Triple Blowthrough Turbo

[rossman]

1 hour ago, Dat73z said:

Do you recall which Jeep mount you used?

Actually, I think I got confused with the diff mount that I used.  I did a bit of searching and I believe it is a GM transmission mount like this one: https://teamenergysuspension.com/product/energy-suspension-3-1108r-transmission-mount/. Dimensions of the mount can be found with a quick Google search.

[Dat73z]

Thanks @rossman I'll take a look and weigh the options. 

 

After getting my holiday lights down I went ahead and quickly cleaned the clutch and trans for reassembly, at least the areas that matter. No leaks from the trans as I had fully resealed it after machining and assembling, so the light oil I saw on the front edge/corner of the bell housing was likely dripping from the rear main as there's no way I can see how it made it there from the pan with the bellhousing plate in place. 

 

This PM I'll start the removal process for the RMS as I've already ordered a new OE Nissan RMS. Hopefully it doesnt take a month to get here. 

[Dat73z]

Last night I cleaned off the rear of the block. For sure the rear main is leaking, but it is questionable if the pan is. The new OE RMS should be in later this week, and flywheel bolts maybe next week. 

 

Since I'm waiting on parts again, the (hopefully) last thing that I found on teardown which needs to be addressed is the loose wastegate housing. 

 

After some research I went ahead and ordered stage 8 locking nuts which were quite expensive but basically like safety wire as it prevents the nut from rotating off. I also found a supplier for 718 inconel studs. Basically the idea is the materials selected should have similar thermal characteristics and also be resistant to high temp creep as to not lose tension and let the wastegate housing come loose as it has for me. 

 

I'll need to teardown the turbo hot side and measure all of the dimensions before I order, so I'll start on that later this evening. 

Edited January 3, 2023 by Dat73z

[Dat73z]

This evening I removed the surge tank to gain access to the turbo.

 

All of the carbs and barrels look good. I'm thinking after I get things reassembled, I will run things in NA for ar least one heatcycle and check the sync on the carbs before putting the surge tank back on. 

 

If I can squeeze in some time in tonight I'll start removing the heat shielding over the hot side. 

[Dat73z]

I couldn't resist just continuing disassembly, since I need to measure out the studs for their inconel replacements. 

 

All of the studs were still tight in the turbo and none of them backed out as I removed the nuts. I think I had torqued the studs in at 30ftlbs or so with nickel anti seize. The copper coating had burned off on all of the nuts which I suppose is expected when things get glowing red hot. 

 

What I suspect happened is all of the studs stretched. Hopefully inconel studs and stage 8 hardware will mitigate this. 

[Dat73z]

Did some more tinkering this AM before work and realized I should probably add some bracing to the downpipe or midpipe as well. Although I welded in a flex on my downpipe I suspect the movement along with the heatcycles, especially with the inconel shielding isn't helping. Likely in its current configuration, I doubt the setup would last a few 20min track sessions. 

[Dat73z]

Looks like parts are finally going to start trickling in starting tomorrow. It will likely be another 2-4 weeks until I get everything I need in. 

 

This AM I removed the turbo studs. Whatever was left of the nickel antiseize had turned into black dust. None of them came out clean but the threads are still there, so I'll need to chase or retap the hot side. 

 

I'm thinking when I was losing timing and throwing fire out the exhaust, my egts were likely spiking contributing to all of this. I'm tempted to pull the turbo and replace the hardware with inconel and stage 8 as well since I'm already this deep. I guess I'll simmer on it over this next couple of days. 

[Dat73z]

Getting rained out again so I put some more time into the build. 

 

Tonight I pulled the leaky RMS, retapped all the hot side bolts, and test fit the stage 8 hardware. As with everything on this build I'll need to clearance some of the stage 8 hardware to fit is tight for a couple of holes. 

Edited January 8, 2023 by Dat73z

[240Z Turbo]

Love the thread!  What size rims and offset do you run in the rear with those 245's?

[Dat73z]

@240Z Turbo I'm actually having a custom square set of wheels barreled for the 245s once my centers get to the builder from Japan. They went via seamail over a month ago so it's been a long wait. 

 

They will likely be 16x8-9 +10 front +12-20 rear with my suspension and no flares, but the plan is to do the final measurements once I get a center shipped back from my builder. 

[Dat73z]

This AM I started gettings things ready for reassembly. The new Nissan flywheel bolts won't require grinding down like the original 240z bolts I had used prior, as the OS Giken spec on the TS2BD is 8-8.5mm. 

 

I'm still waiting on some parts, mostly international at this point but there are some minor reassembly items I'll be tackling this week. 

[Dat73z]

Been rained out and waiting for parts so I started investigating meth injection again. 

