OK, I need to make some twins...... a big set to compete with the other kids


So I have the 88mm-ish HT4C its older sure. not cutting edge technology in the wheels. but its free and in my garage. the 68mm HX55 i can get from work cheap and new..........with they sing together??? external gate obviously.

If brett can pound a manifold for the HX55 flange for me I'll make them.

what size piping do I want for the intermediate pipe? 2.5? 3? 4?

 

The HX55 should be right around 80lbs/min max, and the HT4C should be right around 140lbs/min max. Looks like a good place to start. The HX55 cross's far enough into the HT4C map that it gives you room to goto a bigger primary, if you decide you still need more. Probably could go as big as 100mm if that is where you wanted to take it.

As far as the piping, intermediate pipe on the cold side, it should be whatever the outlet of the HT4C is, so if it is a 3" out then run 3" and use a step up coupler right at the turbo, this helps keep the velocity up between stages.

Intermediate on the hot pipe, well I like 3" as it is easy to make work with the T6 flange, that most secondaries run. I am sure there is some debate as flow vs velocity on that.

I think either a 44mm or 50mm waste gate will be close to ideal.

 

Luke, how are you setting up the pump? Your gonna need some decent rpm to get that big of turbos to start spooling. You could do some little drug spraying. I would go for at least 4kgsk or 5gsk. Once it lites-up, your going for a ride buddy.

As for down pipe size, I would use the T-06 square area determine the pipe size, as that the real restriction. Of course you could just cut a bigger hole into the flange. I have used 3 1/2in and 3 in. I like 3in better, as I just drive wimpy stuff. So I worry about drivablity.

 

Luke, I also used 3 1/2in for my air tubes on this build. My last set was 4in.

I think that I used 1.5 in diameter for the manifold, it works nice on my truck, but I have no fuel. We could try stepping up to the 1.75 or 2in on Luke truck, just for kicks.

Call me if you need help, I owe ya buddy.

 

The mani is 1.5" sch 40. So the I.D is actually 1.61" if anything I think it is a little big for your build Mike, but we won't know till we get that 1.25" sch 40 I.D 1.38" done.

Next jump in size is 2", I.D is 2.07" if Luke jumps to a 100mm + turbo on that primary at some point, then it might be something to try.

My vote is cds 5k gsk I think after the 5k you are into the ag governor.

 

Even with the bigger diameter tubes still spooled my set-up decently. I was pretty impressed just with our quick blast. I'm interested as well in the results of the smaller diameter tubes. I'll be pulling my trailer in a week, so it will be interesting to see what my egt's are like. If you go with 2in stuff, wow that real big.

 

I don't want to hurt velocity. I measured the 4C its a 3.5" discharge. so that'll be ok...3.5 cold pipe.


Ya, the mani. I dunno sizing it is out of my league. no idea whats good or not good. that 1.5" gear of mikes looked real good.

 

Yup we will definitely start with the 1.5" as I have a feeling there are a number of other bottle necks before that.

 

would 3" for the cold pipe be too small?

I can get a whole pile of 3" mandrel bends for cheap. or 4"?

 

Luke, how big is the HT4C? You have any info on that turbo? I do have a GT-88 available, the compressor/turbine housings are sized pretty decently and it uses a T-06 flange. How much room do you have for turbos on your truck?

 

If that is what you can get cheap, that is what I would run.

 

ok I got a bunch of 3 mandrel stuff lined up.........now hear me out on this next part.


the cold pipe intermediate.

seeing as all turbos are engineered to have the suction side drawing air from atmosphere and generally not being force fed.

I'm thinking to tig a machined taper cone in the inlet of the secondary. with the smallest ID being the same size as the housing inlet. opening up to 3" then i have vband rings coming with the mandrels. one ring is steel the other ring is aluminum. so I build the intermediate pipe with vbands on both sides. weld the steel ring to the pipe and tig the aluminum ring to my "new" taper cone insert. and same on the other end. the discharge on the primary, tig the amunimun ring to the outlet and weld the steel ring to the pipe. then just play connect the dots to make the pipe. now my insert piece would be a very gradual grade from end to end. not real obtuse like the silencer ring. and removing the silencer ring the shape of the inlet just doesn't jive with my brain for force feeding air into the secondary.

so thats 10 minutes in Lukes head..................... What say you?

 

I can weld it.

But can you use paint and draw it, I have a tough time visualizing things like that.

I am going to try and get this. You are going to cut off the current "air filter ring" and then we will weld in a new piece that is the same diameter as the inducer. This will connect to the rest of your charge pipe via V-band clamp?

If that is the case, I like that idea, as I really think it will help to keep the velocity up. Vs going 3" and right at the turbo stepping it up to 4"

 

dvst8tr do you have a tig with ac ?

 

Yes I have a Miller Dynasty 200dx. Aluminum is far more my specialty then steel.