HOWTO: RB25DET High Boost mode with standard solenoid

[RyanN]

nah stock boost is 5 - 7psi..

when you go past 4500rpm the boost solenoid thing opens and gives you the extra 2 psi.. so you get 7 in total..

What do you mean 1+ ?

7 on the stock boost gauge means 14psi if thats what your talking bout ?

<{POST_SNAPBACK}>

r34 stock boost gauges go from 0 to -700 and up to +1 on the gauge, anyway i guess its a safe mod to do that wont damage the turbo.

Whats +1kg/cm in psi?

Edited September 29, 2005 by RyanN

[paulr33]

1kgcm2 is 1bar which is 14psi. this will fry your turbo. max you should be running should be 11/12 psi as this is border line. the heat from runing that much boost will fry the exhaust wheel

[RyanN]

1kgcm2 is 1bar which is 14psi. this will fry your turbo. max you should be running should be 11/12 psi as this is border line. the heat from runing that much boost will fry the exhaust wheel

<{POST_SNAPBACK}>

ok, wasn't sure if this mod was damaging the turbo or not, as i dont exactly want to blow the thing yet

Before the mod the gauge would go just below the halfway mark and after, just above it; that would be around the 7-8psi mark?

Its the pressure that shatters the turbine wheel right not the heat?

Edited October 1, 2005 by RyanN

[US_R33]

1kgcm2 is 1bar which is 14psi. this will fry your turbo. max you should be running should be 11/12 psi as this is border line. the heat from runing that much boost will fry the exhaust wheel

<{POST_SNAPBACK}>

hey paul.......i thought .8 bar was around 9-10psi.....is it in fact 11-12 psi? i remember from the discussion over on skylineowners.com that all the guys said not to run more than .8 bar b/c that's the max you can safely run the stock turbo at

Late,

Daniel

[paulr33]

sorry my grammar kinda made my statement a bit strange. here's what i really meant

1kgcm2 is 1bar which is 14psi. this will fry your turbo.

max you should be running should be 11/12 psi as this is border line. the heat from runing that much boost will fry the exhaust wheel.

yes 0.80 is approx 12psi. i run 0.85 daily and its on border line of frying it and it doesnt make any more power past this level either, but stacks more heat, which is the killer

9psi is around 0.65 bar

[US_R33]

okay cool......thanx for the clarification Paul

i'm definitely going to get a MBC seeing as how running .8 bar from .7 bar should give me a noticeable power gain

[paulr33]

each psi is a noticable gain however you should make sure you have a good exhaust and fmic before running that much pressure

[QRI05E]

Hey guys, im another proud R33 GTSt (series II) owner! My R33 is completly stock besides the K&N pannel filter... Can some please either email me or post up some pics showing the factory boost solenoid?

Thanks

[rinmak]

Hey guys, im another proud R33 GTSt (series II) owner! My R33 is completly stock besides the K&N pannel filter... Can some please either email me or post up some pics showing the factory boost solenoid?

Thanks

<{POST_SNAPBACK}>

Heres a pic of one:

http://bur.st/~rinmak/r33/IM001060.JPG

Its the silver thing with one pipe coming off of it and an empty nipple beneath that.

Yours probably wont have an empty nipple though

[US_R33]

each psi is a noticable gain however you should make sure you have a good exhaust and fmic before running that much pressure

<{POST_SNAPBACK}>

i'm hoping to be able to get my downpipe and de-cat pipe done this thursday (already have an 80mm cat-back on the car)

and my friend is going to give me this MASSIVE Calsonic SMIC (over 6 inch thick core)......I think that core will be good up to 300whp

Late,

Daniel

[33GTT]

Hey guys,, just did this mod and am confused as to what my stock boost gauge should read,, The solenoid is operating (I put in a switch,, but the boost gauge only gos to .35,,is that right? I thought I should get more than that,, car is completely stock except for 3 inch high flow cat and nismo exhaust,, Is there something wrong or is that all I can expect without spending some coin?

cheers,

John

[QRI05E]

Thanks rinmak!!! ill have a look this afternoon when i get home from work... damn working on a public holiday!!! hehehe ahhh well.. thanks again!

