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I know heaps of ppl say china manifolds crack n shit, but alot of people say they are fine.

From what i have gathered, a majority of those with china manifolds that have cracked were wraped in heat wrap...

ii currently have hks2535 turbo with gktech dump/front but im suffering from a bit of lag and spiking problems (due to running boost on actuator).

anywho i decided its time to go pfc + gate but i was just wondering if i should just keep the standard manifold - which i heard its very hard to weld a gate on it

or

take the risk and get a china manifold.

if both options are crappy how much for a very decent china manifold or a jap one?

thankyou kindly

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im running a china manifold, modified tho, making 800hp. no cracks as yet, was a tad hard to fit as the stud holes werent perfectly aligned... had to weld a t5 flange on it for the gt45 to fit.

to weld a stock cast manifold is not at all hard, what IS HARD is welding it with a crappy welder. if youv got the good gear youl get good results.

my2.5 cents lol

catcha

dan.

thanks dan

and yeah also i heard that some china manifolds have metal shavings IN the pipes which have to be cleaned up before they are fitted otherwise heat + metal shavings = going into ur turbo :S

which brand china manifold did u go for?

well actually i still have the stock dump + front i have yet to install the gk tech stuff... i just wanted to paint a picture as to what will be on the car when it comes time to the gate...

ah icic

So will you be keeping with the 2535?

A proper dump setup will do WONDERS for the setup you have, im surprised its ridiculously bad with a restrictive dump like the good ole RB20 one :domokun:

I have had a chinese low mount manifold crack...Then I had a custom fab lowmount steel manifold crack..I drew the conclusion that any low mount pipe manifold for the RB25 is likely to crack...

Reasons why:

The RB25 lowmount manifold is long and thin. The pipes run along the manifold and of course expand with heat. The flange also gets hot but not nearly as hot as the pipes...therefore pipes will try and expand a lot more than flange..they run in same axis as the flange so they develop a shit load of stress because that have nowhere to go...high stress in steel means crack...especially if is goes through hundreds of cold hot cold cycles...

Any high mount manifold is a completely different story...The pipes run out from the flange...When they get longer due to thermal expansion they are not constrained by the flange nearly as much...so not nearly as much stress and less chance of cracking...

hope this makes sense

Ok, so forget welding onto the stock manifold or a china one, the factory one has a good heatshield and you wont get hassled over it too.

What about making a turbo spacer big enough to fit a small external to it... ? Positioned correctly you could hang it underneath and blend it back into exhaust with a small flex pipe and flange.. ? I think it was Japanese Motorsport, or whoever HPI were in cohoots with at the time who did this with an rb20 or something ?!

Or its also possible to weld onto the turbine housing... just make sure you get a specialist to do it. .... I am going to go the extension if i continue to have probs with the new larger hiflow as it already had a 10mm spacer to get comp cover to clear manifold ... also just need to extend turbine heat shield cover outwards also.

Ok, so forget welding onto the stock manifold or a china one, the factory one has a good heatshield and you wont get hassled over it too.

What about making a turbo spacer big enough to fit a small external to it... ? Positioned correctly you could hang it underneath and blend it back into exhaust with a small flex pipe and flange.. ? I think it was Japanese Motorsport, or whoever HPI were in cohoots with at the time who did this with an rb20 or something ?!

Or its also possible to weld onto the turbine housing... just make sure you get a specialist to do it. .... I am going to go the extension if i continue to have probs with the new larger hiflow as it already had a 10mm spacer to get comp cover to clear manifold ... also just need to extend turbine heat shield cover outwards also.

You could weld onto the factory manifold with success but you would need to get it done by someone who knows what they are doing...They need to bring the manifold up to a certain temp in a kiln and cool it properly after welding...you average exhaust workshop would have no idea..if they knew their stuff they wouldn't attempt...you need a workshop who is pressure welding certified. If it is done properly though risk cracking is very low...

Dont waste your money with an ex gate or aftermarket manifold on the setup you are running, its just not worth it. Your turbo has been shown to produce exceptionally solid results in low mount internal gate, thats how HKS designed it. So basically check your other options first.

Firstly as nismoid said get rid of your stock dump pipe, a nice bellmouth 3" should do the job well. Dont muck around with a split dump/front pipe, boost controll issues seem to occur (sometimes) with this design. The design listed below is good, shop around on price though.

http://www.justjap.com/parts_ndumps.htm

(X-Force Dump & Engine Pipe - RB20 / RB25, Price: $330, 3 inch Stainless Steel - Suit Skyline R32/R33 GTS-T)

Secondly get some forn of boost control. Try the $22 turbotech manual one, cheap, proven, just do it.

Finally if that still does not fix your problems check the health of your actuator, borrow one or buy one from a wrecker. This could also be causing your problems, not opening or closing properly could be causing the lag and the spike.

Good luck

my mate has a rb20det with a std manifold. He has a huge fck off hks turbo and between the turbo n manifold flange is a external gate adaptor... ill try get pics.. Basically its all bolts on!

ah icic

So will you be keeping with the 2535?

A proper dump setup will do WONDERS for the setup you have, im surprised its ridiculously bad with a restrictive dump like the good ole RB20 one :P

yep im keeping the 2535 for now only done 7500km on it..

i guess before i do anything about this gate thing i should just slap on the dump/front pipe n see what happens..

Dont waste your money with an ex gate or aftermarket manifold on the setup you are running, its just not worth it.

Firstly as nismoid said get rid of your stock dump pipe, a nice bellmouth 3" should do the job well. Dont muck around with a split dump/front pipe, boost controll issues seem to occur (sometimes) with this design. The design listed below is good, shop around on price though.

http://www.justjap.com/parts_ndumps.htm

(X-Force Dump & Engine Pipe - RB20 / RB25, Price: $330, 3 inch Stainless Steel - Suit Skyline R32/R33 GTS-T)

Secondly get some forn of boost control. Try the $22 turbotech manual one, cheap, proven, just do it.

Finally if that still does not fix your problems check the health of your actuator, borrow one or buy one from a wrecker. This could also be causing your problems, not opening or closing properly could be causing the lag and the spike.

Good luck

and then ill put on this turbotech boost tap...

and check my actuator

if i still got problems time for gate lol. the sound will compensate for lag/overboosting :thumbsup:

but nah ill do them 3 things first i guess before considering gate..

dont get me wrong, the lag isnt THAT bad, but just feels like theres room for improvement..

EmreA-Dyno03-03-2007.jpg

when i say lag i dont mean megga lag, im talking it starts boosting at 3100 n hits full at 4 to 4.5k

I've found that, on my RB20, if I unplug the boost controller and run wastegate boost, the turbo is incredibly unresponsive. It takes just as long, if not longer, to hit 13 psi as it does to hit 16 psi with the boost controller on.

I never knew a good electronic boost controller would make lag so much more managable. Maybe try that instead of a bleeder valve? I ran one of those on the stock turbo and it didnt do anything but make lag worse.

Good luck

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