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Triple Blowthrough Turbo


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Re-routing the lines may help.  All you can do is test it out. 


Regarding heat soak...You might consider a turbo blanket on your turbine. I wrapped my turbine, down-pipe, and fuel lines with the DEI stuff and it made a huge difference.


A polished metal heat shield between your carbs and turbo and manifold will make a significant difference too. My heat shield is a piece of sheet metal with PSA backed aluminized thermal blanket bonded to the top, shiny side facing the intake manifold. It seems to work pretty well, although it gets dusty, reducing it's effectiveness. OEM heat shields are made from multiple layers of metal with the shiny side facing inwards and the edges crimped/welded to keep out dust/dirt/road grime.

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Thanks @rossman, always appreciate your insights. 


My AN fittings come in today and I get today off so hopefully I can get that back together. 


This morning I received notice that my heatshield material may be delivered early so I started templating things up. I think I'm going to fabricate some brackets to hang the heatshield off carbs 1 and 3 since carb 2 holds the throttle cable for which I'll need to make a new bracket for that as well to move the throttle cable away from the turbo. As always, everything on this setup is ridiculously tight with considerations to clear everything and serviceability. 


I've also attached a pic of the radiant turbo heat carnage on the throttle cable. I'm hoping the stainless cable, relocated away, and heat wrapped will be ok but we will see. 


I thought I was done with fabrication but I have to remind myself that just a couple months ago the car was in pieces on jackstands with no driveline. Just need to keep pressing forward and developing/improving the setup. 



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After more fitup and consideration for serviceability it is becoming clear that the heat shield dimensions will be critical. 


The surge tank must be bolted on before the heat shield otherwise there is no way to access all of the surge tank fasteners. 


I have some designs in mind, hopefully I can get to a final template later today and keep moving forward. 


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Today I was able to measure and trim the heatshield material. It was quite challenging to do as it is 321 stainless with an internal ceramic liner/air gap. Supposedly it can withstand 1800F continuous and 2000F+ intermittent. I hope it works to reflect and redirect the heat rising off the turbo into the carbs. 


The whole sheet needed to be unfolded, the cuts made precisely with overlap, and the overlap then folded back over. 


I haven't folded it back over yet as I'll need to punch a few holes in the stainless and fold those edges over for the vacuum lines, throttle cable, and mounting brackets. 


I decided to make this a multi-piece heatshield which will be assembled on the car as it was the only way to be able to snake it all in with the surge tank installed. 



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This AM I started draining the coolant down and started back in on bracket fab. 


I think for the throttle cable I'm going to route it just in the space between the surge tank and heat shield. Hopefully with the new stainless cable and heat sheathing there will be no melting from the turbo heat in that location. 


Later today my Bossa Design water pump should come in, and my new Borg Warner Tstat on Mon so trying to get everything ready for that. Always something to do. 


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This afternoon I was able to fabricate the new turbo to tstat coolant line. 


The entire run now gradually rises uphill so hopefully there won't be anymore backflow boiling issues...although I'm now wondering what happens if I park on a downward slope 😂


My Bossa Design water pump came in today so tonight I'll start installing it. 



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Another busy weekend but I managed to squeeze an hour in this AM and pulled the water pump. 


Comparing the Bossa water pump to the stock cast impeller unit is impressive. Supposedly the Bossa will outflow the diesel pumps which are nla and keep temps 5-10deg cooler. After driving around this past few weeks it has become apparent I need to do everything I can for cooling and heat shielding. 


Hopefully I can modify the cutwater and get it back together tonight. Tomorrow the thermostat comes in and the cooling system reconfiguration will be complete. 



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I got most of the cooling system back together last night but I'm still waiting on the new thermostat to come in which is apparently still delayed before buttoning it all back up. 


My lokar cable came in today so I'll see if I can get started back in on that later tonight. Not sure what the inner liner is made of or if it'll melt but I'm thinking I should heat wrap the cable as well once I get it in. 




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Tonight I was able to pull the old throttle cable off with the assistance of my wife and inspect a bit closer. 


Surprisingly it looks like there's no liner in this lokar cable or maybe it melted off over time, I'm not sure. 


