Spiff44
Senior Member
- First Name
- Rob
- Joined
- Aug 23, 2019
- Threads
- 5
- Messages
- 65
- Reaction score
- 19
- Location
- Permanently out to lunch
- Vehicle(s)
- 2019 Civic SI
- Thread starter
- #1
Hello fellow enthusiasts..
Old timer here.. been doing Honda engine swaps since the early 87's... but recently bought myself a new 2019 SI. Its my first turbo application. (have to say.. its no replacement for a mean B16)
I thought I had a pretty good understanding of how turbo's work until I got this car and started watching the boost gauge as I drive. I was very surprised with how often its under negative pressures.. When cruising in 6th at about 3000RPM (80-85), it pretty much stays at -5 pressure. This blew my mind!
I never heard about it before and searching around there is little information on "negative boost". So I am here looking for more information from someone smarter than me. To me, it doesn't make sense.. the only time I might expect something like that would be under sudden throttle back or similar. But under constant modulation? Just seems weird. (then again.. turbos and superchargers sound impossible if I didn't already know that they work....here, have some FREE power!)
Can anyone shed some light? Seems like I have to go to about half throttle to start pushing positive boost.. so what effect is the negative pressure doing/causing in the meantime? Apparently its good for MPG..
Thanks
Spiff
Old timer here.. been doing Honda engine swaps since the early 87's... but recently bought myself a new 2019 SI. Its my first turbo application. (have to say.. its no replacement for a mean B16)
I thought I had a pretty good understanding of how turbo's work until I got this car and started watching the boost gauge as I drive. I was very surprised with how often its under negative pressures.. When cruising in 6th at about 3000RPM (80-85), it pretty much stays at -5 pressure. This blew my mind!
I never heard about it before and searching around there is little information on "negative boost". So I am here looking for more information from someone smarter than me. To me, it doesn't make sense.. the only time I might expect something like that would be under sudden throttle back or similar. But under constant modulation? Just seems weird. (then again.. turbos and superchargers sound impossible if I didn't already know that they work....here, have some FREE power!)
Can anyone shed some light? Seems like I have to go to about half throttle to start pushing positive boost.. so what effect is the negative pressure doing/causing in the meantime? Apparently its good for MPG..
Thanks
Spiff
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