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

[ch1873857]

wow

msglnth

[Zacho]

I modified one of they ebay manifolds. I road raced with this setup this season. It held up but I am building my own manifold over this winter. Simply put - the knock offs are built with too thin of material, horrid collectors and too little filler metal on most joints. The style I have was almost impossible to avoid mad boost creep above 7k rpm before I modified it.

[DailyDrivenS14]

Originally Posted by fliprayzin240sx

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

since the flange that the turbo mounts on is so close to the rear of the manifold, i ran it forward. helped with clearance for the downpipe BUT i dont want to run a screamer so i will have a pretty long tube to run back into the downpipe from the wastegate.

[DailyDrivenS14]

Originally Posted by 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.



If people can't abide by your thread rules, pm a mod or two and have their post deleted.

I might have a picture that i snapped of the thickness. ill check and if i do ill add that for sure. It is a pretty important aspect of the manifold

[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

[DailyDrivenS14]

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

[SlideOrDie831]

even though all the debates about MR coils. their manifolds actually aren't bad. friend used an MR mani on his S14 Sr for two years with no cracks. another friend had a 5zigen mani that cracked twice and he kept on repairing it.

[hungryjoseph]

Thanks for the update. that manifold will definately not work for bigger turbos. does the relocation setup change the location of the bmc or does it just reposition your lines? perhaps you could get your hands on a RHD bmc? either way clearance looks tight.

[DailyDrivenS14]

it eliminates the whole booster... its a pretty clean setup, i am just worried about the pedal feel. havent decided on what im gonna do for sure yet. right hand drive bmc is a good idea. ill do some research on that to see if it would work. yeah clearance is too tight with this mani, i would suggest the the etd motors one if you have the time and patience to see if it will work. it positions the turbo ALOT more forward! only downside to it is that it has a t3 flange. i called them and asked if it was available with a t4 and they said no. so i guess the one picture is not what they are selling

[hungryjoseph]

yeah I've been looking at that manifold for a while. It's made by cx racing. I actually called CX-racing about it back in the summer and had an interesting conversation with the tech on the phone... he pretty much told me he thought that design was crap lol. at least he was honest? but yeah I don't like how it directs the flow. at the same time it does give awsome positioning. only reason I haven't bought it is because I don't like how the flange is angled. I'd like something tha'ts straight and perpendicular to the head if you get what I mean. I've also been considering just throwing down that 400$ and getting that harbor freight tig welder and doing it myself... anyways keep updating whenever you can man, looks good

[ch1873857]

Originally Posted by hungryjoseph

I've also been considering just throwing down that 400$ and getting that harbor freight tig welder and doing it myself...

gotta be kidding me..............

[Coolwhip]

Originally Posted by DailyDrivenS14

That merge collector

[ch1873857]

runners 5 and 6 are my favorite. im pretty sure that stock is the way to go unless you save the money up for a raw brokerage manifold.. it really is worth the money.

[DailyDrivenS14]

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...

Nobody said you are the only one who thinks like this anymore. My original post says I plan on going with a legit manifold later down the road. the whole point of this thread is to compare and let people know who can't afford a real manifold what its likeand how much work it is gonna take to use a knockoff. you have not contributed anything useful to this thread. you have successfully posted about 3 or 4 useless comments that mean nothing and posted 1 picture of your nice shiny manifold. congratulations on your manifold, I'm sure everyone is envious of you, now stay out of the thread if you don't have anything useful to contribute.

[DailyDrivenS14]

Originally Posted by Coolwhip

That merge collector

Strongly agree! its pretty horrible lol

[DailyDrivenS14]

Originally Posted by ch1873857

runners 5 and 6 are my favorite. im pretty sure that stock is the way to go unless you save the money up for a raw brokerage manifold.. it really is worth the money.

Bumping 2000 dollars. That is a lot of saving...

[supersayianjim]

bumppers, anyone try the new cx racing?

[dreaMervaj]

Originally Posted by supersayianjim

bumppers, anyone try the new cx racing?

No responses? I'm also interested in this question.

[jumpman2334]

they have made some recent changes to the 2jzGE turbo manis and the IS300 guys seem to have good luck with them with their NA-T stuff. They will go cheap on the manifold (cx) and then save their pennies for the turbo, wg, standalone, etc. I do not recall seeing any cracked or broken GE manis.


I will say though, the $424 dollar one on their site looks a little rough, im going to assume that is an older style mani..?


https://www.cxracing.com/products-by...0-25det?page=4

[s13silvia123]

Originally Posted by 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.