[US_R33]

John, the boost gauge that is in your OEM gauge cluster should be reading half way above the half way mark on the gauge which works out to .7 bar or about 9psi of boost.......if its still only reading half way below the half way mark (when below 4500RPMs) then you're running .5 bar or about 7psi of boost

hope that makes some sense

Late,

Daniel

[33GTT]

John, the boost gauge that is in your OEM gauge cluster should be reading half way above the half way mark on the gauge which works out to .7 bar or about 9psi of boost.......if its still only reading half way below the half way mark (when below 4500RPMs) then you're running .5 bar or about 7psi of boost

hope that makes some sense

Late,

Daniel

<{POST_SNAPBACK}>

Thanks Daniel,, I bypassed the controller and it spiked (just after the computer confused itself and then re-mapped of course) so I put the controller back into the loop,, it still only goes to right on half way, so I'm guessing that either the gauge is dodgey or the actuator is not quite right,, might just make up a bleed valve and have a play,,

cheers

John

[US_R33]

no problem John if you were running high boost (.7 bar) you would DEFINITELY notice the difference in the lower RPMs when compared to .5 bar at the lower RPMs

what i did was peel back some of the insulation on the black ground wire, spread the core apart in the middle and looped a my additional ground wire through there, I then soldered the wires together, taped them up nice and tight, and proceeded to wrap the other end of my ground wire around the bolt that hold the power steering reservoir bracket onto the shock tower

i hope this helps.......if it make sense

if not i can try and take a picture of my solenoid and wiring as it stands now later on today or tomorrow

Late,

Daniel

[QRI05E]

Hey Guys, you think by running a direct ground signal to the earthwire of the boost solenoid while its still connected to the ECU will damage the ECU??? cause thats what i thought about doing as well as adding a switch but was worried about damaging my ECU.

Regards,

Sarkis

[QRI05E]

Alright guys, i finally had the time to do this little mod on my R33 S2 and it works! i noticed my rev range being more smooth and more comfortable without that nudge you feel at 4500rpm... you can see full boost comming on as low as 2500rpm (little over the halfway mark on the factory guage) acceleration wise i noticed a little increase but nothing too drastic, perhaps its cause i still got a stock exhaust???

i managed to find a way to wire up this mod up without any cutting or soldering! i used the airbox bolt for my earth and fed the wire into the harness as shown in the pics... this way you can remove the mod and everything is still original!

Nice find paul!

Regards,

Sarkis

[33GTT]

no problem John   if you were running high boost (.7 bar) you would DEFINITELY notice the difference in the lower RPMs when compared to .5 bar at the lower RPMs

what i did was peel back some of the insulation on the black ground wire, spread the core apart in the middle and looped a my additional ground wire through there, I then soldered the wires together, taped them up nice and tight, and proceeded to wrap the other end of my ground wire around the bolt that hold the power steering reservoir bracket onto the shock tower

i hope this helps.......if it make sense

if not i can try and take a picture of my solenoid and wiring as it stands now later on today or tomorrow

Late,

Daniel

<{POST_SNAPBACK}>

Thanks Daniel,, I did put a switch in and wired it to the power steering mount bolt, then I taped it all to the harness so that you can only just see the switch hiding behind the air box,,

I will endevour to play around with some sort of bleed valve arrangement and wire in a relay so that it can be switched from factory boost controlled,,to factory maximum boost and also to have a bleed valve arrangement as well (three way switch),,,I will post the results when I'm done,,,

cheers

John

[inissane]

just convinced my dad to let me have a crack at his r33 and do this mod, went for a spin and hes happy with the improvement from 2-2500 up to over 4000rpm great stuff simple easy mod

[Keeper]

I just dyno'd my car with this mod, except when I put this mod on I put a on/off switch for it, the difference between ECU relating boost at low revs, and earthing the wire seamed to be nothing at all!

Saying that I swear it made a difference when I did this before I dyno'd it!

I'm at a small loss now, if you put a couple of washers under the wastegate actuator mount points it increases boost BTW, not the best tho, my fuiel cut defended cut in and shut the car down for %60 of the rev range, when it was boosting hard tho, it was f**kING HARD