Hks Gt-ss Vs. Gt-rs

[GTRgeoff]

Exactly the ones I'm thinking of. Somehow I thought you had them too.

Some are calling them Targa turbos as they look so similar to stock/N1 but give plenty of power and great response so would be good for the RB25DETT

If Benno likes them they must be alright. HKS/Garrett ..... same same but different price as far as I'm concerned.

[Mik]

I have seen a pair of GT-SS's for a GTR that had 0.6A/R front housings. They would have to be good turbos as I guess they would be something in between GT-SS's and 2530's. No idea where to get a set form though.

[lwells]

I just (as in a week ago) installed a set of GT-SS turbos with those trick Greddy/Trust Front Extension pipes (you know, the ones with the long wastegate split). I can't comment much on how they feel as I have been driving extremely cautiously because I am uncertain what the fuel mixture is like (at a rough guess extremely rich, but better safe than sorry until its tuned). I have noticed that, running off the stock soleniod with the boost restrictor in place, boost builds almost exactly at the same time as the OEM turbos, so you get the benefits of decent spool plus they can breath heavier than the OEMs.

I went down the path of the Garret vs HKS thing. The HKS's have ever so slightly different specs (although how much of that is due to rounding to a different decimal place I'm not sure) and also has the benefit of being a bolt-on kit; the Garrets went up in price just before I made my purchase and since they are simply turbo + actuator, there is still a couple of hundred in parts (gaskets/studs/nuts/cooper washers/etc) to get so the price differential is not as great as it looked at first blush. Keep in mind, however, that the HKS kit skimps in certain places: it does not include manifold-to-turbo or turbo-to-dump pipe gaskets or replacement locking tabs for the turbo-to-manifold nuts The turbos are very easy to install -- as Ash said they have an install sheet, but its all in Japanese and when I contacted HKS Europe they said its exactly the same as the workshop manual -- although the same can't be said for the Greddy/Trust dumps which are absolute mongrels to install.

Hope that helps some. Any questions, fire away...

[wrxhoon]

How did you go with the air cond water discharge pipe? Did you remove it?

Did you have to dodify the coolant and vacium lines at the rearof the block so you could fit the rear o2 in te dump?

One advantage with these dumps the front pipes are very easy to R+R.

I find that my GTSS's come on boost slightly later than my stockers did (r34 ball bearing) and they have a little more mid range and top. They are not big turbos by any means .

[Beer Baron]

love to hear the answer to those questions too! also did your trust dumps accept the R32 O2 sensors, or did you have to go 33?

[pnblight]

Justinfox i'm interested to hear you say the 2530hks are to laggy, as they are a very good turbo and spool well when on a properly setup motor. I thing to note is the turbos themselves are not the only factor in what makes the turbo spool fast and early, i would place a fair size bet you have some other issues.

As for turbo choice if you think the 2530's laggy run a mile from the GTRS's the GTSS will be slightly better than the 2530's (but only slightly) the other turbo you should concider is the Garret GT2560R 707160-5 as it spools very well. All these turbos need the engine setup right to get the benefits from them as i have seen a GTR with HKS2510's that felt very laggy and didnt spool well in comparison to mine but i don't believe it was just turbo related i did manage to improve it with some cam timing (which is hughly importane to spool) but yet tthis car still didn't perform as it should. And this was the second type of turbo this car had tried.

So in nut shell i guess look at the whole picture before when it comes to turbo performance as it might be something else letting you down.

pete

Hi all,

I've just sold my HKS 2530's and looking to get either HKS GT-SS's or GT-RS turbos.

I've heard great things about the GT-RS on S15's but nothing about them on GT-R's.

I found the 2530's very laggy down low and very damn punchy up top. Then again I had only done a street tune and not a full dyno tune.

In any case I have sold them. I am looking for something which spools up very quickly for track/circuit work. NOT INTO DRAGS AT ALL. Must be great for track work and come on gradually not like my 2530's which just went insane up 6000/7000rpm but had nothing at all down low.

