neither of those things are restricting you at your power level.

I thought your boost drop was a lose hose clamp? are you sure your wastegate location is ok? has it ever held boost without a controller? but it holds rock steady with the controller?

 

I thought the two T-bolt clamps were the problem (not tight). That didn't solve the problem.

Not sure how the w/g location would cause this, but I am willing to listen if there is a logical explenation.

This is how it sits now:









From what I have been reading, it is an "optimal" location.

 

Looking at it again I would say that it is in a good position. You shouldn't be seeing the wastegate open up at the pressures you are seeing in the system currently.

There is still the possibility that even though 3" tubing is big enough for that horsepower, the double 90 degree could be causing some odd turbulance that affects airflow.

 

Very true about the intake. I have already ordered 3.5" intake tubing just in case. That should be plenty.

 

3" intake restrictive at under 400hp? A simple test is just run an open intake or put the cone filter right on the inlet and see if it still drops. no sense in fab'ing anything new just yet.

When you used your BC you got steady boost?

Hopefully it all gets sorted before MI35th gets his car going

 

Don (MI35th) has a different turbo (6262E T4 .81a/r) and basically no exhaust after the turbo. I am not worried about that setup at all. He also has a Tial 44mm with a stornger spring, and will use a BC as he plans on about 15psi of boost.

I will unbolt my rear muffler and go for a spin on Saturday. That will eliminate one thing, then I will play with the intake on the turbo side.

 

Now that I look at your pic there, I noticed the recirculated wastegate. I wonder if a restrictive exhaust could affect the performance of the gate?

I myself have never recirculated on any kit to date so I'm not quite sure but its a thought.

 

You mean restrictive exhaust after the turbo?

If that was the case wouldn't the exhaust going through the turbine slow down, in turn slowing the compressor wheel causing boost loss?

I just don't like the way it sounds with an open dump. It's like a bad exhaust leak..

 

Everything looks good to me in terms of locations. Just process of elimination to find the issue:

1. Try different wastegate (faulty spring?)
2. Try different turbine (I would do this last as it might cover up other issues)
3. Try filter right on turbine intake
4. Try open exhaust
5. Put pressure sensor on compressor outlet and compare to manifold pressure to detect pressure loss along the way (if you have a boost leak or restrictive piping or IC, this will show it).

 

I just read through this and based one everything I read it seems like the exhaust is really the issue. It's a 3" pipe with a stock style muffler, the exhaust is only as good as its lowest point of airflow.

My friend had a similiar one on his Z to keep the stock look and the power was not coming as it should have. Swapped for a Injen SES and picked up a cleaner power band along with consistent power at less boost. I would think you'd want to look at the exhaust as your first possible issue. It was a turbonetics kit not too mention, but airflow is airflow whichever way you split it. If there's a restrictive point, everything that is airflow based will be effected.

I have seen in numerous cars with piping as tight and turned as yours and in some cases even more so, and power levels and boost pressures never seem to be an issue. Personally I don't think your location is the issue, I would believe it to be in the exhaust.

Have you taken the muffler right off and just tried running it with the 3" pipe open? It may rule it out as a possible issue, or solve one.

 

Beat me to it with the open exhaust lol.

 

Thanks for all the input guys, really apreciate it.

I will start the process of elimination on Friday at noon. I will put the 6162 turbo back on (new 6265 will be here Friday) and go on from there.

The more I think about it the more I think the OEM style muffler in the back is giving me all these headaches. So I will start there first. If that is not the problem, I will move to the turbo intake piping/filter.

Then, if I still have a problem the new turbo will go on.

The wastegate is Tial and brand new, so I doubt that it is the problem. However, you never know.

 

swap the open dump onto the wg real quick and see what happens. it could be having similar problems to what APS ST kits had, too much back pressure right behind the turbo due to the wg gases.

 

It not not like you have a 2" exhaust into a tiny canister. Its a 3" turbo back exhaust with a muffler, they most common setup on a single turbo setup across every platform. I would tend to think TIg is more on track than anyone else.

But regardless, if your new turbo is here Friday, I wouldnt even bother messing with it. Bolt up the new turbo and go from there.

Do you still get all your tubing for free from work? You had mentioned that in another thread, so I was just curious as what your job was

 

The wastegate thing has been brought up by TrackPack. I just don't understand how that would be an issue. Not saying that TIG is wrong, just trying to understand the theory behind it.

This was APS's correction kit for the wastegate problem, and I don't see how it is different than what I have now:





Again I am not being stubborn here, just trying to understand it.




Well, it should be here Friday. I payed $160 for express shipping.

I have a bunch of tubing in my garage, 2.5" and 3". As far as what I do....I have a degree in Electronics with some Civil Engineering in there as well.

I work at a government food research facility, and do all kinds of stuff.

 

that was APS solution, but it didnt work either.

 

Found some very good info on the Supra forums:

To minimize flow disruption to the primary stream, one of the following ideas will probably work for you.
1) If you have a lot of WG flow, route the WG return such that the flow is in the same direction as the primary exhaust flow. This would be most convenient where the primary stream has a bend. Route the return so the flow is inline with the post-bend exhaust flow, and on the outer edge of the bend.
2) If you have lower WG exhaust flow, route the WG return in a place where the primary exhaust flow is more stagnent or recirculating. This would likely be on the inside edge of a bend in the primary stream. Or immediatly after a bottleneck in the system (hopefully you don't have one of those, and if you do...get rid of it first....).
In either case, the further downstream from the turbine outlet you return the WG, the better it will be for minimizing disruption to the flow through the turbo. Route the WG too close to the turbine outlet and as Andy says....you're likely to have boost control problems.



Now I know what you mean by wastegate routing...ect. It makes perfect sense, I will fix this as well or may just dump to outside to confirm problem.

In other words, if my w/g is dumping at full capacity (that would be 60% of total exhaust gas flow) it would be interfeering with overall flow of the exhaust after the turbo. The pressure past the turbo will be great, causing speed drop/exhaust velcity through the turbine.

 

exactly, if your wg is causing turbulent flow at the turbine outlet, exhaust gases cant escape from the turbo causing a decrease in flow and efficiency.

 

That's a very interesting issue, I hope you can get it figured out. I think the easiest things to try right now is just unbolt the exhaust and then the wg recirculation pipe.

 

This is how the down pipe and wastegate is configured now:






I am taking it to work today, and changing thins around. The new recirc. pipe will come at a sharp angle, see how that works out.