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i apologise if this has been covered before, used the search but didnt really come up with much info that i wanted.

i am looking to finish off my cat back exhaust. basically want a few peoples opinions on the best dumps/hi flow cats for r33 gtsts.

car is not highly modified, will be aiming for 200rwkws at the max when im finished with whatever mods i decide to buy in the future. just a quick daily driver.

so what would be the best/most cost effective dump/front pipe and hi flow cat that i should be looking at buying?? want something that is reliable and flows really well.

cheapest option obviously is the xforce range, but ive heard from a lot of people that they are shithouse?

i also have been looking at the BOS importing stuff, and it looks and sounds the goods, but is pretty pricey.

will obviously shelf out top dollar if need be, if its the only stuff that is going to work well, but thought i would grab some opinions from people on what they think or have experienced

cheers

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I have had a bat mbl stainless split dump/front pipe in 1 and catco high flow in 3 inch

with a std GTR cat back on a R32 gts and it made very good power in the mid

range and top end while still being legal.

I revised this to a hks split dump with a hks front pipe with the catco cat

converter with trust pe11 cat back and although these are good well made jap

parts they didn't perform as good as my old set up

If I had my time again I would of stuck with the old set up BUT fitted a flexible

joint to the bat mbl (boss imports) front split dump and front pipe in 1 to make

it fit better but apart from that they do make good power.

I have had the bat mbl pipe next to a just jap pipe I would advise you to steer

clear from the cheaper just jap stuff as they are not as good the flange wasn't even

square.At the end of the day you get what you pay for

^^ that isn't a metal cat xforce cat.. xforce also have metallic substrate cats.. not ADR approved though

my guess after looking at metal cats for a while and still undecided.. xforce metal cat < magnaflow metal cat < catco/Metalcat < sard/apexi cats (ridiculously expensive)

so u guys reckon a split turbo back pipe, rather than a bell-mouth turbo back pipe...

correct?

i heard split ones get bad back-pressure...

i think it was back-pressure...lol

i too am in the market for a turbo-back pipe..

i had a jjr split dump/front and it was fine for the old stock turbo. not a problem in the world!

for the price it was a great mod.

i now run a 4" hks bellmouth and a bigger turbo but installed them @ the same time so cant really comment

I was leaning towards a JJR split front pipe, as at the end of the day its just a welded and bent pipe. i figured that making 200 rwkws, it wouldnt be under too much stress, since some people have said on here that with bigger power they can warp and crack or whatever. If a few people here have said with the same kind of mods i have that it works well then that gives me a bit more confidence in their stuff.

I might spend a lil more on the cat though. ive heard a helluva lot of stories about the xforce ones collapsing/having shit flanges and welds etc.

Might look into a catco cat from bos importing for the cat, what are peoples experiences on them??

Yeah split pipes are a lot better bumble bee, because the bell mouth ones have a larger opening, it can give you a loss in pressure as there is more volume to fill in the opening, whereas the split openings have less space for the exhaust to travel about in the mouth before continuing on its journey to add to the greenhouse effect haha. i believe thats about correct? although i wouldnt imagine the difference in the two to be really huge?

You will be surprised how many times people have bought split dump/front pipes that don't fit and need modifications to get them to fit on the stock turbo. Regardless of what the seller might say it is a "direct bolt on". I ended up sending mine back for this same reason and sticking to a proven 3 inch bell mouth style. As for the cat, very very few will have an ADR stamp on them. Nearly all compliance cats don't have any stamps on them and they are used to first register the car in Australia with no problems. You really won't have any problems with this as long as you have a cat on the car in the first place.

I was leaning towards a JJR split front pipe, as at the end of the day its just a welded and bent pipe. i figured that making 200 rwkws, it wouldnt be under too much stress, since some people have said on here that with bigger power they can warp and crack or whatever. If a few people here have said with the same kind of mods i have that it works well then that gives me a bit more confidence in their stuff.

I might spend a lil more on the cat though. ive heard a helluva lot of stories about the xforce ones collapsing/having shit flanges and welds etc.

Might look into a catco cat from bos importing for the cat, what are peoples experiences on them??

Yeah split pipes are a lot better bumble bee, because the bell mouth ones have a larger opening, it can give you a loss in pressure as there is more volume to fill in the opening, whereas the split openings have less space for the exhaust to travel about in the mouth before continuing on its journey to add to the greenhouse effect haha. i believe thats about correct? although i wouldnt imagine the difference in the two to be really huge?

the bosimporting 5" cats are not catco anymore. the external design is identical (as far as i can see) the welding was decent on mine and it looks for all money like it will flow as well as any other 5" bodied cat on the market.

on bellmouths, back to back we made a little more power everywhere with a bellmouth than with an expensive name brand split dump at or around 230-250rwkw. don't rule out the bellmouth dump as being inferior. i think it is a close thing between them, perhaps higher power levels/exhaust flows are needed to see a clear advantage?!?!

in some cases the extra money for a split may be better being spent elsewhere.

  • 2 weeks later...
if BOS doesn't sell the CAtco any more, who does? and whats the best place to get it for a good price?

why do you specifically want a Catco?

the current bosimporting cat looks the biz, the metalcat looks the biz etc etc. they all seem to flow near enough the same to make decent power.

Good luck finding a CATCO or MetalCat anywhere. I have been looking for the past month and have been unsuccesful in locating any so i have gone with a Magnaflow for now for my gtr. Also the cats now sold by BOS importing are not a metal body but ceramic.

no reason for specifically wanting catco. its just that bos importing's flow test claimed them to be better than the metalcat. if their current flows as well then shouldnt be a problem. anyway metalcat is probably also a bit of over kill on my car. just wanna stay away from the x-force ones. heard bad things

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