by 200cfm » Mon Nov 17, 2008 11:32 am
Update: Tested yesterday in the 1/8 at RDW and motor ran fine with low level boosting. Just glad to get it all from flowbench to track in under 10 days time in the end here. I want repost all the flow data but here is a recap of where port 4 stood from the bench.
Port 4 (45 + 30 backcut)
CFM gain
60.5 0.2 Prt
109.8 8.3 335 350 329 roof
149.8 11.1 320 341 364 mid
163 7.5 305 340 381 floor
171.5 5.6
178 3.2 centerline fps @ 310-320
181.2 2.6
181.6 2.8 SSR
381 386 381
And a final data on port 1
Port 1 (45 + 30 cuts) 11/06/08
1.85
Lift CFM
0.100 58.2
0.200 108.6
0.300 147.7
0.400 171.8
0.450 179
0.500 180.6
0.525 183
11/7/08 Reflow ports 8
Port 8 (45) Port 4 (45 + 30 backcut)
LIFT CFM CFM gain
0.100 60.3 60.5 320 341 362
0.200 101.5 109.8 317 335 350
0.300 138.7 149.8 303 326 378
0.350 155.5 163
0.400 165.9 171.5 centerline fps @ 310-325
0.450 174.8 178
0.500 178.6 181.2 SSR
0.525 178.8 181.6 350 350 350
note: port 8 volume at 142 cc
And here is a look at one exhaust I took time to get data on.
Port 1
Ex 1.600
30 backcut Lift CFM CFM Gain
0.050 29.7 30.9 1.2
0.100 54.5 58.9 4.4
0.150 77 83.6 6.6
0.200 97 105.3 8.3
0.250 113.5 118.4 4.9
0.300 127.7 134.5 6.8
0.350 129.3 142.4 13.1
0.400 147.5 148.9 1.4
0.450 153.1 153.9 0.8
0.500 156.4 156.4 nc
0.525 158.4 158.4 nc
There is some swing among all the ports and weakest one is port 3 which gave 168.8 @ .500 lift and fast centerline of 340 fps. I should have reflowed but had to move on.
SSR came in at 332, 353, 353 on left to center to right of apex.
And the PRt came in at:
367 373 350
370 341 323
370 329 320
So how did the track dyno perform. Car ran the following with
total timing held to 25 degrees, 73/85 jetting, no PV.
Run1: 1.5769 4.4391 6.8196 @ 104.17
Car launched at steady 5 lbs boost. On the converter a long time because other guy would not stage the second bulb. Playing games I guess. Avg boost holding 6 lbs with max of 7 at the line. Made the shift around 5400 which is the choke point according to Pipemax on the cam. Lost my new breather cap. Almost a record, and the best todate for this pressure. The deceased 298 took 12 lbs of boost to pull this low an et for the 1/8.
Video of Run:
Run 2: 1.6585 4.5640 6.9872 102.55
Slowed some and the tree started as soon as I staged so launch boost was mere 2 lbs. Averaged around 5 lbs with a climb to 6 lbs at line.
Video of Run:
Run 3: 1.7189 4.6782 7.1447 @ 100.09
Slowed even more and got a bad pop on deceleration.
Hadn't changed timing or jetting. Did make a compression check on number 7 and came in at 150 psi after 6 strokes.
Pipemax predicted 155 psi with a weak dynamic compression due to this Salt flats cam profile.
Burn out was poor as the line lock is not holding brake pressure and the car moves out early and shifts around, etc.
Just a poor launch, and boost never went higher than 5 lbs. So I suspect or hope it is a exhaust leak gasket that has opened up and is prematurely bleeding of exhaust turbo pressure. I have seen this before in the past and this plumbing has 14 exhaust gasket points for hot gases to leak.
Will know more this week as I make a complete inspection of compression, lash, and plumbing sealing.
Overall I am very pleased with the powerband and results. The ports are still on the conservative side as far as volume with an average of 141 cc and from what I can tell the high fps speeds are not killing the power.
Video of Run # 3