RB25DET knockoff turbo manifold thread (The good, the bad, the ugly)

[DailyDrivenS14]

This thread is for those of us that want a temporary manifold to get us by until we have 14-18 hundred dollars to spend on a legit manifold, Or those that simply choose not to spend that much on a manifold ever.

I searched for a while looking for details on the different knockoffs and for the most part couldnt find any useful info.

If your response or reply is "dont buy a knockoff" or "Buy a real manifold" please save it and dont clutter up the thread with pointless posts.

I am going to start this thread with the OBX manifold since that is the one i just got in the mail...

OBX MANIFOLD

I just got it today. ordered it from eBay heres what I got!



Overall packaging is great. Thanks to ups the box isnt damaged dented etc. -off to a good start!

Opened the box up



Still looking good.



Under all the peanuts the manifold was wrapped in cellophane (i assume to keep the out of the manifold runners)

Out of the wrapper you can feel a heavy coat of oil on the manifold, and smell it too lol



Overall quality of it looks great! I'd give it a 8.5 or 9 out of 10





All of the holes for the studs look to have great clearance except for this one little guy which isnt too awfully bad itself



The gaskets were included with the mani they are paper ones but dont seem horrible either... only time will tell.




NOW FOR THE TRUE TEST... ON THE ENGINE!

First huge problem!
The wastegate tube sits right smack in the center of the steering shaft!! Obviously meant for RHD vehicles. I assumed this would be a problem by the pictures on the auction listing but still think that they should clarify this for those that may be unaware...

Originally Posted by DailyDrivenS14

UPDATE!

Originally Posted by hungryjoseph

Hey man, any updates on the manifold and any more installed pics? I'm interesting in buying this one.

edit

did you have not have issues with master cylinder clearance? It looks like the flange is positioned close to the firewall... I know I had issues when I had the flange center mounted between cyl 3 & 4. If you had pics that'd be awsome

Just have been really busy working lately, here are a few updates.

1-Had to re-route the wastegate - DONE

2-had to shorten some of the studs that were really close to the manifold runners. DONE

3-the flange that bolts to the head didnt fit worth a crap! had to re-drill ALL of the holes to a half inch each to allow for the flange to slide down over the studs. DONE

4- going to have to fab up a shield to keep the direct heat off of the master cylinder and booster or look into a chase bays relocation setup due to the location of the turbo.

PICTURES

[DailyDrivenS14]

I will finish this thread up tomorrow evening...

[slydin240sx]

msglength

[ch1873857]

ugh.. such a waste. you are better off spending to money for a good one up front OR use the stock.

this is mine. bought from an AWESOME Zilvia member.

[Kingtal0n]

FWIW: I have seen those manifolds installed on RB26/RB25/2JZ And I have never seen one fail or crack, ever. Im sure its happened, but it's never happened around me, and I have seen at LEAST ten of them installed and running on those engines for more than five years at a time.


SR20 "cheapy" manifolds are another story; they ALL seem to fail at some point. But for whatever reason, The 6 cylinder versions seem pretty tough. And I am talking about installed with NO support, NO Flex sections, NO extra help or brackets or any kind of help whatsoever. Still running strong, over 800 horsepower single turbocharger setups on those inline 6-cylinder engines.

Like I said FWIW, of course I would instantly recommend a high quality manifold over a cheapy any day- but you cant beat the price even if it does eventually fail or need some "fixing up" at any point.

[memphis180sx]

just get the wastgate runner shortened up to the first weld that looks like it would help it out

[DailyDrivenS14]

Originally Posted by ch1873857

ugh.. such a waste. you are better off spending to money for a good one up front OR use the stock.

this is mine. bought from an AWESOME Zilvia member.

Are you fucking kidding me!? I wish i could delete this post...
Obviously you have better ability to spend money, than you do the ability to read... v

If your response or reply is "dont buy a knockoff" or "Buy a real manifold" please save it and dont clutter up the thread with pointless posts.

[DailyDrivenS14]

Originally Posted by Kingtal0n

FWIW: I have seen those manifolds installed on RB26/RB25/2JZ And I have never seen one fail or crack, ever. Im sure its happened, but it's never happened around me, and I have seen at LEAST ten of them installed and running on those engines for more than five years at a time.


SR20 "cheapy" manifolds are another story; they ALL seem to fail at some point. But for whatever reason, The 6 cylinder versions seem pretty tough. And I am talking about installed with NO support, NO Flex sections, NO extra help or brackets or any kind of help whatsoever. Still running strong, over 800 horsepower single turbocharger setups on those inline 6-cylinder engines.