 

I'm thinking if I could set up a system by rewelding the BOV on the cold side charge pipe so I'm not venting flammable vapors followed by some bungs for the injector nozzles all pre surge tank. It'll be a tight fit but I think workable. 

 

I'm a bit worried about even distribution across all 6 barrels but perhaps the meth would flash off in the surge tank inlet, I'm not sure as I've never run this type of system before. The PO of my car actually had an oldschool meth spray system on the car when it was drawthrough turbo in the 80s but I have long since sold all of that system. 

[Dat73z]

It's been a nice long weekend. Some more parts came in including a new trans mount. I figured I would easily spend a day measuring and fabricating a mount from scrap so I ended up buying one. My engine and diff mounts are all poly, and my sus is all poly or spherical bearings so I think the trans mount is the last rubber piece. 

 

The last item I'm waiting for before final reassembly are the inconel turbo studs, which are apparently waiting to board an international flight so hopefully they get through customs before Feb. 

[Dat73z]

After a long wait it seems my inconel studs will be in tomorrow so tonight I dusted off some parts and started back in on the build. 

 

The stage8 hardware needs to be clearanced to hug the ATP gate. 

 

Edited January 23, 2023 by Dat73z

[Dat73z]

And a quick detail shot of how the hardware had to be modified. 

 

The base of the stage 8 hardware, the head of the nut, and the locking ears all had to be ground down to allow assembly once everything is in the car for 4 of the 5 wastegate housing mounting points 

 

Hopefully I can get the turbine reassembled tomorrow after work. Then the rest of the week will be driveline reassembly

[240Z Turbo]

Why not just use prevailing torque nuts?  That is what my GTR uses from the factory and they don't loosen.  The pic below was from my GTX3071r turbo swap, but you can see the factory stover nuts and they don't budge.

 

 

Edited January 23, 2023 by 240Z Turbo

[Dat73z]

@240zturbo yes that is what I ran before and I'm actually tempted to run them again instead of this stage 8 hardware. Copper coated deformed head nuts from ATP turbo. They didn't loosen on me and so far as I could tell the failure was the grade 8.8 studs stretching perhaps from spiking egts and other failures I've documented in this build thread. I'm sure the inconel shielding didn't help either by trapping the heat in. 

 

Moving on with the build, my inconel studs came in today. They definitely feel quality and the threads are well cut/are not loose at all, but the length of the studs into the turbine housing are a thread or so too long. 

 

Based on some research, I shouldn't let the studs bottom out and instead be able to torque the stud onto the shoulder. So I'll need to trim the studs down a thread or so before installing. 

[Dat73z]

This evening I started shortening the inconel studs which has proven difficult as it's a very hard material. Like everything else in this build, I'm learning a lot as I go. 

 

The shoulder on the studs are fairly precisely machined to I believe 45 degrees or so, I'll need to confirm this with the manufacturer. It seems this mating surface is critical to also ensure it is prepared on the turbine side. 

 

According to a lot of fast track turbo miata guys online, resbond 907ts on the inconel studs and stage 8 hardware is the way to go. Now to find a vendor who sells Resbond in small quanities which is not expired, as it only has a 6 month shelf life. 

 

 

Edited January 24, 2023 by Dat73z

[Dat73z]

Out of time tonight but I got all the studs trimmed to seat on the chamfered shoulders. 

 

Something always comes up but I think I'll course correct this week and hit all the turbine housing holes with my counterbore bit, carefully by hand just to clean up the seats. Order some resbond, and test fit/clearance my inconel shielding as the stage 8 hardware does add some volume. I really don't want to be pulling apart the turbo components again anytime soon. 

 

Either way, things are looking good to get back on the road next month with a more bulletproofed setup. 

[Dat73z]

Been feeling under the weather so I cleaned the house and garage a bit. 

 

My buddy designed and 3d printed a L6 RMS install tool for me which was really solid of him...hopefully I'll pick it up this weekend, and I found a supplier in CA with fresh Resbond 907ts within expiration so I ordered a small quantity of that, just enough to do the turbine studs and nuts at least. 

 

After some research (and it was pretty interesting, at least the materials aspect of it), it seems the turbine m8 nuts should be torqued to 21-23ft-lbs or so with resbond, and the m8 studs to 30-40% of that (~9ft-lbs) with resbond into the turbine housing. The key so far as I can tell is to not overtorque as that will cause the studs to yield/plastically deform thereby defeating the purpose of preloading the stud in tension. Since there is a range of torque the plan is to torque the nuts to the lower limit, and give them a bit more to line up the stage8 hardware against the wastegate housing.

 

A lot of words to lay out a plan to torque a few turbo studs and nuts but there's a lot of conflicting information and opinions out there on what works/doesn't work so if this doesn't work for me then I'll document that here in the build.