Having some Boost Probs....

[zinkrb250]

1995 240sx SE with a 1996 R33 RB25DET SII

Mods are as follows:

rb25det, Mckinney Mounts, Blitz NurSpec Catback, 3" Test Pipe, Mckinney 3" Down Pipe, ACT 6 Puck, Nismo Thermostat, Nismo FPR, Tein HEs, R33 Front Brake Conversion, Walbro Fuel Pump, FAL 220s, Hybrid FMIC, SPL Stainless Brake Lines, HKS Filter, Tomei 256* Poncams, FNo1Rc's 17x9 +15 on all fours

My car has been running great and i have no complaints so far... until tonight....

I drove around town for a while and then started to head back to my house... Hadn't gotten on it alllll night... until i hit the road i live on

Gave her a little bit of hell... and as soon as i reached "redline" on the s14 tach... it wouldn't push anymore... almost like the wastegate vented all the boost...

shifted into 2nd.... got up to redline... and same thing happened... i hear a "whoooshhh" and car goes limp...

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ok so i took it for a joy ride for about 10 minutes.... here's what's going on

i have no boost controller... my car is set at stock boost: 7psi

1st gear dead stop...

pulls ... boost gauge reads 4psi... reaches 7psi... holds at 7psi for a sec. or 2... then "whoooshhh" motor goes limp at approximately redline on the stock 240 tach

2nd gear...

pulls... boost gauge reaches 4psi... almost reaches 7psi... (tach needle close to redline)... then "whooshhhh"... motor goes limp

3rd gear...

same scenario

**note... as soon as i hear the "whoosh" sound... the motor stops pulling... i could keep my foot down on the accelerator and the boost stays down and rpms don't climb too much....

If i let off of the accelerator long enough for the RPMs to fall back down... the motor comes back to life.... same if i shift into a higher gear

Only things i've messed with my car lately are the following:

-Built a CAI out of PVC

-unplugged the maf.. cleaned it with a vacuum... plugged it back up

unplugged

-unplugged a plug... relocated it... plugged it back up... just moved it out of the way too clean up the engine bay... not cutting involved

anything gentlemen anything?????

[urban]

spilt intercooler joiner hose?

don't know it sounds like you have a boost leak somewhere.

[zinkrb250]

spilt intercooler joiner hose?

don't know it sounds like you have a boost leak somewhere.

the silicon pipe fittings that join the intercooler itself to the intercooler piping have began to bulge on both sides... i can squeeze them and feel air .. like a balloon... is this normal?... maybe this is what is wrong?

[zinkrb250]

Checked it out in the daylight today... all my intercooler couplings are tight and no leaking there... couldn't find any suspicious vacuum lines leaking...

However i did find this...

car parked, in neutral... i would rev... boost begins at 20psi vacuum... reaches 0psi vacuum... and at about this time Boost gets dumped and a rubber/silicon coupling (between the compressor and the hotpipe) completely collapses....WHY????

Shouldn't this coupling be channeling air from the compressor down the hotpipe and into the intercooler to be cooled????

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See picture above (the coupling that collapses is circled in red)

I need help in a desperately bad way fellas please!!!

thanx

-Andrew

[CEF11E]

man thats an annoying problem.

The only 2 things i could think of are

1. The solanoid to the wastegate actuator is surging or broken causing all the boost to exit throught the wastegate. and this is starving the engine of airflow. and thats why the hose you mention is collapsing.

2. the bearings in the turbo arfe gone or going or there is to much shaft play and the turbine is coming in contact with the housing at any decent level of boost, this in turn stops the turbo from producing boost and the engine is starving of air flow again.

Either way i would get that piece of hose replaced with something stiffer or possibly get the "hot pipe" extended to be closer the the outlet of the turbo and just have an inch or so of silicon hose connecting it to the turbo.

hope this helps!

[zinkrb250]

thanx for the suggestions guys... i fixed the prob!

The ghetto made CAI i built was made with a 3" -> 2" reducer that attached to the MAF and the 2" PVC i used to plub a CAI... i believe the 2" piping was too restrictive which was causing this problem.

It's getting hot here in the states and i would definately like to use a CAI... Therefore, i'm going to try and use 3" pvc and see how well that works out.