Like I said FWIW, of course I would instantly recommend a high quality manifold over a cheapy any day- but you cant beat the price even if it does eventually fail or need some "fixing up" at any point.

Completely agree with what you are saying, when i get the extra money saved, ill be rocking a legit one. BUT until then I am going to put this one to the test. Its gonna have a hefty PT67 sitting on top of it for a few months while i save up I plan on leaving it unbraced until it cracks (if it cracks) and if it doesnt, great!

[rb20240sx]

Originally Posted by ch1873857

ugh.. such a waste. you are better off spending to money for a good one up front OR use the stock.

this is mine. bought from an AWESOME Zilvia member.

Damn ch1873857 is that going on you're Neo? How much did you get it for? you gotta send me a link to a build.
And to the op and to stay on track show some of the inside welds on that obx mani.

[Kingtal0n]

Originally Posted by DailyDrivenS14

Completely agree with what you are saying, when i get the extra money saved, ill be rocking a legit one. BUT until then I am going to put this one to the test. Its gonna have a hefty PT67 sitting on top of it for a few months while i save up I plan on leaving it unbraced until it cracks (if it cracks) and if it doesnt, great!

Nice! PT6776 Thats the one we used to buy by the dozen for our 2jz swaps. 800 horsepower to the wheels all day long on 26-28psi of boost with oem camshafts! I always said it was too laggy for the street, but people dont care they just want numbers. well, give them the numbers, then!

[ch1873857]

Originally Posted by rb20240sx

Damn ch1873857 is that going on you're Neo? How much did you get it for? you gotta send me a link to a build.
And to the op and to stay on track show some of the inside welds on that obx mani.

Yeah its going on the Neo. Wont talk about it anymore because the OP has sand in his vagina.
My point was simply. why spend a couple hundred bucks on a manifold you have to fix just to fit. i dont care if they last 10 years, its not worth it IMO. you wont get anymore performance out of it than a stock log. stock works just fine for most applications. i especially like the new cxracing manifold where they have runners connecting together right after they leave the head. o_O ill stay in my lane and butt out. cant believe im the only one that thinks like this anymore...

[fliprayzin240sx]

Blah, the whole get "legit manifold" arguement is bullshit. I've had a fucking Mazworx manifold crack on me and I didn't even get the benefit of a reach around because they don't have a record of my purchase from them. I was better off buying some crappy MR manifold, atleast i wouldnt feel bad spending the money on it when it cracks since you pretty much expect it to happen. Come to think of it, my $150 bottom mount MR SR manifold lasted longer than my $800 Top Mount Mazworx Manifold.

[Kingtal0n]

Originally Posted by ch1873857

Yeah its going on the Neo. Wont talk about it anymore because the OP has sand in his vagina.
My point was simply. why spend a couple hundred bucks on a manifold you have to fix just to fit. i dont care if they last 10 years, its not worth it IMO. you wont get anymore performance out of it than a stock log. stock works just fine for most applications. i especially like the new cxracing manifold where they have runners connecting together right after they leave the head. o_O ill stay in my lane and butt out. cant believe im the only one that thinks like this anymore...

Hey man, custom parts are custom fit. I wouldn't buy something that I didn't have to hammer/shape into fitting onto my engine. Otherwise, whats the point? Might as well use an OEM part if fitment is that important!

[xnissan240sx]

Originally Posted by Kingtal0n

Hey man, custom parts are custom fit. I wouldn't buy something that I didn't have to hammer/shape into fitting onto my engine. Otherwise, whats the point? Might as well use an OEM part if fitment is that important!

Are you kidding me? let me just get this straight. You think that all after-market/custom parts should have to be modified when the buyer receives the item rather then having it fitting 100% perfect. I think that is the most ridiculous thing I have herd in a while. I know I am not the only one but if i spent a grand on a manifold and i had to bash it with a hammer just to make it fit, I would be so pissed and more then likely send it back.
People go to aftermarket/custom parts because they want more power, and how is OEM going to solve that.

[ch1873857]

^ i wanna see dyno results of these cheap manifolds...

[Kingtal0n]

Originally Posted by xnissan240sx

Are you kidding me? let me just get this straight. You think that all after-market/custom parts should have to be modified when the buyer receives the item rather then having it fitting 100% perfect. I think that is the most ridiculous thing I have herd in a while. I know I am not the only one but if i spent a grand on a manifold and i had to bash it with a hammer just to make it fit, I would be so pissed and more then likely send it back.
People go to aftermarket/custom parts because they want more power, and how is OEM going to solve that.

