Jump to content
SAU Community

Recommended Posts

Just recently my friend has told me he can do RB conversions to N/A (non-turbo) in his own backyard. I personally thought it was not possible to N/A a turbo RB but my friend insists it can be done.

I was quite interested so I asked him how it could be done and is it street legal/P Plate legal.

Heres what his said:

He said there are different ways of doing, he told me I'll have to block off the turbo lines (oil feed, water feed, and the returns), the air flow meter has to be relocated to a pipe that eventually runs off the throttle body, the exhaust, get a N/A manifold but he wasnt sure if it works with the factory exhaust.

Turbo manifold, remove the turbo itself, and get a pipe made up to match the turbo manifold to the front pipe or he said I can modify the turbo itself and block the front of it.

This is what he told me about it being legal:

He know quite a few people running around in backyard N/A conversions with no trouble at all. He also said its 100% P Plate legal, as long as I can prove its non-turbo. I should just go to EPA or mechanic and get a certificate that its non-turbo.

What do you guys think? So it can actually be done?

Cheers.

Edited by Rallye
Link to comment
https://www.sau.com.au/forums/topic/332441-boosted-rb-converted-to-na/
Share on other sites

Do the smart thing that not many people do

Buy a non turbo Skyline, Drive it, save your money and either buy a GTR/GTST when your done with P's Or spend the money on building a decent engine in the mean time

From the sounds of it your mate doing a 'backyard job' is dodgy at the very least

Just recently my friend has told me he can do RB conversions to N/A (non-turbo) in his own backyard. I personally thought it was not possible to N/A a turbo RB but my friend insists it can be done.

I was quite interested so I asked him how it could be done and is it street legal/P Plate legal.

Heres what his said:

He said there are different ways of doing, he told me I'll have to block off the turbo lines (oil feed, water feed, and the returns), the air flow meter has to be relocated to a pipe that eventually runs off the throttle body, the exhaust, get a N/A manifold but he wasnt sure if it works with the factory exhaust.

Turbo manifold, remove the turbo itself, and get a pipe made up to match the turbo manifold to the front pipe or he said I can modify the turbo itself and block the front of it.

This is what he told me about it being legal:

He know quite a few people running around in backyard N/A conversions with no trouble at all. He also said its 100% P Plate legal, as long as I can prove its non-turbo. I should just go to EPA or mechanic and get a certificate that its non-turbo.

What do you guys think? So it can actually be done?

Cheers.

Of course it is possible to convert a RB25DET to a non turbo RB25DET (notice how I didn't write RB25DE for one simple reason that I will make shortly) no one has ever argued that point. Every one argues the point it is a hell of a lot of work (more so in parts than what you have simply listed), ends up costing quite a bit of money and at the end of the day it will drive like shit and have shithouse fuel economy compared to a factory RB25DE due to the compression ratio! This is the key factor here.

Also as to legalities every state would be different. At the end of the day the car is registered and complianced as a turbo Skyline, when you say taking it to a mechanic to get a certificate, im assuming what you ment to say is to take it to an Engineer for a Engineers certificate and mod plate which in some states may make it legal.

Once again, what the hell is the point?

Edited by PM-R33
Can it be done: Yes

Is it worth it: No not really

Buy a non-turbo Skyline

Just as I thought, can be done but not really worth it.

Lots of work there. It will cost more to buy a turbo skyline, in general, than a non turbo one. Then you'll spend extra to modify it to be non turbo. Unless you were given a turbo skyline for free/VERY low price, this is not economically feasible.

Yeah but I want a R32 N/A which in RB25 is quite a rare find. What do you think if I buy a RB25DE and drop it in a R32 GTST? Same story? Or more practical?

Do the smart thing that not many people do

Buy a non turbo Skyline, Drive it, save your money and either buy a GTR/GTST when your done with P's Or spend the money on building a decent engine in the mean time

From the sounds of it your mate doing a 'backyard job' is dodgy at the very least

Well he is good with engines etc, but if something does go wrong then Im in trouble.

9:1 compression in a turbo engine. 10:1 compression in a non-turbo engine.

If you've ever driven a hyundai getz, that's what you can expect from a deturbofied 25det.

Haha are you serious? Man thats a big turn off lol. Thanks alot.

Of course it is possible to convert a RB25DET to a non turbo RB25DET (notice how I didn't write RB25DE for one simple reason that I will make shortly) no one has ever argued that point. Every one argues the point it is a hell of a lot of work (more so in parts than what you have simply listed), ends up costing quite a bit of money and at the end of the day it will drive like shit and have shithouse fuel economy compared to a factory RB25DE due to the compression ratio! This is the key factor here.

Also as to legalities every state would be different. At the end of the day the car is registered and complianced as a turbo Skyline, when you say taking it to a mechanic to get a certificate, im assuming what you ment to say is to take it to an Engineer for a Engineers certificate and mod plate which in some states may make it legal.

Once again, what the hell is the point?

Ah right, Ill ask him about the compression rate and see what he has to say for it. Im guessing this is when unreliability kicks in aye? Like I said above, what do think if I bought a RB25DE block and drop it in? Still not worth it?

Legality is more important to me than anything else. I dont want to be driving on the edge of my seat everywhere I go. Ive heard that even if you do deturbo an engine/car its still classed as a turbo. Either if its true or not Ill have to heavily research to get a answer.

