R33 Gtr Turbo Conversion

[tommis85]

Hi all,

I've been wading through the threads on here in regards to doing a single turbo conversion but cant find exactly what I'm after. Maybe you could help me or perhaps provide some links to helpful pages? So far I've found a lot on twin-up grades but not so much on singles.

What I've been researching is converting my GTR from twin to single and I have a couple of question below. Please feel free to elaborate or add to the items that need to be covered as I'm sure I'd missed a couple!

1. The biggest question of all I have is can I get away with out a PFC, at least at the start?

2. When not using a PFC (or equivalent) is it OK to just keep the 2 AFM's by using a "Y" pipe?

3. Seeing that you only have the one dump pipe with single turbo, would you simply bolt both the O2 sensors into the one pipe after one or another (or next to one another, whatever is best) ???

4. Is there anything important to look out for with other sensors that are hooked up to the induction system?

5. When running boost levels/air volume levels around the 1 Bar mark, would I still be OK to run my factory cams? I know that these are ideal for running 2560/2860's etc and in some cases have better results than aftermarket cams - but how would I fair with a single turbo conversion.

6. Obviously you have all your oil/water line issues as well etc

7. I'm yet to decide on the turbo itself. So far I've only researched turbo sizes for a twin upgrade (as this was my original plan) but haven't done too much reading into single conversions. I take it that they would be quite similar to the single upgrades on GTST's, in the GT30 to GT35 region???

They are some of the main points I've been pondering about along with what turbo size would run best with a configeration like that. Obviously, you'd have more tuning capabilities with a PFC if you were to run a turbo that has much different compressor efficiency than the two twins combined etc.

Could anyone please shed some light on these issues for me...possibly someone else who's done the same thing? Ie, started off with twin set-up and then converted it over to single configuration. Any experiences would be muchly appreciated.

Thanks!!!

Tom

[Crans]

You will more than likely run into issues with the stock ecu as the turbo will have different flow at the same PSI probably more flow.

If you lowered the boost to get equivalent flow as the stock twins then you may be ok.

The y pipe for the AFM's should work fine as for the 2 o2 sensors i dont see why that wouldn't work.

Get a remap or nistune forget the pfc is you cant afford it straigt away.

Nistune should cost around $200 + Fitting(If your handy with a soldering iron do it your self. TV repair place should charge $30 to do it)

And around $500 to tune

[tommis85]

Crans,

Yeh well I'm thinking that it should be ok as well as long as you dial in a boost level that provides similar air flow / quantity as the 13 odd pounds that the twin stockies currently spool up. Obviously, a T88 running at 10 pounds on my stock engine will probably kill things haha!

My aim at the moment is not to make insane horses. All I really want to do for now is to replace my set of ticking ceramic time bombs with a modern reliable turbo. I know that upgrading with twin 2860's etc or something like that is the easy fix and much cheaper, but I really want to go for a nice single. Personal thing I'd only be tuning in a boost/air flow volume that the engine support systems would allow, whatever that figure may be - probably 280 to 300hp once it's gone through the transfer case etc. So yeh, nothing major.

I probably wouldnt know what I'm doing with Nistune but it sounds like an excellent system for remapping the ECU's. I'll have to see if the local tuner has access to this equipment.

I think that the very least you'd have to do would be to let the ECU learn the new turbo's air flow all over again with a reset. I'm starting to get the impression that it would be a tedious little exercise with the stock ECU but I guess there'd be at least a couple things you can tweak on the settings.

Do you know of anyone who's done this conversion?

Thanks for the help ;-)

Tom

[(OO)SKYLINE(OO)]

Hi all,

I've been wading through the threads on here in regards to doing a single turbo conversion but cant find exactly what I'm after. Maybe you could help me or perhaps provide some links to helpful pages? So far I've found a lot on twin-up grades but not so much on singles.

What I've been researching is converting my GTR from twin to single and I have a couple of question below. Please feel free to elaborate or add to the items that need to be covered as I'm sure I'd missed a couple!

Thanks!!!

Tom

1. The biggest question of all I have is can I get away with out a PFC, at least at the start?

APexi Power FC Is most probley a MUST when you are doing such an upgrade.

