RB30et vs RB25det in GQ

[mr_mike]

looking for some opinions on what route i should take with the engine in my Patrol. Currently has a RB30s (carby) with 240,000km on it roughly, runs fine doesnt burn any oil yadda yadda but it is gutless specially with the 33's.
So i am lookin at options to extract a bit more go out of it and pretty much have 2 options:
1. Chuck EFI of a R31 skyline on it then nistune ecu and whack on turbo gear (fmic,exh etc). would cost about $1500-$2k.
2 Drop in a low km RB25det in there with stock turbo, 3" exhaust and fmic. cost would be about $2-3k

I'm not chasing huge HP more so better fuel economy and reliability.

pro's and cons of each??

cheers mike

[mr_mike]

BTW not intrested in 25/30 combo or LS1 etc mainly due to budget and the fact i want to keep it simple as possible as i will be doing as much of the work myself as i can in my garage.

[Turbo2.6L]

30 gear off a 31. Cheaper, easier, more torque to shift the GQ's big ass

[yeahlow34]

^^ Agree, but with 240k's on it, it's probably worth freshening it up for piece of mind.
25/30 combo would be ultimate though. Improve fuel efficiency too!

[DISTRBD]

1. Chuck EFI of a R31 skyline on it then nistune ecu and whack on turbo gear (fmic,exh etc). would cost about $1500-$2k.
2 Drop in a low km RB25det in there with stock turbo, 3" exhaust and fmic. cost would be about $2-3k


3k for 25det fitted with cooler and 3" exhaust , do it ..

[Turbo2.6L]

LS1 conversion would be cheapish if you are handy with a set of spanners. Buying the mounts/conversion gear is the expensive part, so making them yourself saves plenty.

[Niva]

30 would have a lot more torque wouldnt it? go the 30!!!!

[MrSparkle]

Mike if it was me I would be looking at 25det swap. Cooler and exhaust is easy stuff and later on a bolt on turbo like a 25/30. Neo turbo is cheap and spools up about as fast as anything else, carry on to 250rwhp easy, That's more than my Hilux has so should be faster.

I've never screwed about with 30et's though so I'm a bit bias. To me they seem old and shit but I understand the bigger capacity is awesome for torque and thats something that you could use.

[devilfish]

just do the ratios in your diffs.... cheapest option :)

[Passage GT]

30et, they're a big car and you want your torque as low as possible in a forby, don't need to push them hard to make good low down torque and decent power and will help keep it reliable.

[Brett_J]

Neo RB25DET 362nm Torque @ 3200 rpm
RB30ET 296nm torque @3200 rpm

[mr_mike]

Lol I didn't even think to google torque figures, I know with the 30 I really have to rev it when offroad to get anywhere. I figured a 25 would b the same but more free revving and more power.
I think the 25 also allows more scope for power up mods further down the line. Where as the hi-comp 30 will be close to what a reliable safe power limit would b.

[mr_mike]

LS1 conversion would be cheapish if you are handy with a set of spanners. Buying the mounts/conversion gear is the expensive part, so making them yourself saves plenty.
LS1 would b nice and I could fit it myself the problem is the cost, just the gearbox adapter alone is about $2k plus they only make them
For the 4.2ltr so would mean sourcing another gearbox so there is another $1000-1500 and that's pretty much my budget gone before I even have a motor or think about putting in in the engine bay.

[upgarage]

theres a TD42 on perth4x4 for 1700

[DanWA]

25 all the way mike!

[Brett_J]

Wait, I seem to remember the 25's killing 3rd gear or similar, I just remember Jimmah fixing Natalotto's again and again.

[Passage GT]

Neo RB25DET 362nm Torque @ 3200 rpm
RB30ET 296nm torque @3200 rpm

stock vs stock, surely an rb30et with a modern turbo on board instead of the ancient t3 they came with standard would make more torque down low at the same boost pressures as a newer 25, better top end etc on the 25 would come into it's own as revs climbed.
no doubt the modern 25 is a more efficient motor but in a 4x4 i'd want more cubes.

[DISTRBD]

stock vs stock, surely an rb30et with a modern turbo on board instead of the ancient t3 they came with standard would make more torque down low at the same boost pressures as a newer 25, better top end etc on the 25 would come into it's own as revs climbed.
no doubt the modern 25 is a more efficient motor but in a 4x4 i'd want more cubes.

My 30e with T convo did nothing but pingpingpingping even with 98 in it on 5psi

[Brett_J]

25 NEO will ALWAYS breathe better and produce more Torque, it already has 70nm more advantage.
Mod for mod the 25 will win every day, and you have a newer more efficient motor.

[Passage GT]

keep us posted on how it goes mike, perhaps get some advice on the patrol forums from the guys that have done either conversion and lived with it for a while, especially using them off road as you do.

[DESAM8+PANIK]

Mike I have been down your road already (GQ 25 WA) my old RB powered GQ, looked at RB30DET or stock 25, I chose the 25 route because me and borneo started on saturday morning and were driving it sunday lunch time, its that easy, everything you need is on the original RB30 in your patrol. Don't worry about torque (or what people think is a lack of) the RB30e is as a little better that a carby but no match for rev range (good for big dunes) or maintaining RPM over a distance (beach work). Simon broke gearboxes cause he was trying to race everyone everywhere he went, yes they are strong and handle alot of punishment too.

Things you need
Heavy duty clutch (R33 clutch from SAU is cheap)
China cooler (cheap from Justjap)
Wiring mods
Power steering HP line mods (Speedflo is your friend)

If in the future you keep your old RB30, look at freshening it up and using a cheap 25det head and do a conversion, everything will bolt up when you finish the conversion, the torque of the 30 plus turbo is very noticeable off road mate

I did cooler 3 inch exhaust and PFC and my patrol made 200 HP at the wheels on 33s and about 400+ NM of torque.

An questions PM me and we can get in contact

Clinton