dennisbernal91z

iTrader: (2)

Does anyone have experience swapping from the open to closed style?

I am trying to make my car as quite as possible. I have read that the closed style is more quite.

While I am at it, anyone have experience with a stock Procharger vs a helical cut gear procharger? I have a stock F1, but think it might be too big for my 390 street car and am starting to consider selling it in favor of a helical cut D1 or something like that.

Any help, clips, vids, link to youtube, etc...

Oh and if closed is better, any idea what the best way to swap over is? My open has 50 miles on it, but these damn things are almost $500 so selling would net me maybe $300 if I am lucky. Losing $200 sucks, but if the sound dB is worth it, then I am game. Again, any advice here would be great! Thanks!

Street Lethal

iTrader: (16)

Bingo, which is why helical gears will make no real difference in sound with an open intake right by the supercharger's inlet. Factory supercharged engines are essentially quiet because of their restrictive intake systems, but once you open them up, they become noisy, with or without helical gears...

It's cutting air, your going to hear it unless you muffle/restrict the intake. I would switch to a blow off valve, as well as slow the F1 down if you feel it's too much for the street. I won't recommend restricting the intake, but if you want a quieter system, it's the only real way...

DIGGLER

iTrader: (1)

that is just going to be a loud blower altogether, which is one of the downfalls of superchargers. the helical/straight cut gears have to do with the gearbox noise, not the air cutting noise.
can you adapt some large tubing to the outlet of that bypass valve? i have experience with a vortech mondo bypass and they have the ability to route back to the intake tubing. not sure how much it will help with overall noise, but it should help.

just looked, and they have a version with an enclosure and tube coming off of the race bypass. maybe you can get that enclosure and add it to yours so you can route air back to the intake?

Street Lethal

iTrader: (16)

The "cutting air" noise overcomes any gearbox noise, the helical gearing makes no difference whatsoever. There are before and after videos underlining this, and both systems sound identical because all you hear is the compressor wheel. Whether on a video, or in person, the gears are a waste of money because they make no difference. Like I said, factory supercharged vehicles, especially earlier ones, don't come equipped with helical gears, yet you can't even tell they are blown until you install an open element intake onto them...

Edit: Here is a helical gear system, owner states in his description "quieter setup", but anyone who has run a supercharger knows the difference in sound is so minimal you can't even tell because the compressor wheel and engine itself overcome the sound anyway...

DIGGLER

iTrader: (1)

not my experience with the s trim vortechs. the v1 is much much louder than the v2 due to the gears.
im assuming the op hears a massive amount of air under his hood like an air compressor being drained, correct?

anesthes

iTrader: (12)

Wha? I've run a A-Trim, S-Trim, P1SC, BD11A, an SQ (on a '01 Cobra), and now a T-trim.

All the straight cut blowers sounded like a train locking up the brakes, especially at idle. The SQ was very quiet. Helical gears make ALL the difference.


-- Joe

Street Lethal

iTrader: (16)

I have not heard any difference whatsoever, maybe my ears are shot then. At the track there is absolutely no distinguishing between the two. Maybe it is a driver preference then, being behind the wheel? Hoods up in the pits there is no difference in sound whatsoever, unless when running a factory intake setup, all echoed noises are essentially reduced. Maybe I am misunderstanding the noise you guys are referring to, but again, I hear no difference at all unless opened up, in which then you hear everything...

DIGGLER

iTrader: (1)

vortech v1 is very very noticeable with hood down at idle. you will hear it in a car that is pulling into the parking lot 100 feet away.
with an s trim v2 you might not even know it had a blower if you were 10 feet away from it.

anesthes

iTrader: (12)

Yeah. My V1's (A, S, and now T) all sound horrible, even the day they were unboxed. Idle is probably the loudest, high pitch, grinding noise.

The P1SC was noisy too, although m biggest gripe was the heat. That thing with it's straight vane impeller was just a hairdryer.


-- Joe

dennisbernal91z

iTrader: (2)

Wow. A lot of responses here. Let me try to sort out what I was intending by this post.

I have had the car together before (torn down now) and idling the car sounded like a harrier jet hovering in front of me, hood down. People walking down the street, while I was stopped, looked at me and were like WTF is wrong with that car?

I don't care about the sound of a WOT pull. I expect to make noise then. What I want to be quite is idle and driving 30MPH thru town.

I expect the "air cutting" sound, the whistle sound to be impossible to lose. Fine. But what about the supercharger transmission sound and the bypass valve?

In my original post, my first sentence talks about the closed style bypass valve. I know this must be more quite, but I was hoping for someone to have a video or sound clip, and then advise about what the best way to swap over is.

Street Lethal - I don't understand your posts when you mention having an "open element intake". I have an edelbrock air gap intake with a blow thru carb, carb hat, 4" thick IC, and the procharger. Then a small length of tube and an air filter. Would you call that "open"? If not, then what is "open"? What is "closed"?

Sounds like the consensus is that helical cut gears are more quiet. My issue is that I have an F1 and helical cut gears are not an option. I either deal with it, or sell it and buy a helical cut D1 or something like that.

anesthes

iTrader: (12)

Are you running cog or ribbed belt? COG can't use helical gears, it will break them as they are not as strong.

It's very difficult to build a very fast car that doesn't have quirks, be it noise, idle, etc. I'm with you though. I wish my T trim was quiet. They do make a helical T. I'm running 10 rib.

-- Joe

dennisbernal91z

iTrader: (2)

Totally hear your point about fast cars are going to have something "strange" like being loud, uncomfortable, etc... Unless you spend crazy $$$. Which I can't. Sooooo....

Anyways, I am running a 12 rib. Need to figure out how I want to mount it to the motor still. But I have a 3.4" and a 4.2" pulley to go along with the 12 rib crank pulley. I really want to look into the SBC serpentine setup Procharger sells.

I am leaning towards just keeping the F1, and putting all my effort into getting a closed style bypass valve and maybe routing into the intake. Then get a smaller exhaust (4" now) maybe a 3.5" or even a 3" and a quite muffler setup. Then buy some high end under hood sound deadening material. Also like the inside of the fender skins as well.

What do you think?

DIGGLER

iTrader: (1)

i know exactly what you mean by harrier jet. we had a 30 mile cruise before a race a few years back, and there was a guy behind us about 2 cars back running an f1. just as you said, it sounded like a harrier jet was back there taking off. i have to assume its the massive amount of air the blower is moving getting bypassed under the car.

on the vortech mondo, there is a connection point for a 2" hose. i have to think you could route the air through a muffler of some sort. adding a air filter enclosure made all the difference in the world on my air compressor, so i believe you should be able to quiet your car down in the same manner. im just not sure you can add the enclosure/tubing hookup to your bypass valve.

dennisbernal91z

iTrader: (2)

DIGGER, this is the exact idea I had when I started this thread. Try to find an inexpensive way to swap from the open to the closed style. Not sure if there is an easy way. I may call Procharger and ask them directly.

86CamaroDan

I would probably say this is your only safe bet, Plumb it back into the blower inlet.
http://www.ebay.com/itm/like/370895378002?lpid=82&chn=ps&ul_noapp=trueI would def call them and see what they have for other options

92RSZ

iTrader: (6)

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92RSZ

iTrader: (6)

[QUOTE=92RSZ;6078935]None of the centrifugal blowers are going to be very quiet. Its just the nature of the beast. Paxton and vortech are the quietest I've heard in person. The f1 comes in dead last lol. If u want quiet, a twin screw blower is dead silent until you're on the throttle a good amount. A closed style big red will reduce the air noise, but the gear whine is way louder.