Thanks alot guys, any more comments would be helpful. :)

Edited by Rallye

This has been posted over and over. Don't bother, from what I've heard if you de turbo a turbo car it's still classified as a turbo. Buy a cheap car and then get a turbo skyline when you finish your p's, or buy a non turbo skyline and upgrade to a turbo down the track.

If you take off a turbo from a GTST it is 100% still classed as a turbo car if you get pulled over my a cop. The only way I can see it being legal is getting an Engineers certificate and modification plate and possiblying speaking to department of transport on whether this is enough or if the car has to be re-registered as a NA.

Haha are you serious? Man thats a big turn off lol. Thanks alot.

90% of these guys have popped a turbo hose. They'll tell you how gay that is.

It's the reality of dropping compression dude. Comp = power.

Yeah but I want a R32 N/A which in RB25 is quite a rare find. What do you think if I buy a RB25DE and drop it in a R32 GTST? Same story? Or more practical?

Just keep searching for an origional rb25de r32. Or if you really cant find one- swapping an rb20de for a rb25de is going to cost you the best part of $3k. If your going to keep the car till your off your p's, the rb25de is a great base for a high comp, mild turbo combination... While your at it you might as well throw some coilovers under it and a set of r33 gtst brakes.

If you do go for an engine swap and your keeping the car for a while, start with an r32 rb25de- as all the rb20 loom will plug in. Install a nistune into your rb20de ecu and tune it the best you can with intake and exhaust mods.

No more det to de! (we need bumper stickers)

to the OP, well done for actually doing a little bit of research and not just coming on here saying I want a skyline deturboed I dont care about power as long as there is a skyline and they end up with an illegal shitbox that wont take them up a hill...

Tell your mate there was a bloke on here that did do what he is proposing and after a couple of months couldnt take it anymore and had to put the turbo back on.

It is sensible to get a 33 rb25de and put it into a 32. Not sure on power to weight ratio / engineers of dropping a motor in, so there may still be a few legal issues there but no where near what you would have with a turbo motor. Only cops who a cluey about rb's will be able to tell the difference in motors, but engine number wont match the firewall plate im pretty sure...

Perhaps, just as piece of mind, look into how much it would cost to get a workshop to drop the motor in instead of your mate, probably will come with a few months warranty and if the motor shits itself you can take it straight back to them, instead of your mate saying sorry bud lets start again.

gl with it.

FAIL - P-plates cant have turbo cars, cant have cars that have mods which require and engineers cert (which converting a turbo to non-turbo will need to have) etc etc,

Just buy a bloody non turbo skyline and be done with it

yeah just buy the non turbo one to start with. if it takes you 6 months to find one then so be it.

a deturbofied rb25det will be an absolute slug. the only way to make it as powerful as a rb25de is to raise the compression which requires a rebuild, so just raising the price even more. you'd be better off just buying a commodore because even one with 500,000kms on the clock that is falling to bits would be better to drive than a rb25det-t (det minus t).

and tell your mate he's an idiot.

9:1 compression in a turbo engine. 10:1 compression in a non-turbo engine.

If you've ever driven a hyundai getz, that's what you can expect from a deturbofied 25det.

A Hyundai Getz will be faster than a de-turboed RB25DET....

Guest
This topic is now closed to further replies.


  • Similar Content

  • Latest Posts

    • Lets say I wanted to buy this, specifically for this purpose. How do I actually perform the function. Can I still buy a Consult-1? Am I about to be burned by the fact my car is a 2000 model Series 2 R34 and thus will be some stupid other system? Do I just need this -> https://obd2australia.com.au/product/nissan-consult-14-pin-to-usb-ddl-diagnostic-interface-with-ftdi-ft232r-chip/ And with what software?
    • That's probably OK. That's a face to face compression joint between two surfaces with the clamping load provided by those bolts. So.... it's unlikely that the bolts will end up feeling that load in shear, unless the clamping surfaces are not large enough, bolts not got enough tension on them, etc etc to prevent the two faces from moving wrt each other. Which... I would hope the designers have considered, seeing as it's probably one of the most important things the upright has to do apart from resist collapsing in its own right. But yes, it would definitely be worth asking them what their safety factor on that part of the design was. I tend to think that the casting, being a casting, is not necessarily the strongest bit of material in the world. It's about an inch square, and when you think about the loads that are being put into it, you have to wonder what safety factor the Nissan boys (and every other OEM engineer who has designed all the millions of other uprights that look essentially the same) used to account for defective casting, aging, severe impacts on the wheel, etc etc. 
    • Those bolts would be orders of magnitude stronger that cast aluminium though.  And its mainly clamping force, not shear they are dealing with?
    • Except all that twisting force that is breaking a cast piece, appears to be going through 4 bolts in the picture Johnny posted of the BryPar one...
    • The smart approach is to use the gearbox loom from the manual car. Makes it a lot easier - just plugs into the switches on the box and plugs into the main loom up near the fusebox. Then you only need to deal with bypassing the inhibit switch. The other approach requires you to use the wiring diagram to identify those wires by colour and location, perhaps even indulging in a little multimeter action to trace them end to end to make sure, and then.... you will have the answers you need. The R34 wiring diagram is available on-line (no, I do not have a link to it myself - I would have to do a search if I wasn't able to go to the copy I have at home).
×
×
  • Create New...