do it from scratch, no biggie imo. hopefully it will be totally different weather as well, might give him the opportunity to perfect it slightly.
  24. Rolls
    Varies depending on a lot of factors, as long as its consistent it doesn't really matter, I would only worry if it read really low like 100, even then I had an rb20 that consistently read 110 across all six, burnt a tiny bit of oil but wasn't down on power at all.
  25. Rolls
    155 means it is in great condition
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