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hey, i am contemplating replacing my blown rb20 with an rb25. From what i have read on these forums, the conversion is pretty straight forward. I want to do this, but what would i be up against if i wanted to be legit,

a regency inspection? ohhhh i hate even typing it.... can anyone offer any advice? cheers

Getting the RB25det in to an R32 legally is easy.

Run the R33 front brakes. Be sure its running on the stock ecu, stock airbox, stock exhaust and IC and there won't be a problem. :D

The more mods you do for the initial inspection the harder it is to pass. i.e exhaust, front mount etc.

Its been done many times before.

its probably not worth it in my case then because i dont have any stock parts at all except the starter motor, alternator and powersteering pump. Was just hoping that maybe i would get away without a regency inspection. OR ---- is it only the Marion/warradale RTA inspection? in which case they only come out and check under the bonnet?

In my case, all i had to do was prove that an rb25 was originally offered in an r32 and i got it blue slipped as opposed to fully engineered.

All that was needed was a copy of the page in the r32 manual that states the engine types offered for that model

The fact that it was de vs det didn't seem to matter.

nsw though.....

In NSW you can increase capacity by 10 or 15%, like the old red motors in old Holdens, could go 149 to 186ci with no hassles. Ask your blue slip swtation or engineer.

hey, i am contemplating replacing my blown rb20 with an rb25. From what i have read on these forums, the conversion is pretty straight forward. I want to do this, but what would i be up against if i wanted to be legit,

a regency inspection? ohhhh i hate even typing it.... can anyone offer any advice? cheers

Edited by BezerkR32
In NSW you can increase capacity by 10 or 15%, like the old red motors in old Holdens, could go 149 to 186ci with no hassles. Ask your blue slip swtation or engineer.

Not true. In NSW, there is capacity vs weight laws.

If a car came weighs less than 1100kg or came as a 4 cylinder, then you are allowed to go 2.5 times the weight of the car in cubic centimetres as the maximum engine size for a turbo engine. 3.0 times for an NA engine.

If the car weighs more than 1100kg and came with more than 4 cylinders, you can go 4.0 times the weight for a turbo motor, and 4.82 times for a NA motor.

I asked the RTA about doing a V8 conversion in an R32, they said I could go up to 6.2L Naturally Aspirated.

Also, the R32 was offered with an RB25 towards the end of production, so you shouldn't have any problems with legality. As long as you run the factory RB25 ECU, and the exhaust meets emissions & noise ADRs you should be fine.

sorry guys iam gonna hijak this thread a little

same sorta question will it be hard to go a rb26 in a r32 gts4 the baby GTR. replacing the rb 20.

thanks dan

Hey Dan,

Going to a RB26 in a GTS4 is very easy, as it bolt's straight up, to your current drivetrain. Also if you get the RB26 from an R32, all the computer wiring will match up as well. For your model car the upgrade to a RB26 is easily the best option.

I have put a RB25 into my R32, and the wiring of the new loom is the area that was a nightmare for me, I'm still trying to solve little problems (with the electricians job) 18 months later. Aside from that, the rest of the install was fairly straight forward. In hindsight, if I were to do it again, I would send both looms away (to be spliced together by a specialist) prior to the install.

Ryno

Not true. In NSW, there is capacity vs weight laws.

If a car came weighs less than 1100kg or came as a 4 cylinder, then you are allowed to go 2.5 times the weight of the car in cubic centimetres as the maximum engine size for a turbo engine. 3.0 times for an NA engine.

If the car weighs more than 1100kg and came with more than 4 cylinders, you can go 4.0 times the weight for a turbo motor, and 4.82 times for a NA motor.

I asked the RTA about doing a V8 conversion in an R32, they said I could go up to 6.2L Naturally Aspirated.

Also, the R32 was offered with an RB25 towards the end of production, so you shouldn't have any problems with legality. As long as you run the factory RB25 ECU, and the exhaust meets emissions & noise ADRs you should be fine.

Up until very recently the RTA had a 15% rule. Replacement engines with less than 15% increase in capacity didn't need formal engineering. However you couldn't be too liberal in its application - basically you were only allowed you to put in engines of the same design such as changing a red 186 to red 202 etc. What you couldn't do under this rule was go from say a 202 (3.3L) to an RB20 and argue it needs no engineering because it's smaller in capacity. Totally different design, different ADRS etc.

Non factory replacement engines use the weight multipliers - however the ones you have posted are out of date. The new guidelines have split the weight range into three. For the larger cars they have actually relaxed the NA capacity but tightened up on blown engines.

RB25DET isn't a factory engine for the R32. Maybe some will buy your argument but IMO it is technically something that needs to be formally engineered (which should be damn easy for a conversion to a stock RB25).

i have read the rb25 into r32 tutorial on here, and the way it is written doesnt really make sense about the tailshaft. If i were to use the r32 gear box on the rb25 why would i need to touch the tailshaft?

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