Ramian17":10mnfhp6 said:
Is there anyway to make sure the head flows 80℅?
The port work needs to focus mainly in the bowl area around the valve guides.
The ports walls only need a cleanup without making the ports larger. this will keep velocity high at low rpm.
Here is a good example presently being done by golfmiser
viewtopic.php?p=588394#p588394
You may hit 80% could be a little more with the header and long runner intake.
What size valves will be used?
Ramian17":10mnfhp6 said:
Why is there such a large margin between torque and horsepower at only 200?
Horsepower = RPM x Torque/5252
Ramian17":10mnfhp6 said:
So I read the first 50 pages of that instruction manual. It said that twin scroll housings are better for spooling faster for low RPM. To get that you have to go the B housing Which is the .84? You still confident on the single scroll .64 housing?
The twin scroll housing for the 6258 is a .80 A/R just to be picky.
I know the single .64 will work. It has a small T25 flange which is restriction to high flow. I wish it was at least a T3 flange.
I don't know if the .80 B housing will give you the same low rpm result because I don't have any experience from me or others to draw a positive conclusion.
It may work just as well at low rpm while providing more upper rpm power at the same time. It uses the much larger T4 twin scroll flange.
You will get boost at low rpm just don't know how much.
I personally would go with the twin scroll housing and plumb header tubes 1,2,3 to one side of the scroll and 4,5,6 to the other side.
I would bank on the fact that under the load of 3rd and 4th tranny gear, the 300 six will produce enough exhaust volume to get plenty of low rpm boost.
(I don't like giving away horsepower)
Also need to remember that if you try get too much boost at too low of an rpm, the turbo can be driven into the surge zone.
You are in uncharted territory because most of the time the person is looking to make horsepower and not worried about off idle torque.