Cold boost cut

s300 and SManager software questions & answers
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2x0
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Cold boost cut

Post by 2x0 » Fri Jun 23, 2017 5:59 am

I've been looking through my calibration trying to figure out why this happens:

When the car is not fully up to temp, say 140-160 degree ECT, it acts like it will not let me make boost. If I step on it, as soon as it tries to spool it's like it's hitting boost cut. Once it's up to 180+, no issues.

I thought it would surely be something to do with my boost cut settings, but looking into it I have 20psi set as boost cut whether hot or cold.

Calibration is attached, any other ideas as to why this might be happening?

Thanks,
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5-24-17 Increased Fuel Maps 10-15-20pct.skl
(48.61 KiB) Downloaded 71 times
'91 CRX, B18c1, T3/T4, 17psi on e85, FIC 1000cc's, S300 V3 P28

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Hondata
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Re: Cold boost cut

Post by Hondata » Fri Jun 23, 2017 8:55 am

I'd look at a datalog first and see if it is a boost cut or not.
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2x0
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Re: Cold boost cut

Post by 2x0 » Fri Jun 23, 2017 12:47 pm

Alright I'll try to get a datalog next time it happens.

Thanks!
'91 CRX, B18c1, T3/T4, 17psi on e85, FIC 1000cc's, S300 V3 P28

2x0
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Re: Cold boost cut

Post by 2x0 » Sat Jun 24, 2017 12:49 pm

I was unable to recreate the problem when driving today. However I did not realize before that Smanager shows when boost cut is active, so I will look for that next time it happens.

Thanks for the help.
'91 CRX, B18c1, T3/T4, 17psi on e85, FIC 1000cc's, S300 V3 P28

forevertrj
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Re: Cold boost cut

Post by forevertrj » Sat Jun 24, 2017 6:57 pm

I also noticed that your fuel injectors are 1000cc, and that your overall fuel trim is 30%, it should be at 0%, I'd have a second look at your dead times and make sure they are correct, and if they are maybe your fuel rail pressure isn't correctly set. any chance you have a datasheet for those injectors?
Let's not make assumptions, please leave as much detail as possible!

2x0
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Re: Cold boost cut

Post by 2x0 » Sat Jun 24, 2017 8:11 pm

Fuel trim is at 30% I think for the e85. I have actual flow rate and dead times which I am going to fix once I start fine tuning fuel tables in open loop.
'91 CRX, B18c1, T3/T4, 17psi on e85, FIC 1000cc's, S300 V3 P28

forevertrj
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Joined: Mon May 12, 2014 4:13 pm
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Re: Cold boost cut

Post by forevertrj » Sat Jun 24, 2017 8:28 pm

if you change flow rate and dead times after tuning, you'll have to tune again... and don't you have the ford flex fuel ethanol sensor wired in which is designed to adjust the map for you for e85...
Let's not make assumptions, please leave as much detail as possible!

2x0
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Re: Cold boost cut

Post by 2x0 » Mon Jun 26, 2017 7:33 am

Yeah I realize, it is not tuned yet, just running on an old tune from before I replaced the S300, so there have been some issues.

The 30% was added to the original P72 basemap to account for e85 vs gas, and the injectors scaled to 1000cc just to get it running. So it is still a basemap, and I am starting today by correcting the injector settings so I can retune the fuel maps.

If I take my overall trim back to 0% then I would need to add 30% to my tables, so I don't really see the point.
'91 CRX, B18c1, T3/T4, 17psi on e85, FIC 1000cc's, S300 V3 P28

2x0
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Joined: Sat Feb 04, 2017 6:51 pm

Re: Cold boost cut

Post by 2x0 » Mon Jul 10, 2017 7:30 am

To put some resolution to this thread... I believe the issue is that with colder ECT and IAT it was compensating with more fuel. Under certain conditions it was running excessively rich to the point of misfiring.

Even when warmed up, under heavy throttle, lower RPM it was running pegged rich. So I am pretty sure that's all it was.
'91 CRX, B18c1, T3/T4, 17psi on e85, FIC 1000cc's, S300 V3 P28

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