I've read on some forums that the GT-SS is tiny, small as stock but spool fast but can make a lot of power. I am scared that the GT-RS will be just as laggy as the 2530's as they seem to be even bigger than the 2530!

I am running an RB26 with Tomei oncams (Type-B), HKS rods and pistons, 550 Nismo injectors, stock afms, power FC.

Any advise/opinions especially from experience would be greatly appreciated cheers peeps!!!

[R31Nismoid]

love to hear the answer to those questions too! also did your trust dumps accept the R32 O2 sensors, or did you have to go 33?

You need R33 O2 sensors... hence why im selling the 32 GTR ones i purchased

You can get a stepper bolt or something, but i CBFd finding it. Easier just to get new ones.

I'm in the middle of it all right now

And we have fitted my Trust split dumps while the motor is out of the car, impossible once its in.

So it would be even worse on a GTR

I cant answer the re-location stuff as im not putting it into a GTR and my gear is different.

[wrxhoon]

Pete GTSS's are much smaller than 2530's , they are baby turbos and will run out of puff at top . I run 16psi in my 34 ( totaly stock, unopened engine ) and it drops to 15 psi above 7000 but they spool up almat like my stockers. Actualy the only reason i replaced them was the ceramic wheels, i dont want them to let go and destroy my donk .

Unless you are thinking of the bigger housing GTSS's like the ones used in SR20's, not sure on them and all but one set of the twins ( RB26 sets) i have seen are the small comp housings .

[steve_gts4]

love to hear the answer to those questions too! also did your trust dumps accept the R32 O2 sensors, or did you have to go 33?

i fitted these pipes into my 32gtr... i had to remove the a/c drain pipe as it was ~3mm from the rear dump. my a/c isnt gassed anyway.. so no drama there.

i had to bend up the pipes going around the back of the head as they fouled on the rear o2 sensor.

when i bought the front pipes, they came with an adaptor to fit the r32 o2 sensors.. if you dont have the adaptor, the smaller sensors will not fit.

Edited April 28, 2006 by steve_gts4

[wrxhoon]

You need R33 O2 sensors... hence why im selling the 32 GTR ones i purchased

You can get a stepper bolt or something, but i CBFd finding it. Easier just to get new ones.

I'm in the middle of it all right now

And we have fitted my Trust split dumps while the motor is out of the car, impossible once its in.

So it would be even worse on a GTR

I cant answer the re-location stuff as im not putting it into a GTR and my gear is different.

Its possible to to in the car ( GTR) but its turbos out job, of course its easier off the car .

I wouldnt have them in my GTR though, i would prefer to fit HKS .

[wrxhoon]

i fitted these pipes into my 32gtr... i had to remove the a/c drain pipe as it was ~3mm from the rear dump. my a/c isnt gassed anyway.. so no drama there.

i had to bend up the pipes going around the back of the head as they fouled on the rear o2 sensor.

when i bought the front pipes, they came with an adaptor to fit the r32 o2 sensors.. if you dont have the adaptor, the smaller sensors will not fit.

Thats exacly what i found out when i fitted them in a 34 GTR( not mine) , they are a pain in ass.\

If they ever have to replace the rear 02 sensor they will find it very difficult on the car ( doable though).

Another problem i found because they all the same ( for all model GTR's ) you ahve to weld a bung for the exhaust temp gauge ( only 34's have that ) .

[lwells]

How did you go with the air cond water discharge pipe? Did you remove it?

Did you have to dodify the coolant and vacium lines at the rearof the block so you could fit the rear o2 in te dump?

One advantage with these dumps the front pipes are very easy to R+R.

I find that my GTSS's come on boost slightly later than my stockers did (r34 ball bearing) and they have a little more mid range and top. They are not big turbos by any means .

love to hear the answer to those questions too! also did your trust dumps accept the R32 O2 sensors, or did you have to go 33?

