Jump to content
SAU Community

Recommended Posts

For those who might recognise me, I've decided not to risk driving a GTS-T on my P's for 3 years. But I can't not have this car. So I thought about un-turboing it.

It'll have to be a good enough job to be registerable as a naturally-aspirated engine, so I need all the ideas and help I can get. I'm assuming simply disconnecting the turbo from the intake manifold won't be enough for the insurance companies because the turbo will still be there.

Anyone? Many many thanks in advance.

Link to comment
https://www.sau.com.au/forums/topic/156404-un-turbocharging-a-gts-t-advice/
Share on other sites

It wont be registed as an N/A, the build plate says turbo, the car is legally turbo.

Therefore, thats what the car is.

You must but a N/A car, not de-turbo a gts-t.

That does not circumvent the law

well, it's not that simple.

Your exhaust manifold flows through the turbo. If you take the turbo off, you'll need to get an na manifold.

you'll need to do all the intake piping like the na car.

keep in mind the turbo has oil and water lines. they'll probably need to be removed, and the outlets bunged.

It's not an easy job.

I know that you don't want to think in retrospect, but perhaps you should have thought about it before you bought it? The reason why I brought this up, is what is your added fear now?

If you were to continue driving it (i'm not condoning it), but is there any additional problem to what you initially anticipated?

Perhaps sell it and buy an na? or keep it in the garage for 3 years?

to keep you excited and liking your car during this time, maybe while it's in the garage, you could do a build up. Or just get an older friend to drive you around in it every weekend? I'm sure he/she won't mind.

You wouldn't want to do that anyway. An N/A has a compression ratio of 10.1 or there abouts and a turbo around 8.5 i think. Without the turbo your 'un-turboed' car would be an absolute slug. Don't do it.

I say convert it to NA and drive it around. if you get pulled over the police can see its not turbo.

just find all the bits you need and install it. bung up the holes for the turbo lines and take out the intercooler piping etc etc

It can be done and if you love the car lots then it could be OK in the long run as you can start modding the rest of the car untill your ready.

You may be down on power a little when it comes to other NA skylines but you can always invest in a set of extractors for it and a air filter etc etc.

I say convert it to NA and drive it around. if you get pulled over the police can see its not turbo.

just find all the bits you need and install it. bung up the holes for the turbo lines and take out the intercooler piping etc etc

It can be done and if you love the car lots then it could be OK in the long run as you can start modding the rest of the car untill your ready.

You may be down on power a little when it comes to other NA skylines but you can always invest in a set of extractors for it and a air filter etc etc.

it will still be illegal to drive without a turbo on it as the car was built as a turbo even with the turbo taken off it will be taken on the power to weight ratio of the turbo charged engine.

my advice is park it up and get ya dad to drive it only on weekends buy a 500 buck sh**box to hack around in till you can drive the turbo

Dont know bout the legality's but a turbo motor converted to n/a will be a slug, and would probably be cheaper to remove the turbo motor intercooler etc. and replace the whole lot with a n/a motor rb30 maybe even, If you can do the work yourself even more so. And you would have an awesome project once you do put the turbo motor back in building up the rb30 to be your next motor! :mad:

Just a thought.

im with this guy.

yeah right! THe amount of money that you lose when buying and selling and buying another car, selling that, then buying a skyline again is huge. Think of all the stamp duty, money lost, rego, insurance etc.

you'll hvae to pay stamp duty 3 times!!!

Whatever money you make from 'investing' will be less than the amount lost.

surely if you got pulled over by a copper and told him its non turbo and he checks he wont give two hoots.

if you take it to court you would win anyway.. not that it would ever get that far.

i had an R31 with a RB25det in it before i got my 33, i got defected and had to go over the pits, i found out, if i converted it to an NA rb25 then it would go through without a brakes upgrade, engineers cert etc. (couldnt afford it at the time), anyways, i took the manifold off, put NA one one, plugged up all the fittings etc, got NA inlet piping etc....used turbo AFM, bla bla bla.....RAN LIKE A DREAM. smooth as, and it didn't drive too bad! believe it or not. The Turbo has a 9:1 comp ratio which is the same as an NA rb30 anyways...

cutting a long story short, ended up doin a swap of some 'silver plates of some sort' and had to undo the conversion for no apparent reason. hehe...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Ha, well, it's been.... a bit of a journey. Things have taken much longer than I'd hoped. I'll probably put up a thread at some stage. Hopefully soon. The car's not done any kms since my update in June though, put it that way.
    • Here's the chart for fuel pressure vs. current draw, assuming your base fuel pressure is 3 bar and you run like 0.5bar boost on WOT, you should only momentarily hit 9amps here and there. (Ignore my prev post, I cannot read a chart these days it seems)
    • Those comp test results are not hideous. Whether they are accurate or not (ie, when that comp tester says 140 psi, is the real pressure120, 140 or 160?) is unknown to us. The state of the battery used to crank it over is unknown, etc etc. Many people around here would say that the absolute values and the spread are perfectly fine to just add boost and keep going. I personally would be happier with a narrower spread than that, but even the diff between 125 and 145 is not terrible. That one cylinder at 125 though, has probably copped some damage relative to the others. You should inspect the valves seeing as you've got it open. Do you know how to measure installed ring gaps? That, and an inspection of the rings themselves, is how you will determine whether they need to be replaced. If you're not good to do these things, take the block and the pistons and rings to a shop that is, and ask them for the go/no-go on them. Do the bores need a hone at all? If so, you might well be justified in getting some different pistons in order to get away from the ring supply problem. Whether you're happy to spend a lot more money right now, on more gear, rather than less money, but an amount that looks stupid given that you will only get a handful of rings in exchange for that money, is for you to decide.
    • also possibly backed up to my filler and shat down it! 🤣
    • Ok so i would love some advice here please, i purchased an R33 a few months back and its had a few mods done to the engine, its an RB25det running a Master ECU, 1200cc injectors, bigger turbo, oil cooler, oil filter relocation kit, Spool H-beam rods, acl/ross pistons. When i removed the motor from the vehicle (as its getting a respray) i thought i would compression test it and these are the following results. Cylinder 1-145psi, Cylinder 2-143psi, Cylinder 3-125psi, Cylinder 4-145psi, Cylinder 5-140psi, Cylinder 6-135psi this test was done with the motor on the ground and powering up the starter motor. I dropped the sump and found broken oil squirters on cylinder 3,5 and 6. I was told my rings are probably worn so i stripped the motor completely to get a new set of rings for it. The trouble is no one has these rings anywhere and they have to be custom made by Ross over in the states and will cost about $600+$200 delivery. My question is how can i tell if my rings are at fault and if they are still ok and is this price ok for a set of rings?
×
×
  • Create New...