10psi On A Stock Rs4s ?

[lachlanw]

just put a defi boost gauge on my rs 4 s . is completly stock apart from stainless cat back jasma exhaust . according to defi recall its running the tiniest bit over .7 kgf/cm . which is ten psi . mind you the factory guage also goes up to +7 x 100mmHg which also converts to 13 psi ... am i stupid or do all neo's run ten psi factory ?

Edited August 27, 2008 by Duncan

[pixel8r]

The neo's definitely run the same 5psi / 7psi setup as the series 1's. That is, 5psi and then up to 7psi above 4500rpm - as controlled by the stock boost solenoid. Or you can short the solenoid permanently and run 7psi all the time, for some extra midrange response. Its actually somewhere between 7psi and 8psi from memory...

If its running 10psi either you're measuring a different pressure or yours isn't stock for whatever reason. normal spot to plug in the guage on an RB is on the nipple near the plenum.

[KiwiRS4T]

just put a defi boost gauge on my rs 4 s . is completly stock apart from stainless cat back jasma exhaust . according to defi recall its running the tiniest bit over .7 kgf/cm . which is ten psi . mind you the factory guage also goes up to +7 x 100mmHg which also converts to 10 psi ... am i stupid or do all neo's run ten psi factory ?

Does your boost have a step at around 4500 rev/min as mentioned above? If not someone may have bypassed the boost solenoid for extra boost (a good trick) see http://www.skylinesaustralia.com/forums/Ja...html&st=880

and scroll down to post 884 for a photo of the boost solenoid (near the power steering reservoir).

[lachlanw]

yeah i know exactly what/where the boost controll soleniod is and how it works and everything and dont need a picture to know what one is . and about the two stage boost controll . it all appears stock . soleniod is still plugged in and plumbed in . my gauge is plumbed in right next to the sender for the stock boost guage . it has its own line coming out of manifold and it lives by where the throttle cable goes through the fire wall . also appears to go straight to .7kgf/m regardles of rpm. in saying that it certainly goes real hard and pulls from real low . tuning appears pretty good too. got just over 400 kays from 3/4 of a tank to the fuel light just turned on . not bad for the first 3 weeks of ownership which including taking everyone for "new car man take us for a fang round the block "

maybe my car has a r32 turbo actuator on it , had one here for it anyway so will compare them one day also the "s" is quoted as having ten more newton meters of torque over the autos meh . interesting none the less

[momo]

Mine is the same, defi guage reads 0.7 (rs four s) no modification to anything regarding solinoid or actuator as far as i can see.

this had me baffled for a while too. there is also no step in the boost.

[lachlanw]

oh k sweet another one . just another reason why the neo is better then non neo 25t , contrary to popular opinion of all the half wits in nz

[silva33]

i couldnt feel any step in the boost either in my RS4S when I had the standard turbo on.

[JOHNNNY]

hay lachlanw my s2 manual stag which is stock except for boost controler ,blow off valve , cat back exhaust and k&n filter element . i disconected the std boost controler and fitted a turbosmart one then took it to hunter all wheel dyno in heatherbrae in newcastle got it on the dyno and as it was it was making 147.7 kw on 8 psi then after a bit more boost up to 9.5 psi and a few deg of timing we ended up with 170.8 kw .and the AFR was still nice and ritch so could of gone a bit more but i was very happy with the result and only took us 1.5 hrs now the car har heaps better bottom end torque the mid range hole is gone and it sounds so much better idles smoother. SO MY OPINION IS GO AND GET UR CAR DYNO TUNED IT MAY BE A BIT PRICEY BUT IT IS WELL WORTH IT IN THE END YOU WILL BE IMPRESSED WITH THE RESULTS .