Well, I can't let the fans down

1) Aircon Discharge Pipe:

I removed the pipe and cut the rubber just after it makes its 90 degree turn down towards the ground (ie. almost all the bit pointing down). I then got some copper pipe and bent it in to the same basic shape. Using a ring clamp, I applied some silicon around the top of the copper pipe, slid it in to the remainder of the original rubber piping (ie. the very top bit that plugs in to the firewall), did the clamp up very tight, then used some more silicon around the edge where the rubber and copper were joined. I then removed the plastic clip that holds the bottom of the discharge pipe in place. I went and bought a metal "banana clip" (from Auto1) which had a sort of groove/holder that was perfectly shaped/sized for running a small ring clamp through (~20mm variety). So I simply put the ring clamp in the groove and used some pliers to push the sides of the groove together to hold the clamp. It fitted the hole the original clip was in perfectly; slide the clamp over the end of the copper pipe, did it up, and fanny's your aunt. I should grab some photos as it makes a lot more sense in pictures

2) Rear dump + O2 sensor:

I fitted the O2 sensors before installing the dumps because I remembered how hard it was to try and install them later.

Richard: the pipes are designed to take the R33/34 GT-R sensors, but Trust includes a little adapter that screws in to the hole and reduces the size so you can fit the R32 variety (R31Nismoid: this is included with the front pipes in the bag of nuts/studs/etc). However -- and this is what wrxhoon is asking about -- the ~1cm increase in height caused by the adaptor makes the top of the rear O2 sensor hit the coolant/vacuum lines that run around from the back of the block. Unfortunately the SAU gallery is down, but there are two lines that emerge from behind the engine and are held in place by a bracket towards the back on the right hand side of the engine.

With a fsck load of fiddling I managed to get the lines back on the bracket, and the bracket screwed on to the head/block. The lines are pushing against the top of the O2 sensor, but apart from taking drastic action by attacking the top of the sensor or the bracket there doesn't seem a better way. It may well have bent my O2 sensor.. who knows? With R33/34 sensors this should be a lot easier but I was a little concerned after reading the oxygen sensor thread in general maintainence that there might be some slight differences in composition of the O2 sensors and thus cause issues with the ECU getting correct readings.

3) Support bars:

The Trust pipes do not have anyway to attach them to the bell-house support bars. I had a quick chat to Gary (SydneyKid) about the viability of running without the supports and it was his opinion that it would be a mistake as any weight would be taken by the gearbox mounting (where the cat attaches) which is rubber and obviously moves, hence is useless.

I had a decent think about this and came up with the idea of welding on a nut to the dump pipes so I could attach the support bar. So what I did was test fit each of the turbo + dump + manifold assemblies (individually as it was easier). I then played around with the support bars until I could find an angle so that they were attached to the bell housing but would also be at about the right angle / on the right plan so it could be attached to the dump pipe once a nut was welded. I then marked the approximate positions as best I could on the dump pipes, grabbed some nuts, and had an exhaust shop weld them on in the designated spots. On a tangent, f**k me dead if the welder didn't just hold the nut with bare fingers and no eye protection whilst he tacked it in place (and then grabbed some protection when building up the weld). They be real men in Oak Flats (oh and thanks to 2rismo for the recommendation of Oak Flats Muffler Men).

I also had to modify the support bars. The rear bar needs a small chunk taken out otherwise it hits a rib on the side of the block. It also needs to be bent in to shape. The front bar requires much more drastic modification; I basically had to chop a good third off, remove the middle mounting point for the coolant (or is it oil?) line, redrill a slot for a screw, bend it in to the right shape, etc. Much to my suprise when I did a final test fit (urgh... took two test fits for each turbo before the final proper fit..... got sick and tired pulling the turbo/dump/manifokds in/out really quickly) everything was almost exactly spot on. I tiny bit more bending and everything was peachy. I also fabricated a small piece of aluminium so I could attach the rear coolant (or is it oil) line to the middle hole on the rear support bar. I just cut of the little bracket on the front coolant (oil?) line as there is no way I can connect it to the modified front support bar.