Naw man, the more money you spend the worse it's gotta fit. Otherwise, whats the point?

[ch1873857]

he didnt catch the sarcasm i suppose haha

[b00stinbmx]

cheap ones work great for me, ive been beating the fuck outta my rb25 all year with no issues at all. im running a nozz manifold. it was like 500 on ebay, had to have the wastegate modified, its a t3 top mount. 44 v band wastegate..

im making 422whp on 1 bar and was able to put on 467 on 17 psi on a gt3582r on a bone stock internal rb25det

[DailyDrivenS14]

UPDATE!

[ch1873857]

how much time/money did that cost you?

also did you fix the clearence issue on the exhaust manifold stud???

[DailyDrivenS14]

Originally Posted by ch1873857

how much time/money did that cost you?

also did you fix the clearence issue on the exhaust manifold stud???

i literally broke out the high speed grinder threw a cutting wheel on it and went to town... i used extra bends that i cut out of the wastegate runners to route it back into the collector. All together it took me an hour and a half at the most and 0 extra dollars. (my welder isnt set up for stainless, if it were, the grinding wouldnt have been necessary and it would have been even faster)

I have not gotten to the stud issue yet, i ordered new ones because 7 of mine broke off in the head. They just showed up yesterday so this weekend i will be addressing that issue.

[ch1873857]

your welder wasnt setup for stainless? what EXACTLY was it set up for? im a certified welder on basically every metal and method of welding minus Ti so this is why the red flag was raised..

[DailyDrivenS14]

I just have a home depot lincoln MIG welder with 80/20 argon co2 (I think its it 80/20?) and regular wire in it. I don't know a whole lot about welding but normally I'm not too bad at it. Just for this it was a pain in the ass. I was under the impression that to weld stainless you had to use different gas and wire, but it seems to be pretty solid. I am open to learn anything you can tell me on this.

[ch1873857]

here are my concerns with your setup.

assuming your using a standard el-cheapo (honestly no offense) 110volt MIG welder. I am worried that you did not acheive the proper penetration to complete the weld. also the fact that you ground most of the weldment off with an angle grinder tells me that

A) there wasnt enough heat to lay the filler into the fillet. Lack of penetration to the backside of the fillet will significantly reduce the tensile strength of the weldment.

B) Porosity contaminated the weld completely leaving holes. at any time during your weld did you see almost a volcano of molten metal after your cut your arc off? this is actually oxygen being pulled through the weld from the backside of the weld. This is caused by improper sheilding gas. MIG welding Stainless require a HIGH ratio of Argon to CO2. your most likely using a 75/25 mix. Most common for carbon steel. the best mix to use is IIRC 90% Argon 2% OXYGEN not CO2. The other involves a trimix of helium argon and CO2. dammit im rusty on welding (been deployed all year) haha get it? the biggest problem with porosity is that you will deceived by the thought oh this feels sturdy. but in reality your weld is FILLED with internal cracks and voids. when paired with the extreme heat generated inside of exhaust manifold it will ultimately and surely fail.

Now im confused as to whether you are using Stainless(low carbon) wire or Carbon steel wire. Because if you are using stainless wire in a MIG machine the ONE thing to remember is to keep your hose as straight as possible. Stainless steel is MUCH stiffer than carbon steel. i stole this analogy but its like shoving a coat hanger through a garden hose. make sense? your feeder will get hung up a lot and cause ALL kind of nastiness. make sense also?

if your using carbon wire (which you may have referred to as "normal" wire???) your just plain wrong in general. but its OK. we all make those mistakes. ive made countless stainless and aluminum exhaust systems and intercooler piping. i once grabbed the wrong wire and tried welding aluminum piping together with stainless wire .. holy shit i was stumped. that was for an Audi TT quattro show car too. I was sweating bullets because the weld shop was closed at 2am haha. late night and no sleep. but hey dont feel bad.

your low voltage welder MOST likely used a short circuit method of welding where the wire will contact the steel and short circuit (like crossing battery wires) melting the wire and creating a puddle of molten metal and this repeats constantly very fast. sounds like frying eggs now, still a very effective method for thin metals. im not a fan because im a FREAK about penistration (welding instructor got me stuck on the term) and he drilled me about this every day. a pulse spay or spray method melts the wire before it hits the metal. provides more heat. more penistration. point being your abilities are VERY limited with your equipment.

