22psi Stock???

gtman

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I understand about the MAP intake having poor fuel trims but that wouldn't explain you seeing 22 psi on the stock tune.
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wolfgang82

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I understand about the MAP intake having poor fuel trims but that wouldn't explain you seeing 22 psi on the stock tune.
There might be more to it than just that, but I failed to mention I already put the 1.5R tune on my car. In map 1 which has a target psi of 19.5 I saw 24, so I emailed Phearable and asked for help on the situation, they said it was likely due to the MAF housing. When I change intakes I will post an update hopefully next week.
 

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There might be more to it than just that, but I failed to mention I already put the 1.5R tune on my car. In map 1 which has a target psi of 19.5 I saw 24, so I emailed Phearable and asked for help on the situation, they said it was likely due to the MAF housing. When I change intakes I will post an update hopefully next week.
I'd suspect a wastegate calibration issue.
 

xbbnx

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If you bought it used, my guess is the previous owner sold/traded it with a tune on it. No way you'd see 20-22 psi on a stock Si. Most you'd see stock is probably 17-18 psi max.
I've had my 17 Si since brand new and I've seen 19 PSI a couple times and seen 20 psi like once bone stock.
 
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wolfgang82

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Update, as stated in my last update I am on the Phearable 1.5R tune and was seeing 29 psi with the MAP CAI. I reverted back to the stock intake and took it for a drive. I maxed out my boost on map 3 which has a target of 26 psi, which I hit exactly and did not exceed. So I do believe it was the MAF housing on the MAP CAI.
 


StayAtHomeDad

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I want to preface by saying my car is running great with no issues... That being said, my car is a 2018 Si coupe with only one modification being a MAPerformance CAI. I just went out for a drive and I hit 22 psi on the gage. Itā€™s 56 degrees where I am and this is the first time Iā€™ve ever seen 22psi, but Iā€™ve normally seen 20 and 21 psi several times. This seems uncommon, any thoughts on why? Is my gage just wrong?

I read through this thread before this post, and though from lurking, I trust gtman for input... I now own a 2018 SI sedan (bought with 21xxxk miles last week/10 days ago, just above 24k now) No signs of modification, one owner, local trade, blah blah blah.... anyway, I have definitely also seen above 20psi on the boost gauge on the dash.
I probably don't have specifics enough to help, and my tuner doesn't arrive until Monday night to check for an ECU flash (thanks Two-Step performance - I bought the TSP 1+ tune package w/ ktuner)... but, i read an article on how to read a boost gauge, and thought i'd go try a few things. I noticed while in neutral, no matter how i rev the engine, the BPV doesn't allow boost to build (usually stays at -10, but it did spike at -8 with quick blips of the throttle. I was doing this on a warm engine also). SO finding the ideal RPM to boost point for launch was a bit more work.
Same testing, but now actually driving - varying throttle techniques in different gears regularly had boost above 20psi- without WOT and if i remember correctly, usually in 3rd gear. Temperatures were near 50 degrees Farenheit (maybe a high of 56, low of 45- dont remember exactly)
Running local 93 octane fuel, first fill up was with Kwik Trip top tier gasoline, second was with ethanol free 93 octane from a shell station, and now back to the kwik trip 93 w/ ethanol regularly.
I have knowingly once (one drving trip, through 4 gears) floored the throttle now, and I think i only hit 17 or so psi, and haven't pursued further testing/or pushing the limits too much. Mainly just backroad twisties in 2nd/3rd gear not watching boost gauge so much.

All this testing was done before I found this civicx forum, and learned that my civic won't actually push that much boost on a stock tune... I know this doesn't help, but i do not believe my car has a tune/modified ECU - I guess i'll find out monday (i did test drive one that came tuned with downpipe and intake, and it was a different animal), so the only conclusion is that the boost gauge reading on my dash is inaccurate???
 

