rx-line

I've recently fitted some RC 720cc Injectors and had to do a bit of a re-map on my RB20det. So far things are fine at WOT as per normal. However the idle hunts a bit, but too be expected with 720 low impedance injectors. I have Nistune by the way. However when adjusting the injector latency I began to think about what the correct latency should be and if there is horsepower (kilowatts for you guys) and reliability (Knock resistance) by having the fuel spray early (which may result in pooling at valve) or late (which could be incomplete burn/ reduced atomization). But when is the factory injection time @ 14v and rated injector impedance? Perhaps I am getting to far into this? Is there power to be made?

Although it would the first RB25DET in an FB rx7 i woud think, I like the RB20det and already has proven itself to be faster than vettes and camaros. Plus I have a spare RB20 anyway. The 25's go for around $3k with trannys here. A variable vein turbo will not cost me much as I will just sell the near brand new HY35. The ported head I'm building should compliment more boost down low as well. Here's a rotary with the HE351VE, I think he blew the engine recently.

I have, we have a motorcycle/machine shop and the aerochargers have been round for a while.. As of now a Turbo I4 Kawasaki in the 8 seconds and a supercharged harley soon to be in the same class. None of which use aerochargers atm.

Hey I hear ya, A project with a goal is where I am always at. I do not find this daunting at all, it will work (And work good at that) if the proper unit is selected. There is three ways to control these either with a boost sensing actuator (wastegate actuator), aftermarket standalone controllers or like you have said custom arduino boards. The Holset HE351VE Design uses veins that are connected via a telescopic ring. (See picture below), I have even seen a rotary with some of the highest egt's of any engine run this turbo for some time. Other diesel designs however do seem liable to excess egt's. Most of the gasoline turbos are using titanium bits form what I have researched. *Edit - including picture. Also the turbos usually come with the electronics/servos and just require some sort of computer to tell them what to do. The turbo actually has guides for the fins on the exhaust housing.

Do you have a wideband? Seeing as our cars have fuel pressure regulators that increase fuel pressure as boost pressures increase, I would think you would be fairly safe in that respect. However if your timing map is aggressive for building boost, knock may be of an issue. Call your tuner and see what he says. But if you set your gain for the best spool and it is ultimately not much different than before It's not as much of a worry.

The thing about Diesel turbos is that the factory models are very very small for the displacement in comparison to a gasoline engine. The hy35 (HE341) comes from a 5.9L. So a 2.5L diesel turbo seems quite small (Garrett GT2052V) A twin setup would be interesting i suppose

Also, There is a little info here on a sister site. http://www.gtr.co.uk/forum/154333-first-big-variable-geometry-turbo-rb-engine-tuner-help-needed.html

I would have to put it in the boot seeing as there is an engine in my bay.

Fellas! I have been contemplating how it is I will gain my Low-Mid range power back on the RB20. Of course even with boost sub 5k rpm she's not doing much, but without boost you might as well equip your car with chess board for you and your mate. After thinking about quick spool valves, nitrous and high compression pistons(built bottom end) I started looked into VGT turbos (Variable Geometry Turbos) as most of you already know about. It turns out we are on the cusp sort of speak with these turbos and there relevance in production vehicles. Diesel engine makers and large North American companies have been equipping their production vehicles with these VGT turbos for last 5-10 years. Unfortunately "coking" (carbon build up) in diesel engines can cause failure to units and their veins. Some initial fears with these VGT units on gasoline engines was the increase in EGT's and impact it may have on the vein system. However Volkswagon and Porsche among others (Honda - 1980's legend) have been using these units on gasoline engines in recent times. With the ability to build boost in neutral we are dealing with a new era in turbo charging. For me this alone eliminates a need for launch control as power can be had off the line! What I have come across so far as a viable replacement for my Hy35 is the Holset HE351VE with it's simplistic and rudimentary design. It seems very unlikely to fail from heat. The only concern i have short of converting it from electronic vein control to pneumatically actuated would be that the unit is still far too large for the RB20, as the HY35 is laggy enough. My concern would be that the only gain would be more flow on the high end in which case I would not use. The theory behind these units really make sense for the RB20 but I am unsold on the idea that the HE351VE is the unit for this engine. I am interested to know of other users on here using these turbos with the RB's!. And for those of you that are unsure of what I am speaking of please see the photo below.The holset design is a bit different with far less moving parts. Any comments, concerns or discussion is welcomed.

