Suggestions for bolt on upgrades to LS2 Goat

[tcbnj]

Requesting fellow carjunkie feedback on bolt-on upgrades to the LS2 in my ’05 Goat with 6M.

Requirements: This is my daily driver and the combination of the upgrades cannot negatively affect the drivability, reliability or mileage (combined driving is averaging ~ 21 mpg). The Goat will see track time rarely.

My ideas are driven by SLP’s Bobcat package

1. Kooks long tube headers and cats
2. X pipe (such as Dr Gas cross over tube)
3. Keeping stock mufflers to keep the peace with the ‘next door’ neighbors
4. Exhaust cutouts (such as those from DMH Performance - thanks to Bob/1956NY150) to take away the peace after leaving the neighborhood
5. Under drive pulley
6. 160 degree thermostat
7. Higher ratio rocker arms (1:8 or 1:85)
8. Higher performing valve springs and retainers
9. Dynotune by TTPerformance, Passaic NJ

What do my fellow junkies think and what would you add/change? I would particularly like opinions on the valve train upgrades – what ratio rocker arms and what valve springs (beehive, double) and from what vendor (Crane, Comp).

Much Obliged

[squirrel]

Re: Suggestions for bolt on upgrades to LS2 Goat

I would not lower the thermostat temperature. I saw the chart long ago engine wear vs. temperature...

Also will the underdrive pulley keep the power robbing accessories working properly when you need them, like the AC cool and the battery charged on a hot summer day?

Exhaust mods are definitely worth doing.

[TC]

Re: Suggestions for bolt on upgrades to LS2 Goat

Ya that's one of my concerns with the under drive pulleys, unless the setup comes with a smaller alternator pulley I wouldn't put them on. Under drive pulleys are more for racing when the motor is spinning higher rpm's than stock.

Headers are a good choice, but I don't know how much of a gain you'll see if you plan on keeping the restrictive factory cat back system. And as for the exhaust cut outs and X-pipe you'll probably be better off spending the money on a cat-back system. I know the Flow Master American Thunder system I got for my '99 Camaro isn't really loud at idle, in fact it isn't loud unless you get on it.

As for the 160* thermostat, I run one in my car, but it still runs about 185*.

And as for upping the rocker ratio, remember that for every .10 increase in rocker ratio you'll see about a .030 increase in lift at the valve. And if your opening the valve up more you'll be dumping more fuel into the cylinder which in turn will decrease your gas mileage.

And as for tuning, I'm pretty happy with the DiabloSport Predator programmer I have, but having it dyno tuned isn't a bad idea either.

[CTX-SLPR]

Re: Suggestions for bolt on upgrades to LS2 Goat

I think the best investment would be an HPTuners and do the tuning youself over time in the real world and you can flash the car for the street and 87 octane and then load a track program running on the good stuff and if it's an A4 harder and later shifts.

[JoeyG]

Re: Suggestions for bolt on upgrades to LS2 Goat

Save yourself the time and hassle with the rocker arms. You cam do a 224/224 cam or slightly smaller without sacraficing much of anything in the mpg department and still get a nice power gain out of it. The exhaust is always a good addition as well.

[tcbnj]

Re: Suggestions for bolt on upgrades to LS2 Goat

I would not lower the thermostat temperature. I saw the chart long ago engine wear vs. temperature...

Squirrel come back to me on the thermostat feedback:

Generally what is wearing down - I would think lower temp = less wear since the oil is less subject to evaporating and therefore continues to lubricate (everything else being equal).

Specifically - are lower thermostat temps bad for all engines or just GM motors or just LS series engines or ?

Thanks

[TheSilverBuick]

Re: Suggestions for bolt on upgrades to LS2 Goat

Doesn't the lower temp prevent the water and other ring blow by material from boiling out of the water therefore you end up with dirtier oil quicker?

I would look at how much street time the car will see. Lots of street time I'm with Squirrel, for longevity of the oil and other parts (from the underdrive pulleys).

If not much then I'd run both as the lower temp allows for more ignition timing before it pings, so you do pick some power up, but still a concern for the oil.

If your drives are long enough the water and stuff will boil out of the oil even at 160*F, just takes quite a bit longer.

[CTX-SLPR]

Re: Suggestions for bolt on upgrades to LS2 Goat

Steel and aluminum have expansion rates, the engine tollerances are designed to be optimum at certain temperatures. Too cold and things are to loose in addition to the oil being thicker and not getting into all of the tight places as well due to surface tension and viscosity. Add this to boiling the contaminents out of the oil.

[squirrel]

Re: Suggestions for bolt on upgrades to LS2 Goat

The chart I saw showed cylinder wear vs. temperature, I seem to recall the wear dropped off dramatically over 160 degrees.

If you really are concerned about the slight increase in performance you might gain by running the engine cooler (cooler intake air is more dense, so you make slightly more power) then do your racing after the car has sit for a while to cool off.

[squirrel]

Re: Suggestions for bolt on upgrades to LS2 Goat

That's a really bad chart, needs to be log scale on the wear so we can see what's going on.

[tcbnj]

Re: Suggestions for bolt on upgrades to LS2 Goat

Thanks fellows, now I get it.

I currently have a 160 degree 'stat in the Firebird (LT1) as a result of my thought that it ran hot (nonscientific opinion). That said it is not my daily driver. Now I am wondering if I should go back to the OEM thermostat. Any comments on the LT1?

[JOES66FURY]

Re: Suggestions for bolt on upgrades to LS2 Goat

I have read that cooler t-stats in comp controlled cars will adversly affect gas milage...any truth to it...not sure...but something to look at......

[SpiderGearsMan]

Re: Suggestions for bolt on upgrades to LS2 Goat

195 is the optimum temperature to burn trace amounts of coolant out of engine oil , also helps cat convertor efficency , gets the oil temp up there for low drag , I heard warren johnson say for best ets -cold water -hot oil
the lower temp thermostat was for grand national guys , cooler the better for boost