How did they make the EFI carts so quiet?

[HBR]

Is it all in the muffler or are there some other things they did to cut noise?

I was wondering if the muffler could be fitted to another cart to keep noise down.

[smallblock450sl]

Long list...a whole under body "shield"/ air box intake tubing to the front cowel area/exhaust tube porting thru the "shield"/ pad foaming/ rubber seat seal and more.

[cgtech]

And by restricting the airbox so much that they lowered the horsepower.

[HBR]

Bummer, I was hoping it was something simple like a highly effective muffler they designed.

Thanks for the info.

[olson boy]

Originally Posted by cgtech

And by restricting the airbox so much that they lowered the horsepower.

Have you had any complaints of backfiring on the EFI carts?

[cgtech]

Nope. But I did see one that fouled a plug.

[olson boy]

Originally Posted by cgtech

Nope. But I did see one that fouled a plug.

We have seen a few rich and a few really lean.

[sho305]

Originally Posted by cgtech

And by restricting the airbox so much that they lowered the horsepower.

I was wondering why the 357 was 11.4hp and now its 9.5 or something, what is that?

I piped my airbox to the front of the cart but I used 2" pvc. I do hear the carb suck air a little from the front when I hammer it, it seems to be less now with the 32mm CV carb on it. It is a car airbox out of a chevy and filters are $7 lol but I never have replaced it as it stays way cleaner than the old factory one ever did.

I would guess its mostly about the exhaust, and some sound deadening around the engine compartment. Even old sleds used to have egg crate foam inside and all that. My cart had none I'm sure it would help. I don't care for my use.

[Glid]

From looking at the manuals the 2019 models increased gross HP to 12.29 HP from 11.4 but added listing of net HP of 9.4. Been the same since 2019.