Attn Tuners; The Difficulty Tuning Ball-Bearing T
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Honda-Tech Member
Joined: Dec 2001
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From: NW, FL
Attn Tuners; The Difficulty Tuning Ball-Bearing T
I'm trying to come up with something drivable. A setup that will be smooth (no hesitation), efficient driving around town, still have great traction (power goal less than 320hp), and will carry my fat friends (displacment > 1.8litre)
.
Under 25% throttle, ECU will try to maintain regular A/F ratio of 14.7:1 (in closed-loop operation), and will average short-term to get the long-term adjustment. The ECU uses the long-term once it’s out of closed-loop (at full throttle).
What if the ECU sees boost early at partial throttle from a ball-bearing turbo?
I predict it will become difficult to tune ..especially when the conditions change.
Is it better off going with a non-ball bearing turbo? Or..
Should I disable closed-loop?
But isn’t closed loop needed for the kind of setup I want?: to be efficient in part throttle, and still produce highend power…
How sensitive will spool-up be from a 1.8 - 2.0litre with a GT30 [.70 A/R compressor house & .60 A/R house for turbine]?
I predict it’ll come on @ 3600rpm, and most of the time, at that rpm, the ECU is still in closed loop!
[Modified by Quick 200k Mile Motor, 9:18 PM 1/23/2003]
.Under 25% throttle, ECU will try to maintain regular A/F ratio of 14.7:1 (in closed-loop operation), and will average short-term to get the long-term adjustment. The ECU uses the long-term once it’s out of closed-loop (at full throttle).
What if the ECU sees boost early at partial throttle from a ball-bearing turbo?
I predict it will become difficult to tune ..especially when the conditions change.
Is it better off going with a non-ball bearing turbo? Or..
Should I disable closed-loop?
But isn’t closed loop needed for the kind of setup I want?: to be efficient in part throttle, and still produce highend power…
How sensitive will spool-up be from a 1.8 - 2.0litre with a GT30 [.70 A/R compressor house & .60 A/R house for turbine]?
I predict it’ll come on @ 3600rpm, and most of the time, at that rpm, the ECU is still in closed loop!
[Modified by Quick 200k Mile Motor, 9:18 PM 1/23/2003]
New User
Joined: Nov 2000
Posts: 3,467
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From: Tampa, FL, USA
Re: Attn Tuners; The Difficulty Tuning Ball-Bearing T (Quick 200k Mile Motor)
i suppose you are referring to using Hondata? If that is the case, let your mind at ease. Hondata bases closed/open loop on a changable vaccum/pressure point. Hence, once you cross this threshold, it goes into open loop, regardless of your throttle position. Hope that clears it up 
Joined: Sep 2002
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From: You wish I was..., USA
Re: Attn Tuners; The Difficulty Tuning Ball-Bearing T (VaporTrail)
Even with fuel management that doesn't do this you just buy a bigger turbo so it doesn't spool as early. The whole reasoning behind the ball bearing turbo was so you could run a larger one. 
Get a straight monster. 
Have fun...
Get a straight monster. Have fun...
Joined: Sep 2002
Posts: 1,969
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From: Where Geos Go Fast, 95355
Re: Attn Tuners; The Difficulty Tuning Ball-Bearing T (tzsir)
ball bearing turbo, too is designed for lower rpm spoolup. ala mazda speed BB t-28.. etc..
ball bearing good for quick spoolup where you want it.
ball bearing good for quick spoolup where you want it.
New User
Joined: Nov 2000
Posts: 3,467
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From: Tampa, FL, USA
Re: Attn Tuners; The Difficulty Tuning Ball-Bearing T (Quick 200k Mile Motor)
To answer your IM, because it would not load properly, no it would not hurt you to have an early spool. Hondata reads vaccum/pressure the same at any rpm. The GT30 comes in a 52 trim in a .70 a/r comp housing, nice spool, just make sure you get the .63 a/r exh housing, tough to find but well worth it.
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