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Sunkisst Tunnel 5.3 Turbo

26K views 98 replies 32 participants last post by  Green90 
#1 ·
I picked this boat up from Hotbo back in Aug. Motor is a 5.3 with Ls6 cam and springs, otherwise stock. Fabbed up all of the hardware, set the pump back, painted it, went through the trailer, wired and plumbed it over the winter. Rail kit, mounts, flywheel cover and transom plates were all done on a cheap KBC tools benchtop mill. Headers and hotside were tigged from bends and then coated with jethot 2000. Turbo is a Garrett m1 from a Detroit with 75mm compressor wheel (sorry GN7, no JD parts). Should have the intercooler and hat this week. Ran 70 on gps na, so I'm anxious to see what some boost will do.
 

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#4 · (Edited)
Man thats a cool looking setup, one word of caution though. Those headers will glow red hot while making boost. So without a doubt you will need to heat shield them or they will melt the backs of those seats and everything else around them. And the radiant heat will travel a long ways. Just tig some 1/4" bolts to the headers for studs and build some shields that are easy to remove. Very simple. Check my build thread, its how I did it and they work great.
They will need to shield the plug wires also as they will melt in 1 trip. Ask me how I know ,lol.
 
#6 ·
Thanks for the heads up. I was hoping the jethot 2000 would kill enough of the surface temp that I would be able to get by without shields, but they get pretty hot even running it na. I will probably have to make them clamp on so I don't ruin the coating. I do have some kevlar heat sleeving for the wires, do you think that would work?

Uncle_Tom
 
#11 ·
What are you using for the ignition system ?

The coil packs that mounted on the valve covers would have made a real nice setup.
 
#18 ·
Mark: Using MSD 6010 with stock coils, just moved them down on the rails.
Excellent, I looked up that ignition box. I couldn't find specifics if it gives all the coils a minimum charge time of 5ms which would require charging 3 coils at the same time or just divides the charge time by the crank revolulution in which case it would get shorter as the rpm gets higher.

Those steel sleeves the stock plug boots come with should give some heat protection.
 
#21 ·
What about buying a couple rolls of header wrap and going that route? They have a dark gray, graphite color maybe now. I've used it before on headers and it made a night & day difference, and used probably a mile of that stuff on military trucks last year.
 
#29 · (Edited)
Just to satisfy my curiosity I called MSD and talked to an engineer about the 6010 box.
It appears that it does give the coils a sufficient charge time regardless of rpm.
In other words it is capable of charging multiple coils at the same time.

I am interested to see how this works for you.
The advantages of COP are huge IMO. It has worked great for me at high boost and with a .035 + plug gap.
$ 300. is a good price on that unit too.
 
#30 ·
What's the stock compression ratio on these LS motors?

Also, how do you like the benchtop mill? I've been thinking of getting one, but I've used a real mull before so im afraid I might regret it.

Cool project!
 
#31 ·
Compression ratio is 9.5:1. The Kbc benchtop mill did what I needed it to do. I think its rated for 1/2" endmill max, although I have used up to 7/8" in it. It has its limitations for sure, but I don't see how I lived without it. Same thing for the little AC tig machine.
 
#33 ·
I plan on running pump 91 and around 8-10 pounds of boost. May turn the boost up to 15 with 112 after I get it figured out, after that head sealing and the stock bottom end may become an issue. I looked seriously at e85 and methanol, but the lack of availability of e85 in my area and the fuel system requirements for both outweighed the advantages for me.
 
#39 ·
Methanol is about $100 a drum. And worth every penny.

This is only my opinion BTW

9.5:1 + boost + pump gas = disaster. Don't try it at 8 - 10 lbs. Even intercooled.

You can afford to make the changes if you can afford to build it again if it burns a piston. You will probably have to back the boost down so much whats the point of having that awesome turbo.
 
#47 ·
Intercooler mounted

Built Intercooler bracket and started coldside piping. EV hat should be here tomorrow to finish piping. Looks closer than it is to the crossover and back of the boat.
I appreciate everyone's advise on this project, its my first forced induction build and I realize the wealth of information here.
 

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