heres what i would do if i were you. cut where you welded cut all the filler you put in there OUT. prep the edges completely flat. COMPLETELY even. depending on thickness make a SLIGHT bevel to increase surface area of the weld. will give you a stronger weld over all. leave a gap! not a big one. a general rule of thumb that my instructor who as welded space shuttles and the alaskan pipe line told me. always leave a gap as wide as your filler material. most of the time. its quick and easy. kind of a gee whiz thing. tack it in place. oh and make sure you clean your parts inside and out with acetone to rid of all contaminants. now prep is done almost done at this point. time to set up your purging equipment. purging or more commonly (back-gassing) introduces your sheilding gas to the back side of the weld. i wont go too in depth but it will make the back side of your weld look like the front side. Oxygen is a welds worst enemy by removing it your ensure your weld will be as strong as possible. you could have a beautiful bead on the outside but the backside will sill be porous and contaminated. you can do this by running a splitter off your regulator. best case scenario a separate bottle. shielding gas is heavier than atmosphere so use gravity to your advantage. block off your WG flange except for enough to slide a hose through. let the manifold fill with the gas THEN weld away. the gas i use with stainless is called Stargon. another Tri-mix used mostly with TIG actually MIG too but. google it. also instead of a tradition TIG cup. I alway use a gas lense for maximum purging action.

ok a lot of useless info. also please dont hold me to 100% of what i said. i dont know exactly what you did and how you did it. its also when 10 months since ive welded at all.. let wouldnt even let me weld our weapons racks here because the army didnt teach me how to weld. but im a commo guy working as a supply/ammo tech/personal security?? o_O anyway...

i would take it somewhere and have it done right. i do like the position of the whole thing. you have a good start you had the right idea but you just gotta weld it right man. im not trying to bash on you or anything. i wouldnt have taken the time to try to help you understand WHY thats wrong. i just would want to have my wastegate fall off out of nowhere. then you would be out a 300 dollar wastegate and an X dollar manifold. not worth it.

hope i helped. good luck.

[Boostin240sx]

Been running the godspeed manifold on a DD since April with no issues. 1 bar and over 400 hp is no problem. It left a lot less room for a 3" downpipe than I wanted but custom fabbing a downpipe with a flex pipe in it only took 0.5 a day with beer breaks.

[DailyDrivenS14]

I'm sold will have to read this again to get the full effect lol. I just handed the manifold off to a buddy with the right equipment and knowledge. He is going to basically start back from scratch as you said. I would rather him do it right now than have to tear it all back down later. You were correct about the 110. I will post a little more on this later when I get off work.

Originally Posted by ch1873857

here are my concerns with your setup.

assuming your using a standard el-cheapo (honestly no offense) 110volt MIG welder. I am worried that you did not acheive the proper penetration to complete the weld. also the fact that you ground most of the weldment off with an angle grinder tells me that

A) there wasnt enough heat to lay the filler into the fillet. Lack of penetration to the backside of the fillet will significantly reduce the tensile strength of the weldment.

B) Porosity contaminated the weld completely leaving holes. at any time during your weld did you see almost a volcano of molten metal after your cut your arc off? this is actually oxygen being pulled through the weld from the backside of the weld. This is caused by improper sheilding gas. MIG welding Stainless require a HIGH ratio of Argon to CO2. your most likely using a 75/25 mix. Most common for carbon steel. the best mix to use is IIRC 90% Argon 2% OXYGEN not CO2. The other involves a trimix of helium argon and CO2. dammit im rusty on welding (been deployed all year) haha get it? the biggest problem with porosity is that you will deceived by the thought oh this feels sturdy. but in reality your weld is FILLED with internal cracks and voids. when paired with the extreme heat generated inside of exhaust manifold it will ultimately and surely fail.

Now im confused as to whether you are using Stainless(low carbon) wire or Carbon steel wire. Because if you are using stainless wire in a MIG machine the ONE thing to remember is to keep your hose as straight as possible. Stainless steel is MUCH stiffer than carbon steel. i stole this analogy but its like shoving a coat hanger through a garden hose. make sense? your feeder will get hung up a lot and cause ALL kind of nastiness. make sense also?

if your using carbon wire (which you may have referred to as "normal" wire???) your just plain wrong in general. but its OK. we all make those mistakes. ive made countless stainless and aluminum exhaust systems and intercooler piping. i once grabbed the wrong wire and tried welding aluminum piping together with stainless wire .. holy shit i was stumped. that was for an Audi TT quattro show car too. I was sweating bullets because the weld shop was closed at 2am haha. late night and no sleep. but hey dont feel bad.

