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burn4005

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Everything posted by burn4005

  1. R35 coils and the greatest spark plugs in the world, Denso IK01-24 or NGK R7434-8 and forget about it for a couple of years. they can be had from RHD japan for relatively reasonable money. supercheap will hit you for $99 a plug.
  2. Hi, sorting out some brakes for the skyine. got my spreadsheet out for dynamic brake bias, but I need the height of the centre of gravity. I've managed to find corner weights on the internet but not a COG height. anyone have a number? (can be for 32/33/34 just need something ballpark. I dont have corner scales or a hoist so I can't do the incline measurement test myself. thanks
  3. looks to allow for a lot more customisation in the mapping of it, and introduce wheel speed/slip if you use the additional wheel speed unit.
  4. not too many ECUs have an analog output (only Emtron KV comes to mind) unless you use something like this: https://www.haltech.com/product/ht-038000-analogue-output-adaptor/
  5. the GTIII was a journal bearing wasn't it?
  6. would love to see a datalog of transient boost at 5500rpm from off throttle to WOT between those two.
  7. I would say one of the best pairings to the Getrag is an ATS carbon twin plate. the gearbox side clutch assembly (hub and plates) is unbelievably light. Each carbon disc weighs about 190 grams and really reduces the amount of work the syncros need to do. caveat is if you do a lot of start stop traffic driving (cold slipping) it wears quite quickly. but once hot its a beast.
  8. concept being even pulses? I can see two differing approaches for an I6 engine with regular cylinder pairing (1-6,2-5,3-4) equal length runners into a split T04 collector with seperate wastegates (lets assume each runner in this example is equal length and same cross sectional area): vs a concept like this (shared flow path to collector):
  9. can you elaborate on what a proper pulse converter manifold looks like? my manifold is cyl 1,2,3 -> one scroll 4,5,6 -> other scroll. the first place the gas paths meet is just before they hit the turbine blade.
  10. im in a similar place with similar power. half of the bits in the getrag are becoming rocking horse shit (try to find an input shaft) neat gearboxes are commissioning parts to be made by albins, but they are pricing them like they have a monopoly. only thing you can do is ISF polish the gears and go to a billet centre plate, next step is the big boi boxes.
  11. You need 6.7mm of valve clearance at TDC. Easiest is to determine if you have this after assembly but quite a waste of time.. IF you did your trigonometry at school and have the piston information and valve angle then you should be able to work it out. Ie put the head on a bench and measure relief to deck height, then do the same for the block to piston and add the gasket thickness.
  12. you're overthinking it and your gut feel is way off. Its primarily an oil drainage concern. the axial thrust forces on a compressor/turbine assembly are huge when operating at high mass flows. force on the thrust surfaces due to gravity will be orders of magnitude less. the compressor its trying to suck itself out the front of the turbo and the turbine is trying to blow itself out the exhaust. yes, these forces are in opposite directions but do not cancel completely which is why journal bearing turbos require a thrust bearing as they have no inherent axial stability otherwise. from your chart the most appropriate bearing for a CHRA would either be a pair of identical 7s or a pair of 6s in a mirrored arrangement. main concern is oil drainage and oil pooling at the back of the CHRA if the angle is excessive, for the same reason a maximum of 20degrees of rotation about the shaft axis is recommended. remember, accelerating and braking the car at ~1g is going to impart more force on the rotating assembly than inclining it by even 45 degrees, let alone 10 or 20. this is a question that should be directed at BW.
  13. Variable valve timing should be tuned to optimise VE. The better the VE the more power you can make with less boost. Less boost means less EMAP. Pumping losses are lower. if you improve VE and still run more boost and the engine breaks thats on you. The Dyno told you how much torque you were making. If you try to hit a power target with poor VE, you need more boost. You have more EMAP and higher pumping losses to overcome. The engine is more stressed at the same power output as the losses are higher. You should be tuning an engine to torque. A turbo engine will make peak torque as it crosses peak efficiency of the compressor. This is towards the midrange airflow/revs of most engines.
  14. back pressure not relevant to compressor flow. (in the context of the operating point on a compressor map. yes, it affects VE) but remember that 2.6 bar gauge inlet pressure will end up being more like 3.7 absolute PR (Possibly higher) once you factor in the inlet filter and intercooler pressure drops, which crosses closer to low 80s flow point at that wheel speed. i'd be happy with 750hp at the hubs at this operating point. 900 at the hubs through diffs and gearbox flowing ~85lb/min is asking a bit much isn't it? the Motec will have a logged VE calculated airflow. if your injector data is good and you lambda=target the Motec calculated airflow will be accurate if you wanted to verify.
  15. I need a 700kw turbo and a cable throttle to drive my no aero no slicks car on a twisty track because more peak power is faster. got it.
  16. ok I'll bite. traction control gives you CONTROL to allow you closer to the limit. if it is done correctly, you will be faster. DBW doesnt give you more power. it gives you CONTROL of available power. if it is done correctly, you will be faster. "big turbo good" isnt the answer. the post was about the 8474 coming on too hard. DBW can linearise the power developed. and compared to an 9280, sure the peak power isn't as high, but the spread of controllable power is wider. a larger turbo just gives you a smaller band you have torque demand authority. if your gearing dictates a second gear hairpin or third gear chicane complex down to 4000rpm, i garantee the smaller turbo with DBW torque demand will get you around it MUCH faster than a larger turbo with a cable throttle. if we are talking about turbos of this size you dont need more peak power at the apex, you need more control of midrange torque and having a large turbo so it doesn't come on as hard is a bandaid solution. sure, at QR "big turbo good". but at lakeside/morgan park its not useful.
  17. thats a very non-DBW way of thinking of things. a responsive turbo gives you more control authority.
  18. this is where the significantly more efficient 84 or 91mm compressors would be better over the 83mm at high mass flows. the 91mm is about 10% more efficient above 70lb/min, which corresponds to about 7% extra mass flow that can be bled out the gate due to the reduced shaft power requirement.
  19. or run a screamer. venting ~25% mass flow out a short screamer reduces your full exhaust requirements in a big way.
  20. interesting. which turbo do they reach for these days? the 84 or the 91 or are there tracks that they'd go one over the other?
  21. thats a super interesting comparison.. 0.8 to 1.45 is a pretty dramatic turbine difference to not see any transient difference. Im guessing you had the boost response tuned to be quite soft for the 8474 that wasn't nessasary with the 9174?
  22. My 8374 is at 127krpm at 490wkw (650whp) so it has nothing left. You'll need an 8474.
  23. Did they have to go to a smaller base circle for this? I imagine they would have to in order to effectively add meat to the lobe to get a longer duration.
  24. I've got a Series 6 25 row setrab in a nismo duct and on the track oil temps still get to 120 degrees after 5 laps. on the road im not sure I'd bother. definitely put a temp sensor in and if you are getting over 100 degrees move to a decent synthetic oil then keep it under 120 degrees. if you can't keep it below this, then spend the money on the cooler.
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