HOWTO: RB25DET High Boost mode with standard solenoid

[lighty01]

i finally did this on the weekend

after rigorous testing i found that when your tyres are cold.. even if you take off slowly and then hit WOT, you still loose traction.. i have almost new tyres as well.. so im happy..

[nissanmanS12]

I just did this today...

Honestly cant feel any diffrence on my R34 GTT auto...weird.

Im going to get it dynoed soon so will hav it dynoed with and without the mod, i might be suprised.

One sign tho to see if the solinoid is actaully earthing or not with the wire you used-

Start car, tap the wire on then off the bolt or bracket your fastning it to, the solinoid will make a slight "clicking" noise.

All i did was splice into the black wire and attach a complete new wire coming off the spliced bit onto an earth..

So the black wire still goes into the plug aswell but is earthed BEFORE it goes into the plug.

[WET-25T]

Ok i wanted to do this mod but wasnt too keen on cutting the wire. Well i did it today, took the car for a drive at 6pm and the boost felt more responsive.

I washed the car and took ot for another drive at 9pm, i was in 2nd gear and the car suddenly stopped boosting and kind of felt like it jumped. This also happend in 3rd gear and kept happening for the next 5 mins or so till i got the car home.

What would the cause of this be? Is it wrecking my car? I will see if its the same tomorrow and probably put it back to normal (not too happy after getting a taste of that whole extra 2 psi).

Thanks so much for the help if it wasnt for you guys i would be getting ripped off by a mechanic and not knowing how to or what to do to modify my skyline. Once again thanks guys

Edited December 21, 2007 by WET-25T

[Duncan]

I'm willing to be you've got water in your coilpacks from washing the car if it was OK before and no good after. DId you wash your engine bay?

If not, it could be a miss related to plugs or coilpacks. More boost means you might need to close up the gap on your spark plugs to 0.8mm if your coilpacks are a bit old. Or just grab some new coils.

[PyroIndustries]

Ok i wanted to do this mod but wasnt too keen on cutting the wire. Well i did it today, took the car for a drive at 6pm and the boost felt more responsive.

I washed the car and took ot for another drive at 9pm, i was in 2nd gear and the car suddenly stopped boosting and kind of felt like it jumped. This also happend in 3rd gear and kept happening for the next 5 mins or so till i got the car home.

What would the cause of this be? Is it wrecking my car? I will see if its the same tomorrow and probably put it back to normal (not too happy after getting a taste of that whole extra 2 psi).

Thanks so much for the help if it wasnt for you guys i would be getting ripped off by a mechanic and not knowing how to or what to do to modify my skyline. Once again thanks guys

was the motor cold?

on my 33 i have bypassed the solenoid altogether.

mine never had the top tube going to the solenoid ???

what i done was unplug the solenoid all together and run a tube from the intercooler piping to the actuator.

hits 7psi by about 2200 rpm with a 3"split dump pipe

[WET-25T]

Hey, i wont boost unless my engine is fully warmed up and no i didnt wash the engine bay. Its strange bcoz it hasnt happen since that night. Anyways i put my boost gauge in today and it was showing 9psi. So i disconnected the new earth i put in for the high boost and took it for another drive.

It was showing 7psi for low boost then it goes to 9psi for high boost. The only mods that it has is a turbo timer, the boost gauge i just put in and a pod filter. No other performace mods that im aware of what so ever. Is this normal for 7psi low instead of 5psi and 9psi high instead of 7psi? And is 9psi safe or should i just keep it on the 2 boost setting?

Also i didnt cut right through the wire i made it into a t-piece for the hight boost.

Thanks and thanks for the fast reply Duncan

Edited December 23, 2007 by WET-25T

[Duncan]

well given that it went away I still bet you got the coils wet somehow, do you have a vented bonnet?

anyway - re standard boost, I have done this mod in my stagea, it has a unifilter panel filter and radiator air guide are only mods, but it spikes to about 8.8-9psi sometimes. I think as you free up the intake and exhaust standard boost increases a little.

9psi is fine as long as the fuel system is healthy (injectors and fuel pump) with the standard ecu. just keep an ear out for any pinging as it comes onto boost (mine pings a little and I'm assuming its because the fuel pump is on the way out).

[WET-25T]

Well ur right in the sense that i de greased my engine about 2 weeks ago or so, not sure if the would still b water in it and it was fine straight after i did it. In 2500 k's which will b at 70,000 kms i will do a FULL service like everything. Thanks again

[R34mac]

Just did this mod to my R34 GTT (tiptronic) and made a noticable difference! Power felt alot stronger down low.

