discopotato03

Really with an Evo the turbo trade off isn't that much different to anything else IMO . I totally fail to see why people "hi flow" evo turbos with the 18 and 20G compressors - easy to do for lack lustre results . 16Gs do a pretty good job std with more boost but they're not up to big numbers because the engine package was designed to have strong mid range torque . Their leg up is the twin scrolls and shortish closeish gearing - plus that std intercooler . