GTR Forum banner

1 - 20 of 28 Posts

·
Registered
Joined
·
752 Posts
Discussion Starter #1
Hi, has anyone succesfully used the exhaust manifolds offered on ebay? ie that dont crack in little time?
 

·
Registered
Joined
·
554 Posts
Mmm don't know if I wanna answer for risk of flaming lol .........oh well lol I have a xs power divided with a GT40 on it and have run 600 hp on ot for around 3000 miles and a few track days with no probs, I did give it a bit of a lick up before fitting and added extra down pipe support to help with weight handling ..... Let flaming commence :)
 

·
Registered
Joined
·
2,304 Posts
I think the Chinese manifold quality has got a lot better, I brought one and it seemed strong was welded on inside of the collectors too. I ended up sending back as one of the runners didn't line up to the head flange but if it would have I would have kept and used. I think they are all the same so I would buy the cheapest one
 

·
Registered
Joined
·
3,147 Posts
The thickness of material is very thin, they can crack at any time you just cannot tell. They don't even stress or flow test those manifolds as they are so cheap to make! Go for a custom manifold which will be a million times better.
 

·
Registered
Joined
·
2,304 Posts
The thickness of material is very thin, they can crack at any time you just cannot tell. They don't even stress or flow test those manifolds as they are so cheap to make! Go for a custom manifold which will be a million times better.
What you mean by stress? They are a exact design of Greddy manifolds so Greddy should have flow tested there design? Most custom manifolds have no real flow testing either except good ones like amt,6 boost, full-race etc. as for material thickness they are thin but so are the Greddy/hks manifolds if it was me I would fit a brace with rosé joints so it still has movement but it takes the weight as by the time the turbo is on it the down pipe it's quite a lot of weight
 

·
Registered
Joined
·
494 Posts
To take the stress out the material they heat it up in a special oven then let it cool afterwards . Then machine all flanges as they will have warped . After that it will last years
 

·
Registered
Joined
·
3,147 Posts
What you mean by stress? They are a exact design of Greddy manifolds so Greddy should have flow tested there design? Most custom manifolds have no real flow testing either except good ones like amt,6 boost, full-race etc. as for material thickness they are thin but so are the Greddy/hks manifolds if it was me I would fit a brace with rosé joints so it still has movement but it takes the weight as by the time the turbo is on it the down pipe it's quite a lot of weight
That's what I mean, when they just copy a manifold design and use cheaper material and welding techniques, they don't test them using computer softwares etc.. Full-Race products are just amazing.

The ebay manifolds usually tend to crack on the welds, if you're on a budget then I would still purchase one and add additional bracing to it like you've suggested but you just cannot tell how or when it will let go.
 

·
Registered
Joined
·
494 Posts
Ive run the my xspower manifold for 6 years now without cracking and its been modified to take a 60mm wastegate . Thats on my gtst
 

·
Registered
Joined
·
2,304 Posts
That's what I mean, when they just copy a manifold design and use cheaper material and welding techniques, they don't test them using computer softwares etc.. Full-Race products are just amazing.

The ebay manifolds usually tend to crack on the welds, if you're on a budget then I would still purchase one and add additional bracing to it like you've suggested but you just cannot tell how or when it will let go.


To be fair the Chinese ones can't be any worse than the Greddy ones I can't se how they can. I had a full race manifold on my honda k20 and it was a stunning manifold. If it was me I would buy a true twin scroll. But as others have said they have had good results from xs power manifolds so that maybe worth a try
 

·
Registered
Joined
·
752 Posts
Discussion Starter #12
how thick is too thin or ok? I just saw a obx with 1.5mm wall, are the other custom manufacturers using 2mm?
I think about the heat warping as the main issue, but I guess you could heat up the manifold as evenly as posible and check for warpage and correct it.
About the turbo's weight you could use some support bracing to the head...
 