It basicaly maps out your enitre engine signals / sensors as for tuning wise its is very helpful, especialy towards your single high mount turbo.

2. When not using a PFC (or equivalent) is it OK to just keep the 2 AFM's by using a "Y" pipe?

Yes, pic below.

3. Seeing that you only have the one dump pipe with single turbo, would you simply bolt both the O2 sensors into the one pipe after one or another (or next to one another, whatever is best) ???

Yes, it is just visible in the pic below.

4. Is there anything important to look out for with other sensors that are hooked up to the induction system?

I would say just your Air Flow Metres and your 2 O2 Sensors. They are your main ones and probley the only ones in that area.

5. When running boost levels/air volume levels around the 1 Bar mark, would I still be OK to run my factory cams? I know that these are ideal for running 2560/2860's etc and in some cases have better results than aftermarket cams - but how would I fair with a single turbo conversion.

LOL! One thing leads to another, I would do the cams and also depending how much boost you want to run.

Seeing as that you want a single high mount its gonna be running probley abit more than 1 Bar.

6. Obviously you have all your oil/water line issues as well etc

Yep, car will run abit hotter, so you will need gauges to show the readings and improve / upgrade its cooling systems.

Install an Oil Cooler and upgrade the radiator.

7. I'm yet to decide on the turbo itself. So far I've only researched turbo sizes for a twin upgrade (as this was my original plan) but haven't done too much reading into single conversions. I take it that they would be quite similar to the single upgrades on GTST's, in the GT30 to GT35 region???

HKS T51-SPL, GReddy/TRUST T88H-38GK pretty much do the same job.

I think these turbos have similar specs, so you will get similar results, but also depending on your tuning.

They are some of the main points I've been pondering about along with what turbo size would run best with a configeration like that. Obviously, you'd have more tuning capabilities with a PFC if you were to run a turbo that has much different compressor efficiency than the two twins combined etc.

Could anyone please shed some light on these issues for me...possibly someone else who's done the same thing? Ie, started off with twin set-up and then converted it over to single configuration. Any experiences would be muchly appreciated.

Can I ask why you want to go single high mount?

Whats your purpose? Top end speed / drag racing..?

It will all depend on what you want to use the car for, which will determin your setup.

I prefer Twin Turbo low / highmounts as they are more responsive as with single high mounts, boost will not hit till later in the rev range.

Boost hits at 6000 RPM as I have test in the R33 GTR pic below with 455 awkW's

[unique1]

1. The biggest question of all I have is can I get away with out a PFC, at least at the start?

APexi Power FC Is most probley a MUST when you are doing such an upgrade.

It basicaly maps out your enitre engine signals / sensors as for tuning wise its is very helpful, especialy towards your single high mount turbo.

2. When not using a PFC (or equivalent) is it OK to just keep the 2 AFM's by using a "Y" pipe?

Yes, pic below.

3. Seeing that you only have the one dump pipe with single turbo, would you simply bolt both the O2 sensors into the one pipe after one or another (or next to one another, whatever is best) ???

Yes, it is just visible in the pic below.

4. Is there anything important to look out for with other sensors that are hooked up to the induction system?

I would say just your Air Flow Metres and your 2 O2 Sensors. They are your main ones and probley the only ones in that area.

5. When running boost levels/air volume levels around the 1 Bar mark, would I still be OK to run my factory cams? I know that these are ideal for running 2560/2860's etc and in some cases have better results than aftermarket cams - but how would I fair with a single turbo conversion.

LOL! One thing leads to another, I would do the cams and also depending how much boost you want to run.

Seeing as that you want a single high mount its gonna be running probley abit more than 1 Bar.

6. Obviously you have all your oil/water line issues as well etc

Yep, car will run abit hotter, so you will need gauges to show the readings and improve / upgrade its cooling systems.

Install an Oil Cooler and upgrade the radiator.

7. I'm yet to decide on the turbo itself. So far I've only researched turbo sizes for a twin upgrade (as this was my original plan) but haven't done too much reading into single conversions. I take it that they would be quite similar to the single upgrades on GTST's, in the GT30 to GT35 region???

