boost psi

[bobswagon]

fitted a boost gauge to my sti 8 today,anyone know what psi it should be boosting to?
is there any benefit in fitting a k&n panel filter(or other make)in place of the sti filter?
bob
thanks

[Scott.T]

Something like this ;)

http://img.photobucket.com/albums/v90/Scott.T/boost.jpg

[bobswagon]

thanks scott, what gear do the figures equate to? mine was boosting to approx 15psi w.o.t in the gears,what would it boost to if i had it re-mapped?
sorry about all the questions, still learning about scoobies:mrgreen:
bob

[Scott.T]

In terms of Bar (rather then PSI), at the moment is peaks at 1.2bar (only breifly though, below 5200rpm) then drops to approx 1bar/14.5psi (which would be your overtaking range/rpm, and finally drops to approx 0.8bar at the redline.

If it were remapped, I would expect it to be mapped to approx 1.4bar throughout a large portion of the rev band, before dropping to 1.2bar near the redline.
So in the midrange (where it matters) you would be running 0.4bar more, at the top end also about 0.4bar more.

Power would probably be around the 330BHP mark.

TSL do the tripple 3 upgrade which is 333BHP and 333ftlb or there abouts.

[bobswagon]

thanks for the info, scott.I thought about the tsl package,too!what b.h.p.and torque does the u.k.8 have as standard?(heard various figures from 265-285bhp)do i need an up-rated pump if i get it re-mapped?
bob

[Deano]

wouldnt have though that the boost should be dropping off as scoott has explained

that would suggest to me that the acutator is weak!! but i am no techie

you will get your max boost reading in 5th gear under full load

so do about 60 then full throttle and the turbo will begind winding and you will see the gauge reach it highest point and thats your current boost setup

but please anyone correct me if i am wrong

i myself am after an apexi so that it boost the same in every gear and not just 1 bar in 5th

[Scott.T]

That info/table is read straight out of the ECU, so yes it does tail off like that.

Most mappers hit a higher target boost in the low to mid-range to improve torque then tail it off at the top to protect the engine and allow more ignition advance to be run.


P.S An Apexi ECU will not be able to achieve the same boost in every gear. An Apexi AVCR boost controller will allow you to tailor the boost per gear.
But too much boost in the lower gears can blow the box.

[Deano]

That info/table is read straight out of the ECU, so yes it does tail off like that.

Most mappers hit a higher target boost in the low to mid-range to improve torque then tail it off at the top to protect the engine and allow more ignition advance to be run.


P.S An Apexi ECU will not be able to achieve the same boost in every gear. An Apexi AVCR boost controller will allow you to tailor the boost per gear.
But too much boost in the lower gears can blow the box.

thats what i meant an apexi boost controller as i am sure the lower gears can cope with at least 1 bar

seems my car could be som much faster if it wasnt only hitting 0.5 bar in 1st and 2nd

other cars dont seem to do this little trick so why scoobs?

i see the stats and as stated i asked to be corrected if somone felt i was wrong

but the way i understood it was then an uprated actuator would hold the boost and not allow and loos of boost hence a reason to upgrade

sounds a good idea to have peak boost then give the turbo a rest but would rather it peaked and stayed peaked for better performance

but i do see the logic in allowing a small drop

mine seems to hold at 0.9bar on full load but unless i get it on a digital read out i wouldnt notice the slight loss if your correct

o well its all a lesson for me :D

[Scott.T]

You could fit a uprated actuator, or indeed tighten the standard actuator (as some of them have adjustment). But the ECU would overide this and in some instances it would surge/pulse especially on a motorway cruise at 3/4 throttle.

The tight actuator would cause it to overshoot target and the the ECU pulls it back.

It's alot more controlled then in the old RS Escort/Cossie days, where a quick adjustment of the actuator could see boost jump from 9psi to 14psi ;)

[Deano]

fair one, ****** ecu's lol