I see, thanks my homie g

What is the "SCG_1_Boost" pick up for? Just tracing or is there boost by gear or boost by speed adjustments? I have heard for the S15 Nistune has modules for the factory boost controller? Not so much the RB's?

I have an innovate wideband but have yet to make it compatible with nsitune.

I was thinking GFB Geforce? They seem well equipped for my needs? and not overly expensive. Thoughts?

No idea about the differences between housings, Best thing to do would be to call APexi. Rx,

Did you say you went from one exhaust to another but also changed your fuel to E85?

KiwiRST4 - I am running Nistune, ECU was too old to add the feature pack apparently. GTSBoy - That's what I figured, wasn't sure if there was one that was more compatible with the RB wiring. Having said that what's the best bang for your buck module?

I will also add, that the machinist who had helped me with this mentioned that the gear sets are quite large and seem to be well made. Goes on to mention that they are bigger than even some chev transmissions. The weak link would be the syncros / shift fork.

I don't know much about the different brands of EBC's out there but am looking to buy a new one. I have a tial 38mm with a 15.9lb spring with my he341 holset and RB20det. The wastgate can be heard opening at around 10lbs and and creeps to 15lbs high in the rev-range. I would like to find an EBC that I can adjust gain and get the 15psi earlier and faster. From my understanding a good EBC will improve mid-range boost levels and subsequently HP/Tq I know they have gotten to the point where they will need certain wires spliced form the ecu. I am not looking to spend over 350$ but I would like to know what you guys think works good with the RB's.

Diagnosis: The cast aluminum and brass impregnated shift fork had broken off on one side (glad it wasn't the cast iron one) between 1st and 2nd gear. The syncros and gear were quite beat up. The gear was replaced with the 2nd gear from the spare and the syncro form the kit was added. Obviously there was a fair bit of aluminum pieces throughout the trans. Final judgement: The kit's bearings all acted as replacements for what was in the transmission. However there were a lot of needle bearings separating the shaft from gears that the kit did not come with. We just used the best from both trannies. I believe we ended up using the 2nd, 4th and 5th gear syncros while the other 1st and 2nd in the kit were for smaller gears.The new Nachi bearings seemed to be better in most circumstances besides one of the thrust type needle bearings on the shaft. The only way to truly tell if we are successful is to test the unit in the car. Unfortunately it's snowing here and I have a Competition stage 3.5 clutch to replace after only 3k of driving!

I have ordered http://www.americanpowertrainwarehouse.com/fs5w71c-fs5w71e-f4w71e-nissan-manual-transmission-rebuild-kit-with-synchro-rings-fits-83-93-2wd/ We shall see the quality and fitment of the parts, I shall report back with findings so that others going through the same issues can see. The quest bearings are made by nachi (fairly decent brand form my understanding). The only thing I noticed was that the transmission uses mostly sealed bearings and a roller bearing as well where as this kit replaces it with a ball bearing. Any inputs on why this is? RX,

Took the spare transmission off the engine and the transmission from the car. Both transmissions from the rb20det. One is: RB71c #1 - From car (Found a clutch fork broken on one side. I'm gonna swap second gear from the spare as it's good and get a replacement syncro. RP71c #2. - Full working order, good bearings/minimal play, fair amount of wear on 1st 3rd and 5th I noticed the gears are fairly soft with rounded tops from wear. Obviously not a bad thing. Cheers,

Kits are most definitely available. ATC quoted me $409 for bearings alone, they told me the rb20 uses the FS5W71E rather than the FS5W71C transmission. Other suppliers sell kits that are seemingly universal and fit both for much less. RX

Kits for the FS5W71C are about $100.00 would need to review quality though. I shall try them 89Cal thanks. Maybe they can point out the differences RX

Awesome! Answered so many questions with just this code. Many nissan transmissions are alike i see.

I am seeing no RB20 kits, do you mean KA or CA kits?