your low voltage welder MOST likely used a short circuit method of welding where the wire will contact the steel and short circuit (like crossing battery wires) melting the wire and creating a puddle of molten metal and this repeats constantly very fast. sounds like frying eggs now, still a very effective method for thin metals. im not a fan because im a FREAK about penistration (welding instructor got me stuck on the term) and he drilled me about this every day. a pulse spay or spray method melts the wire before it hits the metal. provides more heat. more penistration. point being your abilities are VERY limited with your equipment.

heres what i would do if i were you. cut where you welded cut all the filler you put in there OUT. prep the edges completely flat. COMPLETELY even. depending on thickness make a SLIGHT bevel to increase surface area of the weld. will give you a stronger weld over all. leave a gap! not a big one. a general rule of thumb that my instructor who as welded space shuttles and the alaskan pipe line told me. always leave a gap as wide as your filler material. most of the time. its quick and easy. kind of a gee whiz thing. tack it in place. oh and make sure you clean your parts inside and out with acetone to rid of all contaminants. now prep is done almost done at this point. time to set up your purging equipment. purging or more commonly (back-gassing) introduces your sheilding gas to the back side of the weld. i wont go too in depth but it will make the back side of your weld look like the front side. Oxygen is a welds worst enemy by removing it your ensure your weld will be as strong as possible. you could have a beautiful bead on the outside but the backside will sill be porous and contaminated. you can do this by running a splitter off your regulator. best case scenario a separate bottle. shielding gas is heavier than atmosphere so use gravity to your advantage. block off your WG flange except for enough to slide a hose through. let the manifold fill with the gas THEN weld away. the gas i use with stainless is called Stargon. another Tri-mix used mostly with TIG actually MIG too but. google it. also instead of a tradition TIG cup. I alway use a gas lense for maximum purging action.

ok a lot of useless info. also please dont hold me to 100% of what i said. i dont know exactly what you did and how you did it. its also when 10 months since ive welded at all.. let wouldnt even let me weld our weapons racks here because the army didnt teach me how to weld. but im a commo guy working as a supply/ammo tech/personal security?? o_O anyway...

i would take it somewhere and have it done right. i do like the position of the whole thing. you have a good start you had the right idea but you just gotta weld it right man. im not trying to bash on you or anything. i wouldnt have taken the time to try to help you understand WHY thats wrong. i just would want to have my wastegate fall off out of nowhere. then you would be out a 300 dollar wastegate and an X dollar manifold. not worth it.

hope i helped. good luck.

[fliprayzin240sx]

So what made you decide to run the wastegate towards the front of the manifold instead of the back?

[Tantwoforty]

I hope this thread dosent get over run with the standard knock off debate..

anyway, a friend of mine is using a OBX manifold on his rb25, hes been running it for about a year now, he tracks it every other weekend and so far he hasn't had any issues with cracking or anything..
Just make sure you use a good flex in the down pipe and there's no unnecessary stress on the manifold.. if your really worried you can weld some support bars.. im really suprized you didn't do that while you had the wastegate relocated.

Ive seen $900 manifolds crack more than cheap ass ones.
However I've seen way way more fitment issues with cheap ass manifolds.

I have a Meagan on my KA-T and its been good so far, but time will tell.

[godrifttoday]

Get what u can afford at the moment

[NoPistons!]

I'll skim over everyones posts but yours (OP).

When you do weld stainless, iirc, you'll want to use at least 90 percent argon if not 100 percent. If you want to backpurge you can but you dont really have to, especially if you are going to get a replacement IF this one shit's the bed to the point where you can no longer repair it or whatever. You are SUPPOSED to use stainless filler but fuck it. Use what you've got. Ideally, i would have tig'd that up and used the post flow to keep the weld cleaner but a wastgate tube and gate doesn't exactly weigh all that much.

I've seen setups where people have welded mild steel weld el's to oem cast flanges. I've seen vg30e people weld their crossover pipes with flux core... I've seen people weld flux core to stainless (flange to stock manifold) on hondas. REALLY GHETTO SHIT but you know what? It held up for the most part, they made boost and were really happy getting results on peasant funds with ugly and less than ideal workmanship.

Look forwards to seeing how well this holds up. When you had the wastegate tube cut you should have snapped a picture of the thickness for us. I'm all for being a frugal fucker when it comes to building cars and making your own stuff whenever possible is awesome.



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