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Why Go From A 20 To 25


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Guest trikdoutvl

k well as the topic states i got a rb20 in my commodore pretty much standard except for a cooler n exhaust and anyways i sold my calibra so i was cashed up n i found another vl with a rb25 in it for a good price n it had just basic mods cooler exhaust n a link ecu, anyways the plan was to buy the rb25 vl n drop the 25 in my good vl that got the 20 in it at the moment but i took the rb25 for a drive n gave it a real good driveing now yes the rb25 is faster then the rb20 is almost both standard form BUT n this is the big BUT by no means is it as better as every makes it out to be and not worth the point of coughing up the money for it and the countless hours of labour to swap for maybe a .5 second gain down the quater mile

NOW this wat the theads about the rb25 is better then the 20 but it is not better to the point where i can see the point of u ppl with r32 spending thousands to have rb25s in ur car when that extra cash could be spent on closeing the gap between the 2 engines

NOW DONT GET DEFENSIVE N RANT N RAGE THAT A 25 SHITS ON A 20 CAUSE IT AINT THE POINT OF THE THREAD..... I AGREE 25 IS BETTER THEN A 20

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hey scott! much defend on your thread!! rb20det vl's FTW! near stock with a bit of boost we got mad fule ecconomy! on the open road i get 10 litres per 100km and my 26 would get no way near that!!

on the plus side the 25 has alot more potential with money sspeant!

20 has less of a bottom end where as the 25 gathers torque down alot lower!, dont have to wring a 25's neck, to make it feel like its pushing! 20 is a wonderfull toy!! ive found mine is bullet proove, spits flames and sounds amazing at 7 g but a 25 with pump, turbo, pump injectors and fuel reg will really show the difference!

good luck with your choices mate!!

much love for the vl's with twin cam nissan conversans champ!! :)

is this thread a joke....... why put a 20 in a vl......i love all rb's but dude a 2 litre in a heavy commonwhore is madness.

james????

dont be an ass hat! ive towwed over a tonne in concrete with my vacationer rb20det powered wagon! u ever driven one???? NO so dont comment!!! like ud know! :)

madness! speak to spartaaa about madness

hahah spartans with maddness.... good movie i will admit lol.

but yer have driven one. i dont mean to pick an argument with u fellow sau'ers but just wanna know why the less torque 20 in the big girls??

naa never pic an argument with ya bud! just the sparkling ale talking!

the 20's do alright and as far as budget is concerned they work pretty well with the old dunga chassis.. under braked overpowered :D fired up my baby today nad she still sounds as tough as ever!! best economical work dunga i could ask for and tonnes more power than a 30e :( get the 20 revvs up and they still tow uncluding the heavy vl chasis... id even rate my mildly worked vl compared to my gtr on stock boost... minus the bottom end

:)

you might not see it as being worth it swapping from your 20 now to a 25, but starting fresh, for the extra outlay the 25 would be worth it. $1000 for .5 sec off your e.t is extremely good value for money. and as you said yourself, both are nearly stock, every mod you add, the gap widens. so if your aiming for 250+rwkw, thats when you will see that its becomes worth it to swap from the 20 to the 25.

anyway, for the point of the thread, dont buy the other car and f*ck around doing more motor swaps, build a 30DET, you should still even be able to use everything you got now, ie loom/computer/manifolds (providing you use the right head), just build the motor, and go do some skids lol

Guest trikdoutvl

yee im just curious why ppl change to a 25 except for the fact if ur rb20 was blown up n u were up for a new motor...

so ye if my rb20 ever blew up n was stuffed and i was up for a new motor id buy the 25 even tho it costs a bit more but yeh who on here has taken out a pefectly good 20 n dropped a 25 in? i think u ppl have way to much money lol

tm r33 1182 is the kerb weight of a manual sl 3l vl mine would properly be lighter cause i took out all the underleigh i got the rb20 instead of the 30 and the aircon and power steering systems are all gone so id rate the car at around 1100kg street trim..

