"Sweet Trav" (thespunbearing)
06/04/2018 at 09:16 • Filed to: sslow6.0, monte carlo ss, dyno
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"Sweet Trav" (thespunbearing)
06/04/2018 at 09:16 • Filed to: sslow6.0, monte carlo ss, dyno | 5
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Well as some of you might know last summer I LS swapped my 1986 Monte Carlo SS. I was finally able to get it on a chassis dyno.
Engine specs are as follows
“120k” mi 2004 LQ4 6.0L V8 long block with 317 heads with 9.4-1 CR
Used LS3 Camshaft -204/211 degrees, .551/ .525 lift - 117 deg LSA
LS3 “Blue” valve springs
Trailblazer SS intake manifold with factory 30lb injectors
G-Plus eBay 92mm Throttle Body
Fuel injection controlled by a Microsquirt ECU
Speed Engineering G-body LS Swap headers
Exhaust is some cobbled together garbage with thrush turbo mufflers
This is bolted to a rebuilt Turbo Hydra-matic 200-4r with a TCI Master Racing Overhaul kit and 2200 stall converter, converted unlocked. Driveshaft is stock, rear end is upgraded with a Torsen T-2 and 28 spline axles.
It made 352 HP and 375 ft/lbs of torque or 262 KW and 508 Nm for you continental types as measured by a rather conservative Dynapack dyno. (for comparison on a mustang dyno Yamahog’s LS3 Camaro made 374hp/366tq)
Sure it’s not the 500 whp that everyone on the internet seems to claim after an LS swap, but hey I’m happy with it. By aftermarket standards that LS3 cam is a TINY LITTLE BABY CAM, and the exhaust is so restrictive that when I did a celebratory burnout, it blew off of the collector. New exhaust and a good cam should see 385-400 hp.
crowmolly
> Sweet Trav
06/04/2018 at 10:29 |
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Plus a stock LS3 has over a point of additional SCR.
Anything going on with that torque dip @ 3200?
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Sweet Trav
> crowmolly
06/04/2018 at 10:58 |
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yes, the TPS acceleration enrichment is going haywire, throwing the AFR to 11-1. need to tune it out, but I have the new exhaust sitting in a box to install sometime after my wedding so I didn’t want to spend loads of time dialing in this combo only to change it in a few weeks.
DeWayneV8
> crowmolly
06/04/2018 at 11:16 |
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Actually, the lead in for the dyno pull always causes a weird torque reading for the first 200-300 rpm. You don’t see this on inertia roller dynos because they don’t actually put any controlled load on the car. An eddy current roller dyno will do this, and you see this on engine dynos too. You’ll notice it does a little uptick at the end of the dyno pull too.
You can actually make this go away by increasing the settle time before and after the dyno pull, but it’s really hard on the trans in automatic transmission cars. You’d essentially be running the engine at WOT while the dyno holds it at the beginning and ending RPM.
This sweep measurement error is why you see manufacturers quote “bhp”, a brake horsepower test involves no rpm rise, they just put the engine at WOT max power RPM and hold it there.
EL_ULY
> Sweet Trav
06/04/2018 at 13:51 |
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Raaad