I think I installed it maybe 7 years ago and recycled it over a few setups so it's about time for a refresh anyways. 




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And after playing with the new cable a bit and starting the fitup/trimming process it is fairly apparent the SS cable is much higher quality. 


I ordered some DEI titanium insulation sheath from my local O'Reillys that said they can get it in tomorrow. 


I'm already missing driving the Z so hopefully I can get this all back together before the weekend. 



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@Dat73z I don't know how to refer to you. Do you have a name or nickname you feel comfortable sharing? Sounds better than "hey Dat73z" hehe. 


I think your solution looks great for a street setup. What you are really doing is shielding the heat-sensitive items from extreme transient heat during boost, which is not all day every day. If this was a track or even drag car, I see issues with heat-sink as eventually everything (shielding or not) will come-up to temperature given high frequency boosting. The oil line is the only thing that will exhibit active cooling from flow. 


So the only thing I would change if you boost a bunch consistently is move-out the oil line so it is further away from the turbine housing. Even if it has to cross the housing as show, maybe just a few inches further out (closer to the hood). 


Quality of your work looks amazing! high attention to detail!


Is that new throttle cable Lokar? That's what I have purchased and fitted-up for mine. 


PS: DUH! i just had to scroll up. Lokar indeed. I also bought the upgraded water pump! looks nifty! I sent him an instagram message suggesting he do a side-by-side test to show an increase in total differential pressure between the pump inlet and outlet. im sure that data will help sell them.

Edited by AydinZ71
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Thanks @AydinZ71. After thinking through your points, I ordered a 1" 4AN straight adapter to space the oil line off the hot side. 


I also decided to sheath the water lines as well. I'm not sure if it'll help but I thought I may as well since I'm still waiting on some parts. It will also keep the line from abrading items around it. 


You can call me Dat73z, Eric or whatever Lol. I'm also on some FB groups and IG. 


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In reconfiguring my throttle cable last night, I was manipulating the linkages to check throw and as a result found some fuel leaks from the carbs as I was actuating the pump circuits. 


Not a major issue, but it seems to jive with the feedback I had received from Rebello where at higher boost levels past 10-12psi fuel would start leaking from the carbs.


It seems the casting area behind these threaded ports is glass thin with the venturis sitting directly behind. 


I'm planning to seal up all the threaded holes with grub screws and loctite 567.


It feels like there are just a lot of time consuming fine details on this build, but I'm glad I caught it now instead of a fire later. 


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Tonight the turbo oil feed extension and Tstat came in so I installed them. 


Normally I don't like additional fittings/potential leak points but in this case I think it's worthwhile as the oil line now spaces an inch or so off the turbo hot side. 


I also verified both the new 170 Tstat and prior 160 Tstat were opening and closing at the proper temps. The new Tstat is some Wahler/Borg Warner unit. I'm surprised at the size difference in the opening over the former (I think) Motorad unit. 


Hopefully tonight I can vacuum test and fill the cooling system...then the cooling system reconfiguration will be complete. 






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I pulled vacuum on the system for an hour and ensured there were no leaks then proceeded to fill. I think I'm going to bleed the car traditionally as well with a no spill funnel and the front elevated as I had the entire system apart and fully drained. 


So now we have rerouted and shielded turbo coolant lines, new tstat, and new wpump. I am confident the heater core branch won't be boiling anymore since the turbo is no longer hooked up there, but I'll keep monitoring for any issues with the new setup. 


Last major things to do are finish fabricating the throttle cable bracket and carb heat shielding. Hopefully I can get to that tomorrow. 


I should probably also change the oil as I'm sure I've flooded it out with gas reworking the throttle setup. 



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Last night I was able to get the throttle cable reroute bracket prototyped. 


I started with a paper template and transferred the general profile to some scrap AL. 


The angle of approach was pretty tricky as the cable not only needed more clearance from the turbo hot side, but also had to run through a 1/4" gap between the carb heat shield and the surge tank.


As with everything on this build, ridiculously tight but I made it work. I also took into consideration for the angle that the cable should be fully controlled in the bellcrank between idle and WOT. 


Hopefully I can get a break tonight and work on making the bracket look a bit better. 





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