JB4 psi variations...

TexE90 · 01-13-2013, 10:21 PM

All I'm running is JB4 map 5, DCI, and 93 octane on my e90. When I first installed the JB4 after 3 WOT pulls, I was getting ~14-15 psi WOT pretty consistently. Now a month later, it seems to top off around 11-12 psi.

Is this fairly normal variation? Should I expect it to climb back to 14 psi in colder (warmer?) weather? Or is this indicative of something amiss?

E90Company · 01-13-2013, 10:31 PM

Normal. I would get an intercooler ASAP. Map 5 is probably picking up timing corrections and lowering boost to account for it. If you can post up a log.

Tdanderson · 01-14-2013, 12:31 AM

Would you say an intercooler is the most important mod after getting the jb4?

BEAR-AvHistory · 01-14-2013, 06:13 AM

You did not state mileage on your plugs or any changes in fuel used.

TexE90 · 01-14-2013, 11:05 AM

Quote:

Originally Posted by BEAR-AvHistory

You did not state mileage on your plugs or any changes in fuel used.

I'm not sure, I bought the car ~3k miles ago. I've replaced one coil in that time, but no plugs (yet). I've used 93 octane 100% of the time. Not sure what the previous owner used.

No USB cable so no logs. Though I plan on remedying this soon.

BEAR-AvHistory · 01-14-2013, 11:12 AM

You might want to think about plugs even if you don't know how long they have been in the car. About 25K is max for a 335 with modified boost. You can get them for about $12 each. You will need a special thin socket, $20, to remove & install them.

2jzn54 · 01-14-2013, 11:13 AM

log and send the csv to terry.. There isn't nearly enough information in your post for us to provide any help.. Do you have any other symptoms?

TexE90 · 01-14-2013, 11:37 AM

^ Nope, everything else feels normal. I'll get a USB cable soon and get a log if it persists.

E90Company · 01-14-2013, 11:41 AM

Quote:

Originally Posted by Tdanderson

Would you say an intercooler is the most important mod after getting the jb4?

Yes

01-13-2013, 10:21 PM	#1
TexE90 Banned 10 Rep 134 Posts Drives: 2007 335i E90 Join Date: Nov 2012 Location: United States iTrader: (1)	JB4 psi variations... All I'm running is JB4 map 5, DCI, and 93 octane on my e90. When I first installed the JB4 after 3 WOT pulls, I was getting ~14-15 psi WOT pretty consistently. Now a month later, it seems to top off around 11-12 psi. Is this fairly normal variation? Should I expect it to climb back to 14 psi in colder (warmer?) weather? Or is this indicative of something amiss?
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01-13-2013, 10:31 PM	#2
E90Company Major General 194 Rep 6,136 Posts Drives: Car Join Date: Mar 2012 Location: FL iTrader: (2)	Normal. I would get an intercooler ASAP. Map 5 is probably picking up timing corrections and lowering boost to account for it. If you can post up a log.
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01-14-2013, 12:31 AM	#3
Tdanderson New Member 4 Rep 16 Posts Drives: 2007 BMW 335i Join Date: Dec 2012 Location: Kansas City iTrader: (0) Garage List 2007 BMW 335i [0.00]	Would you say an intercooler is the most important mod after getting the jb4?
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01-14-2013, 06:13 AM	#4
BEAR-AvHistory 2020 Z4 M40i - 2022 M4C Convt 3127 Rep 5,264 Posts Drives: 2020 Z4 M40i - 2022 M4C Convrt Join Date: Jun 2011 Location: Raleigh, NC - OIB, NC iTrader: (0) Garage List 1965 COBRA (FFR rep ... [8.57] 2023 Jeep Wrangler ... [9.50] 2009 Yamaha V-Star [0.00] Cars 2-BMW, 2-FORD, ... [0.00] 2023 Ford Expeditio ... [0.00] 2020 Z4 M40i [10.00] 2022 BMW M4C [7.25] 1998 FORD Ranger 4X4 [0.00]	You did not state mileage on your plugs or any changes in fuel used. __________________ Kevin Dravit Gray, Black Leather, Moonlight Roof, Red Calipers 2022 M4C - 2020 Z4 M40i - 2023 FORD Expedition XLT Max 4X4 400BHP - 2009 V-Star - 1998 Ranger 4X4 5MT - 1965 Cobra (R) 5MT - 2023 Jeep Wrangler Sport S 6MT
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01-14-2013, 11:12 AM	#6
BEAR-AvHistory 2020 Z4 M40i - 2022 M4C Convt 3127 Rep 5,264 Posts Drives: 2020 Z4 M40i - 2022 M4C Convrt Join Date: Jun 2011 Location: Raleigh, NC - OIB, NC iTrader: (0) Garage List 1965 COBRA (FFR rep ... [8.57] 2023 Jeep Wrangler ... [9.50] 2009 Yamaha V-Star [0.00] Cars 2-BMW, 2-FORD, ... [0.00] 2023 Ford Expeditio ... [0.00] 2020 Z4 M40i [10.00] 2022 BMW M4C [7.25] 1998 FORD Ranger 4X4 [0.00]	You might want to think about plugs even if you don't know how long they have been in the car. About 25K is max for a 335 with modified boost. You can get them for about $12 each. You will need a special thin socket, $20, to remove & install them. __________________ Kevin Dravit Gray, Black Leather, Moonlight Roof, Red Calipers 2022 M4C - 2020 Z4 M40i - 2023 FORD Expedition XLT Max 4X4 400BHP - 2009 V-Star - 1998 Ranger 4X4 5MT - 1965 Cobra (R) 5MT - 2023 Jeep Wrangler Sport S 6MT
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01-14-2013, 11:13 AM	#7
2jzn54 Captain 41 Rep 823 Posts Drives: 07 E90 335i 6MT Join Date: Jul 2011 Location: United States iTrader: (6)	log and send the csv to terry.. There isn't nearly enough information in your post for us to provide any help.. Do you have any other symptoms?
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01-14-2013, 11:37 AM	#8
TexE90 Banned 10 Rep 134 Posts Drives: 2007 335i E90 Join Date: Nov 2012 Location: United States iTrader: (1)	^ Nope, everything else feels normal. I'll get a USB cable soon and get a log if it persists.
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