[lachlanw]

hay lachlanw my s2 manual stag which is stock except for boost controler ,blow off valve , cat back exhaust and k&n filter element . i disconected the std boost controler and fitted a turbosmart one then took it to hunter all wheel dyno in heatherbrae in newcastle got it on the dyno and as it was it was making 147.7 kw on 8 psi then after a bit more boost up to 9.5 psi and a few deg of timing we ended up with 170.8 kw .and the AFR was still nice and ritch so could of gone a bit more but i was very happy with the result and only took us 1.5 hrs now the car har heaps better bottom end torque the mid range hole is gone and it sounds so much better idles smoother. SO MY OPINION IS GO AND GET UR CAR DYNO TUNED IT MAY BE A BIT PRICEY BUT IT IS WELL WORTH IT IN THE END YOU WILL BE IMPRESSED WITH THE RESULTS .

y did you disconnect the standard boost controller ? mine runs ten psi on the standard setup .

[leetom]

y did you disconnect the standard boost controller ? mine runs ten psi on the standard setup .

i'd say the reason johnny went a mbc was to run 10psi thru the entire r/range.... much more responsive and enjoyable than 2 stage like your running if your still soleniod controlled

[lachlanw]

i'd say the reason johnny went a mbc was to run 10psi thru the entire r/range.... much more responsive and enjoyable than 2 stage like your running if your still soleniod controlled

rs four "s" does run ten psi the whole way through the rev range . no step in the boost . read the rest of this thread . it hits ten puond by 2500rpm in third gear and really starts makin some torque

[lachlanw]

and im aware that the bit in my first post about +700mmHg is ten psi being wrong . its about 13 . but u cant edit it

[Duncan]

first post edited

[JOHNNNY]

y did you disconnect the standard boost controller ? mine runs ten psi on the standard setup .

i removed the std boot control because i was having trouble with it . and it is adjustable when on the dyno .

[pixel8r]

Not sure if the original post was answered as to why it was 10psi...

See my other post above - s2's (and s1's) are definitely only ~7psi standard.

The original post mentioned a larger exhaust, which would more than likely account for the increase in boost pressure measured.

On my old s2, installing a full 3" exhaust alone was enough to raise the boost high enough for it to hit R&R, causing it to lose power suddenly and even cut out in some cases...

[lachlanw]

maybe four fuel pump or your fuel or a knock sensor or somethin was shody on your car . i dunno . gonna get a dyno run sometime . to see if its as fast as it feels it certainly aint slow by any standards. and certainly isnt hitting rich and retard

[lachlanw]

"The powerplant is the RB25DET as introduced in the R33 GTS25T. In R34 form, however, the engine is upgraded to more environmentally friendly 'NEO' specs. The NEO RB25DET also features a hot-wire airflow meter, 9.0:1 static compression, air-to-air intercooler, ceramic turbine roller-bearing turbocharger, blow-off valve and variable inlet cam timing. With manifold boost pressure of around 60 - 70 kPa (as shown on the factory boost gauge) the R34 25GTt is listed at 206kW at 6400 and 343Nm at 3200 rpm. The R34 25GTt scores its extra power over previous models thanks to a larger turbo (providing a healthier amount of boost), better intercooler, an improved exhaust system and engine management updates."

By my calcs; 60-70 kPa= 8.7-10.2 PSI

[wolverine]

the larger turbo is the larger turbine housing on the neo's. the compressor is the same.

[JOHNNNY]

glad i brought a s2 now and not an s1 . my mate had a r33 gtst skyline and it had a cooler , 3'' exhaust , pod filter and was running 10 psi even after it was tuned on a dyno it still only made 175 kw , my s2 stagea is basicly stock except for a cat back exhaust and k&n filter element and stock cooler and it still made 170.8 kw when tuned , the neo is an awasome motor im so glad i brought it over the earlyer one .

[BKC34]

Hi there ppls, just picked up my s2 RSFour S 5 speed manual down in newcastle ( i live in cairns lol) goes nice and runs well, but yeh i'd agree that there is no step up in boost, mine seems pretty stock cept for a cat back exhaust and hi flow panel filter, ive driven my mates 33 coupe and it clearly has that step up in boost.

That sounds awesome johnny, i should really go get my tuned, cos mine has the same stuff as yours, and 170kw sounds pretty awesome but yeh still think ill get a full 3" exhaust tho.

ANyone from cairns on here with their stags???????????????????