HKS T51-SPL, GReddy/TRUST T88H-38GK pretty much do the same job.

I think these turbos have similar specs, so you will get similar results, but also depending on your tuning.

They are some of the main points I've been pondering about along with what turbo size would run best with a configeration like that. Obviously, you'd have more tuning capabilities with a PFC if you were to run a turbo that has much different compressor efficiency than the two twins combined etc.

Could anyone please shed some light on these issues for me...possibly someone else who's done the same thing? Ie, started off with twin set-up and then converted it over to single configuration. Any experiences would be muchly appreciated.

Can I ask why you want to go single high mount?

Whats your purpose? Top end speed / drag racing..?

It will all depend on what you want to use the car for, which will determin your setup.

I prefer Twin Turbo low / highmounts as they are more responsive as with single high mounts, boost will not hit till later in the rev range.

Boost hits at 6000 RPM as I have test in the R33 GTR pic below with 455 awkW's

are u for real with some of those answers???? a gt30 or 35 is not the same as a t51r or t88, thats complete rubbish. changing cams is not needed at all if you dont want to, it will make good power with stock cams for sure. The radiator is fine dont touch it, i think u like to make people think its an expensive and difficult exercise with listing some of that stuff, it sounds like u been repeating info u have heard and not actually done it yourself.

give me a pm if u need any specific info to the topic starter i have done 2 single turbo conversions on different setups and they are great if u pick the correct turbo u dont have to choose a t88 or t51 if u go single at all, this is the point people dont seem to understand.

[jay1]

good info thanks

[tommis85]

Hi (00 \SKYLINE/ 00),

Ok, looks like we have some differences in opinion above but that's excellent. It generates more problems and ideas for the conversion which makes sure that as many things as possible are covered before I fork out the big dollars. Up to point 4 or so is excellent, that confirms a fair few things then. However, my opinion differs in these points:

5. If I was to run a turbo that's even half the size of the ones you recommend I highly doubt that I would be running it on more than 1 Bar. Chances are that on my factory support system I'd be running it on a mere 12-13 pounds to start off with due to it's much higher air flow volume (efficiency) than the tiny stockos on there. I'm thinking that if I ran something in the GT30-35 range at 14 pounds it would be equivalent to running the stockies at 17-18 pounds as far as efficiency goes. And that's a lot on stock motor.

6. the car will run as hot as I drive it. I generally drive quite peacefully. On our track days, the engine temp didn't budge from half way and that's on 13 pounds...the only temps that did sore were the oil temp so for that I will need to get decent oil coolers. I'm amazed by how well the radiator works in these RB's....but yes, oil cooling must have been left out by Nissan.

7. yeh this area is open to opinion from everyone. So many turbos to chose from but what I want is to retain drivability which means that boost should come on at around 4000 (a bit higher than the stockies) and not at 6000 lol. That's pretty rough haha - I've seen plenty of youtube videos with big turbos, doesn't look very driveable especially on the circuit. But yeh, I dont think I want a turbine that big - not on a little 2.6L anyway. Them things are the size of soccer balls lol!

The thing is I've seen plenty of very nice GTR track cars with singles in them and they pull out of the corners like crazy. They pretty much bounce from corner to corner so yes, with a nicely sized turbo (or custom turbo) you can get some very decent response for track racing (which I do - which is purpose of car etc). I would like to have both nice responce from the turbo but I also want it to be there all the time when flying down the straight where on this one, you can reach about 220-240km/h in Porsche GT3's. So yes, I don't want the turbo to run out of puff because it's too small or has incorrect ratios.

I might yet go my twin upgrade option...but I want to fully explore both paths. Twins go exceptionally well and new modern small turbos get awfully close in response to the tiny little ceramic jobs from 13 years ago. But as I said, there are some awesome single setups out there that would blow the pants of my GTR on the track haha!

Unique, I'll answer to yours shortly...just have to duck out. Thanks heaps for sharing your knowledge with me so far - very muchly appreciated!!!

