Split Vs Bellmouth

[3LGODZILA]

when asking whether i should get a split dump/front pipe or bellmouth dump/front pipe for my car i get lots of different answers, but no explanations on why i should use that one, the only thing ive heard from the bellmouth boys is that quite a few people have issues fitting the splits on. so is the fitting issuses just a dodgey pipe or if i buy a split pipe am i gonna expect it to not fit properly. i want to fit a dump/front pipe and cat myself to get more experience and mostly coz im a poor bastard now i own a skyline haha.

so what are the pro's and cons, which one works better for you? is how much power i got and what boost im running a factor too?

or am i making a big deal out of nothing and i shud just get whatevers cheeper (bell) and easier to fit (bell)

edit: these are the 2 im looking at, both JJR

bellmouth: http://justjap.com/store/product.php?produ...=276&page=1

split: http://justjap.com/store/product.php?produ...=276&page=1

Edited February 10, 2009 by xdef

[TiTAN]

if you are going to retain the stock turbo and keep to the ~200kw limit that imposes, chances are you wont be able to tell the difference between the two.

[R34_Wong]

Split. I got noticeable extra response from my dump on stock turbo in the ER34.

[Pal]

ive had both, if you gunna stay with stock turbo go split, just check to see that your wastegate doesn't hit when opening. if you are going after market or highflow turbo later or have one already get a bell mouth. splits dont seem to like the higher boost unless it has a decent size wastegate tube.

[PM-R33]

Exactly as said above. Most aftermarket split dump pipes are great for the stock turbo (if they dont foul the wastegate flap).

However if you are going to upgrade the turbo down the track go a bellmouth. I used to have a split dump on the stock turbo and it was great, however the GT-RS wouldnt hold boost with it as the wastegate pipe was to small.

[WhitePrincess]

hey, bit of an essay here, but stay with me

i was deciding a year ago now about exectly this and couldn't get what was the difference either, so i bought the split dump pipe... and that was a wrong move. see, the pipe was not manufactored to a high level of acuracy and, as it's been mention here before, prevented the actuator flap to open fully which resulted to boost creeping. i had a t piece boost controller at that stage - which i blamed and replaced with electronic boost controller which evidently did not fix the problem. the boost would just keep on rising as the car goes through it's rev range and if i don't back off it, it would overboost to 14psi and more potentially. to fix the problem i had to remove the dump pipe and go at it with a grider, sand paper - anything i could find. in the end it all worked out, the boost is not creeping up anymore and the dump pipe is doing what it supposed to do, but if i was to do it again - i'd go for bell-mouth dump.

ps. another interesting thing with my split dump pipe, maybe other as well, is that it increased my boost from 5psi to 10psi (if the EBC is switched off) because of the small bypass pipe or the split dump pipe does not have enough room for the flap to open up fully.