ugently need expert / experienced opinion

[MBS206]

Buy yourself the cooling system pressure tester.

Being able to pump it up, and have a gauge on it, AND have a cold engine makes it much easier / practical to diagnose.

Additionally as the engine isn't running, you can listen for pin hole leaks as well as watching if pressure drops away.

In addition, you can pressurise and while doing so, watch all the little rubber hoses. Some fail very brittle, and will just leak, while others can end up very soft and bulge. While a bulging hose isn't necessarily leaking, one of those small ones starting to stretch / expand in a bad way is an indicator that you'll be looking to replace that one soon

 

Depending on if this is a project car, or you'll be dailying it in the summer months would alter how I'd be most comfortable with driving the car and how I'd replace.

If you're planning to use it as a daily, with no backup, I'd pull the engine, and replace all the external oil/water lines in one big swoop. At the same time do the timing belt, water pump, tensioners etc.

Do not open the engine at all. We just want to replace all the things that are inexpensive as a single item, but a PITA when they go.

By doing the above, you've made the car from a bunch of age related issues more reliable.

If it's a project, and you like swearing while trying to reach into dirty hard to reach places to replace a single hose that may or may not be the leaky one. Just replace the leaking/bad ones as they need it.

If it's a project and you'd rather swear at the car once and enjoy it as much as possible, then refer to the process I mentioned in how I'd want to do it if it were a daily.

However, the approaches above do come down to how much spare pocket change you have. Pulling the engine and dropping over a thousand dollars on parts, may not be practical for you.

Oh, if engine outing, I'd replace as many silicon/rubber inlet joiners as possible too.

[joshuaho96]

3 hours ago, sunsetR33 said:

Yeah I'll do what I can without taking off any major parts for now. If it becomes clear I won't get far with the engine in the car I'll have to think about the next steps. I am not too stuck on keeping everything 100% OEM, if there is better solutions, like converting most lines to braided with AN adapters, I'd rather do that than buy overpriced new "shit" parts.

For all the talk of "these parts are junk" I generally recommend OEM because it's really not as bad as claimed. I have never seen or heard of a case like the N63 where the oil returns completely clog with coked oil for example in ~10 years or less. Would it be nice if it were a straighter path? I guess, but most modern cars use a scavenge pump instead of a pure gravity return. Also the factory lines that would be relatively simple to convert to braided are generally speaking hardlines from the factory. I would consider braided line to be a regression, not an improvement. It's also been engineered such that all the hardlines have appropriate strain relief where needed.

There's absolutely room for improvement, for example the HKS advantage heritage intake piping shows just how much can be done to make the turbos fight each other less in OEM twin turbo configuration and reduce compressor surge but it's rarely a simple/straightforward process. I recommend looking at what the group A/N1 cars did, generally speaking the changes they made were necessary and proven in endurance racing.

[MBS206]

31 minutes ago, joshuaho96 said:

For all the talk of "these parts are junk" I generally recommend OEM because it's really not as bad as claimed. I have never seen or heard of a case like the N63 where the oil returns completely clog with coked oil for example in ~10 years or less. Would it be nice if it were a straighter path? I guess, but most modern cars use a scavenge pump instead of a pure gravity return. Also the factory lines that would be relatively simple to convert to braided are generally speaking hardlines from the factory. I would consider braided line to be a regression, not an improvement. It's also been engineered such that all the hardlines have appropriate strain relief where needed.

There's absolutely room for improvement, for example the HKS advantage heritage intake piping shows just how much can be done to make the turbos fight each other less in OEM twin turbo configuration and reduce compressor surge but it's rarely a simple/straightforward process. I recommend looking at what the group A/N1 cars did, generally speaking the changes they made were necessary and proven in endurance racing.

I wouldn't look too hard at what they did with the R32 GTR in endurance racing in Australia... Lots of things weren't actually available from the factory in the way those cars ran them... Japan also followed what Fred Gibson was doing here with some of there endurance cars in Japan...

Australia is also the reason for things like the Brembo brakes, and the change in the gearbox...

And quite a few other tricks they used to pull.

There's a few other SAU peeps still on these forums that will have heard the stories direct from Alan Heaphy, Fred Gibson, and Jim Richards when we were lucky enough to have a great dinner with them

[Duncan]

Man that dinner was such a long time ago....2010!

