The Quick Boost Mod

[Stagstock]

Guys just after a quick bit of help... I took the hoses off the boost solenoid and just connected the hose from the wastegate straight to the T piece bypassing the solenoid and nothing else. So essentialy pulled the waste gate hose off the boost solenoid and put it straight on the "T". Will that work or is there more to it. Oh, and can I make it more than 7psi, say 10, with anyother backyard mod lol.

Thanks in advance guys

[BKC34]

your car is going to self destruct in 10 secs now

gammon, nah i dunno that should be right, i got a 25 boost controller off ebay, i hope it works lol

[lachlanw]

how the hell is that giong to achieve anything . the soleniod is there to bleed off air to the wastegate so that it can run more boost than the 5 psi the wastegate spring is set to .

[Samon]

how the hell is that giong to achieve anything . the soleniod is there to bleed off air to the wastegate so that it can run more boost than the 5 psi the wastegate spring is set to .

+1 ^^^^

If you have nothing limiting/bleeding the airflow to the wastegate, the spring will open it at 5PSI... you need a boost controller, bleed valve, etc to reduce the pressure the wastegate "sees" so that it opens later (i.e. more boost). a boost controller works by preventing the pressure from getting to the wastegate until the pressure is the desired boost (i.e. 7PSI or whatever)... a bleed valve works by simply bleeding off some of the pressure so that again, the wastegate "sees" less than the turbo is actually making.

[lachlanw]

buy a r32 rb20det wastegate actuator . they are ten psi. 11-12 with exhaust -intake mods. or tie another spring on the outside of the watgate actuator if you really want to blow up the motor as fast it sounds like you want to

[Stagstock]

So 7psi will blow up my motor? That sounds a little finickey for a nissan motor, which parts are made from plastic?

[Stagstock]

Well I looked at the plumbing and your right... the solenoid could only possibly act as a bleeder to the wastegate actuator so I have plummed it all back up and done the earth wire mod instead.

[_Ryan_]

This thread is full of shit,

I bypassed my solenoid, my PEAK boost acheived is .67bar(10psi), it is a pretty constant 6-7psi.

[Granthem]

or tie another spring on the outside of the watgate actuator if you really want to blow up the motor as fast it sounds like you want to

Lol that makes no sense. This sort of mod just acts as the stronger R32 actuator does. It holds the wastegate shut at higher boost levels with the extra tension. Its pretty much a free boost mod, I mean whats a spring cost, 2 bucks? Why it would blow a motor up any quicker then the R32 actuator I do not know...

[KiwiRS4T]

Guys just after a quick bit of help... I took the hoses off the boost solenoid and just connected the hose from the wastegate straight to the T piece bypassing the solenoid and nothing else. So essentialy pulled the waste gate hose off the boost solenoid and put it straight on the "T". Will that work or is there more to it. Oh, and can I make it more than 7psi, say 10, with anyother backyard mod lol.

Thanks in advance guys

Don't earth the solenoid - just by-pass it but not quite like you did. Follow the instructions below (courtesy of SK -photo may be found here on post #40 ): http://www.skylinesaustralia.com/forums/Ja....html&st=20 ) and you engine will not blow up nor the sky fall down and you can adjust it to whatever pressure you want although 10psi is considered safe (some people run 12 without problems - I ran this setup for months until finally, yesterday, I installed and set up my Jaycar Boost controller which is working perfectly:

.

This is the 10 minute no cost boost to 0.5 bar rerouting of the vacuum hoses. Disconnect the two vacuum hoses from the solenoid. Then connect the boost feed (from the cross over pipe on the left of the picture) to the standard T piece. Connect one side of the T piece directly to the wastegate actuator (on the right of the picture). The remaining connection on the T piece goes back into the inlet via the BOV return pipe (on the standard fitting). Make sure to put the standard brass restrictor in that vacuum hose to bypass the desired amount back into the turbo inlet. The standard bypass hole of 1.25 mm bypasses enough air flow for 0.5 bar. (See photo)

PS: If you want more boost you can drill out the bypass, 1.5 mm = more boost (around 0.7 bar) 1.75mm = a bit more (around 1.0 bar). But the Jaycar Boost Controller needs the bypass to relieve trapped pressure between the solenoid and the wastegate actuator. So I don't want to redrill the restrictor only have to solder it back up again

OK, this is the picture of the vacuum hoses. The boost pressure comes out of the intercooler return pipe (that's the big black one on the left) via the standard fitting. It travels down the vacuum hose to the standard T piece.

The right hand side of the T piece goes to the wastegate actuator via another short piece of vacuum hose. It has 2 standard spring clamps on it. So that "some" of the boost pressure goes to the wastegate actuator.

The left hand side of the T piece is connected to another (longer) piece of vacuum hose thaty goes to the standard fitting on the BOV return pipe. You can't see that fitting in the picture as it is hidden by the (big black) turbo to intercooler pipe. I squeezed the standard restrictor into that vacuum hose, it is tight fit, so be patient and use some lubricant (RP7 in my case).

