Hks Gt2530 Dump Pipe Recommendations?

[THENIG]

I have a 2530 that will be going on soon, it came with the top split dump pipe (same as left pic), however.... i already have a JJR (right pic) style dump pipe that is already fitted and has been thermo wrapped and sealed. Do i go out and spend more money on the bottom half to match the hks item or do i keep the one i have already and cut the little waste gate divider off and try and make it fit the turbo?? Does anybody have any opinion as to which would give better results (if any), or where i could buy the bottom half of the dump pipe?? I think i turfed my standard one when i did the last swap.

(pics for illustration purposes only)

VS

Turbo

6 bolt outlet

[Chi100188]

i think i'd use the HKS item....but i don't see why u cant use the JJR one....but yeah for my preference ill use the HKS item

[Duncan]

sorry I might have mis understood, does the JJR pipe fit or not? If so use it, the longer the split in the wastegate line the better performance due to reduced turbulence. The HKS wastegate pipe is so short because thats the longest you can go and still have a seperate dump and front pipe. Since you've already got a better thing, stick to it

[limpus]

Having been in the same boat as you before...i went the hks dump in the end...i had a batmbl dump and front similar to the JJR one you have...i cut the divider off too and then used it on my HKS2535...and i found that boost would spike from the set 1.0 bar or so to about 1.3 bar...i found out that the wastegate flap would foul on the dump pipe...have a look at your JJR dump where the wastegate hole is round...and then look at the hks one where the wastegate hole is elongated...it was made that way for a reason...i've had no problems with the hks dump...just go for it and sell of that JJR pipe...get a GK tech front pipe with flex and you're good to go...

On a side note...is that a gt2530kai? I'd be very interested to see how it performs...could you keep me updated please? Cheers...

[THENIG]

sorry I might have mis understood, does the JJR pipe fit or not? If so use it, the longer the split in the wastegate line the better performance due to reduced turbulence. The HKS wastegate pipe is so short because thats the longest you can go and still have a seperate dump and front pipe. Since you've already got a better thing, stick to it

I havn't tried yet, JJR one is fitted with standard turbo at the moment, i will be putting the 2530 on in the next few weeks, i am 100% sure i will have to modify it (cut the divider off) to make it fit the 2530, because i dont have it off the car and sitting side by side im not sure if the wastegate flapper holes are in the same spot for both turbo's. Im worried now that the JJR dump pipe will create unwanted turbulence with the 2530.

I have had no complaints with the JJR split dump i have now, by far the best BFYB mod i have done soo far.

[black33gtst]

why not use the hks and sell the jjr

[THENIG]

Having been in the same boat as you before...i went the hks dump in the end...i had a batmbl dump and front similar to the JJR one you have...i cut the divider off too and then used it on my HKS2535...and i found that boost would spike from the set 1.0 bar or so to about 1.3 bar...i found out that the wastegate flap would foul on the dump pipe...have a look at your JJR dump where the wastegate hole is round...and then look at the hks one where the wastegate hole is elongated...it was made that way for a reason...i've had no problems with the hks dump...just go for it and sell of that JJR pipe...get a GK tech front pipe with flex and you're good to go...

On a side note...is that a gt2530kai? I'd be very interested to see how it performs...could you keep me updated please? Cheers...

Thanks heaps for your advice, what your discribing bout boost spiking hadn't crossed my mind, but is a pretty good argument to keep the hks dump. I dont want to hack up the JJR only to find its not what i want and then not be able to sell it.

Question:: GK tech?? how much and where from??

Re: gt2530kai?? Yes it is, i will keep you updated on how things go, since i can only take my car off the road on the weekends i plan to change the turbo and cam gear one weekend, and Z32 AFM gtr injectors the following week and towing it somewhere for a remap on the monday. I have a loom that came with a resistor pack already spliced into gtr plugs, but im still not confident i will be able to knock it off in a day so im giving it a whole day. I would love to find a set of series 5 RX7 injectors and drop them in before it gets tuned but i cant find any and from what i can understand you still need to change the plugs to fit and their spray pattern isn't as desirable as GTR injectors. Since im attempting most of it myself i would prefer the RX7 injectors...

Cheers

Rob

[THENIG]

why not use the hks and sell the jjr

Yeah i think thats what i plan on doing, either way i will be selling one, just need to source the bottom half of the dump pipe for HKS pipe if i decide to keep it.

Just wanted to see if anybody else has gone through this and came out with the best solution.

Cheers

[limpus]

Yeah...the wastegate flap fouling against the dump pipe prevented it from opening fully and hence sent boost levels skyrocketing...