·
Registered
Joined
·
2,304 Posts
Hks and Greddy are around 1.5 full-race use 3.5 mm I beleive they use schedule 40 to be safe schedule 10 would be fine what I beleive is 3 mm. Warming the manifold up will not do anything as the manifolds allways get hotter around the collector. I personally think all the obx , xs are all the same. With the bracing I would make something that comes off the rocker cover and bolts to the actual turbo and have it hovering above the manifold so it's not pulling the manifold up just holding weight
 

·
Registered
Joined
·
3,576 Posts
To take the stress out the material they heat it up in a special oven then let it cool afterwards . Then machine all flanges as they will have warped . After that it will last years

it absolutely will not, I have had my hks manifold faced twice and it still warped again and leaked, so I have now stress relieved it on the flange face in 3 positions and so far its not blowing at all.


my hks also cracked and had to be welded all around the collector, I welded it up proper it wont break again, but the mounting face will warp and needs a little room to move then warping isn't a problem.

bearing in mind my manifold was so warped the tension on the last manifold stud was so much it snapped it in the head !
 

·
Registered
Joined
·
752 Posts
Discussion Starter #15
do you guys think the plate that faces the head should have some thin cuts in order to prevent problems with that warping?
 

·
Registered
Joined
·
3,576 Posts
do you guys think the plate that faces the head should have some thin cuts in order to prevent problems with that warping?

lol that's what ive just said ive done above.

I put 2 slots in it between 2 and 3 and between 4 and 5, not right through though just about half way.
 

·
Registered
Joined
·
752 Posts
Discussion Starter #17
lol that's what ive just said ive done above.

I put 2 slots in it between 2 and 3 and between 4 and 5, not right through though just about half way.
oh ok i didnt quite get it, so the cut doesnt have to be all the way... are you happy with the single turbo setup? I just finished tuning a megasquirt3x ecu for a 2jz and i loved how the medium sized single sounded, turbine sound with the typical "shu shu shu shu" shuffle which we know is not good for the turbo but hell it sounds cool haha
 

·
Registered
Joined
·
2,304 Posts
lol that's what ive just said ive done above.

I put 2 slots in it between 2 and 3 and between 4 and 5, not right through though just about half way.

Did you tig or mig weld it? The only problem with putting slots through the flange is if the stress is pulling the flange back and you cut it the flange will be weak and bend even further. Why don't you buy a 15 mm flange and weld it to your flange so you have lots of strength ?
 

·
Registered
Joined
·
3,576 Posts
Did you tig or mig weld it? The only problem with putting slots through the flange is if the stress is pulling the flange back and you cut it the flange will be weak and bend even further. Why don't you buy a 15 mm flange and weld it to your flange so you have lots of strength ?

im not cutting the flange of mate when what ive done has worked, its pointless.

the mounting flange was so warped when cold when it was bolted up it was putting far to much stress on the end bolt to pull it in and that's what broke the stud, it pulls up easy now flush to the head with a lot less stress on the studs.

I put the manifold on my mill bed and tried to clamp it down at both ends with heavy duty g clamps and I physically couldn't clamp it down, after cutting the 2 slots in the face about 7mm deep I could comfortably clamp it down ;)

I mig welded all around the collector with my 1mm wire welder, I weld 30mm thick steel with that welder on our much shifting equipment. it hasn't cracked yet at all.
 

·
Registered
Joined
·
2,304 Posts
im not cutting the flange of mate when what ive done has worked, its pointless.

the mounting flange was so warped when cold when it was bolted up it was putting far to much stress on the end bolt to pull it in and that's what broke the stud, it pulls up easy now flush to the head with a lot less stress on the studs.

I put the manifold on my mill bed and tried to clamp it down at both ends with heavy duty g clamps and I physically couldn't clamp it down, after cutting the 2 slots in the face about 7mm deep I could comfortably clamp it down ;)

I mig welded all around the collector with my 1mm wire welder, I weld 30mm thick steel with that welder on our much shifting equipment. it hasn't cracked yet at all.

Good to hear mate, all I ment was if you have any more problem welding a 15mm flange on top of your flange could be a option
 
1 - 20 of 28 Posts
Top