LS6 to ported FAST 92/90... very disappointing dyno session
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so ive got a C5Z and thought icould benefit from a nice manifold swap, i sourced a good deal on a Vengeance ported FAST 92 with a ported LS2 throttle body, installed them and these were the results...
dyno session 1:
-77* day
-1.120 correction
-118 tractive effort (loaded dyno)
-21* total timing
-462/434
dyno session 2:
-Vengenace ported FAST 92 w/ ported LS2 90mm TB
-91* day
-1.129 correction
-118 tractive effort (loaded dyno)
-23* total timing
-477/438
MODS:
-stock short block
-livernois stage 3 243's milled to 59-60cc
-230/230 .598 .605 111+2
-vararam with duct
-1 3/4" LT's>3" off road X>Ti cat back
The dyno graph shows loses in HP and TQ in multiple places along the pull and the "gains" being 6,200 rpm to redline (6,800).
BEFORE any timing adjustments were made the car was down on power across the board, A/F being between 12.4-12.7 throughout. Im VERY disappointed in these results.
NOW! i get in the car and i want to say it feels stonger, but maybe that just my brain trying to justify this $900 endevaor lol.. last time i was at the track was 2 saturdays ago and it was ~95*, ill be there tomorrow and the weather is calling for very similar conditions, so we shall see tomorrow if i have any REAL gains, if not, this hunk of plastic (as far as im concerned at this point) is for sale!
thoughts???
dyno session 1:
-77* day
-1.120 correction
-118 tractive effort (loaded dyno)
-21* total timing
-462/434
dyno session 2:
-Vengenace ported FAST 92 w/ ported LS2 90mm TB
-91* day
-1.129 correction
-118 tractive effort (loaded dyno)
-23* total timing
-477/438
MODS:
-stock short block
-livernois stage 3 243's milled to 59-60cc
-230/230 .598 .605 111+2
-vararam with duct
-1 3/4" LT's>3" off road X>Ti cat back
The dyno graph shows loses in HP and TQ in multiple places along the pull and the "gains" being 6,200 rpm to redline (6,800).
BEFORE any timing adjustments were made the car was down on power across the board, A/F being between 12.4-12.7 throughout. Im VERY disappointed in these results.
NOW! i get in the car and i want to say it feels stonger, but maybe that just my brain trying to justify this $900 endevaor lol.. last time i was at the track was 2 saturdays ago and it was ~95*, ill be there tomorrow and the weather is calling for very similar conditions, so we shall see tomorrow if i have any REAL gains, if not, this hunk of plastic (as far as im concerned at this point) is for sale!
thoughts???
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Last edited by FRiCK; 07-20-2012 at 01:34 PM.
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You increased the size of the runners without increasing the demand from the motor. Bigger is not always better. I'm sure you will be happy with it in the long run, but put more cubes in the bottom end and you will see the difference that will really make you happy. You just need the ability to move more air in order to use a larger intake. Even still 477whp is a very respectable number...
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I was under the impression the correction factor would keep things semi consistent.
I thought I wa moving enough air to take advantage of the manifold. I'm also at ~11.5:1 compression.
I thought I wa moving enough air to take advantage of the manifold. I'm also at ~11.5:1 compression.
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Respectable gains and it was much hotter on this dyno run. With it being as hot as it is right now, don't expect miracles at the track either. This heat won't be friendly for your e.t's or traps. Take that into consideration. Ive never heard a legit disappointing story about a FAST "92" that was correctly setup.
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The dyno graph shows loses in HP and TQ in multiple places along the pull and the "gains" being 6,200 rpm to redline (6,800).
BEFORE any timing adjustments were made the car was down on power across the board, A/F being between 12.4-12.7 throughout. Im VERY disappointed in these results.
BEFORE any timing adjustments were made the car was down on power across the board, A/F being between 12.4-12.7 throughout. Im VERY disappointed in these results.
thunderstruck507- with the power numbers he was already making I'm sure he wasn't expecting to be losing HP and TQ in multiple places along the rpm range. As long as he dyno'd on the same dyno the two different outside temps (77* and 91*) shouldn't make a whole lot of difference, the correction factor is there for a reason. Only making decent gains at the peak is not respectable gains, nor fairly normal in this case.
But OP hopefully next time you hit the track you have very similar weather conditions as the last and you pick up some speed to reverse that disappointment. Good luck!
Last edited by R6cowboy; 07-20-2012 at 01:02 PM.
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seems about right considering the dyno temp differences.When i went from the stock ls6 intake with ported throttle body to my ported fast 90/90 setup i gained 20rwhp and 17rwtq just fwi
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Just left my tuner. Put the timing back down to 21.5. 23 was pinging pretty hard today in 3rd gear in this 90* heat. You have to remember I'm in California with 91 octane and I'm at damn near 11.5:1.
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