Cheers,

Tom

[(OO)SKYLINE(OO)]

Hi (00 \SKYLINE/ 00),

Ok, looks like we have some differences in opinion above but that's excellent. It generates more problems and ideas for the conversion which makes sure that as many things as possible are covered before I fork out the big dollars. Up to point 4 or so is excellent, that confirms a fair few things then. However, my opinion differs in these points:

5. If I was to run a turbo that's even half the size of the ones you recommend I highly doubt that I would be running it on more than 1 Bar. Chances are that on my factory support system I'd be running it on a mere 12-13 pounds to start off with due to it's much higher air flow volume (efficiency) than the tiny stockos on there. I'm thinking that if I ran something in the GT30-35 range at 14 pounds it would be equivalent to running the stockies at 17-18 pounds as far as efficiency goes. And that's a lot on stock motor.

6. the car will run as hot as I drive it. I generally drive quite peacefully. On our track days, the engine temp didn't budge from half way and that's on 13 pounds...the only temps that did sore were the oil temp so for that I will need to get decent oil coolers. I'm amazed by how well the radiator works in these RB's....but yes, oil cooling must have been left out by Nissan.

7. yeh this area is open to opinion from everyone. So many turbos to chose from but what I want is to retain drivability which means that boost should come on at around 4000 (a bit higher than the stockies) and not at 6000 lol. That's pretty rough haha - I've seen plenty of youtube videos with big turbos, doesn't look very driveable especially on the circuit. But yeh, I dont think I want a turbine that big - not on a little 2.6L anyway. Them things are the size of soccer balls lol!

The thing is I've seen plenty of very nice GTR track cars with singles in them and they pull out of the corners like crazy. They pretty much bounce from corner to corner so yes, with a nicely sized turbo (or custom turbo) you can get some very decent response for track racing (which I do - which is purpose of car etc). I would like to have both nice responce from the turbo but I also want it to be there all the time when flying down the straight where on this one, you can reach about 220-240km/h in Porsche GT3's. So yes, I don't want the turbo to run out of puff because it's too small or has incorrect ratios.

I might yet go my twin upgrade option...but I want to fully explore both paths. Twins go exceptionally well and new modern small turbos get awfully close in response to the tiny little ceramic jobs from 13 years ago. But as I said, there are some awesome single setups out there that would blow the pants of my GTR on the track haha!

Unique, I'll answer to yours shortly...just have to duck out. Thanks heaps for sharing your knowledge with me so far - very muchly appreciated!!!

Cheers,

Tom

Cool man!

Btw didn't mean to confuse anything. LOL!

When I said "HKS T51-SPL, GReddy/TRUST T88H-38GK pretty much do the same job.

I think these turbos have similar specs, so you will get similar results, but also depending on your tuning"... I was compaing the actual 2 turbos NOT against your GT-50-35.

Just going from the set up I had seen thats all.

I still think you should upgrade the cooling side of things, doesnt hurt but I guess you and your mechanic can sort that out and you will eventually find out if you need to or not, thats if you do go down the track with a single conversion.

I still prefer twin set up, just my liking of the quicker response.

Anyway let me know how you go.

Thanks.

[unique1]

Cool man!

Btw didn't mean to confuse anything. LOL!

When I said "HKS T51-SPL, GReddy/TRUST T88H-38GK pretty much do the same job.

I think these turbos have similar specs, so you will get similar results, but also depending on your tuning"... I was compaing the actual 2 turbos NOT against your GT-50-35.

Just going from the set up I had seen thats all.

I still think you should upgrade the cooling side of things, doesnt hurt but I guess you and your mechanic can sort that out and you will eventually find out if you need to or not, thats if you do go down the track with a single conversion.

I still prefer twin set up, just my liking of the quicker response.

Anyway let me know how you go.

Thanks.

lol fair enough, i dont see why a smaller sized single with same power output as a set of twins will be any worse off really for response, i realise the long runner manifold wont help but the lag difference is gonna be minimal at best. I think anyone who goes single usually goes for the dirty great turbos (t51r, t88, t04z, etc) and then people compare them to a set of n1's, etc and say the singles are laggy.

If u are only chasing around the 400hp max mark, i would look at a gt3076, 0.82 housing, they max out around 410hp at wheels or so, but are super responsive and would be awesome on a 2.6L, i have one going on my 3l at moment, will be running in a couple of days, so will be interesting to see how it goes. my other engine has a t04z which doesnt make decent power until 4500rpm and then its flying, the 3076 should be pulling well around 3000rpm i reckon.

