Header dyno / track updates
09-20-2008, 08:43 AM
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Header dyno / track updates
On Thursday I went to the dyno and tweaked the tune slightly to accomodate for the "Hedders" as Hedman spells them.
I went with 1 3/4 long tubes, they are made by Hedman and sold through BRP Hot rods.
The motor is from a 98 Z/28 and has an LS6 intake manifold and comp cams camshaft, springs and pushrods. Otherwise the motor is stock. Tranny is a 4L60E w/ Vigilante t/c.
I did three baseline dyno pulls with exhaust manifolds and the first one was 322 @ 5850, the next pull was 312 and after letting the car cool I backed it up with another 322 RWHP pull.
On to the "Hedder" dyno pulls :bowtie:
On the first pull we only spun it up to 5700 and it made 338, we tweaked the tune a bit and it ran it up to 6200ish and it made 355.9 RWHP @ 6150 and torque went up from 273.8 to 304 @ the same 6150 rpm. Peak torque was 327 @ 5200, the previous peak torque was 303 @ 5200
I backed up the 355RWHP run with another 355 RWHP pull and spun it up to 6500. HP remained at 355, it flatlined from 6150-6500 @ 355.
Of course with new found power a trip to my local track (New England Dragway) was required so off I went last night to make a couple of passes
My previous best was 12.730 @ 106.39, other pases that day was 12.781 @ 106.14, 12.794 @ 105.92 and 12.757 @ 105.55. Sixty foot times ranged from 1.821 - 1.848 on the above passes.
With the increase in power my sixty foot times improved to 1.782 1.792 and 1.755.
First pass I cut a .080 light and my sixty foot was 1.782, 7.842 @ 88.03 in the eight and then I bounced off the rev limiter a couple of times and as I ran thought the lights I looked up and saw 12.330 (well actually I only saw the 33) but you get the gist... so it was a 12.330 @ 109.60, next pass I red light by a c/h (.004) and sixty footed to a 1.792 and ran 12.384 @ 109.26 with again bouncing off the rev limited on the 2-3 shift. I decided to give it one more shot before I left and cut a 1.755 sixty foot (.102 light) and ran 7.790 @ 88.62 and again as I go through the lights I crouch down and lookup and saw a "25" :bowtie: , drive around and get my slip and it's a 12.256 @ 109.96 with again bouncing off the rev limiter twice before it shifted into third. My buddy has the laptop with EFI live so at the time I was stuck and couldnt' make any changes.
Bottom line I picked 34 RWHP, 30 RWTQ on the dyno and a solid 3+ mph and almost a half second at the track.
Uncle Marc
I went with 1 3/4 long tubes, they are made by Hedman and sold through BRP Hot rods.
The motor is from a 98 Z/28 and has an LS6 intake manifold and comp cams camshaft, springs and pushrods. Otherwise the motor is stock. Tranny is a 4L60E w/ Vigilante t/c.
I did three baseline dyno pulls with exhaust manifolds and the first one was 322 @ 5850, the next pull was 312 and after letting the car cool I backed it up with another 322 RWHP pull.
On to the "Hedder" dyno pulls :bowtie:
On the first pull we only spun it up to 5700 and it made 338, we tweaked the tune a bit and it ran it up to 6200ish and it made 355.9 RWHP @ 6150 and torque went up from 273.8 to 304 @ the same 6150 rpm. Peak torque was 327 @ 5200, the previous peak torque was 303 @ 5200
I backed up the 355RWHP run with another 355 RWHP pull and spun it up to 6500. HP remained at 355, it flatlined from 6150-6500 @ 355.
Of course with new found power a trip to my local track (New England Dragway) was required so off I went last night to make a couple of passes
My previous best was 12.730 @ 106.39, other pases that day was 12.781 @ 106.14, 12.794 @ 105.92 and 12.757 @ 105.55. Sixty foot times ranged from 1.821 - 1.848 on the above passes.
With the increase in power my sixty foot times improved to 1.782 1.792 and 1.755.
First pass I cut a .080 light and my sixty foot was 1.782, 7.842 @ 88.03 in the eight and then I bounced off the rev limiter a couple of times and as I ran thought the lights I looked up and saw 12.330 (well actually I only saw the 33) but you get the gist... so it was a 12.330 @ 109.60, next pass I red light by a c/h (.004) and sixty footed to a 1.792 and ran 12.384 @ 109.26 with again bouncing off the rev limited on the 2-3 shift. I decided to give it one more shot before I left and cut a 1.755 sixty foot (.102 light) and ran 7.790 @ 88.62 and again as I go through the lights I crouch down and lookup and saw a "25" :bowtie: , drive around and get my slip and it's a 12.256 @ 109.96 with again bouncing off the rev limiter twice before it shifted into third. My buddy has the laptop with EFI live so at the time I was stuck and couldnt' make any changes.
Bottom line I picked 34 RWHP, 30 RWTQ on the dyno and a solid 3+ mph and almost a half second at the track.
Uncle Marc
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