1-4 and 2-3 pairs for twin scroll (and for N/A, too) is actually the correct way to do it as far as my research has led me to believe. Love seeing a long tube turbo manifold, so many seemingly fail to learn about these. Bout the only thing you could do to improve this design outside of materials (321 stainless, 2mm wall) would be to make the primaries and secondaries have stepped diameters for even more anti-reversion. No doubt, being long tube is already a huge benefit to lowering pre-turbine back pressure and improving your EBP to Boost ratio, but anti-reversion mods to the exhaust ports and manifold also help, and all the small things add up across an entire build.
Ive learned a while ago to size the runner to the power...not to what the head port is. My current theory is 90 gross HP per square inch of manifold runner area. Which on my car dictated 1" diameter runners. It felt so weird and wrong. But gotta keep the gases hot and fast to expand thru the turbine not before it. My "micro-tube" manifold has been treating me very well and I have awesome response and torque to the point where I have to deliberately numb my boost control curve to keep the rods in 😂
What power levels are you trying to get out of this 1.8? Also curious if your using an AEB head or a small port? Variable valve timing? Im trying to save for a gtx2867r build on my vw 337. I have a b5 a4 quattro as well. That garret turbo is my dream for the 1.8t same compressor size as a ko3 but can handle 800hp
1-4 and 2-3 pairs for twin scroll (and for N/A, too) is actually the correct way to do it as far as my research has led me to believe. Love seeing a long tube turbo manifold, so many seemingly fail to learn about these. Bout the only thing you could do to improve this design outside of materials (321 stainless, 2mm wall) would be to make the primaries and secondaries have stepped diameters for even more anti-reversion. No doubt, being long tube is already a huge benefit to lowering pre-turbine back pressure and improving your EBP to Boost ratio, but anti-reversion mods to the exhaust ports and manifold also help, and all the small things add up across an entire build.
love the simplicity of the design. looks well good !
that looks so good in there! good stuff. awesome idea with the air box too
Nice progress on the build 😎 looking forward to the next update. Thanks for sharing 👍🏽
Woah! That is a gigantic turbo!
Looking good, a Turbo beanie will cook the turbo.
Looks good dude. All sounds perfectly logical. Subscribing to this!
Nice design...
Ive learned a while ago to size the runner to the power...not to what the head port is. My current theory is 90 gross HP per square inch of manifold runner area. Which on my car dictated 1" diameter runners. It felt so weird and wrong. But gotta keep the gases hot and fast to expand thru the turbine not before it. My "micro-tube" manifold has been treating me very well and I have awesome response and torque to the point where I have to deliberately numb my boost control curve to keep the rods in 😂
Well the gasses will move faster through a smaller orifice so thats why you have great response.
Hopefully you are monitoring the back pressure
Great project, coming along very nicely. What have you used to coat the manifold?
What power levels are you trying to get out of this 1.8? Also curious if your using an AEB head or a small port? Variable valve timing? Im trying to save for a gtx2867r build on my vw 337. I have a b5 a4 quattro as well. That garret turbo is my dream for the 1.8t same compressor size as a ko3 but can handle 800hp
Do you have a video or videos on how you decided to use a 1.8T, and how you adapted it to the transaxle or if you used a VW transaxle or something?