I would stay away from the gt3540 (now called 3582), my mates ones running one is not much more responsive than my t04z and he is running poncams too, its not making anything under 4k rpm, not ideal for any street action, and only benifits is if u wanna make over 500hp at wheels. Then again some people claim these are fine and lag isnt too bad, i suppose its personal opnion, as u will know its a compromise between power capability and lag, you generally cant have both

I dont know if going single is worth it for the job u want though, by the time u buy the oil and water lines, turbo, manifold, gate, modify exhuast, intake pipe mods, its not that cheap really. oil and water lines in braided last time cost me around $360 mark, in alloy metal hard lines and fittings (the stock look), cost me in the $180-$200 range. manifold depends on brand, usually around the $1200 mark for a good steam pipe one, wastegate $500-$800, turbo is $1800 or so, and then exhuast and intake mods depends on who does them.

anyway thats my 2c worth on the subject

[tommis85]

Unique1,

Well, thanks for the discussions above. That's exactly what I was hoping for - to uncover some more areas on it and maybe hear from people who've done it. Chances are, that I'll most likely go for a set on twins (GT2560's for similar response, or GT2860/disco potato for big twin upgrade).....but this would only be to guarantee very similar response on the track also because it will only cost me around $3800 minus the dyno tune's.

I've been in a mates R33 GTST with a fully worked engine running 418rwhp with a GT3540 (i think from memory) and wow, the thing howls. These turbos don't 'woosh' or 'whistle', they HOWL like a bloody jet engine and once it does kick in it really throws you back. Quite violent, because of the lag period and then the lurch when it builds up the 18 odd pounds.

So yeh, the sound and engine bay looks associated with medium to large single unit are pretty awesome in my opinion. Also gets rid of some of the clutter in the engine bay and is all very easy to access compared to a set of low mounted twins.

I dont know if going single is worth it for the job u want though, by the time u buy the oil and water lines, turbo, manifold, gate, modify exhuast, intake pipe mods, its not that cheap really. oil and water lines in braided last time cost me around $360 mark, in alloy metal hard lines and fittings (the stock look), cost me in the $180-$200 range. manifold depends on brand, usually around the $1200 mark for a good steam pipe one, wastegate $500-$800, turbo is $1800 or so, and then exhuast and intake mods depends on who does them.

Yeh I know what you mean there. With a PFC included, the single conversion will set me back at least $8 to 9000 I reckon...probably less the more time you spend shopping around or even doing the work yourself like some people on here.

I've had my chance with serious car mods - my previous cars were a Mitsubishi Cordia and R33 GTST and both went a lot harder than my GTR went when it was stock, but they didnt come close to the GTR's stock handling!!! No way. But yeh...I put in many thousands into engine mods and re-builds and am now wishing that I put all this hard earned money into the GTR instead - with the same style and type of mods in would be seeing well over 500hp. (engine rebuild with forge's, ignition system upgrade, fuel pump and lines, turbo upgrades, exhaust and induction upgrades, gearbox......you know, all that stuff that could have seen so many more horses when put into the GTR!) But that's an old story lol - don't wanna bore you with it.

Ohwell, what can you do hey? I sold them cars and now have a clean slate but don't know if I want to spend that heavily again. I also know, from experience that one thing leads to another with cars even when you limit yourself at the start.

[saliya]

Hi all,

1. The biggest question of all I have is can I get away with out a PFC, at least at the start?

Yes.

However, you will be severely limited as to the airflow you can run as the stock computer simply isn't mapped to the levels you're going to be wanting to flow

unless you go down the path of a single that is almost exactly equivalent to the stock twins (in which case, why bother?).

If you have a budget issue, stay away from a single conversion - a decent manifold, new turbo, inlet piping, oil/water lines, and exhaust will probably run to around $6k not including labour to fit.

If you want to do it with new clutch, potentially gearbox, injectors, fuel pump, cams, headwork, other (depending on how far outside the original performance envelope you are and how good/bad the condition of relevant parts in your car are) budget another $7+k not including labour to fit - start getting quotes...

