Blew my SR20DE up in my S14; two of my friends have RB20DEs sitting around, and I have an RB20 crossmember in my shed so I figured it could be a good option to boost one as opposed to sourcing another SR / CA in the current market. Have done a fair bit of reading but most threads I've found are a fair few years old with incomplete / inconclusive endings. Just wanted to know if anyone has done it, knows someone who has done it, and more importantly had a running reliable car that was done on a relatively small budget. Threads found so far: https://www.sau.com.au/forums/topic/33407-how-to-turbo-your-na/ http://www.driftworks.com/forum/technical/76242-turbon-rb20de-2.html http://www.driftworks.com/forum/engine-drivetrain/220981-what-can-i-do-rb20de-neo.html http://www.driftworks.com/forum/technical/141283-rb20de-rb20det.html Weekend Workshop: Plus T conversion — The Motorhood From what I understand, RB20DEs run a 10:1 compression compared to the DET's 8.5:1, along with more aggressive cams and no oil squirters. To boost an RB20DE in my car, I'd need: Turbo manifold Turbo FMIC + piping including metal crossover T'd coolant pipe and oil feed fitted Downpipe Some sort of ecu, be it a chipped DET ecu or a standalone (can I run off a DE loom?) Ideally a wideband Ideally an oil cooler Walbro 255 270cc or bigger injectors Colder grade spark plugs Decent clutch / fly Seems like general consensus is to run a bigger than standard turbo at a low-ish boost to make use of the high CR and to keep EGTs down to help stop det. I guess my question is what small stuff am I missing off this list that would make it a pain? Who's a decent mapper in the southeast and how much am I looking at for getting a basic setup mapped at 7psi or so? What can I get away with and without? To do an SR20DET full conversion on mine in todays market is looking like the best part of 2k. Is that beat-able? I've also heard a few stories of people running full 20det setup on an unopened 20DE; ie 20DET turbo, 20DET ecu with std map and it lasting a fair while. What can I get away with in terms of cost to create a 200bhp-ish engine that will last a year or two of daily driving and drifting? I've always loved RB20s and if I can make this setup work then I will crack on and hopefully have a running car by the end of Jan. Any info is welcome!
Ok, first up what gearbox you going to use? If you have access to an RB gearbox then you will be good to go. If you think you're going to bolt up an SR box to an RB20, or swap the front half of the SR gearbox case to an RB you're in for a bad time - the RB gearbox has a longer front half and shorter rear half of the case. Swapping the front halves result in the input shaft being too short for the flywheel. If you have access to a gearbox and auto CA trans crossmember (to fit the RB box) then the swap can be done. You'll need a CA radiator: RB water outlets are on the same side like a CA, as opposed to SR being opposite for top and bottom. Also, the clutch fan won't fit unless you notch the radiator support panel, or run 2x 12" pusher fans on the front (you can fit a slim 10" on the rear drivers side too if you need it) If you can source an RB25 turbo in good nick then that's your best bet for turbo - the dump pipe / elbow / downpipe bolts to the standard SR20DET exhaust too, making it easier to mate to an off the shelf 3". Make sure to grab a decent gasket set As far as mixtures, as long as you have a rising rate FPR (or just a stock DET FPR) cheapest options are either run a Nistune and get it mapped or grab a secondhand Apexi SAFC and wideband and road tune it yourself. If you go the chipped ECU route i'd still grab a wideband to make sure the chip is safe. Not 100% on running a DET ECU on a DE loom but pretty sure it isn't an issue. Don't forget the RB20 AFM too. You can get away with the standard injectors if you run a Walbro and adjustable FPR and bump the base fuel pressure up, but won't leave you a lot of headroom. But if you can source 270's cheap then go with them. Don't worry too much about running coolant for the turbo if you run an oil cooler. Oil cooler is worth it, as a lot of RB oiling problems come from overheating and the oil thinning out. Also means when you fit a sandwich plate you can fit an oil pressure gauge, which is a key thing to keep an eye on. Ideally, the R33 crossmember is best at putting the engine in the right position - R32 and A31/C33 put it further forward and lower (oil pan below crossmember = bad time). Keep an eye out for an A31 or C33 front swaybar as the CA & SR ones won't clear the sump If the engines are in reasonable condition and all compression test fine then i see no reason not to run 10psi through them, which an R33 turbo will do on the factory actuator with an intercooler, exhaust and filter. I was tutoring at a day last week with a guy running 16psi through one but blew the headgasket due to running it without water for half the day (ie stupidity) Also note - the NEO RB20's need a little more work to get running and will be harder to tune. IMO a good condition early model RB20 is the best option but the NEO RB20's flow a better up top due to the better designed heads Hope you go ahead, and am happy to help with any questions / point you in the right direction (have done +T's a couple of times with mates back in the day)
