# Ported Chinafold (JBS) Vs. Ported Stock Exhaust Manifold



## TT Tom TT (Oct 9, 2015)

I'm hoping some of you are familiar with the Chinafold that is a clone of the JBS cast manifold that was produced for the 1.8T. This manifold was ultimately a failure in stock form requiring significant porting and machining to flow well as it was intended to - in its unported form it caused misfires on two of the cylinders (not sure which).

My question is, looking at the manifolds side-by-side I don't see the benefit to porting the Chinafold over porting just a stock manifold. The reason for me saying this is the runner design on both manifolds looks very similar to me, the only difference being is I notice that runners 2 and 3 merge together on the stock unit (possibly causing restriction) whereas the JBS manifold has runners 1 and 2 merging (possibly causing restriction although it looks somewhat LESS restrictive).

A side-by-side comparison can be seen here:


I am aware that Madmax has ported the stock manifold as I read his thread over on Vortex (Page 6):

http://forums.vwvortex.com/showthread.php?5788526-Chronicles-of-a-track-TT/page6

Stock manifold before porting (credit - Madmax):


Stock manifold after porting (credit - Madmax):


Chinafold (JBS) manifold before porting (credit - AtomicEd):


Chinafold (JBS) manifold after porting (credit - AtomicEd):


Does anyone have any information on the benefit of porting the Chinafold (JBS clone) over the stock exhaust manifold?


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## Nem (Feb 14, 2005)

Not sure, but I thought the pathways are slightly better on the chinafold over the oem one, and possibly a larger bore?

My part ported chinafold is for sale anyway if anyone was interested...


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## TT Tom TT (Oct 9, 2015)

Nem said:


> Not sure, but I thought the pathways are slightly better on the chinafold over the oem one, and possibly a larger bore?
> 
> My part ported chinafold is for sale anyway if anyone was interested...


Is it in the for sale section Nem? Do you have pictures? How come you decided to bin it off and go for the Relentless V4?


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## Nem (Feb 14, 2005)

It's not but it can be 

I was still getting misfires on cylinder two with the chinafold fitted when hitting 6000rpm in any gear and it's 100% down to the manifold. It was ported as best we could do with it but obviously not enough to solve the issue. With how big a job to remove and refit basically porting it blindly I gave up and bought a Relentless V4 which went straight on, had no misfire issues and has been amazing.

Someone who wants to play with it and port it to get it to work would be fine with it but I just didn't have the time to do it. Was only on the car about 2 months I think in all.


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## 3TT3 (Aug 30, 2014)

I dont know 
but.

The standard one seems to have 1,4 and 2,3 respectively linked almost to turbo entrance.
Firing order is 1,3,4,2 ? 

bang down tube1,bang down tube 2,bang down tube 1,bang down tube 2 etc.

The other one looks like it has some kind of triple inlet even after porting and adjacent firing order cylinders mixing pre turbo.

Thats my "ghostbusters" theory :lol:


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## Madmax199 (Jun 14, 2015)

Tom, there are much greater gains attainable from porting the JBS-clone (Chinafold). First is runner diameter, the Chinafold has more consistent runner diameter while the stock ones tapers considerably when it get closer to the collector. The collector shroud on the Chinafold has a much bigger footprint and is as robust as tank. This means that you can get more deliberate with your porting without running into thin walls that are prone to cracking. The Chinafold is made of better materials and has a more robust construction, therefore will last longer with abuse.

With that said, of you can find a good stock core, it could be ported to offer 90% of the flow and performance of a Chinafold. Most stock manifolds have micro cracks of various severity, therefore finding a good suitable core for porting can be a challenge. The work involved is much more demanding to get the stock unit ported properly. You have create some tool to port the runners all the way through, and finding a solution for the curved port requires some ingenuity. I did mine with a combination of flex joints on various grit hone balls. Then after that it's just about opening and smoothing the collector.

Target collector porting

















Ported collector ID vs a T25 flange

















Tool I made to port the runners:

The whole contraption (1" bit)









The highly flexible primary flex point









The stiffer secondary flex point









The bore/hone bit that gets tacked into the flex shaft









Finished work after porting, cryo treating and ceramic coating:

*Top*


















*Ports and runners opened all the way to the collector (40 mm at the flange)*


































*Bottom and collector*


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## 3TT3 (Aug 30, 2014)

We can see, fairly easily thx to the pics.. that standard manifold,even with porting is almost a 1/4 and 2/3 input .Is that significant?

Ok so what about ghostbusters  1,4 and 2,3 linked pulse? kinda twin port turbo and the bam exhaust manifold of some semi exotic alloy compared to prev 1.8T exhaust manifolds?
Im just wondering is there any relevance , ? or not


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## Gonzalo1495 (Oct 13, 2014)

Does anyone have active links to the chinafold? I spent a good while searching and nothing.


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## Nem (Feb 14, 2005)

http://www.ebay.co.uk/ulk/itm/400347322156


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