Gear-based boost control?
#31
Nordschleife Master
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Originally posted by NZ951
Whats that remark about the nippon denso unit not being able to realise 18psi in first gear? They are one of the most expensive and highest quality units in the market. I know what you mean by consistent. As I explained it earlier. A dual port had not been mentioned in the point earlier about spooling. Serious lack of accuracy and detail in expressions here.
Whats that remark about the nippon denso unit not being able to realise 18psi in first gear? They are one of the most expensive and highest quality units in the market. I know what you mean by consistent. As I explained it earlier. A dual port had not been mentioned in the point earlier about spooling. Serious lack of accuracy and detail in expressions here.
It's pretty obvious we're talking about dual-port wastegates when comparing the features between MBC and EBC.
And even though some engine/turbo configurations doens't make 18 psi in first, a correctly set up EBC will at least not go beyond 18 psi in higher gears, whereas a MBC continue to rise the boost bit by bit in higher gears.
#32
Race Director
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Duke read more carefully, plenty of notes about my EBC unit specifically I dont need to calm down, I am calm. No it is not obvious about the type of WG and MBC or EBC, why is it? I only changed to a dual port WG last week after 6 months of EBC on the stock WG, More poor assumptions.
Your last comment has already been noted a lot.
Your last comment has already been noted a lot.
#33
Nordschleife Master
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Originally posted by NZ951
Duke read more carefully, plenty of notes about my EBC unit specifically I dont need to calm down, I am calm. No it is not obvious about the type of WG and MBC or EBC, why is it? I only changed to a dual port WG last week after 6 months of EBC on the stock WG, More poor assumptions.
Your last comment has already been noted a lot.
Duke read more carefully, plenty of notes about my EBC unit specifically I dont need to calm down, I am calm. No it is not obvious about the type of WG and MBC or EBC, why is it? I only changed to a dual port WG last week after 6 months of EBC on the stock WG, More poor assumptions.
Your last comment has already been noted a lot.
Anyway, the discussion was about EBC and MBC capabilities. And when talking about all the EBC capabilities one must assume that we are talking about an environment where all these capabilities can be utilitzed. Meaning we are not talking about an environement with a $700 EBC and a stock crappy wastegate.
But if the better control of the EBC is worth its price that's a tough question.
#34
Race Director
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NZ, if you're using the EBC function of the Link EFI boxes, you actually don't program in the boost in the boost-map. You're programming in a duty-cycle figure and you can vary that figure in 500rpm increments to make up for turbo-efficiencies and exhaust-pressures on the wastegate. By increasing duty-cycle in the upper-RPMs (or decreasing depending upon how you have the ND solenoid hooked up), you can compensate for exhaust-pressure to maintain a flat boost-curve. However, this duty-cycle table still needs to be different for each gear in order to achieve the same boost-level in each gear. Even with larger turbos, the accelerating air-flow volume needed in the lower-gears still require custom-mapping on an individual gear basis.
So what you guys are actually discussing is the variations in the algorithms that various EBC units use to control boost. The more sophisticated ones allow you to program a target boost-pressure based upon RPM and they calculate the required duty-cycle on the solenoid automatically. Then they can also modify the duty-cycle to adjust the actual boost-level to match the desired. Those with fuzzy-logic feedback can even anticipate the turbo and wastegate and modify the next cell in the duty-cycle table based upon the results of the current one.
As far as I know, only the AVC-R can allow custom-programmed boost-levels on an individual gear basis. Using one, I was able to achieve a flat 15psi boost-curve that came on as early as 2200rpm on the stock K26/6 turbo in ALL gears. Was even able to do it at 18psi as well. This gave tremendous gains in torque, but not much more HP since the air was getting really hot at that flow-rate in the upper-RPMs (+100F over 15psi).
Using the EBC's gear-based boost-settings for traction-control on drag-cars like Rage2's is a great idea. Using the right-foot to modulate traction on 375rwhp+ cars is really tough, expecially with the types of torque-curves we have on these cars that go up with a concave shape. Torque literally hits instantly when max-boost hits and torque can increase by over +100lb•ft within just 500rpms; really difficult to control.
So what you guys are actually discussing is the variations in the algorithms that various EBC units use to control boost. The more sophisticated ones allow you to program a target boost-pressure based upon RPM and they calculate the required duty-cycle on the solenoid automatically. Then they can also modify the duty-cycle to adjust the actual boost-level to match the desired. Those with fuzzy-logic feedback can even anticipate the turbo and wastegate and modify the next cell in the duty-cycle table based upon the results of the current one.
As far as I know, only the AVC-R can allow custom-programmed boost-levels on an individual gear basis. Using one, I was able to achieve a flat 15psi boost-curve that came on as early as 2200rpm on the stock K26/6 turbo in ALL gears. Was even able to do it at 18psi as well. This gave tremendous gains in torque, but not much more HP since the air was getting really hot at that flow-rate in the upper-RPMs (+100F over 15psi).
Using the EBC's gear-based boost-settings for traction-control on drag-cars like Rage2's is a great idea. Using the right-foot to modulate traction on 375rwhp+ cars is really tough, expecially with the types of torque-curves we have on these cars that go up with a concave shape. Torque literally hits instantly when max-boost hits and torque can increase by over +100lb•ft within just 500rpms; really difficult to control.
#35
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NZ951,
FWIW, I have a cheaper ProfecB EBC, a Tial46mm, and EVO diverter valve (that I had to shim) and I can get 18lbs boost in all gears instantly - by that I mean, it just jumps to 18lbs very quickly and holds all the way to redline - although I have not had the opportunity to try 18lbs in 5th - I'm sure it can hit and hold in 5th, but I would only try that at the track.
Good Luck!
FWIW, I have a cheaper ProfecB EBC, a Tial46mm, and EVO diverter valve (that I had to shim) and I can get 18lbs boost in all gears instantly - by that I mean, it just jumps to 18lbs very quickly and holds all the way to redline - although I have not had the opportunity to try 18lbs in 5th - I'm sure it can hit and hold in 5th, but I would only try that at the track.
Good Luck!
#36
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I had no chance of getting 18psi in first, but I have not tried it with the new turbo yet with the Tial. It will be interesting to see how it goes. You must have a hell of a turbo to jump to 18psi instantly in first gear.
#37
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[QUOTE]I had no chance of getting 18psi in first, but I have not tried it with the new turbo yet with the Tial. It will be interesting to see how it goes. You must have a hell of a turbo to jump to 18psi instantly in first gear.
I don't have a very big turbo - it is a Garrett (sp?) TO4B #8 - maybe why it jumps so fast is because I have short gears (ring and pinion) - it simply winds up real fast.
I also can control how fast it winds to full boost with a control on my ProfecB called "Sharp" - I have it set full clockwise - anyways, short gears on the street and track works good for me.
I don't have a very big turbo - it is a Garrett (sp?) TO4B #8 - maybe why it jumps so fast is because I have short gears (ring and pinion) - it simply winds up real fast.
I also can control how fast it winds to full boost with a control on my ProfecB called "Sharp" - I have it set full clockwise - anyways, short gears on the street and track works good for me.
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