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[Honda Bob]

I usually know what I'm doing when it comes to boosted hondas. I've come across a real stumper, and am hoping for some help.

Brand new REAL Garrett 60-1, 60 miles on it.
Go autoworks mini Ram
Ebay intercooler
Brand new charge piping
Brand new bisi 3.6 cam, properley degree'd in
Vitara/eagle build
KMS valvetrain .5mm over
Omni 4 bar
EBC through eCtune
Brand new turbonetics wastegate with 9psi spring
Brand new tial 50mm bov

On the dyno right now.

This car had a china 50trim on it and had been sucessfully tuned at 28psi. Life was good for almost the whole summer. One day it wouldn't make over 13psi. Boost leak test was performed and found some minor boost leaks. They were repaired. Still made only 13psi.

Compression test was done, and it was dead even across the board. The wastegate was under warranty still, and it had some scoring on the valve. Maybe it was hanging up, and we replaced it. Still 13psi of boost.

We then turned our eyes on the china turbo. Shaft play felt fine, wheels looked great, no big deal. But it was still a china turbo. Also wanted to make more power and the turbo was maxxed out. We replaced it with a brand new garrett 60-1.

Voila. We had boost again. The car was retuned and it picked up 40whp at the same boost level. Got it unstrapped from the dyno, and took it on a road test. It felt strong as hell... for 2 pulls. Then there was a small pop from under the hood, and now only 13psi of boost is all that could be made.

WTF.

Brought the car back into the shop, and the camshaft was falling apart. The crower cam's regrinded welds were just flaking off. A bisi cam was ordered. At the same time, we upgraded the leaking turbonetics bov to a Tial, and also changed over to some nice charge piping, with all new couplers. Another boost leak test was done from the turbo's compressor housing to the intake manifold, and it would easily hold 28psi.

AFR's are mint for 13psi, and the car is running great. It just will not make any boost. The turbo is not to large. It has spooled to 30psi before. We even swapped it out for another new turbo of the exact same model and had the same results. The old turbo was put onto another car and it proceeded to make 25psi.

We even got ballsy and removed the wastegate and then put on a block off plate. Still didn't make more boost. Doing that we should have maxed out the turbo well over 30psi.

Also, we have tested open downpipe, and removed the air filter.

Knowing that cam timing is spot on, ignition timing is spot on, fuel is great, brand new turbo, no leaks in the charge piping from the turbo to the throttle body, good compression, no exhaust restriction, no air intake restriction, I'm now confused.

Anyone have any ideas? Tittys in return for good replies.

[Avistar23]

I encountered this before, solution ended up being both a cracked manifold and cracked intercooler, as you said you have boost leaked many times, my only advice would be a through run down of the manifold, put some gear oil or similar in the intake.. just a bit... and see if smoke rises anywhere from the manifold etc...

[ratcityrex]

Exhaust mani leak? Intake mani leak? what motor? And is this driving or just sitting in one spot? load/no load

[ratcityrex]

Did you pressure test the intercooler? Leak down test?

[Honda Bob]

This is on a d16 vitara build.

We went through the manifold and intercooler pretty good. I got the intercooler up to 40psi, and stopped.... If it held 40, it will hold 20. or atleast 15... and that would be an improvement.

Also, this is all being diagnosed on a mustang dyno, with load. Produces the same force as the road, just safer.

Also I have smoke tested the entire engine system with a smoke pro. We have smoked the intake and the exhaust, and couldn't find any leaks.

[ratcityrex]

Damn dude, got me.

[Robb]

Ive seen intake mani bolts back off before, checked that yet?

[TTC]

Maybe 13lbs is the threshold when someting starts to expand and piss boost away. Leak test it to 30lbs and let it set for 5minutes and see if ti creeps down.  You have a cat?

[Uncle Fester]

You have a cat?

That's what I was thinking. Build up of back pressure not allowing it to spool. Test it with an open downpipe.

[DasPoop]

Also, we have tested open downpipe, and removed the air filter.

That's what I was thinking. Build up of back pressure not allowing it to spool. Test it with an open downpipe.

Its called reading everyones doing it

[keelay]

Get a Holset.


/thread

[shanerv]

weak spark?

