MI 35th

iTrader: (16)

Ok Here is the issue.

My car is waste gated at 12psi and on pump gas makes 16psi with the Haltech BCS.

As of right now the highest boost my logs or boost gauge are registering are 6psi.

I am losing boost tremendously and I am not sure why. Here are the steps I have taken so far.

Jacked Car up &:

Checked all IC piping, Tightened all the T-Bolts
Check all the reference hoses to the BCS & Waste gate, BOV, at the source and they were all present.

What to check next then?

I am thinking maybe I have a split in the couple or something the only way to know for sure would be to replace them all. That would be a MoFoPITA!

Anything else you can think of?

Basic setup:
Haltech w/ BCS
BP 6262 Kit
Built Motor

jdm5596

Do u know Howmto do a leak test with a compressor, if it's that big of a leak it shouldn't be hard to spot it, but the leak test would help... Just find a spot you can push air into the charge pipes and have a buddy or you look around for a leak....sounds to me it's not a leak problem though... Might want to check that waste gate again...

MI 35th

iTrader: (16)

Thats a good Idea, but I do need to make a boost leak tester then.

binder

iTrader: (8)

could be an exhaust leak pre-turbo which would make it hard to build boost.

It was running fine at 16psi before, correct? when did the symptoms of no boost occur? I know i've blown out a couple of those 2 bolt gaskets on the drivers side pre-turbo and it's common for people to blow out the 3 bolt flange gasket that goes to the headers.

Do you have open dumps? if so when you boost up to 6psi do you hear the dump open up making noise? If they aren't opening then the spring is doing a fine job of holding it closed and that isn't the issue.

Boosted Performance

iTrader: (14)

Another thing to check is the waste gate diaphragm, it could have a crack in it and leak. Be very careful when removing the top half of the waste gate, there is a lot of spring pressure there, and it can really hurt you.

I doubt that a coupler is split (not impossible though) as they are 4-ply silicone.

Exhaust leak is a strong possibility, although it would have to be a large one. Like binder said, you can check for exhaust leaks. Look for black residue on the outside edges of the flanges on the header and up pipe. The turbo inlet gasket is metal, so that would not blow out. Using high temp RTV is also a great way to seal a flanged exhaust leak.

If you need the 3-bolt gaskets just let me know. I use Berk Technologies gaskets and they are good for 2000deg F.


EDIT:

Do you have dual widebands with the Haltech? If so, they will also tell you if you have an exhaust leak by showing lean conditions.

MI 35th

iTrader: (16)

All good points I am going to check all of that tomorrow. Ill pull off the waste gate and inspect it. It seemed to go out sometime after the hard runs of the dragon on the way home. I don't hear the waste gate opening. So its very possible I have a big leak pre-turbo. Then again Its open dump off turbo and open off waste gate its hard to tell apart.

350Z400rwhp

iTrader: (4)

I made this DIY on how to make a boost pressure test kit. I have a supercharger but the concept should be the same.

https://my350z.com/forum/engine-driv...ml#post5989613

binder

iTrader: (8)

if the gate isn't opening then it's probably not it. Check it anyways though.

Exhaust leaks can be sneaky. Sometimes they don't make any noise until you get pre-turbo pressure building then they start to leak but at that point the engine noise will drown it out.

My best guess is it's probably a bad turbo. You'll just have to buy a new one and donate this one to me

Boosted Performance

iTrader: (14)

Jeff is on a mission...you guys should just swap and both would be happy.

binder

iTrader: (8)

IDK if the 62 turbine wheel will flow enough for my ported heads and cams though. if it was a 65 wheel i would in a heartbeat.

wouldn't mind testing the 6262 though......for free

Boosted Performance

iTrader: (14)

Hal managed to get 6262 487whp (I think) out of the 6262 t4 .81 a/r on pump. Safe to say that the limiting factor was the turbine (although not confirmed, speaking from experiance). I think the 6266 would be a perfect turbo for you Jeff.

psychoballistic

iTrader: (8)

Sounds to me like something with the wastegate more then the turbo. Does the turbo still spool to 6psi the same? If spool is the same right to 6psi, that would lead me to believe it is exhaust based in either the Diaphragm like BP mentioned before, or something gasket related.