I would only replace the rubber coolant lines with silicone these days; cheap, readily available and will last for ever. You will need new hose clamps though eg https://justjap.com/products/cooling-pro-silicone-engine-heater-hose-set-black-nissan-r32-gtr-rb26dett

[r32-25t]

I wouldn’t put those silicon hoses on my worst enemy’s car 

[The Bogan]

44 minutes ago, r32-25t said:

I wouldn’t put those silicon hoses on my worst enemy’s car 

Why?

I just replaced every coolant hose on my NC with silicone hoses

From my understanding they last much longer than rubber

[r32-25t]

They all end up leaking, used all different brands and everyone of them has either leaked straight away or not long after 

[sunsetR33]

13 hours ago, MBS206 said:

Buy yourself the cooling system pressure tester.

Being able to pump it up, and have a gauge on it, AND have a cold engine makes it much easier / practical to diagnose.

Additionally as the engine isn't running, you can listen for pin hole leaks as well as watching if pressure drops away.

In addition, you can pressurise and while doing so, watch all the little rubber hoses. Some fail very brittle, and will just leak, while others can end up very soft and bulge. While a bulging hose isn't necessarily leaking, one of those small ones starting to stretch / expand in a bad way is an indicator that you'll be looking to replace that one soon

I know it'd be much much easier with the tool. I hope I can find one that won't take 3 weeks to get to me an isn't a "Asian models kit" that has tons of (to me) useless adapters for a load of cash.
 

Quote

Depending on if this is a project car, or you'll be dailying it in the summer months would alter how I'd be most comfortable with driving the car and how I'd replace.

Oh, if engine outing, I'd replace as many silicon/rubber inlet joiners as possible too.

It's a summer project/fun car. I do wanna enjoy it, without endless downtime over and over. So yeah I would even go and buy an engine crane + stand to save myself the trouble of hard to reach or unreachable places going bad later on. Would also be a good opportunity to put on a Fluidamper, renew the mains seals and stuff like that. I have some money on the side that I can use for that, what I wouldn't want to or be able to do is let everything be done by a shop or have my engine completely rebuild right now. I intend to do most of the "doable" jobs myself. Pulling an engine can't be that hard, can it?

[sunsetR33]

10 hours ago, joshuaho96 said:

For all the talk of "these parts are junk" I generally recommend OEM because it's really not as bad as claimed. I have never seen or heard of a case like the N63 where the oil returns completely clog with coked oil for example in ~10 years or less. Would it be nice if it were a straighter path? I guess, but most modern cars use a scavenge pump instead of a pure gravity return. Also the factory lines that would be relatively simple to convert to braided are generally speaking hardlines from the factory. I would consider braided line to be a regression, not an improvement. It's also been engineered such that all the hardlines have appropriate strain relief where needed.

There's absolutely room for improvement, for example the HKS advantage heritage intake piping shows just how much can be done to make the turbos fight each other less in OEM twin turbo configuration and reduce compressor surge but it's rarely a simple/straightforward process. I recommend looking at what the group A/N1 cars did, generally speaking the changes they made were necessary and proven in endurance racing.

I know most issues are just age related. But for example the turbo oil drains, there is dash adapters for these and you can just make a braided teflon line for them and (probably) never have them leak again. Also not terribly expensive.
Can you even get the factory hardlines from new? Or are they repairable if they break?

[sunsetR33]

3 hours ago, r32-25t said:

I wouldn’t put those silicon hoses on my worst enemy’s car 

2 hours ago, The Bogan said:

Why?

I just replaced every coolant hose on my NC with silicone hoses

From my understanding they last much longer than rubber

I have some silicon hoses already, for example engine to watercooler. But yeah, I get the sentiment. The lower intercooler silicon hose is drippy too, despite not being very old.

8 hours ago, Duncan said:

Man that dinner was such a long time ago....2010!

I would only replace the rubber coolant lines with silicone these days; cheap, readily available and will last for ever. You will need new hose clamps though eg https://justjap.com/products/cooling-pro-silicone-engine-heater-hose-set-black-nissan-r32-gtr-rb26dett

Does anyone except Nismo make these same lines out of rubber? Long term I think they'd be the better replacement, especially since the car won't live as hard a life anymore as in the past nor be driven as often.

