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Discussion Starter #1
I'm pretty sure this is a no brainier, but I had my car running up in the air on a lift after doing some repairs and inspecting. I noticed that the dump tube off of my waste-gate is puffing. Am I right to assume that the waste gate should not let anything past until it's spring pressure is overcome? I just did a complete overhaul off my engine/build and haven't got everything dialed in. Messing with fuel pressure and a number of things. I did notice that it doesn't really want to go into boost. I discounted it as another tuning issue because I've only just got it back up and running. But now that I found that, am I correct in thinking that the waste-gate is stuck open or has failed? It doesn't go into boost and is audibly puffing out of the dump tube at idle and can be felt of course by hand. Or is some bypass normal and I'm just tripping? I am going to upgrade to a Tial 44mm WG if this one is having trouble. It is just a cheapo that came with my CXRacing kit.
 

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Discussion Starter #3
When I test drive it, it won't go into boost. Not talking about under no load. But under no load it is allowing exhaust to pass. That's what I am assuming isn't normal. I ordered the Tial WG anyway. I'm sure mine has failed. I just don't know how. It worked fine before my rebuild. Sat in a safe storage place still on the manifold, never touched. Just isn't working after getting it running this time. But my build has become too expensive to run Chinese junk anymore. I need a good WG to keep my engine safe. Will see how this makes a difference.
 

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Discussion Starter #4
I could also use a little guidance on what spring pressure to run. My current one is 8lbs. But after my build I plan to run maybe into the 20's psi. Pressure will be adjusted up from the spring pressure with my Turbosmart MBC. So would I be good to start with a 10lb? 12lb? Or higher spring? My tuner said to start with the 10. But how much psi can you get from a 10lb and an MBC? Double the psi? Less? I don't want to be screwing around with replacing springs on dyno time if the 10 wont be enough.
 

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WG should be shut under the conditions you’re describing, with no leakage out the dump tube

WG base spring pressure can typically be doubled when using a boost controller. So for example a 10psi WG spring will hold ~20psi with a boost controller. Sometimes the base spring may or may not give you exactly the base pressure that they’re rated for.
 

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Discussion Starter #6
Thanks, ya I figured no bypass should be happening, so I ordered the new Tial one. Sounds like I should go for an 11-12lb spring then. The ones it comes with are rated in kpa or something like that, so the numbers in psi are in between, like 9.8 11.4 etc. if I remember. So something in the 11-12psi range should be good.
 

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Its really just a trade off between the lowest target boost you want to run, and the target boost that you want to reach.

Good move to replace your WG, it was definitely leaking. Was the cheap one a 2 bolt 38mm, or a 4 bolt 50mm?
 

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Discussion Starter #8
I feel you. It's a 44mm v-band from CXRacing, replacing with a Tial MV-R 44mm. Same size so it clamps right onto my manifold.
 

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Think I have a 12psi spring in my Tial 44. Max boost is 18psi on pump 91 on an unopened 2jzgte VVTi. Probs could go a bit more, but no need for me. Need to get the flex fuel tuned.


Pressure will be adjusted up from the spring pressure with my Turbosmart MBC.
I think I read you have an AEM Infinity, right? I would recommend getting a 3 port MAC valve (they’re like <$50) and use the AEM for boost control. Get your duty cycle tuned and set up the boost goal. You can do boost by gear or rpm or load or whatever melts your butter 👍🏼 I’d let the standalone do everything it is capable of, you paid for it.

Not to thread derail, but I’m curious what rear end ratio you’re running. You can run the taller set (3.27 I think) in a GS. Tallest I can run in my IS (without major mods) is the 3.58 from a Tacoma.
 

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Discussion Starter #12
Hell ya man I’ll look into it. Hadn’t really thought about it. I’m running 3.92 gears. Stock ratio on the 2nd gen GS300. Have an OS Giken 1.5 lsd in there too.
 

