Dump Pipes On R32 Gtr

[Beer Baron]

they have always had a flex as far as i know.

[itbmils]

I'm in Brisbane - and have used the Customer Ex dumps, and they are a compromise I agree. I already had non-standard engine pipes - so I did not want to change them as well. I also went for the heat coating. They cost me $880 with the coating and gaskets I think.

Sorry – I can't quantify the delivered performance difference 'cause I did it as part of a full rebuild.

All I can say is that I'm happy with the results I have seen (which is the main thing). My R34 N1s spool much quicker and boost harder than the R32 N1s I had on previously. I do have back to back dyno results comparing power and torque before and after the rebuild run on the SAME dyno. ( i have posted this info in the past).

I started with 210awkw @ 1.0 bar and now get 292awkw @ 1.2 bar – but as you can see I've done a LOT of work to see that gain.

[lows_13]

Is it the same principle for the front pipe, if they branch down and stay separate for longer will that give you more power?

Stock dump pipes + long branched front pipe?

Edited October 20, 2005 by lows_13

[my_gtr32]

Interested, how much and where are you?.

I am currently talking to Trevor at CES at the moment, as their comp pipes are an option. he wants $1500 for them in mild steel. I would also be interested in a group buy but I need to get the pipes soon though. Trevor makes them up once ordered and doesn't have them on the shelf.

We have a set of the Trust split dump/front pipes in stock if anyone is after a set but doesn't want to wait  Can't do them as cheap as the group buy was going to be though 

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[Ronin 09]

Yep, good point the Nengun option is always worth considering. 

I thought the trust pipes had no flex but i've seen photos of something similar, like those posted by Ronin, that has a flex joint. are they copies or have trust changed the design?

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Mine are Trust unless I've been ripped!!

I have also seen pics of both - some with and some without the flex.

[R31Nismoid]

Interested, how much and where are you?.

I am currently talking to Trevor at CES at the moment, as their comp pipes are an option. he wants $1500 for them in mild steel. I would also be interested in a group buy but I need to get the pipes soon though. Trevor makes them up once ordered and doesn't have them on the shelf.

$1500 for mild steel is very expensive IMO, even for the work as material costs are even lower as opposed to the Trust which isnt

[linksys76]

Hey hows it going, can you PM on the cost, time taken and how about you went finding the mech. I have a recently imported myself a R32 GTR and want to do pretty much the same except get diff rods..... how does this fiar up to most cars on the street eg std SS's typhoons exotics and Sti's?

Im in Perth btw.

Cheers man

I bought my R32 GTR about 18 months ago - and it was clearly a 'renovators delight' - if you know what I mean. The engine was already tired (READ: rooted), but the body work and interior was/are in good shape. So I set about 'renovating'. I replaced the turbos and did a FULL engine rebuild about 6 months ago. This is what I did ....

forged pistons (Weisco – only one size over)

shot peened and balanced everything

ARP rod bolts

std rods (shot peened and balanced)

N1 water pump

N1 oil pump

N1 bearings

port and polished head

the non-turbulance dump pipes 

3" (no cat) exhaust

R34 N1s 

Apexi PFC

Apexi EBC

Tomei Adjustable CAM gears

Tomei fuel pump (about 130% over the std pump)

Tomei 1.2mm head gasket (yes – that's 1.2mm)

Tomei timing belt

SX fuel regulator

std GTR injectors (but no for much longer)

I have HKS 550cc injectors, RB25 AFMs and probably the Tomei CAMs on my radar for my next power upgrade - and I expect to see 350awkw when I'm done. I may also look at an upgraded FMIC to keep things nice an cooool.

If you have not figured it out yet - this rebuild cost me my left one, but it's a fairly conservative and solid build. I did a lot of research before starting, spoke to guys that have owned GTRs for a long time, and I spent a lot of time looking for a mechanic I could trust. The only thing I would change if I was doing it again would be to use forged rods and stronger head bolts. These items will limit me to around the 350awkw mark – which was kind of easy to get to by the way.

I'm happy to share all the gory details of my experiences if your interested

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[Duncan]

what on earth is a diff rod?

[jonn]

what on earth is a diff rod?

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I think he means, different rods, as in conrods.

[GTR32]

what on earth is a diff rod?

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Duncan don't you know anything?

[Duncan]

hahaha I think i am with the program now....

[m&m]

HPI make a short straight fit dump pipe where the wastegate section vents to atmosphere,I gather by the previous posts no one has tried these.I have a HPI manifold on my S15 and the quality is awesome,I need to replace the front pipes on my 33,it already has HKS dumps,thinking of getting the HPI ones.

[lows_13]

Is it the same principle for the front pipe, if they branch down and stay separate for longer will that give you more power?

Stock dump pipes + long branched front pipe?

<{POST_SNAPBACK}>

Does anyone know what i mean?

[Scooby]

i think that the length of the pipes after the dumps is of minor importance as long as they are sufficient diameter and have a good collector design at the the tail pipe. it's not a scavenging scenario so the issue of length and pulse tuning is less important.

[Scooby]

just spoke to Trevor - they didn't do the dyno run with the stock GTR and comp pipes, he has it arranged for later this week. i think we're close...

[lows_13]

Its going to be interesting to see what figure arises from the dyno run.

[itbmils]

Hey hows it going, can you PM on the cost, time taken and how about you went finding the mech. I have a recently imported myself a R32 GTR and want to do pretty much the same except get diff rods..... how does this fiar up to most cars on the street eg std SS's typhoons exotics and Sti's?

Im in Perth btw.

Cheers man

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PM sent

[steve_gts4]

for anyone that has fitted a set of the trust extension pipes before... what did you do with all the heat shielding and support brackets that bolt onto the stock dumps? im a bit apprehensive to just leave it off...

[lwells]

for anyone that has fitted a set of the trust extension pipes before... what did you do with all the heat shielding and support brackets that bolt onto the stock dumps? im a bit apprehensive to just leave it off...

Hi Steve,

Been there, done that To quote myself (bit self-indulgent I know ; you might like to check out some futher replies in the linked thread too)

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?

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.

In regards to the heatshields, the ones that hang off the turbo will still fit although without one of the nuts. The manifold heatshields will obviously fit (unless you are changing the manifolds). Given how close the dump pipes come to the aircon piping and the underneath of the car, its definately preferable to apply some sort of heat shielding. I used DEI thermal tape and paint due to time constraints. Whilst its good stuff, its annoying to apply and not particularly cheap (contact Racespec on SAU for some pricing). If time had not been a constraint, I would have had the trust pipes ceramic coated.

I only installed mine a month or two ago, so its still fresh my mind; if you have any other questions, fire away. I am currently in Japan so it might take me a few days to reply.

[Beer Baron]

lucien in japan eh? how is it going?