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LS3 Low dyno numbers, head scratching

Old 08-10-2018, 12:55 AM
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Default LS3 Low dyno numbers, head scratching

hi all,

I’m at the tail end of a LS3 conversion into a Mazda RX8.

I rebuilt the LS3 with
new SRP Pistons and ring
Cam 224/230 114 LSA Cam set mark to mark
New stock timing gear and chain
LS7 Lifters
New chromly pushrods (cant remember the size but I specd them at the time)
Long Tube Headers
refreshed heads with LS9 gaskets
All new seals

It is running a ECU Master EMU black with wasted spark setup.

It start up fine, straight away with good oil pressure which was a relief!
It has run in on the dyno properly for a couple of hours,
the power run for its final tune though ended up with only 355 whp and 390wtq.

too me this is very low for a Cammed LS3 with headers.

The shop has checked the timing and also the pushrods length because I thought I had screwed it up. This all seems normal.

Where do we look next for those lost HP!!

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Old 08-10-2018, 04:50 AM
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is this through an auto or manual? what type of rear? what type of dyno and whats the overall compression ratio, 10.7:1? do you have a graph of the dyno? what gear and RPM did it go up to? need these types of info lol
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Old 08-10-2018, 11:32 AM
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As the above the more details the better. Like stated was it in the 1:1 gear? What rpm at hp & tq peak numbers? Graph. Don't think that intake tube is helping power up top but? Also the exhaust from headers back. Is it a small single pipe?
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Old 08-14-2018, 03:59 PM
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Originally Posted by slash695 View Post
......the power run for its final tune though ended up with only 355 whp and 390wtq......
1. What's your compression ratio?

2. How high did you rev the engine?

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Old 08-15-2018, 03:40 PM
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Something isnít right...youíre probably down 80whp
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