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-   -   any problems w/ the dump tube be routed back into the exhaust (https://www.rx7club.com/single-turbo-rx-7s-23/any-problems-w-dump-tube-routed-back-into-exhaust-104136/)

untaymd 08-10-02 09:35 AM

any problems w/ the dump tube be routed back into the exhaust
 
Anyone that has the dump tube routed back into the exhaust , have you had any problems with boost spikes?

untaymd 08-10-02 03:38 PM

anyone??????maybe even know of someone?????

Silver93T 08-11-02 12:56 AM

If anything, I think it would make it easier to control boost do to possibly more backpressure. Also keeps the sound down.

Sidestick 08-11-02 01:06 AM

No problems with mine, XS T04E kit. Kills the noise from the wg too.

AJatx 08-11-02 11:52 PM

None at all with my old FC set-up.

If you see boost spikes, it'll most likely be your boost controller duty cycle and/or wastegate spring tension.

J

soul assassin 08-12-02 12:07 AM

yeah, one problem! its to quiet!!!

1FooknTiteFD 08-12-02 01:09 AM

I don't know why anyone would want to get rid of that sound...the sound of an external wastegate sounds so damn mean and also beautiful:cool:

fastrotaries 08-12-02 02:16 AM

Yeah like a cow burping

Rx-Revin 08-12-02 02:51 AM

fookntite i guess u dont have your wastegate plumbed back into the down pipe.

silver0ckt 08-12-02 07:41 PM

doesn't the wastegate remain closed at idle so all the exhaust is being routed through the exhaust? and when you are under boost and load, it will open (either at spring pressure or when the boost controller gives the signal to open) and then vent the exhaust gases through the dump tube? So the car will only be really loud when under WOT with the wastegate open venting exhaust gases through the dump tube?

Just don't drive fast, then it won't be too loud. :)

fastrotaries 08-12-02 07:51 PM

yup it only opens when the desired boost level is reached.

1FooknTiteFD 08-12-02 07:53 PM


fookntite i guess u dont have your wastegate plumbed back into the down pipe.
No way, I love the sound of an open wastegate it sounds so damn mean. The other night, I was driving around and at a stoplight this mustang pulls up next to me and starts revving. I totally ignore him and as the light turns green I drive slowly but the guy wouldn't leave me alone and just paces me. This happens for about 3 stoplights and then finally he starts to slowly take off, then I just floor it in second gear and the wastegate screams open when I pass him. My friend in my passenger seat saw him jump up while I was passing him :D

needless to say, I'm one of the few?? people who don't want to plumb my wastegate back into the downpipe because I love the sound tooo much :)

fastrotaries 08-12-02 07:55 PM

still sounds like a cow burping top me though.

Astro 08-12-02 11:53 PM

haha
cow burping...
never heard that before

machinehead 08-13-02 12:00 AM

I like the sound but... I was afraid i might cause an accident on the freeway with it open. I mean you are driving along and out of nowhere there is this tremendous noise... I think it freaks people out... that being said, now that i routed mine back in, I did lose a little power. Plus you can really hear any engine missfire at WOT with it open.. which I liked.
And back to the topic. My boost is much easier to control with the watsegate piped back in.
I am thinking about trying it open with a small muffler... anyone try that yet?

Snufelupogus 06-30-03 11:57 PM

Is there any power advantages with the wastegate vented into the air or does it make no difference... just with sound?
Thanks :)

ludeowner 07-01-03 04:20 AM


Originally posted by Snufelupogus
Is there any power advantages with the wastegate vented into the air or does it make no difference... just with sound?
Thanks :)

Open looped WGs (out into atmospehere) usually have slightly more HP then the closed loop WGs (back into the exhaust).

donny 07-01-03 08:25 PM

I never had any problems with mine either. An open wastegate draws far too much attention and sounds like a chainsaw..It is kind of cool though to hear the rotary screaming, but not on the street..Just my opinion, but I am also 32 years old. When I was 18, an open wastegate would have been the schnizzle dizzle, or whatever...

93redFD 07-02-03 12:41 AM

How much power loss is there? Im thinking like 3-5 hp? is that about right? My dump tube is open to the armospher and I can here it a idle. Its sounds like a exhuast leak(tick tick tick), or is that a exhuast?

1FooknTiteFD 07-02-03 03:20 AM


How much power loss is there? Im thinking like 3-5 hp? is that about right? My dump tube is open to the armospher and I can here it a idle. Its sounds like a exhuast leak(tick tick tick), or is that a exhuast?
XS told me that they've seen up to 20-30 rwhp loss on the dyno after they've had the wastegate routed back into the exhaust due to higher backpressure readings.

rx7tt95 07-03-03 06:35 PM

Sounds like one of your exhaust gaskets are leaking...could be manifold to turbo, turbo to downpipe, manifold to wastegate, etc....take a piece of tubing (vacuum type) and with the engine cold, start the car up. Put one end of the tubing up to your ear and place the other end near all of the gaskets mentioned above to determine which is leaking. There will be a noticeable increase in sound at the leaking gasket.

weaklink 07-03-03 10:43 PM

I think I might have a leak somewhere. When cold the car sounds different...kind of a bleat bleat bleat, or a ticking exhaust. I have the dump tube routed back in. It's very loud still. Sounds cool flooring it under an underpass. Backpressure reduces peak horsepower, but reducing backpressure costs torque (speaking in absolute terms). I think torque is more important in real world application.

J Oliver 07-10-03 10:45 AM

wide open
 

Originally posted by machinehead
I like the sound but... I was afraid i might cause an accident on the freeway with it open. I mean you are driving along and out of nowhere there is this tremendous noise... I think it freaks people out... that being said, now that i routed mine back in, I did lose a little power. Plus you can really hear any engine missfire at WOT with it open.. which I liked.
And back to the topic. My boost is much easier to control with the watsegate piped back in.
I am thinking about trying it open with a small muffler... anyone try that yet?

I used a lawnmower muffler on mine and it can't the heat it basically just melted. Then I used a motorcycle muff. and it lasted 4all of six passes.

Wide open or nothing baby.:D

JScott 07-10-03 03:22 PM

Re: wide open
 

Originally posted by J Oliver
I used a lawnmower muffler on mine and it can't the heat it basically just melted. Then I used a motorcycle muff. and it lasted 4all of six passes.

Wide open or nothing baby.:D

I just put a small "cherrybomb" on mine. They make a 1.75" model that's only a 17" long. I used some smaller 1.5"(than my 46mm Tial 1 5/8" outlet) mandrel pipe back about a foot and a half. Still a little loud when it opens but nice and deep. It resonates with the N1 and sounds great. Hope it doesn't burn out:eek:

BLUE TII 07-20-03 11:18 PM

I have a 2 1/4" downpipe and generator baffled tube muffler on my externally vented internal WG.

It has broken up the baffles a little so it rattles when you shake it (been on for ~1 month), but still quiets it down.

I mainly put it on because the stock internal flapper WG does not seal well at idle, but it does quiet down WOT nicely.


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