Patrick's build thread. (IT RUNS!)
#1247
Rennlist Member
Thread Starter
So the new 2-1 (x2) headers are on the motor with double bungs for EGTs and Lambda. A ton of work has gone into them to make everything fit and also allow for max expansion. So far there's 7 slip joints on the system. Bit more work to go and then off to be coated. Much more time con$uming than I'd imagined. It's almost like running two 2 cylinder motors. Obviously quite a different motor to Shawn's latest build but promising numbers / curves for that give me hopes for this one.
Last edited by 333pg333; 03-04-2017 at 01:53 AM.
#1251
Rennlist Member
Thread Starter
Thanks guys. Few more bits and pieces to do and then finish the exhaust. We bought a new radiator too for a bit of preventative maintenance so that's going in shortly. Then a bit more wiring to run the new ECU / Dash. Then just wait for the intake. We're in a queue for that. Probably still 4-6 weeks away on that as his multi axis router was down for 4 weeks waiting on parts itself.
#1253
Nordschleife Master
Looks very nice. The twin scroll will allow you to get enough separation between cylinders that the 180-degree exhaust interference is eliminated. That'll allow you a lot of freedom with cams.
What are the ports for in the primaries? EGT sensors, or high-sampling-rate pressure sensors?
The pipes have a quite a bit of surface area. Have you considered thermal barrier coating them? Purely functional, hiding all the beautiful stainless there...
Any thoughts on how well those slip fits will seal over time? Double slip? Also, will you have spring loaded locks on those?
Does the pipe size got up at the first Ys that combine 1&4 and 2&3? Have you given consideration to what sort of wave will that junction send back to the exhaust port? Just thinking out loud, I don't have any terrible well organized thoughts on that. Some people talk about "cross-tuning" in 4-2-1 headers and then some headers have steps to send back a reflected negative wave timed to the point when exhaust valve seat would otherwise go "sub-sonic". But as I said, just thinking out loud.
What are the ports for in the primaries? EGT sensors, or high-sampling-rate pressure sensors?
The pipes have a quite a bit of surface area. Have you considered thermal barrier coating them? Purely functional, hiding all the beautiful stainless there...
Any thoughts on how well those slip fits will seal over time? Double slip? Also, will you have spring loaded locks on those?
Does the pipe size got up at the first Ys that combine 1&4 and 2&3? Have you given consideration to what sort of wave will that junction send back to the exhaust port? Just thinking out loud, I don't have any terrible well organized thoughts on that. Some people talk about "cross-tuning" in 4-2-1 headers and then some headers have steps to send back a reflected negative wave timed to the point when exhaust valve seat would otherwise go "sub-sonic". But as I said, just thinking out loud.
#1255
Rennlist Member
Thread Starter
Looks very nice. The twin scroll will allow you to get enough separation between cylinders that the 180-degree exhaust interference is eliminated. That'll allow you a lot of freedom with cams.
What are the ports for in the primaries? EGT sensors, or high-sampling-rate pressure sensors?
The pipes have a quite a bit of surface area. Have you considered thermal barrier coating them? Purely functional, hiding all the beautiful stainless there...
Any thoughts on how well those slip fits will seal over time? Double slip? Also, will you have spring loaded locks on those?
Does the pipe size got up at the first Ys that combine 1&4 and 2&3? Have you given consideration to what sort of wave will that junction send back to the exhaust port? Just thinking out loud, I don't have any terrible well organized thoughts on that. Some people talk about "cross-tuning" in 4-2-1 headers and then some headers have steps to send back a reflected negative wave timed to the point when exhaust valve seat would otherwise go "sub-sonic". But as I said, just thinking out loud.
What are the ports for in the primaries? EGT sensors, or high-sampling-rate pressure sensors?
The pipes have a quite a bit of surface area. Have you considered thermal barrier coating them? Purely functional, hiding all the beautiful stainless there...
Any thoughts on how well those slip fits will seal over time? Double slip? Also, will you have spring loaded locks on those?
Does the pipe size got up at the first Ys that combine 1&4 and 2&3? Have you given consideration to what sort of wave will that junction send back to the exhaust port? Just thinking out loud, I don't have any terrible well organized thoughts on that. Some people talk about "cross-tuning" in 4-2-1 headers and then some headers have steps to send back a reflected negative wave timed to the point when exhaust valve seat would otherwise go "sub-sonic". But as I said, just thinking out loud.
Two sets of bungs per cylinder. One for EGTs and the other for Lambda sensors. Want to have as much control over the tune of this motor as possible.
All the pipes will be coated once they're finished. Yes a shame to hide the steel but we've never had an issue with the coaters we use. Definitely more efficient than uncoated.
Hard to say on the slip joints. There's a lot of them so hopefully they can work together to minimise individual movement. Some will have the lock tabs.
I think with the headers unless you have access to powerful CFD or are willing to make a number of versions and just do trial and error, it is just too expensive and labour intensive and we come down to the 'best guess' method. Interestingly when you see the turbine housing, both split sides are not identical looking. Not quite sure what effect this will have but assume Borg Warner has done a lot of R&D to come up with this arrangement.
Thankyou. I just pay the bills.
#1256
Rennlist Member
Thread Starter
Wastegates now tied in.
#1257
Nordschleife Master
#1260
Rennlist Member
Thread Starter
Lol...so do I in some ways. This whole idea of changing the turbo and going twin scroll has been a major exerci$e. Much more than I'd imagined. As Gustaf says, he made his decision on ROI and he might well be correct. I based much of my decision on Rod's experience with Twin Scroll turbos being very favourable.