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Discussion Starter #1
After doing several mods (heads, 1.6's, longtubes, ported intakes, etc...), some will recall that I had very bad luck on the dyno....soon after I found out I had a wiped cam lobe and a semi clogged catalytic converter. :(

http://forums.corvetteforum.com/showthread.php?t=1660265

anyway...
Went back today to see if my luck had changed. Car's been running nice with new $60 Summit cam/lifter package. I did have a few CEL issues that I traced to a bad CTS sensor connector. On the 60 mile drive up, I felt that car was "close" to running as good as it probably could. Very smooth, no driveability issues, no idle issues, all was well....

Tuning parameters were as stock....6* base timing, 38psi base fuel pressure.

Fresh off of I-95, I made a 2200-5800rpm pull....

http://home.comcast.net/~rel3rd/wsb/media/373752/site1437.jpg

http://home.comcast.net/~rel3rd/wsb/media/373752/site1438.jpg

As you can see, there is plenty of torque damn near everywhere, and no TPI "cliff" where horsepower dropped off rapidly, as many insist every Long Tube Runner intake will do. I love a broad, flat power curve and this car has it. A backup pull was near identical.

After nothing more than a base ignition timing "bump" up to 12* (something else that many say is a worthless mod), we made another pull (2200-5400 rpms)...This pull wound up being best of the day...and what I ended up with. My a/f ratio was right where I wanted it, hovering around 12.8:1, and stayed pretty constant throughout rpm range.

Again, very nice broad and flat graphs, which makes for a fun street car.



Check out the torque numbers....
http://home.comcast.net/~rel3rd/wsb/media/373752/site1440.jpg

Overall, I cannot complain at all with end results of this combo. I have about $2000 invested in engine mods and I wanted a lower rpm, decent idling combo that didn't "need" a chip to run decently. I honestly cannot see where any chip can improve what I already have, to be honest. Alvin @ pcm4less said that my stock 1985 #870 pcm should stay right on the money as far as a/f ratio, and he was right.

Combo is as follows:

Summit (TFS) 170 heads (2.02/1.60 valves)
Crane 1.6 roller rocker arms
Summit 1102 camshaft (hydraulic flat tappet, .448"/.471" lift w/1.6's)
self ported 3860 Edelbrock base intake
self ported and siamesed SLP runners and plenum
24# Bosch (Ford Racing) injectors
Hedman Elite 1-5/8" longtube headers
2-1/2" front & rear Y pipes, gutted cat
Dynomax Ultra Flo stainless mufflers

Cliff Notes:

275rwhp/356rwtq, bumped up timing 6* and got 287rwhp/374rwtq
 

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Official Forklift Driver
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That looks real good. :thumbsup:

I had about the same mods done to my 87. I had about the exact same exhaust. My cam was a little bigger 218/228 @.050 and a roller but the ported Edelbrock TPI you have flows a little better than my stock ported TPI. I'm comparing the rest of our mods and the give and take about cancel each other out. My stock dyno showed the peak hp right before 4400 rpm's. My peak tq was under 3k rpm's and dipped below 300 ft. lbs. at 3400 rpm's.

After I did the mods, I did not dyno but I swore it was pulling into the 5k rpm range. You dyno proves what I was feeling. Thanks for posting. :cheers:
 

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Discussion Starter #3
After I did the mods, I did not dyno but I swore it was pulling into the 5k rpm range. You dyno proves what I was feeling. Thanks for posting. :cheers:
I'm still looking on the graphs for the TPI long tube runner CLIFF that the power is supposed to drop off of....:laughing:
 

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Glad to see you have it back on the road! Those numbers look good, and I bet you love the way it drives!

Steven
 

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Discussion Starter #5
Glad to see you have it back on the road! Those numbers look good, and I bet you love the way it drives!

Steven
I absolutely do!

Not to mention I had asked Alvin at pcm4less about whether my car had anything "left in it" and after looking at the dyno sheets and combo he assured me it's a combo that is darn near optimized already. :thumbsup:
 

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Official Forklift Driver
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I'm still looking on the graphs for the TPI long tube runner CLIFF that the power is supposed to drop off of....:laughing:
I heard that before too. :rolleyes:

By looking at my stock dyno there is no "cliff". Both hp and tq are almost flat as a board. Comparing both our sheets it's safe to say the cliff myth is BUSTED! :laughing:

 
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