If people can't abide by your thread rules, pm a mod or two and have their post deleted.

he MIG weld it. 10% co2 and 90%argon doesnt work well with SS. so he'll have to switch it to a tri-mixed of c02, helium and argon

[RB25GUY]

^ I have the newer style manifold as a backup and its really stout for what it is (comparing to the older manifold) only thing i had to do was have the flange planed it was uneven and would've just ate a few gaskets. My buddy made 600 whp with his no issues other than the flange. Gonna mod flange to accept Greddy 3 bolt flange since that's the route i'm going but have my buddy revising it, cutting the runners and make it a mid mount setup.

[dreaMervaj]

Originally Posted by RB25GUY

^ I have the newer style manifold as a backup and its really stout for what it is (comparing to the older manifold) only thing i had to do was have the flange planed it was uneven and would've just ate a few gaskets. My buddy made 600 whp with his no issues other than the flange. Gonna mod flange to accept Greddy 3 bolt flange since that's the route i'm going but have my buddy revising it, cutting the runners and make it a mid mount setup.

Anyone else tried the new CXRacing manifold? I want to retain ac. Will the manifold clear the ac compressor?

[180sxLove]

Originally Posted by dreaMervaj

Anyone else tried the new CXRacing manifold? I want to retain ac. Will the manifold clear the ac compressor?

the new style CX Racing mani clears the ac compressor and their downpipe clears the steering shaft as well

[dreaMervaj]

Originally Posted by 180sxLove

the new style CX Racing mani clears the ac compressor and their downpipe clears the steering shaft as well

Are you using this manifold? If so what turbo did you pair wuth the manifold? I'm thinking hx40..

[feito]

I bought my cx manifold about 3-4 years ago, the $500 one, not sure if that's the newest style. Running strong for over 2 years. Gt3076r, custom downpipe. Im running a/c in my car, manifold clears it just fine. will try to get pictures later.

[Kingtal0n]

Same manifold on two different setups can crack or not crack due to stress/support.

temperature causes metal to expand, and when something tries to expand and cannot, a force is developed internally.
Add to that a shear force from weight/gravity of whatever is hanging on it.
Add to that the force of bending, to the uniform axial distribution of normal forces,

Many forces at work. All accountable for by engineers who design these materials and know how much stress the metal can take before it yields.

So whats the problem then?

The setup itself, the weight and location of what is hanging off the manifold, is different on every car. Sometimes a downpipe has no support and the whole weight hangs on the manifold. Sometimes the engine twists and this causes stress to form where the manifold/turbo/downpipe resists the motion. bouncing/jostling in unrestrained setups also causes bending/torsion/normal forces to form instantly then disappear.

The solution is a realization that the cracking of a manifold goes beyond it's construction, and into/complies with the rest of the setup which hangs on it. You need to account for engine twisting, downpipe bouncing/jostling, the weight of everything, the temperature of everything involved, as it all comes together to result with stress.

[dreaMervaj]

Originally Posted by feito

I bought my cx manifold about 3-4 years ago, the $500 one, not sure if that's the newest style. Running strong for over 2 years. Gt3076r, custom downpipe. Im running a/c in my car, manifold clears it just fine. will try to get pictures later.

Would appreciate it. You're running ac? Did you run custom lines?

[dreaMervaj]

Originally Posted by Kingtal0n

Same manifold on two different setups can crack or not crack due to stress/support.

temperature causes metal to expand, and when something tries to expand and cannot, a force is developed internally.
Add to that a shear force from weight/gravity of whatever is hanging on it.
Add to that the force of bending, to the uniform axial distribution of normal forces,

Many forces at work. All accountable for by engineers who design these materials and know how much stress the metal can take before it yields.

So whats the problem then?

The setup itself, the weight and location of what is hanging off the manifold, is different on every car. Sometimes a downpipe has no support and the whole weight hangs on the manifold. Sometimes the engine twists and this causes stress to form where the manifold/turbo/downpipe resists the motion. bouncing/jostling in unrestrained setups also causes bending/torsion/normal forces to form instantly then disappear.

The solution is a realization that the cracking of a manifold goes beyond it's construction, and into/complies with the rest of the setup which hangs on it. You need to account for engine twisting, downpipe bouncing/jostling, the weight of everything, the temperature of everything involved, as it all comes together to result with stress.

A Holset sitting on top won't be so nice on a manifold I would guess....