Wastegate recirc or dump?

[Hiitman]

So who does what? What are the pros/cons of dumping or recirculating your wastegate? Also, sorry if this has been covered but when I searched recirculation all I got was info about bovs.

 

[snowborder714]

Here are some search results for O2 housing dump/recirculation:

http://www.dsmtuners.com/forums/search.php?searchid=3529256

That's probably what you're looking for (unless you have the wastegate off the manifold).

 

[1bad92awd]

I have my wg dump tube "dumped". I think the main benefit for recirculating the dump tube for the wg would be sound minimization. As far as a decrease in performance, I dont think you will even notice one.

 

[snowborder714]

I have my wg dump tube "dumped". I think the main benefit for recirculating the dump tube for the wg would be sound minimization. As far as a decrease in performance, I dont think you will even notice one.

You also will not be able to pass inspection if you have it dumped.

 

[unlmtdndeavor]

dump it.

 

[Hiitman]

You also will not be able to pass inspection if you have it dumped

Really? I passed tech up at fontana with mine dumped.

That's probably what you're looking for (unless you have the wastegate off the manifold).

I do

Also the guys at rre told me that sometimes a dump pipe can cause phantom knock from the pulse of the exhaust. Is this true?

 

[Hiitman]

That link didn't work. What did you search?

 

[Boosted98gsx]

Technically, dumping a wastegate will mess with the A/F readings that you would get from a wideband, because you're allowing out, the oxygen that the O2 senses that's leftover from burning.

 

[snowborder714]

That link didn't work. What did you search?

I typed in o2* dump (you need the * because o2 is less than 3 characters long).

 

[Hiitman]

Good idea. I was trying to figure something out when I would search GM 3.5 bar.

Technically, dumping a wastegate will mess with the A/F readings that you would get from a wideband, because you're allowing out, the oxygen that the O2 senses that's leftover from burning.

Would it throw them off this much?

 

[dnhieu]

Technically, dumping a wastegate will mess with the A/F readings that you would get from a wideband, because you're allowing out, the oxygen that the O2 senses that's leftover from burning.

I have always wondered if this actually mess with o2 readings

 

[2gGSX]

A dumped wastegate should theoretically only slow down the readings of the wideband, not alter it. The only time a wideband should have altered readings is if it's
1. Uncalibrated
2. Sensor's dead
3. Exhaust leak, which could suck air into the exhaust and thus lean out the air/fuel mixture
4. Located behind a catalytic converter or something similar

 

[Mr Peepers]

A dumped wastegate should theoretically only slow down the readings of the wideband, not alter it. The only time a wideband should have altered readings is if it's
1. Uncalibrated
2. Sensor's dead
3. Exhaust leak, which could suck air into the exhaust and thus lean out the air/fuel mixture
4. Located behind a catalytic converter or something similar

I agree. While the exhaust gases come out in a pulse, the length of the tube should keep any reversion and outside o2 from getting into the exhaust stream. The WG only opens when there is a large amount of pressure in the manifold anyway.

Edit: In theory.

 

[daren_p]

I first ran my 3052 setup with the WG dumped externally, then I had a section welded in to recirculate it back into my down pipe about a foot down. As far as a differece in WB readings, I didn't notice any. Not saying there weren't any at all, just if they did change, it wasn't enough for me to take note of. Some people argue that a recirculated WG will slow spool. This is the reason why I wanted mine dumped back into the downpipe instead of the O2 housing. This way the turbulance would be created much further away from the turbine wheel. Mine was dumped back in at an angle that wasn't perpendicular with exhaust flow to minimize the turbulance. As for the difference in spool, same thing if there was a difference it was very minimal, maybe like 50 rpms or something. The biggest difference is obviously sound. Personally I didn't mind how loud it was but to me it also wasn't a good sound. Basically sounded like a cars who CAT has blown a hole in it everytime I'd get close to full boost. I was always worried about who was around me (cops) & I would much rather hear my GT BB center section spool, then what sounded lika a large exhaust leak. For me internal routing was the much better choice & passing emissions visual isn't an issue this way.

 

[Hiitman]

Thanks for the input everybody. I was looking at this recirc O2 housing http://www.slowboyracing.com/estore/product.php?productid=6771&cat=593&page=1 since I'm running an SBR manifold and G50. I emailed SBR and they said it would bolt right up. Back to one of my other questions that I had about phantom knock, could the pressure from a dumped wastegate cause knock?