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Rs4-s Owners - What Have You Done To Overcome The Boost Solenoid To Run 7+psi Or Is My Understanding Wrong?


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so is your post twice as useless as mine ??

and how many people do you see when you look in the mirror??

I know this is off topic, well I'm 50% certain. :banana::ninja:

i have an rs four s

it has a catback exhaust , gutted cat , HDI fmi . standard air box .defi boost gauge

when i fitted the fmi it would run an unstable .8 bar on standard boost controll and was not happy . surgey . hit boost cut a couple of times

i bypassed the stock solenoid and and swapped the waste gate actuator for a r32 one plumbed straight off the compressor housing , rock soild .8 bar car not happy . started pulling timing between 4500 and 6000 rpm

i now have standard waste gate actuator back on and old school avc-r boost controller . .7 bar and car is happy . goes hard . standard coils .standard ecu. what ever plugs came in it . 126000 kays . no hint of a stain above the exhaust 0-100 in 6.2 seconds

im with you mate. considering there are only a hand full RS4S drivers and prob half of those have no idea, its hard to get solid info.

the problem is alot of the info that is being posted is opinion. noone who has posted except lachlanw has experienced something like it. someone earlier suggested to meet up and compare, which is a good idea. its hard to communicate the symptom in text for a start let alone the cure. good luck mate. when you find out the winning combo share it round. always comes in handy for the rest of us.

its late, ill take any flack you think i deserve.

So I'm willing to be labeled a slow learner to get this right :) I didn't install my boost controller and I want to ensure it was done right..

So... Below are 2 pics. One shows the Boost Solenoid and you see the top line is still connected and is plumbed in just above the pod intake. (Is this right??? Reading this re r33 install it doesn't seem right.. http://www.skylinesaustralia.com/forums/In...st-t183405.html

The other photo shows where the boost controller is plumbed in x mark the spot where the line starts then it goes the T piece (its hard to get a photo due to lines running everywhere) and that runs to the wastegate actuator - Im sure thats right.

So should I disconnect and block that hose to the top of the solenoid? Would this be conflicting with the after market boost control?

Cheers again.. Been a nice crash course in bits and pieces re turobs

post-69406-1274483758_thumb.jpg

post-69406-1274483778_thumb.jpg

Edited by BCCairns

seems like its set up a bit wierdly

the line that runs to the solenoid should be plumed into the pressure side of the boost controller or blocked off if the bc has a good source already

the arrow on that small block should point to the wastegate

unplug the old stock solenoid and block off that line, its probably giving you a boost leak <----- Try this first and tell us how you go

:):D :D :):D

It's a new car!!!!!!!! being my first turbo car I didn't know what to expect.. I just thought it took ages to build boost but it looks like I just had a massive boost leak cos that solenoid was still connected on the top hose... Looks like SA user I bought the car from just hooked up the boost controller wrong, man i reckon if he knew he would spew.. With this hose plugged it builds boost in a instant and man it is way more responsive!!!! Look like this could be the reason I couldn't run above 7.5psi I will do some more tests over the weekend... All I have to say is F$u)K yeah, you all rule and thanks for your responses and help... Tom cheers again u rule.....

no worries mate, glad to hear your enjoying it

i had a 32 that ran like crap, put with it for about 6 months and sold it - found out from the ppl i sold it to that the exhaust cam was 1 tooth out and it goes like stink now :) if only i had known

oh well, my stag shits on that thing anyday

I've had a boost leak in my Stagea for the last few weeks. I found that the vacuum line from the back of the engine to the MAP Sensor was barely on the block. Hopefully that was my source of my boost leak. I used the article Bypassing the Stock S2 boost limiter to see what difference it makes to my car. Here's hoping the trip to work is a little better than it has been for a while.

The bottom line from the boost solenoid was the line I blocked when I installed my Turbosmart single stage BC. I have left the top vacuum line connected from Boost solenoid to the intake manifold. It has never bothered me until I noticed the Stagea was really hitting boost like it used to. Current setup is stock turbo, stock ecu, HKS pod filter, stock SMIC, running approx 10psi.

I've had a boost leak in my Stagea for the last few weeks. I found that the vacuum line from the back of the engine to the MAP Sensor was barely on the block. Hopefully that was my source of my boost leak. I used the article Bypassing the Stock S2 boost limiter to see what difference it makes to my car. Here's hoping the trip to work is a little better than it has been for a while.

The bottom line from the boost solenoid was the line I blocked when I installed my Turbosmart single stage BC. I have left the top vacuum line connected from Boost solenoid to the intake manifold. It has never bothered me until I noticed the Stagea was really hitting boost like it used to. Current setup is stock turbo, stock ecu, HKS pod filter, stock SMIC, running approx 10psi.

Let me know how you go.... I'm still mucking around with the impact of removing the top line from the boost solenoid. I definitely found the boost is building up quicker and the car is quicker in the lower rev range. Previously it was like the car had long legs and started to boggie later in the rev range.

Let me know how u go.

I've had a boost leak in my Stagea for the last few weeks. I found that the vacuum line from the back of the engine to the MAP Sensor was barely on the block. Hopefully that was my source of my boost leak. I used the article Bypassing the Stock S2 boost limiter to see what difference it makes to my car. Here's hoping the trip to work is a little better than it has been for a while.

The bottom line from the boost solenoid was the line I blocked when I installed my Turbosmart single stage BC. I have left the top vacuum line connected from Boost solenoid to the intake manifold. It has never bothered me until I noticed the Stagea was really hitting boost like it used to. Current setup is stock turbo, stock ecu, HKS pod filter, stock SMIC, running approx 10psi.

is there any reason why you couldn't hook the MAP sensor back up? was it damaged or something? you shouldn't have to worry about the factory boost limit unless your running 14psi and higher, which is aftermarket turbo territory. the boost limit wont cause any kind of underperformance or sluggish boost. it is a hard cut out of the engine, as i said in that topic, it feels like you've driven into a solid wall.

i only mention it as i have been told by a tuner that they have seen leaner mixtures once the MAP was disconnected, although this wasn't what i experienced, i could have easily added fuel to compensate. you wont have this option on the stock ecu, do you have anyway to check your mixtures? if not i'd reconnect it to be on the safe side.

Edited by QWK32

It hasn't made much difference in hitting boost haveing disconnected the MAP sensor. It still is a bit sluggish in 2nd gear up in hitiing boost. It kicks in about 5000rpm, whereas it used to be about 3000rpm or thereabouts. I'm guessing it could be clutch related, had a similar problem in my S13. Although for my wallet's sake, I hope the clutch isn't on the way out.

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