I am extremely pleased with how this turned out given the extreme time pressure we (my dad and I) were under on that day and how it all could have been way too hard.

4) Installing the dump pipes on to the turbos:

You will need to use the included studs in the turbo as the piping of the dumps is angled such that longer studs will mean you can't actually screw it down. There is also a design fault in that it was simply impossible to install one of the nuts; it would not fit. I had to file down the pipes and flange a little and take off the top of one of the nuts with a bench grinder before I could actually get the nut to fit without hitting the piping (sorry, can't remember exactly which dump it was). Trust also laughably includes locking nuts (ie. the thread inside tapers), but there is no way to do them up enough so that they actually start to lock.

Also, the turbo-->dump gaskets they include are that will shaped so in certain (inner) areas of the gasket are very close to the edges of the flange. Be careful when placing them

5) Installation into the car:

The rear turbo was very hard to get in place because of the length of the dump pipe; it hits the side of the gearbox or part of the chassis directly opposite and takes a lot of twisting and turning. If I recall correctly (IIRC), the best method was to try and place it in as it would sit and then rotate it counter clockwise (ie. towards the engine), slide it further down, then rotate it back. Again, IIRC I also had to place the manifold on at the same time because it wouldn't fit once the turbo/dump were sitting in the engine bay. The front was much easier although again having to put it in with the manifold at the same time is a PITA. The good news is that actually doing up the nuts that hold the manifolds on to the head was much much easier; I was able to get the torque wrench on every nut (unlike the OEM setup where I could only get access to about 1/2 the nuts with a wrench and the rest only with spanners). Likewise you can torque 3 of the four turbo-->manifold bolts on each turbo with a wrench; you'll need a spanner for one on each (the bastard one that sits under a manifold runner).

Hope that covers most questions.

[R31Nismoid]

Hmm... i probably lost the bag with that crap.

I've got stuff all over the place.

But still, as you said, the O2 then becomes a mission (more-so)

Im happy using 33 gtr ones

[lwells]

Hmm... i probably lost the bag with that crap.

I've got stuff all over the place.

But still, as you said, the O2 then becomes a mission (more-so)

Im happy using 33 gtr ones

It shouldn't be too difficult without the additional 1cm in height but as I said, I was concerned the sensors might be slightly different and I have no desire to rip things out yet again.

Perhaps you ordered the R33 or R34 version of the pipes, hence no adaptor? Regardless, you'll need that bag as it has the stainless steel studs and nuts; as I said above the studs are slightly shorter so you can just fit a nut on. I'll be interested to hear if you also have a problem with fitting one of the nuts on (ie. it physically will not fit no matter what). Although the pipes are beautifully made, I'm not all that impressed with Trust selling an item that has a number of fundamental problems when you actually come to install them (atleast on a R32 GT-R; I can confirm I had the appropriate version too as the box clearly states R32).

One thing I have noticed is that the sound of wastegate gasses dumping is much louder than previously. Objectively its not hugely loud compared to some of the aftermarket bovs, but its noticeable.

[R31Nismoid]

I dunno what i had or didnt... but they are on there now either way

Motor being picked up tomorrow.

So ill have a look Sunday and see if its all on there perfect re: that odd nut.

I'll check the box and see what mine had on it. I dont recall seeing anything but then, i didnt look

[wrxhoon]

It shouldn't be too difficult without the additional 1cm in height but as I said, I was concerned the sensors might be slightly different and I have no desire to rip things out yet again.

Perhaps you ordered the R33 or R34 version of the pipes, hence no adaptor? Regardless, you'll need that bag as it has the stainless steel studs and nuts; as I said above the studs are slightly shorter so you can just fit a nut on. I'll be interested to hear if you also have a problem with fitting one of the nuts on (ie. it physically will not fit no matter what). Although the pipes are beautifully made, I'm not all that impressed with Trust selling an item that has a number of fundamental problems when you actually come to install them (atleast on a R32 GT-R; I can confirm I had the appropriate version too as the box clearly states R32).

