2.5" DP and Magnaflow--RESULTS UPDATE
#21
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Boss and boss'* boss are traveling, so I went home after lunch
LEAK FIXED!
But I didn't use the donut...it wasn't going to fit anywhere; I guess the different years used different DP'* and/or EM'* after all. Wonder if napa will take a return? (If not, anyone need a donut?)
Problem was something I mentioned earlier...the left side rear EM stud wasn't seated all the way in the manifold flange (I think you can make that out in one of the earlier photos); removed it, cleaned the threads with a dremel and wire brush, and it went back in smooth as butter. Reused the original flat gasket, flanges mated up nice, and BAM! No leaks
(Note to self: don't screw up the stud seating when doing the heads later )
Freeway testing confirms..."pfft, pfft" is gone.
Sound is "growlier" than before, which I like. Seems to accelerate better...and oddly, it seems like it doesn't decelerate as quickly when I take my foot off the gas :?:
Scanning and tuning (perhaps this weekend) should say for certain if I gained anything.
LEAK FIXED!
But I didn't use the donut...it wasn't going to fit anywhere; I guess the different years used different DP'* and/or EM'* after all. Wonder if napa will take a return? (If not, anyone need a donut?)
Problem was something I mentioned earlier...the left side rear EM stud wasn't seated all the way in the manifold flange (I think you can make that out in one of the earlier photos); removed it, cleaned the threads with a dremel and wire brush, and it went back in smooth as butter. Reused the original flat gasket, flanges mated up nice, and BAM! No leaks
(Note to self: don't screw up the stud seating when doing the heads later )
Freeway testing confirms..."pfft, pfft" is gone.
Sound is "growlier" than before, which I like. Seems to accelerate better...and oddly, it seems like it doesn't decelerate as quickly when I take my foot off the gas :?:
Scanning and tuning (perhaps this weekend) should say for certain if I gained anything.
#23
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Where have I been? Totally missed this thread. Glad you got it fixed, Andrew... I hope you have some good results with the 2.5" DP, as I'm itching to get one myself. Let us know how it fares in your VE tests.
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Originally Posted by big_news_1
Where have I been? Totally missed this thread. Glad you got it fixed, Andrew... I hope you have some good results with the 2.5" DP, as I'm itching to get one myself. Let us know how it fares in your VE tests.
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UPDATE: After it cooled down to 70* F this evening, I took some more runs with scans, and did some more VE calcs...
WOW! Just WOW!!!
Preliminary estimates are +15-20 ft-lb torque at 4200 rpm, and at least +15-20 hp at 5200 rpm...and these scans (and estimates) were with PE turned off (i.e., with no added fuel under WOT, or 14.7:1 all the way to 6k rpm with no KR ) and without the extra 4 or 5 degrees of WOT spark advance I expect to be able to add before my tuning'* all done.
I had heard a bigger DP would reduce KR, but this is unreal. Also, I see nothing in the scans indicating any "low end loss"; makes me wonder if my old cat was plugged up or something...
I hope to have the full story by early next week.
WOW! Just WOW!!!
Preliminary estimates are +15-20 ft-lb torque at 4200 rpm, and at least +15-20 hp at 5200 rpm...and these scans (and estimates) were with PE turned off (i.e., with no added fuel under WOT, or 14.7:1 all the way to 6k rpm with no KR ) and without the extra 4 or 5 degrees of WOT spark advance I expect to be able to add before my tuning'* all done.
I had heard a bigger DP would reduce KR, but this is unreal. Also, I see nothing in the scans indicating any "low end loss"; makes me wonder if my old cat was plugged up or something...
I hope to have the full story by early next week.
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I gotta say, if it'* true that my old cat was plugged or whatever, this new cat may mostly be "giving back" lost power...I have GOT to get to a dyno sometime.
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did you look in youre old cat could you see daylight true it .i don't think mine was plugged but my new one is half the size
#29
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Originally Posted by agrazela
I have GOT to get to a dyno sometime.
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Originally Posted by agrazela
Preliminary estimates are +15-20 ft-lb torque at 4200 rpm, and at least +15-20 hp at 5200 rpm...
After a number of additional tuning runs over the weekend, the final tally is about +4 to 5 ft-lbs @4200 rpm and +4 to 5 hp @5200 rpm.
Originally Posted by agrazela
...the extra 4 or 5 degrees of WOT spark advance I expect to be able to add before my tuning'* all done.
I'll post the final VE curve tomorrow.