someone tell me if this sounds like a boost leak?? and how best to check?

[jimBNR32]

i recently lowered the turbos on my r32 gtr to install some hks oil feed restrictors (jun pump, 2860-7s).
in the process i removed the usual items;

TT pipe and fittings connecting it to the turbos
the hks hard pipe i have after the TT pipe
actuators so i could get to the water feed on the turbo
downpipe
lowered the turbo from the manifold about 1inch which gave me enough room to swap banjos.
removed/blocked return hardline that feeds into the intake after the mafs from the boost solenoid
(both solenoid pipes were blocked anyway as im running actuator pressure).

that was pretty much it.

car idles and drives ok, a bit richer than i remember on cruise and idle. (tho no smell or smoke)

soon as i hit boost its very laggy. it barely reachs 0.6bar until after 4+k rpm (0.3bar at 3k etc) previously hitting 0.7bar very early in the revs as expected on these turbos, ie 2-3k rpm.(currently setup to run actuator pressure of 0.7bar and no more).
soon as i see boost also my AFRs go straight into the 9s (my aem wideband only reads lowest of 10:1, but am sure its seeing richer than this at it goes straight to 10:1). the car used to run mid low 11s on boost. i dont notice or smell any overfueling smoke tho.
it feels very laggy and slow to pick up. doesnt hestitate, not that ive noticed.
the air filters do seem to be louder, but that could be in my head. louder intake=turbos working harder to get up to speed?

this typical signs of a boost leak??
it doesnt buck or stall.

i cant see anything obvious leaking. its obviously not a completely popped off pipe as i wouldnt make any boost right?


i want to purchase a compressor to check for leaks.
whats the correct procedure?

i was thinking remove mafs, block both intake pipes but install a tire valve in one.
block the breather line on the intake
block the pcv line
remove the oil cap

put in 5psi air to start?

ive not made or performed a boost leak test before, but this is what ive found on the web seems to be the correct way, i just wondered if this was the correct way on the RB26??


any thoughts or opinions??


cheers
jim

[jimBNR32]

? Anyone :-)

[jimBNR32]

Lots of views

Not a single one had a boost leak before ?

:-/

[sb119]

Yeah sounds like you've got it pretty much figured out. Your diagnosis method sounds good, try it out and spray some soapy water on all connections and look for bubbles. The best way to test for boost leaks is with a smoke machine but with the tools you have the method you outlined should work

[cortexx]

There is a distinct possibility that one of your waste gates is either partially stuck open . Something binding on it , or the vac lines not reassembled in the same locations. Also a vac line caught and piched will also cause this.

[Skym]

i recently lowered the turbos on my r32 gtr to install some hks oil feed restrictors (jun pump, 2860-7s).

Have you got a ECU tune to suit?, as engine will run rich at mid to high rpm (where injectors are open more), easily into 10's and be less responsive with bigger lph fuelpump. Also have you hardwired the fuelpump?

Also engine will be laggy with those turbo's, stock cams. Need Tomei Type B cams, Tomei valvesprings (Tomei lifters or new stock lifters, shim kit with new cams, as cams, lifters are bed in together and affect's reliability), adjustable camgears, ECU tune to match (Nistune for stock ECU or aftermarket ECU like Link G4, ViPEC ECU, Motec, etc). Also make sure exhaust is fully opened up from turbo's (not using factory dumppipes).

in the process i removed the usual items;

removed/blocked return hardline that feeds into the intake after the mafs from the boost solenoid
(both solenoid pipes were blocked anyway as im running actuator pressure).

Also this (lack of stock ECU controlling boost level). Electronic boost controller helps.

DIY testing for airleaks (including making equipment) -

http://www.youtube.com/watch?v=atretf9u-Mc

Where to buy pro intake leak testing equipment -

http://www.siliconeintakes.com/index.php?cPath=8&osCsid=b93f0f11876d00a9cb1d69e80c31c4d9

[jimBNR32]

Have you got a ECU tune to suit?, as engine will run rich at mid to high rpm (where injectors are open more), easily into 10's and be less responsive with bigger lph fuelpump. Also have you hardwired the fuelpump?

Also engine will be laggy with those turbo's, stock cams. Need Tomei Type B cams, Tomei valvesprings (Tomei or new stock lifters, shims kit with new cams), adjustable camgears, ECU tune to match. Also make sure exhaust is fully opened up from turbo's (not using factory dumppipes).



Also this (lack of stock ECU controlling boost level). Electronic boost controller helps.

DIY testing for airleaks (including making equipment) -

http://www.youtube.com/watch?v=atretf9u-Mc

Where to buy pro intake leak testing equipment -

http://www.siliconeintakes.com/index...1d69e80c31c4d9

im running the same map on the poweFC as i was before. (running in map). the car was already fitted with the jun pump, 2860-7s, all i was doing was fitting some restrictors, no other changes other than removing the return pipe from the oem solenoid (which was blocked off anyway and doing nothing).

i already said what afrs it was running before, and what its running now.

all ive technically done is swap in some hks restrictors, that is the only change.

the car was not laggy before i did this restrictor swap, so something is a miss, hence why i suspect a boost leak, just after confirmation these symptoms are what a boost leak would do??

i have a boost controller to go on, but im not installing it until its back to how it was.

[Skym]

Oh, ok. I assumed that was before and after fuelpump upgrade, etc.

Boost leak is obvious, as can get a whistle sound if airleak is after turbo's (before turbo's is harder to detect) when intake hose clamps are loose. But if airleak after turbo's is small enough, the engine can become a bit laggy.

Also, did you replace gasket's on downpipes??? Exhaust leak might be one area to look at. You can test this by blocking exhaust tip while engine is idling for a few seconds at a time and have someone listen for exhaust leaks.

[jimBNR32]

ive got some new downpipe gaskets to go on, as the ones on the end of the oem dumppipes looked ropey. not broken, but old, wouldnt have thought anything was escaping tho and enough to cause this much lag and rich afrs tho. ill change them anyway.

[Xeno-Vibe]

sounds like a french ambulance

[jimBNR32]

Well I spent the day making my own rb26 boost leak tester kit.
Turns out my neighbour had a compressor, happy days.
But i had to by a fair few fittings and regulator also.

Wernt until I had it all hooked up, things blocked/removed started using it and couldnt get hardly any pressure.
Popped a good light down by the twin turbo pipe so I could see for bubbles and what do I see, the rear Twin turbo pipe gasket on the rear turbo hanging down! Seems I must have completely screwed up fitting that gasket! Was blocking the rear turbo flow by a huge amount and I'd guess leaking also.
Reinstalled properly and I was back in business!!
All that effort making parts, sourcing parts seemed a waste!
I've no idea how I didn't spot it before.
Afrs back in the low 11s, car pulls strong and quicker, seems I'm back to normal!

Woo!

Thanks for ideas and help.