One thing I have noticed is that the sound of wastegate gasses dumping is much louder than previously. Objectively its not hugely loud compared to some of the aftermarket bovs, but its noticeable.

I fitted them to a 34, i had no problems doing any nuts on and i used the locknuts supplied as well .

The o2 issue is the same on the 34 mate , i had to bend the pipes , reshape them so they are out of the way . I also had to get a bung welded on trhe rear dump for the exhaust temp ( only 34's have it factory fitted) .

I agree that the pipes are well made but i would never fit them to my car, i would go for HKS, they probably just as good and direct fit without any issues, even the turbo support bracket fits !

Of course you will hear the w/gate more than stock, the s/s tube is very thin , the cast factory dumps are much thicker . I actualy prefer to use Nismo dumps but they are very pricey!

I still have stock s/s dumps on my car and they are staying there as i only use baby GTSS turbos i can see the point in changing them but if i had cast 32 dumps i would replace them with HKS.

[lwells]

I fitted them to a 34, i had no problems doing any nuts on and i used the locknuts supplied as well .

The o2 issue is the same on the 34 mate , i had to bend the pipes , reshape them so they are out of the way . I also had to get a bung welded on trhe rear dump for the exhaust temp ( only 34's have it factory fitted) .

I agree that the pipes are well made but i would never fit them to my car, i would go for HKS, they probably just as good and direct fit without any issues, even the turbo support bracket fits !

Interesting. As I said above, there was absolutely no way one of the nuts would fit without modification. Clearly there is some variation in the manufacture of these parts. I am suprised you still had clearance issues without the adaptor as the lines were only just touching the top of my sensor; perhaps the O2 sensors on the R33/34 are slightly longer or maybe its just more manufacturing variation (ie. the bung was in a slightly different place on mine)?

Of course you will hear the w/gate more than stock, the s/s tube is very thin , the cast factory dumps are much thicker .

Sorry, I wasn't stating this as some sort of revelatory fact, just thought it was worth mentioning regardless

As for the HKS dumps, I can see your point but I would rather take a punt on the longer split having some advantage. The HKS dumps aren't exactly cheap (new especially, although there are a lot of second hand and copy versions floating around) if you need to replace the front pipe as well (which I did as mine was completely rusted through). Although it took a day, I also have the benefit of the supports so no real advantage there either way. The only thing would be heatshields I guess (I assume the HKS can use the standard dump shields or have their own?).

[R31Nismoid]

Kinda off topic

There are Trust copies out there, so be very wary... i've seen one set and they had a few issues with alignment and what not

[wrxhoon]

I think if you were to use the whole package, including turbos ( the pipes are designed for their turbos) then its a different story . You probably dont have any issues with fitting anything then, maybe the air cond discharge pipe would be ok then too . I know on HKS turbos they are a pain in the ass to make them fit .

Lwells, i didnt have any problems with any nuts not fitting at all, sure some are a very tight fit, but never the less they did fit, maybe you got a set made on Friday afternoon .

Yes the pipes have to be changed around and by a long way for the 02 sensor to fit , i put the sensor on first and then had to bend the pipes around it, this was all done with the donk on the floor so i didnt find out about air cond pipe until the donk went back in the car.

I think you will find that there wouldnt be any difference in performance between the HKS and these , using the baby GTSS's . As for price, i dont know how much ( if any ) difference there is by the time you get the front pipes as well. I picked up my front HKS pipes in japan ( up garage) for 8000 yen, used by looked like new .

The main thing is you fitted them in now so its all good. Personaly i wouldnt fit them in car even if they worked out to be much cheaper, to many hassles for my liking

[Beer Baron]

what an effory Lucien. good work mate. now i know who to call when it comes time to do mine!! lol.