I was driven to do it because I had been getting the missfire at 5000rpm when the boost levels changed. My engine is stock except for an apexi power intake. I only started getting the missfire since I installed that.

I skimmed through most of the 22 pages in this thread and saw a few people saying to run it on a switch - so you can switch it back for highway runs. Though I don't understand why? On the highway my boost guage sits at around -300mmhg (about half way in the negative) and after the mod continues to do so unchanged.

So as far as I can understand this mod shouldn't make any difference to fuel usage except the times when you're on boost below 5000rpm? (at which point it rose to the higher boost level anyway?) Am I wrong?

Edited January 7, 2008 by R34mac

[Wayne_J]

Just did this mod to my R34 GTT (tiptronic) and made a noticable difference! Power felt alot stronger down low.

I was driven to do it because I had been getting the missfire at 5000rpm when the boost levels changed. My engine is stock except for an apexi power intake. I only started getting the missfire since I installed that.

I skimmed through most of the 22 pages in this thread and saw a few people saying to run it on a switch - so you can switch it back for highway runs. Though I don't understand why? On the highway my boost guage sits at around -300mmhg (about half way in the negative) and after the mod continues to do so unchanged.

So as far as I can understand this mod shouldn't make any difference to fuel usage except the times when you're on boost below 5000rpm? (at which point it rose to the higher boost level anyway?) Am I wrong?

I reckon the switch would be a good idea, so you can keep it off boost while the engine is still cold... once she's warmed up - switch over to the modded boost levels. Or for wet/greasy roads (like today)... it'd just be good to have to option to change it quickly and easy IMO.

Cheers

[Whooby]

i havent made changes to the solenoide wire, it looks to be standard.

Although my stagea makes a lil bit under 9psi on full boost, but this is showing on the guage before 3000rpm. The car does have a MiNes ECU would this possibly ignore the 'half boost' mode? It still feels like it pulls harder from 4500rpm, but still makes same boost level.

Car also a 3 inch exh. from the turbo.

Any ideas would be great.

Thanks.

[Kinks]

Or for wet/greasy roads (like today)... it'd just be good to have to option to change it quickly and easy IMO.

Yeah, rain adds 25kw - so i flick high boost on and then it feels like it's added 50kw

[tom_v]

Ill try this tonight on my 96 S2 33 and see how it goes

[jrocket]

I have done this and it seems to work well. Dont worry about putting in a switch. Just control the boost with ur right foot ffs.

[e_Dog]

Apologies if this question has already been answered. 420 odd posts is too many to go through.

Wondering if you need to make this solenoid mod if you have installed manual boost control i.e. a T piece or bleed valve???

At the beginning of the thread it says if you have aftermarket boost control that you no longer need to do the mod. But it seems as tho if you just put a T piece or bleed valve in-line, the ecu is still controlling the operation of the solenoid and so would you be running say 9psi to 4500 rpm then 11psi til redline?????

thanks

Edited February 26, 2008 by e_Dog

[SiR_RB]

i was bored and decided to do this mod, took 10 mins. took the car for a wrap and noticed the stock boost gauge needle alittle bit higher then the line under 7. which is around 8ish psi?

felt good down low and pulled up harder. 3" dump/front pipe hopefuly going on this weekend

[e_Dog]

Anyone got an answer.

Do you have to do this mod still if you have an aftermarket MANUAL boost controller??

i.e. does the manual boost controller require removing the stock solenoid.....or is the stock solenoid still in operation with a manual boost controller????

[Luciano]

great little mod this one. did it on my mates 33 this morning and you can definitely feel and hear the turbo spooling up that extra bit in the lower revs.

[chef_stagea]

did this mod other day couldnt relle fell much difference... tryed tapping my ground but couldnt hear much coz of engin noise... i cut the black wire, the one that goes back down that tube casing got grounded. the other end just got taped of. is this correct? cheers

[DaveB]

Anyone got an answer.

Do you have to do this mod still if you have an aftermarket MANUAL boost controller??

i.e. does the manual boost controller require removing the stock solenoid.....or is the stock solenoid still in operation with a manual boost controller????

well I don't know about solenoid operation with an aftermarket boost controller but in the first post it says:

Background:

As you all know the standard R33 RB25DET boost solenoid (value controller) is 5psi until rpm is greater than 4500rpm and then its 7-8psi. Continue reading if you wish to always be in high mode (7-8psi). If you have an aftermarket boost controller then you can stop reading now.