How to turbo your N/A

[Hanaldo]

hey martin,

i checked the valve, i can push it with my thumb but its quite stiff....

jason

Yeh that's how mine is... Could you maybe take a photo of how you've plumbed up the bov, perhaps I'm picturing it wrong?

[gts25]

Hey Martin,

Yep will do. I will take a photo

Jason

[gts25]

HI Martin,

I haven't taken a photo of my engine but used a photo from the web to explain how I have plumbed it.

Is this correct?

Jason

Edited May 17, 2012 by gts25

[Hanaldo]

Hey mate,

Ok, I'll start with what I know for sure. Number 3 looks like the hose for the IAC valve. Which would explain why the bov did not work, because once the car is warmed up, that hose is blocked from the plenum and essentially does nothing. So that would work exactly as it would if you teed into any other pre-throttle body source.

Number 2 is a bit confusing. That looks like factory plumbing, but the bov should be plumbed into a source AFTER the throttle body. Plumbing it in before hand would serve no purpose, the bov would not function. So not sure why it's been done like that unless again, I can't see something. It's different to the RB25 setup so I can't compare.

Number 1 looks like it should work, but I can't see where the port below it is going so it may not. For science sake, try tapping into a line that you know is working AND gets it's vacuum source from after the throttle body. The fuel pressure reg for instance.

[gts25]

Hey Martin,

Yes the BOV is plumbed in using the factory piping/hoses. The small hose connects to one of the 3 metal pipes that bolt to the inlet pipe (that goves over the engine). On the other end is a hose that goes to the top of the manifold as shown. (number 2 connects to number 1 in the picture)

Just so I am sure when you guy's say AFTER the throttle body you mean on the inlet manifold side don't you. If so haven't I got it in the correct location?

Where does the RB25DET gets it vacum source for the BOV?

Jason

Edited May 18, 2012 by gts25

[Hanaldo]

Hey Martin,

Yes the BOV is plumbed in using the factory piping/hoses. The small hose connects to one of the 3 metal pipes that bolt to the inlet pipe (that goves over the engine). On the other end is a hose that goes to the top of the manifold as shown. (number 2 connects to number 1 in the picture)

Just so I am sure when you guy's say AFTER the throttle body you mean on the inlet manifold side don't you. If so haven't I got it in the correct location?

Where does the RB25DET gets it vacum source for the BOV?

Jason

Oh I seeeee, fair enough. In that case the RB25 gets it's source from the exact same place, it just has a hose that goes directly there instead of being run underneath the crossover pipe. And yes, after throttle body meaning plenum side. Reason being is all the piping that is pre-throttle body is still going to be pressurized when you lift off the throttle, therefore holding the bov shut. You need a source that will be under vacuum when the throttle body closes, which is anything on the plenum side of the throttle body.

But, it sounds like you have it setup correctly. I still recommend trying to tee into a different source just to be sure (perhaps use a different length of hose instead of cutting anything so that it is easy to return to how it was if it doesn't work). If that doesn't work then I would suggest trying a different bov, one you know is working properly.

[gts25]

Great - thanks Martin.

I will try another source of vacum and/or another bov

Jason

[asps91]

havent you forgotten to list pistons ?

you need low compression pistons, otherwise using the standard high compression pistons that NA's have will just F*&k ure engine VERY quickly.. although i have heard u CAN run a turbo, low boost (such as 7psi max) and still get a very quick car outta it without changin pistons.

Can't the headgasket just be changed to decrease compression and therefore run more boost? Thats what we used to do to n/a supras when we went turbo.......

[blk94r33]

Can't the headgasket just be changed to decrease compression and therefore run more boost? Thats what we used to do to n/a supras when we went turbo.......

Yes, you can use a thicker headgasket to lower the compression. Most people including myself don't though as it gives better response, more bottom end torque and saves alot of hassle of removing and re-fitting the head. So long as you can prevent the car from pinging with conservative boost, timing and good quality fuel, high compression won't cause problems.

