Hi everyone, I have been having some bad problems with my N/A VL for the past few days and I finally got it into the mechanic. He called up and said they found compression loss in cyclinders 4 & 6. So this will mean removing the head and crack testing - etc etc... It is going to cost a fair bit all up and I was thinking it would be easier (cheaper?) to just put a new engine in... My mum's boyfreind has an RB20DET he doesnt need from a 260Z conversion.. only mods are an RB25 sump. Would it be worthinwhile doing this conversion, or should I put in an RB30 again.. or - just fix the head? The only problem with putting in a RB30ET is i dont have the money and can get the RB20 cheap - free. Thanx guys,

The RB20DET will not have as much low rev torque as even the RB30E. There is a bit more work in changing to an RB20 than just bolting the motor in. Personally I wouldn't bother, changing head is no big deal. Is your mum's boyfriend mechanically minded at all? Get him to help you take the head off your car, that saves labour costs.

Yeh, he is a mechanic. The problem is that he lives up in Bega, while im down here in Melbourne. But if im going to convert i guess ill either need to get the car up there or the engine down here. I thought that the RB20DET would be faster than an atmo RB30?, thats the reason for me wanting to do it (I cant afford a VLT engine) Also, the mechanic said a straight forward 'drop in' motor conversion would cost $450. Does this sound about right? ... or would I also need an auto-elec for the wiring loom etc?

The problem with the RB20DET in the VL's is you need to fiddle around with the ecu etc. The RB20DET makes 160kw at the flywheel however nothing starts happening until around 3000-3500rpm it will pull nicely all the way to 7000rpm. The Skylines have a diff ratio of 4.363:1 to help with the huge lack of torque from the RB20t. The RB20t's are really really gutless off boost. With the VL's stock 3.45:1 diff ratio the thing would be horrible to drive. I've pumped 16psi in to mine with a bodgy wastegate mod so that it holds the boost up to 7000rpm otherwise it will drop boost to 12psi around 5500rpm. On 15psi it made 164rwkw with the fuel AFR's in the low 12's.

yeh you will need a aftermarket ecu to get some power, but i may be able to get you a rb20 block and head with plenum comp etc for 500. al you have to do is injectors and computer and i know some ppl that have gotten 270kw with that setup. let me know

I think you will find the RB20t to be too laggy for much over 220-230rwkw. A mate of mine recently made 243rwkw with a TO4 (smaller exhaust a/r) full boost was coming on at 5000rpm then reving to 8000rpm. He ran a 12.8 on street tyres in his R32 GTS-T. I have never seen 270kw at the rear wheels from a RB20T. They simply do not have the cubes to spool up a turbo that big. You also start to run in to some major surge issues due to the turbo's simply being too large for the type of engine. If all you want is a max of 220-230rwkw then get the RB20t. Bolt on a HKS2530 pump 1.1-1.2bar in to it and you will have the power with full boost hitting around 4000rpm. Which isn't to bad IF you have the diff ratio to suit the revvy nature of the RB20t. One good thing about the RB20t is its damn good on fuel. I get 500km's to a tank of juice which generally sets me back $50 to fill. Nissan quoted the R32 GTS-T RB20DET as having 10.5Litres per 100km's fuel consumption.

Mate dont forget that there are actully 2 Versions of the RB20DET 1 is the old version from the R31 Skyline and then the newer 1 from the R32 Skyline both have different power output aswell if i were u and u want somthin good get a RB25DET or get a S2 RB30E drop that in then later on just chuck a Rb25 head on it with Nissan computer turbo and all cause the S2 Engine are supposed 2 be as strong as the S2 RB30ET so ive been told. can i ask is it the rings on ur Piston or ur vavles? or u dunno yet?

Ring around a few wreckers, pick up a set of cheap used R32 RB25DE pistons slap them in the RB30, drop on the R32 RB25DE head ($750 for purchase) this will raise the compression some where up around the 10:1 mark. You will be looking at around 160kw at the flywheel + exhaust another 10kw then ecu-remap maybe another 10-15kw. Before you go down the RB20t route pop down a jap importers and drive a R32 GTS-T.. BUT remember.. the diff ratio makes a big difference.

to all the people who say the vl with the rb20 in them are crap, how many of you have been behind the wheel of one, ive done the conversion, and lets put it this way my rb20det powerd vl up against a rb30e will ****n kill it! and any v6 commodore, get your facts right before sayn stuff..... i will admit that the rb20 is not the powerhouse of the rb30et but for a good powerup its cheap and they go reasonably well, the diff is the main problem as it it 3.45 and the skyline r32 uses a 4.3 ratio, as for not makin power till 3 grand, that depends on turbo mods etc.. i was runnin 15psi with a 3"zorst etc and it worked well, it even bet my mates 180sx

