Jump to content
SAU Community

Recommended Posts

Hey,

I want to put a FMIC on my car... 1989 R32 4 door with RB20det. Mods are 3" turboback exhuast with 2.5" split dump, turbo smart bleed valve, and a rebuilt highflow rb20det turbo.. think its rated 450hp. ATM i am running below stock boost as i dont have a boost gauge... Need to see how my mates justjap gauges look cause i cant justify $1000 on gauges for defi.

Anyways what i want to know is with the forward facing plenum i know the throttle cable will have to be shortened / lenghened. I was also thinking about getting a new throttle body.... would i need managemnt for this or it should be ok without it. Im guessing it is s my brothers s14 has a bored throttle with no management.

Anyways i have a hybrid core at home i got for free... vgc. I was thinking custom piping so i wanted the forward facing plenum to help reduce the pipe lengh to reduce lag with that turbo. It doesnt start really getting into it till around 4500rpm.

So question is what else will i have to do to all the hoses and stuff that go into my stock plenum. Can someone please post pics of their forward facing plenums, or brands of recommended plenums.

thanks

Link to comment
https://www.sau.com.au/forums/topic/183361-rb20det-forward-facing-plenum/
Share on other sites

also forgot to mention it has a walbro pump and fuel pressure regulator. All of which were on the car when i got it.

Yeah that might be true but it will help a bit and when i put everything on... i want it done properly the first time round. Dont wanna slap on a cheap kit then want something better later down track.. if you know wat i mean.

Im not to sure but i havnt seen any known brands (greddy etc.) who make forward facing plenums for rb20's but correct me anyone if im wrong. It would probably cost an arm and a leg anyways.

Another option would to have the original plenum modified. As in cut off where the inlet pipe would normally go and weld it shut. I had one on my car (still have it sitting in the shed) but had to go back to the stock one since i was defected. (supposedly it changes the numbers whilst testing for emissions).

As for the intercooler piping i personally dont think it makes a difference except maybe the looks with the extra piping needed.

obviously shorter piping is going to meen less lag. Hence why wrx has a top mount... or mad drifters have v mount... less piping meens more response... anyways.........

I dont know if the greddy plenum is forward facing or not. I have found a few but there is a pic... it looks forward facing but it sais we have these to suit... rb25, rb20, sr20, etc... so i dont know if it might be a sr20 one or what in the picture.

strich9 just did a wicked right up on a greddy style ebay plenum for a rb25. would presume fairly similar to rb20. link below

http://www.skylinesaustralia.com/forums/in...howtopic=181826

I would have thought a rechip would be higher on the list of next mods than a plenum.

especially since you have a hi-flow turbo and fuel mods and nothing controlling how it all gets mixed.

the stock plenum has been used by people making 300rwkw on the RB20

Search the NSW forum for user "Legend01" I think it is..

Also speak to user CEFFIE about re-chips.

he has/had a similar turbo to you on his RB20 and programmed his own ecu.

making 240rwkw and boost coming on ALOT earlier than what you are describing..

Your choice..

just think money would be better spent on tuning rather then "fully sick forward facing plenum bro"

when the stocker is a good unit.

upgrading to a forward facing plenum is an excellent idea IMO i'm currently doing it in my s13 Rb20 conversion.

It Shortens the IC piping required and you can shorten it even further by mounting the intercooler upside down with the outlets at the top of the core.

Have heard that it offers midrange and top end power gains (i cant confirm this as yet).

And even if you dont need the plenum (to make the power your aiming for) yet it will always be there in the future if and when you need it. And you will not need to modify your intercooler piping setup twice.

Having said this there is no point to the plenum at all if you do not use aftermarket management to take advantage of the gains the plenum can offer wether it be a rom, emanage, ems or powerfc etc ideally you will need one of these and a full retune.

The retune will be required due to the turbo upgrade regardless of the plenum to prevent it from leaning out.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...