[sunsetR33]

2 hours ago, r32-25t said:

They all end up leaking, used all different brands and everyone of them has either leaked straight away or not long after 

Can you enlighten me on your best practice regarding these hoses? I don't wanna make the same mistake if you already got a better solution.

[Duncan]

8 hours ago, r32-25t said:

They all end up leaking, used all different brands and everyone of them has either leaked straight away or not long after 

I don't know why we've had a different experience, but I've had them on the race car for 18 years and not a drop, and have them on the stagea too, same, no problems.

 

[r32-25t]

7 hours ago, sunsetR33 said:

Can you enlighten me on your best practice regarding these hoses? I don't wanna make the same mistake if you already got a better solution.

I just replace them with factory Nissan hoses

[GTSBoy]

I only use rubber also. I have an intense distrust of silicone for coolant.

[MBS206]

2 hours ago, Duncan said:

I don't know why we've had a different experience, but I've had them on the race car for 18 years and not a drop, and have them on the stagea too, same, no problems.

 

I wonder if part of it has to do with when you've each bought the kits.

I honestly have the feeling that the silicon joiners in the 2000s were actually better quality than most of what you can find these days. Even in the same brands. Everyone racing to the cheapest price while still trying to make profit means lower quality parts.

For coolant, I personally would be going with rubber, OR, converting the radiator and engine to use the huge AN fittings hose for radiators.

[The Bogan]

2 hours ago, MBS206 said:

I wonder if part of it has to do with when you've each bought the kits.

I honestly have the feeling that the silicon joiners in the 2000s were actually better quality than most of what you can find these days. Even in the same brands. Everyone racing to the cheapest price while still trying to make profit means lower quality parts.

For coolant, I personally would be going with rubber, OR, converting the radiator and engine to use the huge AN fittings hose for radiators.

I also think it comes down to the dollars spent for quality items, there's some cheapie versions out there, which look fine, but, there are versions of much higher quality out there, but, you obviously pay more for the quality of materials used and quality control

When I first got work done by Advan Performance on my old R33 the silicone joiners were cheapies and actually blew out on a joiner heading to the plenum, when I then took it to Unigroup they said that the silicone hoses they used and were junk, Unigroup replaced every hose on the engine with much higher quality items and from then I never had a issue with any hose

Additional cost and quality gets you quality silicone base materials and quality reinforcement fabric stuff

As for OEM rubber hoses, again, quality materials and strict quality control will give you quality hoses, but only to OEM spec, I believe using quality silicone replacements is a upgrade

I  saying this I have only dealt with vehicles I own and play with

[joshuaho96]

17 hours ago, sunsetR33 said:

I know most issues are just age related. But for example the turbo oil drains, there is dash adapters for these and you can just make a braided teflon line for them and (probably) never have them leak again. Also not terribly expensive.
Can you even get the factory hardlines from new? Or are they repairable if they break?

Most hardlines are available new still. But unless they're rusted to the point of needing replacement you can just zinc or cadmium plate them to keep them going for decades to come. Regarding the turbo drains it really depends. Braided lines might be better if it's a straighter path than OEM but I would not assume braided teflon lines will never leak. Teflon is a very durable material but you can still abrade, erode, or otherwise compromise its integrity. The return hoses on the bright side are not that hard to access relative to a full turbo removal so if things go wrong you can always put it back to stock.

You can very easily drive yourself insane analyzing every little change, or maybe that's just me.

[sunsetR33]

On 29/03/2025 at 9:46 PM, Duncan said:

I don't know why we've had a different experience, but I've had them on the race car for 18 years and not a drop, and have them on the stagea too, same, no problems.

 

Who made the hoses you used?

[sunsetR33]

23 hours ago, r32-25t said:

I just replace them with factory Nissan hoses

22 hours ago, GTSBoy said:

I only use rubber also. I have an intense distrust of silicone for coolant.

I saw on Amayama most of the rubber hoses are actually available and mostly very inexpensive, but I don't think I can get every single one.
Is it possible to make these hoses myself?

[GTSBoy]

1 minute ago, sunsetR33 said:

Is it possible to make these hoses myself?

If it doesn't have a bunch of funky bends, then yes, you can just use straight hose.