i must say i dont think either engines are all that much chop the way ppl talk about skylines on here its like there the greatest engines eva made.. im still yet to go in a rb26 power car tho..... ppl have trouble having unbiasit opinions cause there always gonna defend wat eva they own

put your care on a set of scales, i cant see it being only 1100kg, dont go off what vicroads/the manafacturere tells you your car weighes either, alot of the time its dry weight, or just too low

people will drop a perfectly good 20 for a 25 if they are chasing decent power, like 250rwkw+, or even if they just want a nicer car to drive. adding 25% more capacity and the torque that comes with it will make it heaps better to drive off boost, and give heaps more mid range torque, by the sounds of it, something you werent taking note of, sounds more like you were just holding it flat and seeing how fast it was, pointless for everyday driving (well, everyday driving when cops are around/your in school zones)

Edited by VB-
Guest trikdoutvl

i drove it normal as well as 200+k run up the hwy with the guy who owned the car driving,,,, the 20 may have less torque but makes up for it with instant boost, i found it slightly annoying havin to wait that extra few hundred rpm properly just im used to instant boost....

i think 2jz is the way to go

the 20 may have less torque but makes up for it with instant boost

That is one of the most confusing statements :laugh: if you get instant boost, you should be getting good torque as well :D after all, boost is what makes power in these engines :P

I've driven plenty of 20 and 25 powered cars, (some factory, some converted) and the 25 is easily the pick for a daily driver. Nice amounts of low to mid range grunt, gets up and goes along nicely without needing bulk revs. My 32 (with stockish RB20) tends to need at least 3g on the tacho to start providing serious boogie, and thats with a relatively small turbo. The upside is it will sit on 8k wheelspinning for a while without complaint :)

Edited by AndrewJZX100
Guest trikdoutvl

lol wat i was sayin is as soon a i hit the accelorator in my rb20 the cars on boost form like 2000rpm maybe less, the turbo on the 25 doesnt work till about 3 thousand.......

thats wat i dont get about all u ppl rb20s lack torque cause it dont matter cause the motor makes boost instantly............ but i could imagine a rb20 with a big turbo would be slower but ive neva been in or driven a worked rb20 or rb25 only standard 1s......

i should of added i have no plans of making my car have 400hp or anything like that, i just want about 250hp at the wheels or so n maybe a mid 13 second passes.... j

just enough to lay the smack down on the hsv's :starwars::D

the 20 may have less torque but makes up for it with instant boost, i found it slightly annoying havin to wait that extra few hundred rpm properly just im used to instant boost....

the only explanation for this is that you have mistyped the spot of the 20 and 25.

are you saying that a stock turbo'd RB20 has more instant boost than a stock turbo'd rb25?

bro you shouldn't drink when on cold/flu medication.

500cc less, 0.5 less compression and you think it has instant boost?

NO.

the rb25 has the instant boost over the RB20.

as for your original question?

no.

ripping out a working "stock turbo'd" rb20 to replace it with a "stock turbo'd" rb25 is not worth it.

but when you start to replace turbo's, cams, etc etc.

the rb20 quickly becomes a pig.

apart from when it had a stock turbo, the rb20 is always going to be a lag monster.

On a side note, I have no idea why anyone would rip out a torquey RB30et or even an RB30e and replace it with an RB20.

I'd much prefer to have spent about $2K of turbo parts on to the non turbo 30e and get a lazy (torquey) 200rwkw.

especially if you are not changing the 3.7:1 diff that the VL have.

Just a few assumptions.

you spent about $3K on getting an RB20 in to your VL.

you then spent about $2K in getting exhaust, filter, FMIC, boost etc.

and if I remember, you've run a string of mid 14's.

correct?

If you had spent that $5K on turboing your 30e (would have got ecu and injectors and bigger turbo and tuned for that kinda cash)

you would have had over 230rwkw.

Considering people with 200rwkw R33 whales (1390kg) run 12.9's, and your car weighs less than 1182kg as you say, you would have been closer to low 12's.

so while you are wondering why on earth people would swap out a perfectly good rb20 for an RB25 for .5 seconds quicker, I'm wondering why you spent money to run 2 seconds slower.

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