Ive searched and read, but it seems the majority of the info is in regards to full o2 dumps, and not a divorced/tubular style recirculated o2 housing.

As of right now my car is basic bolt on (perrin intake, 3 inch turbo back, ETS 3.5 etc) and making 330/300 on virtual dyno. The car will not see anything bigger than an FP RED on a stock block. My front o2 sensor needs replacing and is stuck to hell in the factory o2 housing...so time for an upgrade.

at this point im looking at the following:

MAP titek style -stock style, 2.5 outlet, low cost

MAP recirculated eliminator downpipe - very well made, vband connection (big plus), 3 inch exit to true 3 inch dp, downside is the ~$650 price tag.

JMFAB - good construction but will keep the 2.5 outlet, pricey but still cheaper than option 2.

i guess my question is, is a true full 3 inch setup worth the money? how much benefit could be seen on my setup? More importantly does anyone have any dynos?

if there any any other options i will glad take the advice!

 

Bigger than HTA GREEN or BBK FULL stay with the 2.5 outlet anything larger go with a 3", but a 2.5" with a external dump will make the same power as a full 3" o2 housing,sincethe wastegate flow is sharing the same space as the turbine exhaust

 

hmm...i find it kinda hard to believe that full 3 inch wouldnt have any benefit until much larger turbos...but maybe im wrong?

 

Take this dyno chart as you will...there are more changes other than the MAP o2 eliminator dp.

Blue line: Stock 8 turbo w/ 9.8, hks 272 cams, 3" tbe, intake, ported exhaust manifold, ETS 3" IC w/ full piping, 23psi

Red line (1 year later): Only changes...Same stock 8 turbo but w/ ported 10.5 housing, MAP full 3" o2 eliminator dp open dump, 25psi



Notes: In both tuning sessions we weren't making any more power when raising boost, so its safe to say both tunes were maximized. What I'm trying to say is the extra power wasn't made just by raising 2psi, but in the combination of upgraded parts and tuning which allowed us to effectively raise boost and make more power. I LOVE the MAP o2 elim pipe...it's a pain to install but is worth some power and spool even on the stock turbo...

 

Here's some larger turbo and built motor results...I wouldn't expect results of this magnitude on a stock turbo, but I would expect some scaled down power gains

https://www.evolutionm.net/forums/ev...aust-mani.html

https://www.evolutionm.net/forums/ev...p-results.html

 

those are all DUMP results that ive read multiple times. im looking at a recirculated setup not a dump.

 

so no one runs a divorced but recirculated housing?

 

I am. But I dont have back to back or before and after data.

Here is my VDyno.

https://www.evolutionm.net/forums/ev...ane-28psi.html

 

yeah i saw one of your other posts about the MAP setup. i think its not worth it cost wise for me at this point. I read up more on the titek tonight which i guess the map housing is a copy of, and i think im just gonna go with that to save some cash.

need injectors and a pump anyway.

 

The Map/Titek/Greddy O2 outlet is probably the worst o2 housing upgrade you can buy thats a fact, it makes more then stock but less then all the other options. Search and you'll see, the Titek V1 was great but the current one is garbage, even the cheapo megan outperforms the titek.

 

...everything i read on the v2 said the opposite, ive read all the stuff on the megan, but i dont want to have to mess with porting it.boost creep and buschur sells it uncoated for 200!

 

Which map o2 housing? They offer 4 different types.

I'm running the 3" o2 housing recirculated with vband disconnect from downpipe. Then they have 3" with integrated downipe and dump. And then the 2.5" ("titek" v2 style) recirculating and another 2.5" dump style o2 housing.

Your right, it is really expensive. Actually its over my budget so I went into debt to get it. However from visual perspective of its design, it seems pretty well designed for flow and especially the recirculating merge angle. Also its well constructed with thick stainless tubing material. (dont know the exact gauge)

However there are somethings I dont like or at least with the one I got.

1. The pictured item has a interlock v band. Meaning on the o2 side, an inner pipe sticks out the vband and its actual purpose to slide in to the downpipe vband for aligning and further creating a leak free seal.

My vband setup came with just 2 female (non interlocking) vbands. So no matter how i tightened it down it would have an exhaust leak!! Trust me I'm not a novice to mod'ing cars/parts. I tried it all, even tapping it evenly on all the sides etc.. My solution was trimming the little excess pipe inside the vband down to near the welds, to allow space for a pipe to slide in a little. The inner diamter of the vband flange is slightly over 3" which allows me to slide in a 3" pipe. This allowed like 1/2 inch space, so then I took a 3" O.D. pipe cut 1" length and slid it in. So now it looks like this in the picture as it should have been made for me, in my opinion:

Notice the lip on the vband. Mine didnt come like that!


2. They did offer a free o2 bung which I am great full for. However I would have gladly paid more for it to not be welded at the location it is at. Pretty much all the downpipes have the o2 bung welded near the cat side flange. Either vertically (my preferred location) or at the least horizontally.

However the o2 bung came welded right near the Chassis K member. Its a major pain to route the wideband o2 sensor there and it's just not a clean route no matter what. Also had to trim the factory undertray as well so it wont push against and melt on the o2 sensor. Kind of bothers me in the back of my mind. One of these days I'll either weld another bung or get a regular downpipe with a normal bung and replace the flange with a vband to use with the downpipe.

Now, at that location the o2 sensor might react quicker since its closer to the exhaust manifold, but I didnt notice any difference and I dont think its worth it there at all. And no I didnt bring this to their attention, I already was done installing it and its my daily driver so I can not have any downtime for that stuff.

Hopefully if they read this they can use it to maybe revise it a little.

 

You should see gains going to a divorced recirc setup.... on a turbo car just about anything that adds volume to the exhaust will show at least SOME gains.....the bigger your turbo the more gains you will see. Optimal exhaust for any turbo would be just enough pipe to keep from melting anything. The turbo itself provides the needed back pressure for the engine.

As far as how much you'll see, on a smaller stock frame turbo (Green, BBK Full) I can't imagine you'd see more than 5-10whp, even going to a open dump won't get you much on that setup.

 

English Racing just posted up a dump vs non dump dyno and the results were pretty staggering. I can't find the link (Love my evom search <3) but if I come across it, i will relink the thread.

Michael

 

yup, i read it and it was very good info. they were running big motors + big turbos. i doubt the gains will be even close on a stock turbo.

if i could be 100% sure or no boost creep with a megan, id be all over it.