Boost gauge fitted, so now know what mine's doing while still stock!

[elnevio]

The clue is in the title - I have now fitted a boost gauge - with thanks to Spirit's excellent article: http://www.clubvr4.com/forum/showthread.php?t=1154

Have also had the chance to drive about 150 miles today to see what the boost is doing. At WOT in 1st and 2nd, I get a steady boost of 7psi. At WOT in 3rd and 4th, I get 9psi. Both readings seem to start dropping slightly as I pass 6500rpm. Changing from 3rd to 4th gets a spike of 11psi. When idling, I have a vacuum reading of around -20inHG. Hopefully that's good?

Anyway, from looking at other threads, I thought the PFL auto was about 7psi stock at most, but maybe someone else can shed some light on this?

I will be winding up the boost shortly, but am wondering whether the spiking I am seeing is normal (changing gear is the only time it happens)?

For example, if I turn it up to 14psi at WOT in 3rd and 4th, if it spikes to 16psi when changing gear, is that bad? Will it hit boost cut and how bad will that be?!

I'm still pretty new to this proper turbo lark, so any help from the experienced will be greatly appreciated!

[martin_y]

I think on our cars the fuel is cut , not the boost.

[elnevio]

I think on our cars the fuel is cut , not the boost.

Oops, yes - I did mean fuel cut! I'm not planning on going down the route of getting an FCD though at any point. Decat pipe and boost controller will be it.



For now...

[White Lightning]

If you get an electronic boost controller then it may well not spike as it should be better at controlling the boost level.

What gauge did you get ?

[elnevio]

An Autogauges electronic one. I've got a Dawes Device to go on, although it's a hybrid version, that supposedly reacts faster and helps reduce/eliminate spiking.

The proof is in the pudding I guess.

Back to the gauge - I was thinking of checking its accuracy. I have installed Evoscan, and just need to sort out my cable. I assume Evoscan can track the boost level and I will be able to see if it correlates with my gauge.

[martin_y]

I've read on here that Evoscan doesnt show boost. Havent connected mine yet.

[bradc]

A lot of cars run at slightly higher than what should be stock. I wouldn't worry about it too much at all. Just increase the boost and smile

[Turbo_Steve]

elnevio, it sounds like you've just got a slightly tired actuator spring or possibly a weak pipe which is bulging. As brad says, I wouldn't sweat it.

[elnevio]

I was getting a nice steady 8psi today. I was also, after backing right off the throttle, getting a vacuum reading as low as 28inHG - isn't that quite close to a total vacuum?!

Anyway, boost controller fitting to commence shortly! Although probably when I get back from me hols...

[White Lightning]

Evoscan shows boost as an option on the screen but I have not tried recording it yet. I have also read that it cannot be detected.

[pitslayer]

mines all over the place, idle im at about 25inhg, slowing down, hit about 30inhg. as for boost well it shoots up to about 8psi then wavers for a bit then drops down to 6 psi, followed by a spike upto 10psi on gearchange. and thats without a boost controller

[Adie]

mine does that to i dont have a boost controller but mine spikes on a cold night up to 0.9 bar and normally spikes to just over 0.8 then settles around 0.6 to 0.7 somewhere, so if i want my boost to be more well behaved i need a EBC not a MBC? as i was planing on using a MBC till i get my ecu and stuff sorted

[Ryan]

The clue is in the title - I have now fitted a boost gauge - with thanks to Spirit's excellent article: http://www.clubvr4.com/forum/showthread.php?t=1154

Have also had the chance to drive about 150 miles today to see what the boost is doing. At WOT in 1st and 2nd, I get a steady boost of 7psi. At WOT in 3rd and 4th, I get 9psi. Both readings seem to start dropping slightly as I pass 6500rpm. Changing from 3rd to 4th gets a spike of 11psi. When idling, I have a vacuum reading of around -20inHG. Hopefully that's good?

Anyway, from looking at other threads, I thought the PFL auto was about 7psi stock at most, but maybe someone else can shed some light on this?

I will be winding up the boost shortly, but am wondering whether the spiking I am seeing is normal (changing gear is the only time it happens)?

For example, if I turn it up to 14psi at WOT in 3rd and 4th, if it spikes to 16psi when changing gear, is that bad? Will it hit boost cut and how bad will that be?!

I'm still pretty new to this proper turbo lark, so any help from the experienced will be greatly appreciated!

-20 is the same vacuum reading as mine so think that's normal.

Mine spikes to 17psi going up hill in 4th or 5th but normal max boost is between 13-15psi.

If I wound my boost up anymore I'd get fuel cut so basically I've got mine configured at the highest reliable setting.

[Oblivion]

Any specific things to check if boost is spiking between gears?
I used to have a solid 10psi but now it spikes to 11-12 just after shifting and then drops back to 8psi I've tightened every hose clamp I can find but still the same...

[Ryan]

A faulty BOV perhaps (eg: sticky spring)?

[orionn2o]

This is one of my boost graphs, you can see a graph change about halfway across the screen - this is a gear change. I would say that this is quite acceptable.

(Ignore the square bit at the end, thats where i ran out of road!)

[Ghost_2008]

I adjusted my manual boost controller and found fuel cut at approximately 16psi, no problem until a raced a BMW and I hit fuel cut in 4th.......... turned it down, so now I get a steady increase to about 10psi in first and second, increasing to 14-15psi in 3rd 4th and 5th. As yet no fuel cut, and no real spiking but the increase in boost from 8psi up to 14psi seems to be a lot quicker than 0-8psi. However this is all estimated as i tend to watch the road rather than the boost guage...........

I had it on the rolling road at Eurospec on standard boost, they said the MBC was a little twitchy but not bad, my BHP was estimmated at 250 and 200 at the wheels. I deffinately feels quicker so I am hoping for about 210 at the wheels, but I am also considering an EBC to get a more acurate increase......

[aboo]

My boost before I fitted mbc was a steady 8psi never droped off, vacuum was 20.
I'v now got it up to 14psi then drops off to 12psi, vacuum still 20 but when I 1st fitted mbc it would'nt screw out enough and it would fuel cut at 16psi.

I was told on another thread that when standard the 8psi and 20inHG was about right for a pfl.

[Oblivion]

A faulty BOV perhaps (eg: sticky spring)?

My BOV is adjustible, shld I try set the spring harder perhaps?

[Fully]

If its sticky, clean it out.
If you make it harder when it sticks you could make it worst.