[gts25]

Oh I seeeee, fair enough. In that case the RB25 gets it's source from the exact same place, it just has a hose that goes directly there instead of being run underneath the crossover pipe. And yes, after throttle body meaning plenum side. Reason being is all the piping that is pre-throttle body is still going to be pressurized when you lift off the throttle, therefore holding the bov shut. You need a source that will be under vacuum when the throttle body closes, which is anything on the plenum side of the throttle body.

But, it sounds like you have it setup correctly. I still recommend trying to tee into a different source just to be sure (perhaps use a different length of hose instead of cutting anything so that it is easy to return to how it was if it doesn't work). If that doesn't work then I would suggest trying a different bov, one you know is working properly.

Hi Martin,

I believe I have found the issue. The vacuum source on the inlet manifold that I am using for the bov (the charcoal canister port on the na setup) has some kind of restriction. I have a complete rb20det where I sourced all the turbo bits from and pushed a piece of wire into each port. On the BOV port the wire goes right into the manifold whereas on the other port the wire only goes in part way. There must be a valve of some sort.

Whilst I could go through the big task of swapping the top of the manifolds over, I really do not want to if I could get away with using another source for vacuum.

I had a quick look and don't know the best place I can use. I looked at the fuel pressure reg but this size of this port is smaller then I need.

Do you know (or anybody) where I could plumb it in? I thought about having a fitting made up that I could screw into where the factory boost gauge plumbs into (a t fitting that would allow me to plumb both the bov and boost guage). Could this work?

Jason

Edited May 23, 2012 by gts25

[Hanaldo]

Ah yeh, that would explain it.

You should be able to plumb the bov in to anywhere that gets both vacuum and boost. The boost gauge source should work.

[gts25]

Thanks Martin,

Let's see how we go....

[Manuel Kasko]

Hi Martin

[Hanaldo]

Hey...

[Dan_J]

Done this turbo conversion last weekend with my rb20de.

Thought i should take some pics of the plugs on the side of the block for people as i dont think i have seen any on here yet.

for the oil return i used proflow part no. PFE841-12 3/4 NPT to Barb.

Also fuel economy is pretty much the same too.

if thats the case and no drilling is required on the 20de's that are thread taped from factory, how does one tell a rb20det long motor from a rb20de long motor ?

Edited May 24, 2012 by Dan_J

[Grey]

Hi guys, so I've just read through all 37 pages of this thread and from what I could saw, at the start there was a LOT of interest going on in favor of getting the conversion done. Towards the middle there was some doubt and some people were saying, JUST BUY A GTT or a car that already has a turbo in it!!! Saves a lot of headaches...

Now it is 2012 and this thread started wayyyyyy back.... Since R34 GTTs are almost the same price as 25GTs now, considering the drop in price for the parts for the conversion, do you think it is still worth it to do a turbo conversion for my R34 neo rb25de? I've actually spent a fair amount of time and money on the car already, and I know my car hasn't been thrashed around like most of the other R34 GTTs on the market.

I'm considering doing everything myself and getting the most BUDGET aka cheapest bits for my car, leaving the internals stock and getting a professional tune. How much rwkw am I looking at? And also how much will it cost as of may 2012?

Figures that I predict are from 100rwkw ---> 150-160rwkw?

Price about 1000-2000 dollars for parts and tune?

But I guess power isn't everything, I just want a really responsive car that has massive amount of torque lol.....

Car is pretty much stock as rock and I want to go for a sleeper look.....(personal reasons)

All help welcome =D

[Hanaldo]

Hi guys, so I've just read through all 37 pages of this thread and from what I could saw, at the start there was a LOT of interest going on in favor of getting the conversion done. Towards the middle there was some doubt and some people were saying, JUST BUY A GTT or a car that already has a turbo in it!!! Saves a lot of headaches...

Now it is 2012 and this thread started wayyyyyy back.... Since R34 GTTs are almost the same price as 25GTs now, considering the drop in price for the parts for the conversion, do you think it is still worth it to do a turbo conversion for my R34 neo rb25de? I've actually spent a fair amount of time and money on the car already, and I know my car hasn't been thrashed around like most of the other R34 GTTs on the market.