2. When not using a PFC (or equivalent) is it OK to just keep the 2 AFM's by using a "Y" pipe?

Yes, but you will probably find you need to use pods as there probably won't be room to connect a Y pipe and AFMs back to the factory airbox.

3. Seeing that you only have the one dump pipe with single turbo, would you simply bolt both the O2 sensors into the one pipe after one or another (or next to one another, whatever is best) ???

Yes. Mine are side-by-side; but I can't imagine it would make all that much difference.

4. Is there anything important to look out for with other sensors that are hooked up to the induction system?

Not really - for the intake part you will be messing with, the only thing you need to figure out is whether you

want to keep the BOVs and if so, allow for a return for them upstream of the compressor (i.e. into that Y pipe - most don't have this).

5. When running boost levels/air volume levels around the 1 Bar mark, would I still be OK to run my factory cams? I know that these are ideal for running 2560/2860's etc and in some cases have better results than aftermarket cams - but how would I fair with a single turbo conversion.

Yes. However, I found that with my T04Z and stock cams, power delivery was very on-off and quite high in the rev range.

HKS 272 step 2 cams changed the power delivery from light-switch-like to something that was more controllable and about 500RPM lower.

You will probably find something similar with anything flowing substantially more air than stock.

6. Obviously you have all your oil/water line issues as well etc

Yes. Those can be a pain.

7. I'm yet to decide on the turbo itself. So far I've only researched turbo sizes for a twin upgrade (as this was my original plan) but haven't done too much reading into single conversions. I take it that they would be quite similar to the single upgrades on GTST's, in the GT30 to GT35 region???

I like my T04Z; but were I to do it again I'd probably go with something slightly smaller. The T04Z is just that little-bit-too-big for a stock GTR -

to use all of its airflow capacity on an RB26 you need to upgrade a lot of other stuff (fuel pump/fuel system/injectors/clutch/gearbox) which is time-consuming and spendy.

Remember, the farther outside the stock performance envelope you go, the more stuff you'll break

Regards,

Saliya

[tommis85]

Saliya,

Thanks for all that info - very well set out! All your points are so valid, especially your first and last ones and yes, rough estimates/quotes have put the cost for a single turbo conversion around the 7 to 8 grand mark - but that's with a slightly expensive mob here in town.

To be honest I think that for me the best thing to do would be to upgrade my twin's with a set of modernised N1 style turbos, ie, the 2560's. They will bolt on directly and all you may have to do is replace some banjo fittings if required.

In all honestly it would be cheaper to buy some poor bastards GTR with all the work (not just turbo) already done on it - but then you never get the experience the feelings of it being all your own work etc as you upgrade step by step.

If I was to upgrade with a set of twins I'd be able to run a even Bar everyday wouldn't I? I'm thinking that the stock support systems (fuel, iginition, AFM's etc) should easily be capable of running 14 to 15 pounds and from memory, the 2560's are rated all the way to 17-18 pounds max (to be confirmed lol!) Obviously I'd want to get some dyno tune runs in before and after to make sure that it's all working properly.

But yeh, from all the discussion above and from what my mechanic has told me, it'd be best if I went with a twin upgrade with new, modernized turbos of roughly the same caliber with the main reason for doing so being to replace the inferior ceramic time bombs that could, even at stock boost levels, blow up at any time depending on how you treat them.

Tom

Edited November 16, 2008 by tommis85

[(OO)SKYLINE(OO)]

Thanks for the info unique1.

we cleared things up. Hehe!

Peace!

[tommis85]

Yeh that wasn't too bad an effort at all people - thanks for the info. Off course people out there can still add to it, but so far it's already a pretty good reference for anyone tossing up between the twin and single turbo options.

For those people who are reading this, my mechanic has quoted me a maximum of $3800 to get two GT2560's fitted not including a couple of dyno runs for tuning etc. These turbos should give me very similar performance to the N1 units.

If you go for this option it leaves money that can be spent on other bits and pieces needed for track events like oil coolers, brakes, tires and possibly suspension although this is not half bad in the GTR in stock trim.