Boost Solenoid Mod 0-100 Times

[groonsnout]

Modded my boost solenoid, So just a quick post with some 0-100 times on my stock S1 RS4. All recorded on a g-tech at night (canberra = cold)

Before mod (stock boost cut until 4500 rpm)

Run 1: 8.28

Run 2: 8.37

Run 3: 8.19

After mod (full boost throughout range)

Run 1: 7.31

Run 2: 7.38

Run 3: 7.29

worth your time!

Cheers!

[Terminal]

how did you 'mod' your boost solenoid?

[ssshonky]

has anyone gone to the effort to extend ( what I beleive ) is an easy mod one step further?

would be good if you could get a 2 way switch to allow you to go between the 2?

Ie .. stock setup - low boost till 4000rpm

then full boost from 0 - redline

could be a good thing to do

[mitchy_]

not worth the effort, leave it at full boost, and control it with your foot.

[groonsnout]

not worth the effort, leave it at full boost, and control it with your foot.

Just the standard ground the solenoid so it's open all the time (or just bypass it..) but as far as having a switch for it.. I don't see a lot of point, as it's much more responsive with it fixed, and uses a reasonable amount of less fuel. More midrange = less right foot.

But was good to see a difference in numbers, not just feel. It was mainly off the line where it made the difference. Up to 50 kph or so was HALF the time. I also tried one run with loading up the stall but the brakes couldn't hold it under full throttle.

fun stuff anyway I would have done some 0-400m but not a lot of ACT roads where doing 150kph recommended..

[thrtytwo]

how do u do this mod ? is there a tutorial thread ?

[Stinky Rooster]

I don't suppose you could follow this up with some numbers on your fuel economy?

Anywhoo, thanks for sharing the lurve

[groonsnout]

I don't suppose you could follow this up with some numbers on your fuel economy?

Anywhoo, thanks for sharing the lurve

When I did the mod I went from about 390k a tank to 450k a tank, but it's all really down to driving style I guess.. I'm pretty easy on the car, doesn't spend much time above 3500rpm, but doesn't have to now.. before you really had to wring the neck out of it for any sort of performance, so effortless now. Different car! Even feels better down low than my TT 300zx which is 3L and has 2 turbos (manual)

The mod is just in the sticky section under DIY.. I think it's called full boost modification or similar.. 5 mins work..

[mitchy_]

its called rb25 boost solenoid mod i think.

essentially you ground the solenoid, so its always open (the ecu opens it at 4,500rpm, so you have 5psi boost to 4500rpm, then 7 over that)

you can either ground the solenoid, or just rip the thing out and join the 2 hoses (make sure you dont use a joiner that will restrict the hose I.D. otherwise you might get too much boost, ideally use a single piece)

very good, cheap mod to perform on the rb25.

[nuffsaid]

I did it on my R34, but not so sure if it works because I dont have an aftermarket boost gauge.

Any other way to test?

[leetom]

its called rb25 boost solenoid mod i think.

essentially you ground the solenoid, so its always open (the ecu opens it at 4,500rpm, so you have 5psi boost to 4500rpm, then 7 over that)

you can either ground the solenoid, or just rip the thing out and join the 2 hoses (make sure you dont use a joiner that will restrict the hose I.D. otherwise you might get too much boost, ideally use a single piece)

very good, cheap mod to perform on the rb25.

why not buy a manual b/c and try ten psi, even better

[Ska]

Yeah buy a turbotech, $35, fully adjustable, better than my greddy ebc!

But if you are so cheap that you dont want to spend $35, then yeah ground the wire, hey presto

[mitchy_]

why not buy a manual b/c and try ten psi, even better

thats what i did

ripped the 2 hoses off the solenoid, joined it with a manual BC, and cranked it up to 13psi, 300rwhp goodness

[captinsane]

i tried this...grounded the wrong wire (no boost) - then figured... bugger it, got an MBC and ran round all day with 12psi in my pocket

[ssshonky]

hmmm a manual boost controller does seem a good alternative

and yes I can vouch for the turbotech ones.. very good indeed! and so simple!

[webng]

Hmm.. very interested in this mod for my S2 when i get it but i may be showing my age here with this question... is it a legal mod? i.e. if the car is totalled, can insurance pick on this to not pay out the damage?

[Duncan]

mate not a chance in the world anyone would ever notice even if it was illegal...you cut one wire and ground it to the chasis.

the beauty of this mod is it gives you power in the midrange, doesnt affect top end (and therefore should be super safe for the motor). And cost is about 10c...5cm of wire and a eye terminal

[joe26f]

old mate asking bout it with the R32 wont need to worry coz he's car runs 10psi all day