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Alan L Alan L is offline
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Join Date: Apr 2006
Location: New Zealand
Posts: 3,261
Thanks for the flow calcs. Will try them. Yes agree - around 420-450HP at flywheel would be my guess. Well, if I am supposed to have 1600cc/30 sec, I have definitely run out of fuel.
What I did do when I got the 007 head back was as you suggest. I opened one port so I got about 10-20% more than the balanced flow it came back with. Then set about raising the other 5 to match. All went well until I got to the last port and could not match the flow. So I had to dial the others back. So it is basically set at the max flow I can balance. But it does seem to be unstable like this - as Brian has suggested. I have had erratic results this time around. And there seems to be a big variance between the ports in terms of what they will flow. Some ports I am consistently trying to dial back (20% above others that will give no more). But I am near getting it back to a stable balanced flow. Looks like I may need to try the 044 pump after all.
I think I have put a soft spring in the WUR for the boost drop - I have a range of springs I had made up. Some of them were harder than original - because initially I was struggling with the boost dump. Then I struggled with not enough fuel - over the progression of mods. So I am fairly sure I have a very soft spring in the WUR to get 2 bar drop in CP at 0.5 bar boost. 1 bar boost gave no more drop. So the WUR is basically wide open with this spring. I will put a harder spring in while I can get at everything - maybe 1 bar drop. If the heat soak won't make any difference to CP, I am already 0.5 bar below WP spec.
Thanks for the thoughts. Just want to get the FD nicely balanced near max flow right now. But there definitely seems to be a sweet spot where the tweeks all work predictably. Then you seem to move in to a zone where more turns on the adjusters make no difference. You need to know each port is in the sweet spot zone to balance them. Previously on other heads it has taken me no more than a couple of goes to balance the flows. I have spent near a full day on this one. Because it was past the point where all ports would respond.
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 11-01-2017, 11:47 AM
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