I don't believe any one has said the RB20 in the VL is crap its just not all that good. I'd like to know what mods you have to make the rb20t pull hard under 3grand. A tip is to use the RB20DE's inlet cam as it has a smaller duration & lift which helps with power down low & dosn't tax power from the top end of the rev range. Was the 180sx a sr20det? If so it would have been dead stock as the 180sx's are damn light, with a little boost & exhaust they generally pull a low to mid 13 sec 1/4 providing they can drive. VLRB20DET, I just realised you are talking about killing another RB30e or any v6 commodore.. RB30e's & v6 commodores are slooooow. Also are you running an ebc to hold 15psi all the way to redline? I had to extend the wastegate actuator holes so that I could pull the wastegate back (tighten it up & reduce the travel) in order to hold boost up top. Made a huge difference, power feels much better than a EBC that fluctuates slightly. I used to run a Blitz SBC-iD. Some original photos have not been recovered yet.

joel, if you want to make a rb20 pull hard under pull hard under 3 grand, you want to put in some hks cams and the right turbocharger then it will but cams for an rb20 aint cheap.. The SR20 turbo was stock except a large exhaust and adjustable boost and i blew it away even with a slippn clutch yep i agree v6 are slooooooooooow mine held 14 (sorry not 15) PSI, im just using a turbosmart bleed valve I have a Garrett T3G turbo to go on my rb20, should work ok. but anything to do with aftermarket engine bits for rb20 are expensive ------------------- as for RULOCAL it would be cheaper to change the headgasket, i did one, took me 4 hrs to do it, simple...

Quote: Originally Posted by R32-Joel I don't believe any one has said the RB20 in the VL is crap its just not all that good. I'd like to know what mods you have to make the rb20t pull hard under 3grand. A tip is to use the RB20DE's inlet cam as it has a smaller duration & lift which helps with power down low & dosn't tax power from the top end of the rev range. Was the 180sx a sr20det? If so it would have been dead stock as the 180sx's are damn light, with a little boost & exhaust they generally pull a low to mid 13 sec 1/4 providing they can drive. VLRB20DET, I just realised you are talking about killing another RB30e or any v6 commodore.. RB30e's & v6 commodores are slooooow. Also are you running an ebc to hold 15psi all the way to redline? I had to extend the wastegate actuator holes so that I could pull the wastegate back (tighten it up & reduce the travel) in order to hold boost up top. Made a huge difference, power feels much better than a EBC that fluctuates slightly. I used to run a Blitz SBC-iD. This VLRB20DET obviously hasn't been in a good Holden V6 then,that is one which has been rebuilt with a decent timing chain,intake,exhaust mods and Shell Optimax fuel and Oh I forgot a 5 speed really gets the full amount of torque to the back wheels,my brothers VN is quicker than an automatic Gen III Commodore off the mark as it runs all of this (including K & N air filter) and the Supra 5 speed,it still gets good fuel economy too,it is also in a wagon which is loaded up with amps,imagine how it would go in a lighter body like a VL. I agree the RB30E's are a "little" on the gutless side but I have found they respond well to a higher compression ratio and a higher flowing head,you can actually still run the same diff ratio without feeling like you are pulling off in 3rd gear as you would if retaining the 3.45:1 ratio with an RB20,I can still pull around fairly effortlessly in mine (RB30DE) with the standard diff ratio and pulls "better" than an RB30E all over,I tried it the other day at 3,500 RPM and I could feel the power coming on,revving it right out in every gear is a different story. On the Rb20,dropping the VL's diff ratio is a must but both my engine and the RB20 the maximum performance is generated in the upper RPM band but in mine where I was say pulling up an incline in overdrive and accelerating,no positive engine response is felt with the RB30E but I can actually accelerate with this motor when it's under the same load,I have a rebuilt 2 pinion LSD spare I need to remove some lash on,I believe I need to fit this because ever since I have fitted this motor I have noticed the diff clashes a lot more. I would love to get the power and torque output measured on a chassis dyno as I don't know for sure actually how much power and torque it has,on the SDU forums they estimated a power output of 170 KW and a torque output of 300 NM with the stock ECU like I have,I believe the torque output as it pulls better than an RB30E,pulls more like a stock VLT on boost only this engine is an N/A. Some original photos have not been recovered yet.

mate v6's are ****n crap get with it! yeah ive mucked around with n/a vl's, ive had 3 of them but you cant beat forced induction either turbo or supercharged...

