VY SS 235kW Engine rough revving

**PedroWilsoni** · 05-05-2011, 05:14 AM

Hi, my LS1 VY SS, when flat to board revving in park gear gets to about 6000/6500 RPM and then goes all misfire, rough revs, shaking in it's mounts, and won't rev higher than that.

Is that normal? Not like I ever do 6500RPM on the street...Any clues, as I don't have a buddy mechanic and it was supposedly tuned 2 months ago?

Replies appreciated!

**Knight** · 05-05-2011, 05:47 AM

What is your rev limiter set at?

**Spikito** · 05-05-2011, 05:48 AM

for some reason detonation comes to mind....

what octane are you running?

**cammed goat** · 05-05-2011, 06:18 AM

Are you running with a MAF or without? If you are running a MAF, check to see if it's clean.

**PedroWilsoni** · 05-09-2011, 12:20 AM

Hi Cammed Goat, Spikito and Knight.

Knight I don't have a clue what the rev limiter is set at. Is that something that can be altered? I can't seem to find anything on how to.

Spikito I use 98 octane, but occasionally tank it with 91. The specs say the Gen 3 motor is designed for 91. Could it be something like a timing chain issue? (Has done 149k, don't know it's history)

cammed goat - it has a Growler, and the pod filter box doesn't mount very well to the intake hose/clamp. In fact a couple of wks ago I noticed the hose had worked itself loose from the filter pod box and was sucking hot unfiltered air from under bonnet through the MAF unit. Maybe I should start by cleaning the MAF unit/sensor, but can only find instructions for a VZ. Anyone know a link to instructions or are they similar?

Thanks for all your tips, will check out all your ideas and hope one or more solves it.

**cammed goat** · 05-09-2011, 04:47 AM

Clean the MAF first then work on tightening the hose to the MAF/growler pod. Let us know if you need anything else.

**PedroWilsoni** · 06-25-2011, 06:36 AM

I fitted the full SS Inductions Growler kit - Big Mouth throttle body, intake pipe and MAF parts. Result? Gas guzzler, running like sh*t.

Got a dyno, new 02 sensors, they remapped the transmission shift points and suddenly I have a 300fwkw, 230.6kw at rear wheel LS1 rocket.

SS Inductions kit added 36fwkw. Dyno added 29fwkw on top.

Very happy!