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Sup. Just like my cat thread, I need some advice.

I was wondering if you guys have had much experience with the HPI exhaust products, specifically the bellmouth dump pipes for the rb26.

After a few quality probs with some exhaust products I purchased, and some info I've found on here re: split dumps - I've decided to go back to stock manifolds, with bellmouth dumps.

I've been told by JJ's that these dumps are very high quality - and I'm told they are manufactured in Japan.

Thanks in advance for any advice. I'm sure a few people must have these fitted, were the welds good? Decent thickness? Noise levels?

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Just to complete my thread. I received these ones today from JJ's. The welds are practically immaculate. There is no excess weld, dags, or loose steel in these. Compared to the .. other product, these are mint. Cost 900 odd (from a trusted company), overnight delivery, thick steel. The only gripe I have is they don't have provisions to mount the old shrouds, but that's a small niggle about a very good product.

Will be fitting them with new -5's this weekend. Might come back once more in a few months to add whether they've lasted or not (which I think they will :D)

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  • 3 weeks later...

the current hpi ones are definately better than the current tomai ones.

hpi is a fantastic brand, a lil exxy but the quality that i have seen first hand is top notch

the x force are good too though a bit cheaper too

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I've been researching a fair bit regarding replacement dump pipes for my GTR. It seems as though the single bell units offer better performance gains making them a worthwhile upgrade than the dual channel variants.

I have noticed that these enlarged single dumps that are say, a foot in length cost upwards of $860 for a pair.... I know they are stainless but that is a fair bit in comparison to some of the other split dumps that exist.

So i guess what I'm asking is, are there any similar brands offering bell dumps for say $600??

Thanks

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Don't bother with the split designs (HKS and every person and their dog who has copied this design like CES, XForce etc have done, and just about every Chinese knockoff, autobahn888 etc), the split is just too short to be worthwhile. Also bear in mind at the bare minimum, the rear turbo (or front if I've got it backwards) has to be removed to fit new dumps, unless you are making over 350kw I would stick to stockers.

If you have your heart set on bellmouth dumps, wait abit for the australia dollar <-> japanese yen to get better and you could import a pair (HPI, Tomei etc) for just alittle over $600

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Thanks lance, i gathered that would be the case. I'm looking at upgrading turbo's so i considered looking at doing the dumps aswell. Really curious as to why other manufacturers (locals) haven't had a go at putting together a decent bell dump.

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I am pretty sure the HPI dumps are quality items. I was trying to bid for some on yahoo auctions but they just got to expensive.

You get get some tomei ones these days for around $700-$800.

I ended buying some 2nd hand ces race pipes. They are a split pipe design but they are similar to the trust front pipe system, not just short dumps.

Anyway let us know how you go with the -5's. I have a pair of these also waiting to go on.

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I have noticed that these enlarged single dumps that are say, a foot in length cost upwards of $860 for a pair.... I know they are stainless but that is a fair bit in comparison to some of the other split dumps that exist.

So i guess what I'm asking is, are there any similar brands offering bell dumps for say $600??

Thanks

One of the reasons the split dumps are cheaper is because when you look at them, the pipes are the same diameter from one end to the other. This is a simple case of bending the pipes to the right angles, and welding away. The bell mouth adds complexity to manufacturing, which adds to the cost. You aren't getting "ripped off" paying extra for the bell mouths since they cost more to manufacture.

From what I've read, the split dumps will give you boost creep on upgraded turbos. On a side note with the splits they usually come with a "divider" that sits in the turbo's exhaust housing to split the gasses. Well my -5's have sort of a divider in them already, and it's got a vein cut in it (I assume for better backpressure/wastegate gasses control) so I wouldn't be using the"divider" that came with the pipe. And besides the ones that come on the dump pipes aren't the same shape as the one's that come with the -5's. Steer clear all together with the splits.

Basically, I went through this a few weeks ago with the same things in mind. I didn't want to spend $800+ on dumps, but now I have, and I know I've made the best decision. (bar looking for 33/43 dumps for my 32)

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