I'm considering doing everything myself and getting the most BUDGET aka cheapest bits for my car, leaving the internals stock and getting a professional tune. How much rwkw am I looking at? And also how much will it cost as of may 2012?

Figures that I predict are from 100rwkw ---> 150-160rwkw?

Price about 1000-2000 dollars for parts and tune?

But I guess power isn't everything, I just want a really responsive car that has massive amount of torque lol.....

Car is pretty much stock as rock and I want to go for a sleeper look.....(personal reasons)

All help welcome =D

First of all, this is not the attitude to have going in to these sorts of jobs. It's a lot of work, and you need to be prepared for costs to get out of hand. Take your budget and triple it. Take your time frame for when you want it back on the road and triple it.

Secondly, your comment about most other 34 GTT's on the market being thrashed is also a bit naive. There's plenty of blokes like yourself who look after their cars.

My advice? Buy a GTT. It is honestly a hell of a lot easier. I went down the path of converting my GT to a GTT by simply swapping engines/gearbox/diff etc. etc. I've suffered for it ever since. I don't know if I would say I regret it, but I will tell you that the headaches are endless.

Edited May 31, 2012 by Hanaldo

[Grey]

Hanaldo: I understand where you're coming from, but from what I've read, some blokes are starting the job at 7.30pm and finishing the job at 5am the next morning, so apparently it's an 'easy' conversion, you just have to pick up the bits and pieces from this forum somewhere..... I want to experience the learning and go through what it's like to slowly and carefully put on a turbo and all the other bits and pieces then get it tuned, without the hassle of buying a GTT and not knowing how the engine is like, or what has been done to it. What I meant by budget, was BANG FOR BUCK. I don't want to be lazy and just sell my car and buy a turbo one, I like to do these conversion things, it sounds fun, but I'm not rich and I don't have all this extra money to be going into a car, so I would like a BANG FOR BUCK conversion....

Did you say you popped an RB25DET in? I don't want to do that, i'd rather buy a GTT but where's the fun in that? There is insurance, stamp duties, transfer fees, RWC, finding, selling, rego fees to pay that is involved with selling a skyline and buying another one. Instead I want to bolt a turbo on. Plus I've heard that the difference between a GT and a GTT is just brakes, ecu, and pistons. If i leave the pistons/brakes stock, all i'll need is a few bits and pieces and it should be fine, with the possibility of forged pistons later down the road for higher boost.

reason i said it was cheap and easy was because after reading the 37 pages, I get some people saying that they've done it for under 1.5k.

[Hanaldo]

You're going about it the wrong way. You've just compared selling/buying a car, to turbocharging a motor that was never designed to be turbocharged. I realize I might come across as a prick in saying that, but I honestly don't think you're understanding what's involved here. You don't want to do the brakes later. The stock GT brakes are absolutely rubbish, I didn't want them on the stock NA motor let alone a turbocharged motor. Do the brakes and suspension first, then think about turbocharging it.

This also definitely isn't an easy conversion. I've read Gerg_31's build thread on here, he made building an RB26/30DE look ridiculously easy. It isn't. This conversion might be easy compared to other things, but it is by no means easy in reality. There's so many things that can go wrong. Don't pay attention to the ones that say it is cheap and easy to do, pay attention to the ones that are saying it isn't. You need to over budget not under budget, and trust me, it is so ridiculously easy to under budget. You've said you don't have a lot of money to be putting into the car, how much would you consider a lot of money?

With that all said, it's refreshing to see someone doing the research before saying they want to do something, so I commend you for that. I suggest you do more reading than just this thread though. Also talk to people who understand what is involved, people who have done the conversion, workshops who have done this sort of work.

[Grey]

Alright Hanaldo, I'll take your advice and look into it more at exact price, time etc. But you have to admit, some people make the conversion sound like a piece of cake.