The V6's do lack it up top. Excellent torque down low and in the mid just a pitty they run out of breath so quickly. Excellent motor for a turbo in my opinion. Bit like the ol' 250 For motor.. Those things with a turbo strapped on the side have insane amounts of torque. A good example is to watch the chassis twist on that green XF on fullboost.com.au when it is dropping its burnout.. My VL NA Auto 3ltr with an exhaust used to be quicker once up and rolling than my mates VN V6 with an exhaust, it had 150,000km's on the clock and my vl had 180,000kms on the clock. Off the line he used to absolutely kill me. When I put the 5 Speed in the VL it used to fly. I traded the VL 5 speed in for a VS V8 5Speed with IRS,SRS,FE2, 3.5" exhaust, extractors. First time I gunned it in the VS I was majorly dissapointed with its off the line acceleration in first. It had the worse gear ratios (70km/h in first) that made it a pig to launch and accelerated slowly.. second went good then third would have you thinking come on.. hurry up.. The line still makes me happy every time I wind third or even fourth out. Can't beat the feeling of turbo how you squeeze the accelerator to 1/4 boost kicks hard & it feels like you have the accelerator flat. Especially in second pulling out of a round about and the thing is trying to break traction with the front of the car lifting up (I have stocker suspension ) Some original photos have not been recovered yet.

Alot of reply's (thanx) and I havn't been around.. well first off... I decided that the mechanic's quote to fix the head (basically sounded like he said he'd pull it off then chuck on a new gasket etc) for OVER 1 Grand! - was crap. So i went down to pick-a-part and grabed a head off a vl ... im getting it swapped (so condition of pick-a-part head doesn't matter) reco'd, port and polish etc etc. While it's off prob chuck in a new cam. So HYBRID VL - im yet to take of my head and have a look at whats wrong (doing that tomorow morning) I was thinking that the RB20DET engine mod would have been great fun (And im sure it is VLRB20DET ), but I have only had the car for two weeks, and my insurance would be huge with that mod (I think??). It's already $710 (third party) for an 'almost' stock atmo VL. God damn insurance. So, ATM, im going for the new done up head (as long as the bottom end is O.K), and while I was at pick-a-part I grabed an intake manifold, TPS and XF throttle body that ill setup after I know the new head is ok. All this should satisfy my atmo for the moment, and on the side ill start building the new RB30 with RB25 head-turbo hybrid. That's what meant to be the goods. (Or should it be an RB26 head?.. or leave the RB30 head?) Cheers guys, Al. Some original photos have not been recovered yet.

There is no doubt the RB30 SOHC has proven its self many times over. It works well. The main advantages with the twin cam head is the ability to rev higher with good drivability, improved fuel consumption & in turn quicker 1/4 times due to more power and if the diff gears are changed to help with 1/4 times again it won't limit your top end. + the heads don't crack like the sohc heads. If insurance is a problem get just do up the sohc head, some nice port work, port match everything, nice new ball bearing HKS/Garret turbo and you will be very happy. The RB26DET head is exactly the same as the other RB25 heads. Only difference is it runs solid cams with a higher lift. Definately not worth the extra $$ over the RB25 head. VLRB20DET, You forgot an important part to making any turbo engine feel more responsive off boost.. The Exhaust manifold. What cams are you talking about.. Only the exhaust cam? Changing the inlet cams tend to reduce bottom end power where as to a certian extent the exhaust cam actually picks up power both down low and up top, basically everywhere. Some original photos have not been recovered yet.

old sayn joel, you cant have your cake and eat it! as for goin to the rb25 head you will find the ports are a lot smaller than the rb30's after seeing how quick jpc's vl goes with a rb30 head it seems like it works well or hi RPM work.. thats my 2 cents anyway

ill be as blunt as possible champ its **** dont do it get a rb 30 and do it right even a rb25 - not a piss rb20

The RB25's ports are 49mm wide by 32mm high. The inlet valves are 34mm dia. & the exhaust valves are 29mm dia. There is no doubt the Twin cam head flows better than the SOHC head however the SOHC is good and does the job. The Twin cam just makes a nicer more streetable car thats all. The RB20t head flows roughly the same as the SOHC head. Its valves are much smaller (29mm inlets & 27.5 exhaust)& ports are roughly 5mm smaller than the RB25de head all round. The difference is with the twin cam head you can run a higher static comp & require less boost to make the same power as the SOHC head. Airflow is what makes power not boost, boost is the restriction of airflow. It would be interesting to see what sort of power a RB30ET makes with the following mods. HKS3037 .87a/r Custom exhaust manifold 550cc injectors ECU 20psi of boost On a RB25DET the above setup will make around 320rwkw.

Quote: Originally Posted by Petros ill be as blunt as possible champ its **** dont do it get a rb 30 and do it right even a rb25 - not a piss rb20 Sounds good, so ill do that. I have decided to keep the RB30, the RB20 was a whim. Like you said, do it right the first time. No point pissing about. Quote: Originally Posted by R32-Joel HKS3037 .87a/r Custom exhaust manifold 550cc injectors ECU 20psi of boost Maybe ill try that setup up Joel, but will be a few months till the new engine is ready to drop in. For the moment I just want to get my Atmo head etc in and going so I can get my VL back on the road. . Then time to work on the new engine. Hopefully ill give JPC a run for there money Cheers guys, Some original photos have not been recovered yet.