The restrictor limits the amount of boost pressure that is bled off, so that the "some" pressure that goes to the wastegate actuator is actually less than the boost pressure. This means you get more boost before the wastegate opens at its usual 4-5 psi. How much more depends on the size of the hole in the restrictor, the bigger the hole the more it bypasses and the higher the boost.

The standard hole is ~1.25 mm and gave ~0.5 bar on my Stagea, which has standard everything else (no exhaust, no FMIC, std filter, etc). If you have mods, you may not get the same boost pressure, so you may have to adjust the size of the hole in the restrictor, it is brass so you can easily solder it up and redrill the hole smaller if necessary.

[Stagstock]

I haven't yet done the reroute mod as listed above but I'm curious as to where the brass restrictor came from as I can't see one in my standard set up just the T piece and the solenoid. Hence the reason I haven't tried rerouting the hoses yet. I did the earthing mod and that works a treat. Even in my awd auto stock rs4 series 1 stag it was a fairly noticable difference.

[DaveB]

That pic' of the S1 looks a little different to S2... anybody got one of the locations on a S2?

[KiwiRS4T]

I haven't yet done the reroute mod as listed above but I'm curious as to where the brass restrictor came from as I can't see one in my standard set up just the T piece and the solenoid. Hence the reason I haven't tried rerouting the hoses yet. I did the earthing mod and that works a treat. Even in my awd auto stock rs4 series 1 stag it was a fairly noticable difference.

You won't see the brass restrictor but you should be able to find it by squeezing the hoses. An alternative is to remove the restrictor altogether and solder up the bit of the T that goes to the blow off valve return and drill it out to the required diameter. Apparently some people cut off the ends of welding tips (thus getting a known sized hole) and push them in the pipe. I am using a needle valve which gives me infinite adjustment and made it easy to go from the rerouted hoses to my EIBC but that is probably overkill.

The reasons not to earth the solenoid are

1. You are limited to the amount of boost you can get

2. Obviously as it is now on all the time not just when boost is required you will wear it out sooner ( but not in the short term - it will work as you say in the meantime).

[KiwiRS4T]

That pic' of the S1 looks a little different to S2... anybody got one of the locations on a S2?

I haven't seen under the bonnet of a Series II but the written instructions should still apply. Start from the solenoid and you should be able to trace the hose from the intercooler pipe (probably the top pipe on the solenoid) the one that goes to the T: one to the wategate actuator and one to the bov return pipe.

[DaveB]

Thanks KiwiRS4T! What sort of needle valve are you using? I also have to install my (built) IEBC sometime, and I haven't tested hole size yet.

[DaveB]

Quick question: the solenoid (to right in picture, with the two hoses going to it), if wired for 100% duty cycle, would just be like an open valve wouldn't it?

isn't the simplest way to understand this 5-minute vacuum tube re-routing then to think of just removing the tubes from the solenoid and connecting them together?

[KiwiRS4T]

Quick question: the solenoid (to right in picture, with the two hoses going to it), if wired for 100% duty cycle, would just be like an open valve wouldn't it?

isn't the simplest way to understand this 5-minute vacuum tube re-routing then to think of just removing the tubes from the solenoid and connecting them together?

Yes but it is quite important that you do it in the right way and relocate the restrictor as per the instructions.

[KiwiRS4T]

Thanks KiwiRS4T! What sort of needle valve are you using? I also have to install my (built) IEBC sometime, and I haven't tested hole size yet.

Sorry,I read your last post first. If you have an IEBC I wouldn't bother with the temp rerouting - get the IEBC fitted. If you are not confident in hacking in to your ECU it should only take a sparky used to working on car computers half an hour to make the necessary connections for you.

I got a needle valve from an engineering pipeline supplies outfit but together with the connectors needed to accept the piping that you are using you could easy spend $60. I would recommend using the restrictor found in the system (sometimes there is a band on the hose to indicate its position or you could just squeeze the hose till you find it) or if you can solder up the T and then drill a hole in it that would be satisfactory too (but get the restrictor out of its current position as well).

[DaveB]

Sorry,I read your last post first. If you have an IEBC I wouldn't bother with the temp rerouting - get the IEBC fitted. If you are not confident in hacking in to your ECU it should only take a sparky used to working on car computers half an hour to make the necessary connections for you.

I got a needle valve from an engineering pipeline supplies outfit but together with the connectors needed to accept the piping that you are using you could easy spend $60. I would recommend using the restrictor found in the system (sometimes there is a band on the hose to indicate its position or you could just squeeze the hose till you find it) or if you can solder up the T and then drill a hole in it that would be satisfactory too (but get the restrictor out of its current position as well).

Thanks, yes did spot a banded one:

I'll install the IEBC as soon as I can find an electronic boost guage; I guess that I shouldn't play with the boost without one. Any suggestions for a guage to use?

[KiwiRS4T]

Thanks, yes did spot a banded one:

I'll install the IEBC as soon as I can find an electronic boost guage; I guess that I shouldn't play with the boost without one. Any suggestions for a guage to use?

Electronic gauges seem to be very expensive. I can get ordinary ones second hand for $20 or $30. You could just run a plastic tube around the side of the bonnet and through the door until you can find/afford your ideal electronic one ...you can't tune the IEBC without one.