Why are supercharged LS style motors not popular? (in offroad)

[hci127]

Originally Posted by 9toebandito

I've ran superchargers in a few race cars of different kinds and they are awesome.....IF you are careful. The forged internals are only a margin of safety. A powdered metal piston does not hold up to much detonation, so most install the forged piston/crank. On the other hand, stock LS internals are known to be pretty durable. It's not impossible to do, but it does present more challenges and prep costs.

found that out the hardway
Joey

[dan58]

Originally Posted by hci127

thats at the flywheel im sure not at the wheels

Indeed.

[laproscopic]

all forced induction has some lag. not as predictable in race apps.

ive been tweeking the turbo on my wheeler for 4 years now and am running 10 lbs boost now. 2nd turbo. 2nd manifold. 3rd boost controler.

for the monwy you spend getting the forced induction right you can do a lot to a NA motor

[Lee N]

Originally Posted by laproscopic

all forced induction has some lag. not as predictable in race apps.

I would disagree with the lag statement regarding an LS motor a blower. I am running a roots style blower on an LS motor in a 69 Camaro and there is zero lag. Pulls like a scalded ape right off idle and never looks back.
Problem I see with a blower in the dirt is belt slippage and clean air. When that filter gets dirty a blower has a nasty habbit of imploding them! Not a good thing if you are out in the middle of the desert.

I will agree that they are less predictable in a race situation because when the boost builds it has such a massive influx of power its hard to keep things in a straight line.

[Xjcrawler736]

Originally Posted by Lee N

I would disagree with the lag statement regarding an LS motor a blower. I am running a roots style blower on an LS motor in a 69 Camaro and there is zero lag. Pulls like a scalded ape right off idle and never looks back.
Problem I see with a blower in the dirt is belt slippage and clean air. When that filter gets dirty a blower has a nasty habbit of imploding them! Not a good thing if you are out in the middle of the desert.

I will agree that they are less predictable in a race situation because when the boost builds it has such a massive influx of power its hard to keep things in a straight line.

And that is why my filter will be in the cab with a pre-filter around it. I would rather not destroy my blower on my first race.

[laproscopic]

Originally Posted by Lee N

.

I will agree that they are less predictable in a race situation because when the boost builds it has such a massive influx of power its hard to keep things in a straight line.

thats what lag is-non linear power. in desert racing and especially in short course like events (rock racing) the right foot is moving up and down all the time. forced induction can make such driving frustrating.

and nothing is worse than trying to wind up the torque converter while modulating boost. just as the torque converter is right where you need it the truck start making all this power and you launch all over the place

[hci127]

Originally Posted by laproscopic

thats what lag is-non linear power. in desert racing and especially in short course like events (rock racing) the right foot is moving up and down all the time. forced induction can make such driving frustrating.

and nothing is worse than trying to wind up the torque converter while modulating boost. just as the torque converter is right where you need it the truck start making all this power and you launch all over the place

the only lag i've experience is when it would strip the ring gears right off

[Lee N]

Originally Posted by laproscopic

thats what lag is-non linear power. in desert racing and especially in short course like events (rock racing) the right foot is moving up and down all the time. forced induction can make such driving frustrating.

and nothing is worse than trying to wind up the torque converter while modulating boost. just as the torque converter is right where you need it the truck start making all this power and you launch all over the place

I personally would rather have a big cubic inch NA motor for anything offroad (especially the rocks).

Generally speaking most people consider "lag" the time it takes for the boost to add power. More common with turbo's. A twin screw roots style blower develops boost right off idle. No time delay. It builds more power as the rpm's increase of coarse, but is in direct relation with the rpm. Its not a sudden hit unless you hit the throttle suddenly. I have never experienced any issues with being on and off the gas, loading and unloading the converter much less any frustration when driving anything with a this style blower. I can not see an issue do to "lag" for a desert car (possibly a few other issues). For the rocks I can not see a reason to put forced induction on an LS motor. Maybe bragging rights or if you just like the sound of broken parts.

[Nevada Ben]

I would see a greater advantage from trying forced induction on smaller engines to maintain adaquate torque while trying to reduce weight but it hasn't worked out.

The supercharged Buick V6's are a great example of a try. As it worked out, the N/A LS V8's worked out better in every way.

I would love to see the powerplant drop 100 pounds from LS weight levels but the only way I see that happening is with a an inline four and high speeds to make the power. The bottom end torque won't be there.

To get torque at low speed takes displacement, compression or forced induction and all those things add a lot of weight (turbo diesels are the ultimate example of everything in that list and look what they weigh!)