capri93

Well I was watching monster garage the other day and got to thinken about putting zoomies on my race car is rotary engine dependant on having some back pressure like small cylinder engins or can you run straight headers like the old v8? It s probably loud as hell but not to worried about it if im only useing it at the track. Oh and is this allowed at the tracks befor i go doing it and not be able to run the car

Illswyn

Depends on the track. I hear they're getting regulated as far as sound, so check first.

Jeff20B

iTrader: (13)

I said it before and I'll say it again. Backpressure is the devil.

I still don't understand why this backpressure myth keeps resurfacing. A rotary engine is quite different from a small cylinder engine. Just because it has a metering oil pump does not make it a two stroke boinger. A rotary benefits from 'pressure wave tuning' which is not backpressure. Others will explain more about this.

The rotary is loud, but you shouldn't run a restrictive exhaust. It's ok to be a little loud, as long as backpressure is kept to a MINIMUM.

vipernicus42

iTrader: (4)

Unless he's running an -SE and wants his 6-ports working! Then exhaust pressure is required.

But he *did* say it was fora racecar, so chances are his 6ports wouldn't matter to him if he had an -SE.

Jon

Kenku

The whole backpressure thing is a myth for boingers too, anyway. Pipes like you're talking about though... well... you may *think* tracks won't have any noise restrictions, but they really generally do. We're experimenting a bit with mufflers on our Improved Touring prepped '7 to try to get more power without being illegal.

Wear hearing protection if you try!

YapaKanichi

if it s a 6-port why doesn't he just get the RB presilencer? Thta thing is a free flowing cat basically. It has the back pressure thing on it so he would just have to hook it up.

YapaKanichi

oh and by the way you can make an illegal exhaust quiet.......hinse my exhaust. I think it's funny spitting flames out the exhaust when flooring it beside people

Kenku

Yeah, uh... what we have on the race car is several orders of magnitude worse than any setup that has RB products in it in terms of noise. Nothing against RB, but they really do make stuff for street cars.

Zoomies means essentially having the two primaries of the header just exit the car. No collecting, no muffler, no nothing. That's just about as loud as you can make it without specificially trying to be louder.

For reference, my dad had the exhaust pipe come off at the header flange (there's a strap, of course, to keep the exhaust from dropping and hitting the ground) So it was an open header. He said the corner workers were holding their hands over their hearing protectors when they saw him coming, and even with earplugs and a helmet he was kinda hard of hearing after a race like that.

So... yeah.

Lotus00

Yeah, after we got my engine put back together 2 years ago I started it with only the racingbeat header... I think my ears are still ringing

YapaKanichi

I have a racing beat header to a racing beat presilencer to a dual n1 style muffler.......it's loud. The guy at racing beat said it's probably due to the muffler.

YapaKanichi

I have a racing beat header to a racing beat presilencer to a dual n1 style muffler.......it's loud. The guy at racing beat said it's probably due to the muffler.

Lotus00

haha, mines loud too. I have a racing beat header and presilencer, and a nice monza muffler that lets exhaust come out both ends!

(It developed a huge crack near the inlet piping after about 4 months)

I think that a car with zoomies would be almost too loud to drive. even with ear plugs.

85rotarypower

Try reving to redline on a 12a in a small 2 car garage with only the header on the car. The garage was totally closed up too. I was wearing hearing protection and it was overbearing. Thats under no engine load either, just reving it.