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Avg Peak Boost on Stock Turbo - Custom JST Tune

Messages
241
Likes
125
Location
Santa Rosa
#1
Hey All,

I'm curious about what peak boost numbers people are seeing who have a similar set up to mine and are tuned by JST. (see details on car below).
Upfront, the car maybe sees 24-24.5 at most in peak boost, during a 4th gear pull. This has been consistent since i got the tune nearly 4 years ago.. and boost never came up as a concern.

Here's the stats:
I'm running a custom JST tune (91 & E30)
Car is 2015, 115k on the clock.
Car basically just has panel filter, intercooler and exhaust(really no power gain here) stock dp, GFB DV+, J-pipe & cooler ngk plugs— for power.


To be clear, I don't care that much about peak boost numbers, more so what i'm getting throughout the curve, HOWEVER...I tried a new flash tune recently from Dizzy and Jason said my peak boost was below (nearly 24 psi or so) what he likes to see closer to 26psi— so I'm curious about maybe a boost leak which another tuner pointed out looking at my recent datalogs. Checked boost hoses and they'are all clamed up nice.
 


Last edited:

dhminer

2000 Post Club
Messages
2,453
Likes
2,878
Location
Burlington, NC, USA
#2
Hey All,

I'm curious about what peak boost numbers people are seeing who have a similar set up to mine and are tuned by JST. (see details on car below).
Upfront, the car maybe sees 24-24.5 at most in peak boost, during a 4th gear pull. This has been consistent since i got the tune nearly 4 years ago.. and boost never came up as a concern.

Here's the stats:
I'm running a custom JST tune (91 & E30)
Car is 2015, 115k on the clock.
Car basically just has panel filter, intercooler and exhaust(really no power gain here) stock dp, cooler ngk plugs— for power.


To be clear, I don't care that much about peak boost numbers, more so what i'm getting throughout the curve, HOWEVER...I tried a new flash tune recently from Dizzy and Jason said my peak boost was below (nearly 24 psi or so) what he likes to see closer to 26psi— so I'm curious about maybe a boost leak which another tuner pointed out looking at my recent datalogs. Checked boost hoses and they'are all clamed up nice.
Can’t speak to JST but I was always 26+ on Dizzy’s stage 2 and E30. You have stock BPV?
 


OP
HAHAFiST
Messages
241
Likes
125
Location
Santa Rosa
Thread Starter #3
Can’t speak to JST but I was always 26+ on Dizzy’s stage 2 and E30. You have stock BPV?
I have that tune as well, and similar peak numbers. I'm running a DV+ which i service every other oil change. I do get the occaional evap code for the cannister, I think it might be time to do a smoke test. My dry compression test came back pretty good, 180+ on all cyls. I'm still on stock boost hoses and they have 115k on them. I'm not loosing boost per se, just not hitting peak. What's funny is Dizzy never mentioned boost being a concern when I dataogged that stage 2 E30 tune.
 


dhminer

2000 Post Club
Messages
2,453
Likes
2,878
Location
Burlington, NC, USA
#4
I have that tune as well, and similar peak numbers. I'm running a DV+ which i service every other oil change. I do get the occaional evap code for the cannister, I think it might be time to do a smoke test. My dry compression test came back pretty good, 180+ on all cyls. I'm still on stock boost hoses and they have 115k on them. I'm not loosing boost per se, just not hitting peak. What's funny is Dizzy never mentioned boost being a concern when I dataogged that stage 2 E30 tune.
I wouldn’t worry much about it then. Keep in mind a smoke test won’t tell you anything about boost leaks unless it’s egregious since they’re typically at a very low pressure. I use a boost leak testing plug on the compressor outlet and charge the whole system up to ~20 psi and spray dish soapy water to leak test. Pain in the ass to do but works great.

Link to testers if interested https://turboboostleaktesters.com/how-to-boost-leak-test/
 




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