Was hoping you'd reply haha! I know DE+Ts are more common in NZ, seems to be where most of my info has come from. Some good info there, didnt know about the box differences but luckily I have access to an RB20 box. CA crossmember will need to be sourced, didnt know about the R33 xmember or ARB; I was planning on using my R32 one so we will see, if I can find an R33 xmember I will go with that but if not then the R32 one and some raised mounts will have to do. I'll be using an early RB20DE out of an R32. My mate has a hybrid R33 RB25 turbo with a bigger exh housing which should be ideal for a DE+T build. Great news RE downpipe, that will make things alot easier and mean I can run a twin pipe japspeed one and bolt right up to my current exhaust system. Was planning on running twin electric fans off the rad, do you think I will have airflow issues to back cylinders? As obviously no space for any cowling of any kind in an RB s-body. I'm not aiming for big power at all; if it even touches on standard RB20DET power I will be more than happy, and compared to my car history (Standard CAs, 328s and SR20DE) it will feel balistic even with 210ish BHP so I will keep it at 7PSI for peace of mind. So list of what I have/can easily buy and what I need to source: Already or will have: R32 RB20DE with loom & AFM (will DE AFM run well @ 7psi?) RB20 gearbox R32 crossmember RB25 hybrid turbo with std manifold Air filter To source: CA Auto xmember (will R32 RB20 one fit? I have one) FMIC piping (will I need custom piping?) 3" SR downpipe w/ high qual gaskets & nuts Chipped DET ecu solution / standalone Wideband Walbro 255 Rising rate FPR Oil cooler, sandwich plate & lines CA Ally rad Twin elec fans Additional stuff which would be good: A31 / C33 ARB (will R32 fit?) R33 Xmember Light fly & fresh clutch Anything else I've missed off of that list?
Sounds like a good list, don't forget the 270cc injectors too. The R32 gearbox xmember i think doesn't line up as well as an auto S13 CA one, but i'd imagine the CA one's will be common as hell over there. Not that hard to make an extension to one anyway, so it's not a biggy Bigger exhaust housing (like a 0.63) is a good idea - the extra compression will give the engine good low-mid, and the bigger exh housing will allow it to flow up top. Airflow isn't a problem if you make up some simple ducting around the intercooler to the radiator. No need for cowling tbh. FMIC, if you can get your hands on a front facing top half plenum it makes the job much easier (and engine bay cleaner). You can always get the standard plenum modified and cut & shut the throttle body to the front if you know of someone who welds alloy - just get a small extension done to put the throttle body lower and towards the battery: That way it won't come close to fouling on the bonnet. If you have to go with the standard position throttle body then it's better to run them both to the same side, and run a top-to-bottom intercooler with inlet and outlet on the same side: You can use a lot of the factory piping for this kind of setup making it cheaper, just harder to find an intercooler to suit, however some old Supra intercoolers run this design so could be an option for the budget conscious. DE AFM will be fine, 90% sure they are the same between DE and DET. If you're running an alloy radiator, go for the 42mm one to ensure you don't have pulley clearance issues with the R32 crossmember. It will still mean you won't have a lot of space behind the radiator so will have to mount the fans on the front. And if your water temps are ok you can probably do without the oil cooler until you push some more power out of it - should save you some coin Wouldn't worry about the lightened flywheel, just a resurfaced good condition factory 9 bolt one will do the job. 5/6 puck sprung clutch plate with a reasonably heavy pressure plate is a good mix of solid clamp and comfortable daily use.
Brilliant info, thanks man! Will keep this updated with how I get on, I think standard plenum with a top/bottom exit intercooler will be the way to go for me.
Also been reading up on how Apexi SAFCs work; from what I understand they intercept the MAF signal and trick ECU into thinking less / more air is coming in, thus allowing you to adjust fueling. So in the case of a 10:1 boosted RB20, I can adjust the fueling to match the 270s, turbo and CR to create a safe map? SAFC also seems to have knock control / warning so I wouldnt need det cans? Theoretically I could get a safe setup just by road tuning, adjusting fueling on the fly using a wideband as reference right? Would I need to knock timing back? Also apparently theres no way of setting seperate cold and warm idles on SAFC is that true? Also when you adjust fueling on SAFC, say you bump it up 20%, will the std ECU not change timing to suit? As the std ecu will read from its cylinder pressure table based on what the SAFC is saying in terms of air. Does this mean timing gets retarded as you jack up fueling or is it other way around?
Older models of the SAFC tend to be better as they are less complex, but the newer models do have some better features if you want to push it. But considering the cheapness of a Nistune these days i'd use an SAFC & wideband to get a car running safe, then go to a Nistune to get it running as good as it could. The standard ECU will only react with timing changes and other changes if it sees something incorrect from one of it's sensors, be it the coolant temp sensor, knock sensor, O2 sensor etc. I've only used one once and it did tend to run a little too rich on really cold mornings, but considering the SAFC and the wideband cost $400 all up as opposed to over $1k for a PFC/Link at the time, plus $$$ dyno tune, it was a no brainer.