gtman

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I read through this thread before this post, and though from lurking, I trust gtman for input... I now own a 2018 SI sedan (bought with 21xxxk miles last week/10 days ago, just above 24k now) No signs of modification, one owner, local trade, blah blah blah.... anyway, I have definitely also seen above 20psi on the boost gauge on the dash.
I probably don't have specifics enough to help, and my tuner doesn't arrive until Monday night to check for an ECU flash (thanks Two-Step performance - I bought the TSP 1+ tune package w/ ktuner)... but, i read an article on how to read a boost gauge, and thought i'd go try a few things. I noticed while in neutral, no matter how i rev the engine, the BPV doesn't allow boost to build (usually stays at -10, but it did spike at -8 with quick blips of the throttle. I was doing this on a warm engine also). SO finding the ideal RPM to boost point for launch was a bit more work.
Same testing, but now actually driving - varying throttle techniques in different gears regularly had boost above 20psi- without WOT and if i remember correctly, usually in 3rd gear. Temperatures were near 50 degrees Farenheit (maybe a high of 56, low of 45- dont remember exactly)
Running local 93 octane fuel, first fill up was with Kwik Trip top tier gasoline, second was with ethanol free 93 octane from a shell station, and now back to the kwik trip 93 w/ ethanol regularly.
I have knowingly once (one drving trip, through 4 gears) floored the throttle now, and I think i only hit 17 or so psi, and haven't pursued further testing/or pushing the limits too much. Mainly just backroad twisties in 2nd/3rd gear not watching boost gauge so much.

All this testing was done before I found this civicx forum, and learned that my civic won't actually push that much boost on a stock tune... I know this doesn't help, but i do not believe my car has a tune/modified ECU - I guess i'll find out monday (i did test drive one that came tuned with downpipe and intake, and it was a different animal), so the only conclusion is that the boost gauge reading on my dash is inaccurate???
I've always wondered about the accuracy of that dash gauge and wonder if that's the part of the issue here. The stock tune does technically peak at 20 psi but I think that's only briefly at 5500 rpm or so and then it tails back off. And again, anecdotally, few people with Si's are seeing much more than 18 psi regularly in real world driving. But I guess in certain conditions a boost target overshoot is possible.

On the other hand, that TSP 1+ will have your car feeling like a different machine.
 
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scottgas

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I get 93 octane and average 30mpg.
is that mixed driving. I commute 110 miles per day usually at 80mph and average 36mpg. Even with mixed driving I average 33-34 mpg. 2019 Coupe Si. This is usually on 87 octane and a heavy foot
 
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wolfgang82

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is that mixed driving. I commute 110 miles per day usually at 80mph and average 36mpg. Even with mixed driving I average 33-34 mpg. 2019 Coupe Si. This is usually on 87 octane and a heavy foot
Yes, this is just my overall gas mileage including commute and city, mainly city.
 


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You might try a higher octane fuel. 91-93 will make more power. I didnt think anyone was running 87 in the si.
You can run it since thatā€™s the minimum octane required on stock tune, but around here on this forum, itā€™s not common. I know both times when I purchased my Siā€™s, they put 87 in, since thatā€™s the minimum requirement. Before my tune, I ran 91, mostly because it felt better. I still do even though Iā€™m tuned, cause next level around here is 94 and that shits expensive in Canada lol
 

vandalSI

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Right on. I have a 93 station right by my house. Have to travel about 20 minutes for my e85 though. ā˜¹ my si loves ethanol but i only run it maybe 1-2 tanks a month.
 

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One last update for anyone that cares... I was able to reflash to stock, no problem. Using Ktuner was simple and straightforward. Only problem now is the car is disappointingly slow
and rev hang sucks lol. I think I'll hang on to the Ktuner, just in case ;) Thanks guys!

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I've always wondered about the accuracy of that dash gauge and wonder if that's the part of the issue here. The stock tune does technically peak at 20 psi but I think that's only briefly at 5500 rpm or so and then it tails back off. And again, anecdotally, few people with Si's are seeing much more than 18 psi regularly in real world driving. But I guess in certain conditions a boost target overshoot is possible.

On the other hand, that TSP 1+ will have your car feeling like a different machine.
It never boosts that high stock, at those rpm (5500).

Ive seen 20 psi stock maybe a half dozen times and it is always just below 3k rpm. Stock boost tapers off quite rapidly above 5000rpm.

If anyone stock is seeing 20psi regularly, then either something is wrong with wastegate or they have a tune.
 


 


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