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ƒ=1/2π(√k/m)
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It is just a cheapo that came with my CXRacing kit.
Just to add to the conversation, but back in the day CXRacing (and many other knock off kits) were selling HKS and GReddy wastegate clones, and were not including the fire-ring flange that sealed the wastegate.

I used to have one of their 50mm gates, and I always thought my system was laggier than it should have been. Turns out it was a massive exhaust leak out of the gate.
252387
252388
 

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Discussion Starter #14
Ya I'm learning the value of quality components. Never planned to be going this far with my build when I installed this kit. just wanted high 300's to 400whp. So I was ok with the mediocre parts. But since my pistons couldn't handle it and I've now gone to forged internals, now I'm looking for 700-800. I'll be limited to what this turbo can do though. Still going to be using the CXRacing one since it's in good shape with no play or oil leaks and it is a dual ball bearing and balanced one at least. But the wastegate and BOV need upgraded for sure from the cheapo stuff.

Good find on your wastegate flange, this one does use a v-band though, so I don't think it's the same kind of leak. Mine is actually flapping open and close from a dislodged or broken spring, or a crappy seal or whatever's in there. I'll inspect when I remove it to install the TiAL unit to find out what happened.
 

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just wanted high 300's to 400whp. So I was ok with the mediocre parts. But since my pistons couldn't handle it
Same. I had bought a NA-T kit from XS Power but the more I thought on it, I decided it wasn’t a good idea to test the limits of the VVTi GE internals. I sold everything but the turbo, bought a VVTi GTE and a CX hotside/coldside and a Tial 44, and a NRG BOV. It snowballs on you real fast. When I pulled the chinacharger off for the BW, there was nothing wrong with it. It was a decent turbo but just old tech, so I bet your dbb CX will work OK till you want to upgrade.


actually flapping open and close from a dislodged or broken spring, or a crappy seal or whatever's in there
Sounds like your diaphragm is ripped or the spring is broken. Be interesting to autopsy it.

this one does use a v-band though, so I don't think it's the same kind of leak.
You should still have a “fire ring” valve seat on the new Tial. You may already know, but make sure you seat it square/concentric or it won’t seal. The tolerances are machined very tight and mine always gives me hell lining back up after I’ve taken it off, and it’s kinda hard to see it in our chassis. The Supra engine bay is much more spacious than the GS/IS.
 

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Discussion Starter #16
I'll pay close attention when I go to install, thanks for the heads up man 👍 I'll post about what went wrong in the CXRacing wastegate next week when I swap it.
 

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Just as an aside, did you get better quality oil lines for the turbo, when you bought your cx raing kit?
 

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Just as an aside, did you get better quality oil lines for the turbo, when you bought your cx raing kit?
Yeah I made my own with AN10 braid for the drain. The drain the kit came with was sketchy AF it had brass fittings and worm clamps with a piece of rubber hose better suited for a vacuum line haha. I bought a AN4 feed but the CX one looked fine. The BW turbo had a built in restrictor, so I didn’t use the kit one. CX may have stepped up their oil line game since I bought mine 3 years ago. Honestly think the manifold/downpipe/dumptube, and the cold side plumbing is all I have left of the CX stuff. I can’t complain one bit about it either. There’s not a ton of choices for the IS/GS chassis like there is for the Supra. I’m sure a better intercooler would benefit me, but I’d have to lose my bumper bash bar and that’s not a good trade off IMO.
 

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Discussion Starter #19
I'm pretty much where KrisOK is at. The CXRacing kit is great for fitment and hard parts. I customed my own oil return and am still using their oil feed that came with the kit. Do I need to be upgrading it? Probably a little small in diameter for what I'll be asking of the turbo huh? I just looked at the kit on their website, it doesn't mention the oil feed line and I don't remember what it is. Just that it is a ss line and doesn't leak, so I've been happy up to this point. What do you recommend Mr Ree NZ?
 

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Discussion Starter #20
From what I see, all they have is 4an and they look like what I have. And the return is 10an. So anything better than a 4an feed and 10an return?
 
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