GK Tech is a sponsor from nissansilvia.com...he's one of the few people around that sell aftermarket front pipes for rb20/25s...stuff looks top notch too...don't quote me on that...but in the end...the front pipe is just a pipe...

And yes...please keep me posted on the 2530Kai results...i want to see if i should shoot myself for not going down that path...PM me if you want to keep it confidential...cheers...

Edited January 24, 2008 by limpus

[THENIG]

Yeah...the wastegate flap fouling against the dump pipe prevented it from opening fully and hence sent boost levels skyrocketing...

GK Tech is a sponsor from nissansilvia.com...he's one of the few people around that sell aftermarket front pipes for rb20/25s...stuff looks top notch too...don't quote me on that...but in the end...the front pipe is just a pipe...

And yes...please keep me posted on the 2530Kai results...i want to see if i should shoot myself for not going down that path...PM me if you want to keep it confidential...cheers...

Thanks for the info limpus, i found the pipe that you were talking about through NS, will probably buy one this week, i would have prefered a solid pipe, but im guessing the flex joint is there for a reason and is designed not to leak or rust out. Will let you know how everything goes, good ot bad.....

[Adz2332]

hey mate,

just off topic have you had any probs with your JJR pipe? as im looking at getting there front pipe for my gtr??

[THENIG]

hey mate,

just off topic have you had any probs with your JJR pipe? as im looking at getting there front pipe for my gtr??

Not sure what their GTR dump pipes are like, the split dump for the RB20 is very good quality, went in without any clearance issues, welds were cleaned up nicely, O2 sensor fitted without any dramas, i never did get around to checking if the flanges were proper 300 series stainless with a magnet, its been on the car maybe 6 months and there isnt any sign of corrosion yet. As i said i wouldn't be able to tell you what the GTR dumps are like, but their overall customer service and postage costs are pretty reasonable. I think i have read before on the forums that they are all made here in oz(as opposed to taiwan/china knockoffs with questionable quality materials), im not sure if thats still the case, ring them up and ask them, i would only be speculating.

[limpus]

I have gotten a fair bit of stuff from just jap over the years and with them its abit of a hit and miss...i won't bad mouth them because some of their stuff is pretty good...all i'll say is do your research first...

[Jmaac]

I'ld go the JJR unit (rhs one), the split pipe should be plumbed in at least 18" back

[limpus]

I'ld go the JJR unit (rhs one), the split pipe should be plumbed in at least 18" back

Did you not read the rest of the posts? the wastegate flap on the turbo will foul the on the JJR pipe...hence causing uncontrollable boost...the HKS pipe is designed the way it is for a reason...which is to allow the flap to open fully when on full boost...unless you want to grind a fair bit of the jjr pipe...which will probably weaken it...then its better to stick with the dump that it came with...

[Duncan]

will foul or might foul? limpus was using a different front pipe (not JJR) and different turbo not 2530....

[Syphon]

Probably a bit late now but since Duncan has bumped this thread

I'm using one of the JJR split dumps on a HKS 2535 with no issues that I am aware of.

I am running 17psi with no boost spike, and tapers off to 15psi over the rev range, which is more likely an exhaust restriction, or possibly a creaping wastegate, but certainly no issues as suggested above with massive boost spikes.

Save yaself some cash and just chop the divider off the jjr and bolt the turbo up.

[rev210]

I found the JJR pipes have poorly aligned pipes to the flange. Mine required plenty of time with a die grinder and I needed to machine the flange flat. The welds protruded into the path of the turbine exhaust gas in a very nasty way not to mention the wastegate.

I had to also grind off weld around the holes for the Turbine studs as the alignment caused there to be no room to put one of the nuts on.

Go the HKS or something actually good. end of story

[limpus]

Probably a bit late now but since Duncan has bumped this thread

I'm using one of the JJR split dumps on a HKS 2535 with no issues that I am aware of.

I am running 17psi with no boost spike, and tapers off to 15psi over the rev range, which is more likely an exhaust restriction, or possibly a creaping wastegate, but certainly no issues as suggested above with massive boost spikes.

Save yaself some cash and just chop the divider off the jjr and bolt the turbo up.

Interesting...i've had the problem on my 2535 and i have encountered the same problem with a 2530 which i installed on another car too...maybe i was unlucky and you're in turn lucky...

THENIG...since some people don't have issues with the JJR pipe...might be worth giving it a go...remove the actuator arm and then try to to flip the wastegate flap open...mine would only swing open about 50 degrees before the flap fouls the dump...if yours opens fully with the JJR one...then its your call to use it...

[Adriano]

I would definately try to use the JJR one if you can modify it to fit. It will be cheaper and better in the long run, as long as the wastegate gets full movement