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I've been running mine set all the way to min. so far. I remember reading other posts suggesting that this could happen to me during setup depending on circumstances and that it varies quite a bit from motor to motor even in the same model and year. My particular setup is '95 stock'Teg VTEC with the only mods being JRSC @ 6psi and JR BTC, using Sunoco 94 octane gas. Stock intake, stock header, stock exhaust, no headwork, no cam adjustable cams - just the blower and the box.
Seems okay, but I haven't rung the system out yet, so it might be running rich. One of the things I need to find out yet is how much of a difference putting 92 octane will make. I suspect that it will lead to running several clicks clockwise from where I am now. Also the weather here is 70's max during the day now, which probably makes a diff as well.
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Raffe, that's brilliant. Where do I get one?
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'00ITR#739
JRSC, JR Walbro FP, JR intake, J&S SafeGuard, JR BTC
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Under $10 in parts from Radio Shack. Sorry, I'm not packaging it, I don't want the liability or hassle, but I'm happy to share the design as there's not much to it.
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Raffe, I'm also instead if you don't mind giving us some instructions. Thanks.
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Me three! I lost the link to the schematic you have out there.
Thanks.
Greg
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Raffe, I thought you mentioned in one of the message that with the installation of the BTC, the problem with the TPS and ECU was eliminated??
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The combination of more initial timing and elevated baseline fuel pressure (plus reduced rise rate on the regulator to compensate for the higher baseline) virtually eliminated the hesitation brought on by the lean condition. More timing makes the motor more responsive reducing the hesitation caused by the lean condition to the point where it is less or completely unnoticeable depending on how you drive, but the lean condition is still there. Just for a briefer period and with greatly diminished effect on drivability.
The ECU stays in closed loop until the throttle's down a bit and this is not good when there's significant boost. The problem gets worse when running more boost due to the reduced responsiveness caused by running even less timing and, in the case of a JRSC, the increased boost present at lower RPM with even less throttle.
The addition of the TPS relay circuit I described eliminates the lean condition and arms the J&S as soon as there's enough boost to open the pressure switch. It's convenient that the pressure switch opens at 1psi as this not only works well with the JR enrichment relay, it also works well with the TPS trick. Different pressure switches that open at different pressures could have been used were it necessary, but on my setup, there's no apparent need.
I can take credit for the implementation as it's mine, but I can't take credit for the idea, it came from JeffM of ZDYNE. Perhaps the post where he mentioned it is still on this board somewhere if anyone's interested.
Anyhow, it's no big deal. I'll start a new thread which references the schematic and describes the installation.
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I would like to see the schematic or even buy the schematic from you! http://www.hostboard.com/ubb/biggrin.gif Thanks!
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It take a Nation of Millions to hold Us Back!!!
http://www.bocajuniors.com.ar/escuani.gif
C-SpeedRacing
[This message has been edited by MouhadIb (edited October 17, 2000).]
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I've just installed mine over the weekend. One thing I'm curious about is how you guys can run the BTC 3 or 4 clicks from minimum. My initial timing before BTC was 9 degrees. Doing the simple math, I've set my BTC at 12 o'clock (1 degree per lb. of boost) so at full boost it will be 9 degrees TDC at 6 lbs.
I don't have any guages or J & S and Cartech not installed, which is the reason for my 15 degree timing and BTC knob setting. Can anyone explain?
Thanks,
Adrian.
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Isn't each click 0.2 deg retard/lb boost? That means 5 clicks is 1.0 retard/lb boost right? And the 12 o'clock position, which is roughly 7-9 clicks is more retard than that.