[dvst8r]

Pressure test from an open downpipe, you may have a leak on the hotside. Same way you would pressure test an from the compressor housing. Cap the open downpipe pressurize it and the turbine housing and the exhaust mani and you may be surprised at what you find.

[glustic]

In for updates

[DasPoop]

Based on how this guy says things. He doesnt do any of the work he brings it to a shop and has them do it so its a bought not built kinda car.

Any suggestions you give him will just warrant him to relay them to the shop. if it was my problem i would be giving updates every hour well i would also know how to figure it out 

[Minor Threat]

Your Bisi cam is probably a giant pile of junk.

[clwtwizted]

Piss injection?

[Dr. D-Series]

This is a longshot..

Check the inside of the intercooler. Blockage ? I know you pressure tested it. But does it flow THROUGH.

Like I said. Longshot.

Good luck

[DasPoop]

This is a longshot..

Check the inside of the intercooler. Blockage ? I know you pressure tested it. But does it flow THROUGH.

Like I said. Longshot.

Good luck

thats actually a really good point i bet its full of oil and shit. and depending on where the wg gets its signal from it could easily be 20psi on one side and 13psi on the other 

[Honda Bob]

Based on how this guy says things. He doesnt do any of the work he brings it to a shop and has them do it so its a bought not built kinda car.

Any suggestions you give him will just warrant him to relay them to the shop. if it was my problem i would be giving updates every hour well i would also know how to figure it out 

Contrary, It's a customers car and he has brought it to my shop. I'm usually very good with this stuff, but this has completely stumped me. I am just trying to get outside opinions from others so we can get this car back on thed road for him by the end of the season.

I'm pretty sure its the rings. I was told that there was a compression test done by the customer, and that a co worker had done one as well. So i took their word for it. I decided to do one myself, and there is 40psi of compression across the board, and there is plenty of blow by. Now I'm pretty sure I degreed in the cam right, but I'm going to mess with that again just to double check thats not the issue. The car just runs too good to only have 40psi compression.

I can see through the intercooler, it's not blocked. atleast not 6" of it height wise, and its a 12'' intercooler. People are making more than 13psi on smaller intercoolers.

[keelay]

I am betting on cam timing. Maybe timing belt tensioner? Even with piss poor compression, you should still make some boost. You did pressure test up to the level you are boosting, no? Could be a weak or mal adjusted BOV.

[ratcityrex]

Bov blowing open?

[patsmx5]

Bov blowing open?

+1, could be it. My miata once had a small leak on the exhaust manifold, spool was late, and it wouldn't make but ~5psi. Only leaked when you went into boost too.... Made it a bit hard to diagnose.

[Foowee]

Is there a gasket between the fire ring n the wg elbow? 

How did you pressure test the charge pipes?  I've used soup cans w/ one end cut out n put a bolt in schrader valve in the sealed end.  It'll look something like this...



You can put the cans in the tb side and the compressor end of the charge pipes to test the entire system.  This will also let you know when your bov starts to leak.

[bigdaddyvtec]

I usually know what I'm doing when it comes to boosted hondas. I've come across a real stumper, and am hoping for some help.

I usually know how to make your mom cum when i Put it in her pooper... Butt  (LOL) when Im stumped and cant get her off, I just give her the fist

[Corey]

slightly bent valves?

try putting a stock cam in it to eliminate the possibility of the cam being the issue.

also check to make sure nothing went through the exhaust wheel and tore it up.

[TTC]

I usually know what I'm doing when it comes to boosted hondas. I've come across a real stumper, and am hoping for some help.

I usually know how to make your mom cum when i Put it in her pooper... Butt  (LOL) when Im stumped and cant get her off, I just give her the fist

the luls are strong

[rawr2d2]

I'd guess clogged cat/ exhaust restriction or leaky bov.

[jarebear667]

bisi cam 40 psi on comp test? is the cam bleeding that much off?

[HiProfile]

That's what I was thinking. I'd do a leakdown to check if it's the cam, valves, or rings doing that. I doubt it being rings if it's that even, and if it's valves - the cam probably is off or has zero P2V clearance.

I'd also check for a collapsed flex pipe. Someone here with a slow blownup car had that issue, and it was the difference of >200whp IIRC.