Is anything else different when you drive the car besides the lower boost?

MI 35th

iTrader: (16)

495 was on E85.

565 DJ number on E85.

on the 6262. It will make much more on a 7175 CEA

MI 35th

iTrader: (16)

Ok Figure out the problems. Now to find a solution. Yes I states problems there are a couple.

Issue 1:

LH (Driver) 3 Bolt Gasket from the header to the Turbo Piping is blown out.


Issue 2:

Welds on the top side of WG have cracked to a point where if you pull down on the WG it would creat a 1/8" gap

This was caused due to weight stress from the WG and dump pipe not being attached to anything.

My buddy and I have figured that it needs a gusset plate for extra support and that we are going to re-weld that spot and look for any other spots that may have cracked.

Ok So I have at least come up with a viable solution to one of the issues, and the other one I don't want to keep changing out these crappy gaskets if they are going to continue to blow out.

I logged for 20 minutes tonight and it supports my theory.

The IC piping was tested to 25 psi and it held solid.

I will say on the editorial side of things, they car is never abused but it is used for its intended purposes and pushed to the limits that dynosty has set upon it. At the limitations of my setup on the Dragon, Airstrip, in 100 degree plus heat a weak point was bound to show. I would recommend to Sasha that in this design put a small triangular gusset in the pipe coming from the turbo up pipe to waste gate. I am glad it was something minor like this and something can be learned and a weak spot was found before even more harsh trials began.

jerryd87

iTrader: (4)

something i found when hooking up my exhuast again is the mr gasket copper 2.5 inch header collectors will fit with some trimming to the bolt holes and they have a raised section that you have to crush when bolting them up. i dont have mine running but its what i used since no one had new header gaskets for our car in stock, trimmed all three bolt holes and just made sure the gasket stayed lined up till i got some torque on it.

you will have a slight gap and it might be wise to torque them a second time after one heat cycle(i know its a good idea with copper head gaskets) but shining a light into the small gap i can see the raised section sealed against the pipes. they are thick too about 3/16ths of a inch thick, betting you will snap a bolt before you completely crush the gasket flat and they are reusable.

Boosted Performance

iTrader: (14)

Don, I am glad you found the problem, but not so much that it is a crack on the waste gate. That is very strange to be honest, as I have never had a weld crack on me like that. I would be more than happy to get it fixed up for you if you choose to do so at no charge.

This is how your waste gate looks:



The design has changed to this:




The waste gate now sits on top of the weld so to speak, vs. putting strain/leverage with it's own weight the way you have it. In addition, the section of pipe is much shorter, and there is a lot more weld holding it as it sits at an agle, more parallel to flow. The waste gate you have is also much larger than the standard one used since your kit went out.

With all the changes made, I do not see this probelem repeating on another kit.

As for the gasket, I can send out a set of new ones if you wish just let me know. The gasket supplier was also changed, and the new ones are much better quality. The important thing with the gaskets is that you should go back and tighten the bolts after a few heat cycles. Not sure if this was done after the last install, but could be a contributing factor.

MI 35th

iTrader: (16)

Sasha, I am not worried about the crack I can weld it up not problem. I need to pull it off anyway to change out the gasket.

That is a good change you've made to the kit. I personally love the 44mm Tial WG its been great thus far.

As it sits I would be happy to purchase the updated hot-pipe if you could make one to support a 7175 CEA along with my 44 Vband.

But in the meantime if you get me the contact info on the gaskets I would gladly order one ASAP.

Boosted Performance

iTrader: (14)

I still use tial waste gates, just the smaller MV-S units, also V-band..just smaller. The hot pipes are H compressor cover specific, as well as an alteration to the down pipe is made since the turbo is a bit higher.

The turbo intake is also upgraded to 3.5". Will PM you on the 71mm turbo details..

PM sent regarding gaskets.

OMERTAITALIA

iTrader: (5)

I'm having the same issue, gear heinz(my mechanic) just informed me of my turbo exhaust gasket was gone and I'm missing two bolts on one of my exhaust manifolds, well see if it resolves the issue but I'm confident it will

G3po

iTrader: (8)

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