Adam86

iTrader: (10)

Hey guys, had the car out a few times and seem to be having an issue. Have a 76mm turbo with a 44mm TS Hypergate and boost is coming on ridiculously slow. Doesn't start to build until 3500-4000rpm and I have to shift before I even see the full 7psi from the WG spring. My first thought was an exhaust leak, but it would have to be a pretty extreme exhaust leak!
Wastegate would be a possibility as well but I'm more concerned about the turbo. The turbine seems to have a pretty noticeable "squeek" like it isn't getting enough oil to it. That would be my only other thought as if the turbine isn't turning like it should, it would probably be a safe guess that it would hurt my spool time.
Am I off the mark on my thinking? Any opinions or thoughts would be appreciated.

1999Black_Z28

iTrader: (1)

Couple questions to help diagnose the problem...

What gears are you running in the rear?
Are you hitting 7psi (WG spring pressure) in higher gears?
Are you referencing your boost from the compressor or the intake manifold?
How much restriction do you have in your exhaust (post turbo)?

FLASH1970

iTrader: (1)

To check if your turbo is getting proper oil amounts, I'd mount a tee fitting right by where the feed line attachs to the turbo and get an oil pressure gauge. Also, do a boost leak test. You might be leaking air from somewhere in the charge piping.

Adam86

iTrader: (10)

I'm running stock gears. 3.43's I believe.

I haven't tested pressure in higher gears. So far I've only gone to boost in 1st and 2nd. I'll take it out for a drive later and try it out in 3rd and maybe 4th. 4th might be scary. This thing pulls like a raped ape once the boost comes on!

Boost reference to the wastegate comes from the compressor. There is also a manual boost controller in there. Maybe I'll try taking that out of the equation and seeing what happens? I have a vacuum distribution block referenced from the manifold that I could use if you think I should.

Post turbo I have a 3" downpipe running to a Magnaflow catback. There is also a cutout, and when I drove around the other day with the cutout open there was no real difference in when boost came on.

I really appreciate your time man

Adam86

iTrader: (10)

But if it was a boost leak I wouldn't be seeing full boost at all would I? It goes up to 6psi with an intercooler on a 7psi spring before I get close to redline.
I did check for a boost leak earlier and didn't see any bad couplers or anything like that.

JAX04

iTrader: (17)

As said above, check all the connections, id fashion and air test cap for it from a pvc cap of sorts and block off the opening to the turbo.

When i couldnt build boost with my 7mm Tnetics, it was becuase of two things, my vbands didnt seal worth a **** and the exhaust i had after it sucked ***. Even with the cutout open, it still sucked.

What are you running for a filter? that makes a pretty large difference as well.

Marty Staggs

Did you install the valve seat in the gate?

1999Black_Z28

iTrader: (1)

Those of us with a manual trans are at a disadvantage for spool...normally geared more (less load on engine) and we lose boost during shifts. My TC78 doesn't spool very well in first gear but once I shift to 2nd or 3rd I am always at full boost almost instantly. I suspect that once you start hitting the higher gears you wont care about the delay in first gear It's especially bad for me in 1st gear with my 4.11's (changing soon).

It's fine to reference the boost for your WG at the compressor but you should expect less peak boost than if you referenced it at the manifold (due to losses in the I/C, etc). Since you have a boost controller you can easily make up the difference...No need to change the location.

I run 3" pipe from my turbo dumped behind the k-member. Any restrictions post turbo will affect spool. I suggest you remove your exhaust after the downpipe just for a test to see if that makes any difference...I'm guessing you will probably leave it off after you try it :p I love the way it sounds!

One final thought I had is wrapping/blanket. If you don't already, I would wrap your crossover and put a blanket on the turbo to retain heat for a faster spool. I've always had mine this way so I don't have a good comparison but most people claim it's very noticeable.

Adam86

iTrader: (10)

It's an off brand 4" conical. Think I should try going without a filter and see what happens?

I could maybe potentially see if being an exhaust issue, but there seems to be quite a few guys running the same exhaust without issues. My gut really says it's not a boost leak. It's just not acting like it and if it was I would think that I would be losing some boost since my wastegate is referenced at the compressor. I would place a good amount of money on exhaust leak.

I honestly have no idea lol. I just ran the wastegate the way it came in the box from Turbosmart.
It is worth mentioning that my stupid *** dropped the wastegate 8 feet down onto concrete in my pit when I was taking it off one time. The housing seems fine though and I didn't see any noticeable damage.

Hmm... maybe this will be something I'll have to live with. It's a bit of a dog out of boost but after 3500 RPM it's an absolute monster even at 6-7psi. Maybe once the T56 busts and I go with a stalled 4L80 it'll get better.

Good to hear. Would a faulty boost controller be a potential problem? Only one way to find out I guess. I'll just hook the WG directly to the turbo and see what happens.

With the cutout off I really liked the sound but it was nearly impossible to hear the person next to you and it took all of one drive-by to get some complaints from the neighbors lol. But I will take out a section of exhaust after the downpipe to try it out. I actually used u-clamps on one section almost expecting something like this to happen

Yup I wrapped everything from manifolds to downpipe and have a turbo blanket. I can't imagine how hot it would get under the hood without anything!

LS1NOVA

iTrader: (12)

Has this been fully tuned? Dont be afraid to post this stuff on the local board and spice things up a bit.

Adam86

iTrader: (10)

It has not. Still running on the base tune. Ha I'll do that Nate

Fb0dy0nly

iTrader: (10)

what size crossover? truck manifolds?

Adam86

iTrader: (10)

Yup truck mani's. I believe the crossover was 2.5" IIRC

Adam86

iTrader: (10)

You know you're an FI noob when it takes you about a half hour of searching for "wastegate valve seat" on google to figure out what exactly it is and then another 2 hours for you to think to yourself....

"HEY DUMBASS! REMEMBER THOSE TWO ROUND RINGS THAT WERE LEFT IN THE TURBOSMART BOX THAT YOU DIDN'T THINK YOU NEEDED????"

I would like that think that any complete dumbass could have mistaken them for flanges

Thank you to everyone here for helping me out. And a big thank you to Marty and LS1nova for gradually assisting me in pulling my head out of my ***.

Marty Staggs

LOL - it happens.

ittwgn

**** happens mate !!!! anyway should be an interesting first drive once fixed???

stock48

iTrader: (17)

Don't feel bad. When I first built my truck I ran it for almost 2yrs with no seat in the wg, and at 6600' elv to boot lol.

Adam86

iTrader: (10)

Got the seat in tonight. It was DEFINITELY the problem. Went from starting boost at 3500rpm to full boost at 4000rpm. This thing runs like it was set on fire. Thank you again for the help guys.

Sales@Tick

iTrader: (3)

Bet it feels like a totally different car now.

Adam86

iTrader: (10)

The difference was unbelievable. I was pretty disappointed the first time out without the seat thinking this might just be part of the "turbo lag", but I never would have thought that such a small part could let so much exhaust escape. Starting to think that the still smoking hole in my wallet may have been worth it