Mx40i / B58 JB4 & Decat Setup

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DEJM140
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Mx40i / B58 JB4 & Decat Setup

Post by DEJM140 » Wed Mar 28, 2018 12:24 pm

Hi guys,

I've been reading over quite a few posts from the past that there have been issues with installing decats to the B58 / Mx40is and was wondering if there have been any solutions to these issues?

I spoke to my tuner this morning who has advised that throttle closure issues do happen, but apparently even as standard these cars with log throttle closures as it's the cars way of regulating boost pressure to a degree, but people only notice it happens as they start data logging once they have tuned their vehicle.

Anyway, I'm booked in for decat and JB4 this week, but wondering if anyone is still facing any issues with this setup?

Thanks in advance.

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Re: Mx40i / B58 JB4 & Decat Setup

Post by Blind Pugh » Wed Mar 28, 2018 12:58 pm

If yr tuner is installing just JB4 w/o add-on harnesses for EWG and FP then yes yr B58 logs may see DME closing throttle to regulate boost to keep within predefined timing and fuelling caps.

If yr tuner is installing both extra EWG and FP harnesses then the concern about and probability of throttle closures occurring reduces.

EWG harness - JB4 controlling Electronic WasteGate [EWG] directly should see WGDC reduce which will mitigate boost / creep and unplanned throttle closures.

FP harness - JB4 direct connection to Fuel Pressure [FP] allows Jb4 to monitor fuel rail pressure directly and tweak signal to help DME keep fuel trims and AFR in check at higher boost/load levels.

If running a decat DP and hoping to hit high/stable boost numbers on 98/99RON SUL fuel then I'd recommend adding both EWG ad FP harnesses to get the most out of the decat DP.
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Mrpink
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Re: Mx40i / B58 JB4 & Decat Setup

Post by Mrpink » Wed Mar 28, 2018 6:13 pm

there is a lot of confusion around throttle movement.

It’s perfectly normal for the throttle to move.

The issue some are having with their B58 is excessive throttle closure which causes physical hesitation.

You can tune this out with the JB4
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Element
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Re: Mx40i / B58 JB4 & Decat Setup

Post by Element » Fri Mar 30, 2018 8:10 pm

Leave the decat/downpipe out of the mix. There is no performance benefit and is more trouble than it's worth in terms of troubleshooting even with the tweaks and addon harnesses.
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DEJM140
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Re: Mx40i / B58 JB4 & Decat Setup

Post by DEJM140 » Sat Mar 31, 2018 1:14 am

Element wrote:
Fri Mar 30, 2018 8:10 pm
Leave the decat/downpipe out of the mix. There is no performance benefit and is more trouble than it's worth in terms of troubleshooting even with the tweaks and addon harnesses.
I'm due to have my JB4 installed in a couple of weeks. I've already purchased the Decat from JB4Shop as I was under the impression it was a requirement to make full use of the JB4.

Can Map2 etc still be used to good effect without the decat?

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Re: Mx40i / B58 JB4 & Decat Setup

Post by Blind Pugh » Sat Mar 31, 2018 8:50 am

Element wrote:
Fri Mar 30, 2018 8:10 pm
Leave the decat/downpipe out of the mix. There is no performance benefit
Removing (or reducing from) 1000cpi DP will be beneficial if wanting raise boost reliably.
DEJM140 wrote:
Sat Mar 31, 2018 1:14 am
I'm due to have my JB4 installed in a couple of weeks. I've already purchased the Decat from JB4Shop as I was under the impression it was a requirement to make full use of the JB4.

Can Map2 etc still be used to good effect without the decat?
Suggest you read/save to favourites this link.

http://www.n54tech.com/forums/showthread.php?t=31429
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DEJM140
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Re: Mx40i / B58 JB4 & Decat Setup

Post by DEJM140 » Sat Mar 31, 2018 12:51 pm

Blind Pugh wrote:
Sat Mar 31, 2018 8:50 am

Suggest you read/save to favourites this link.

http://www.n54tech.com/forums/showthread.php?t=31429
Thanks buddy, appreciate it

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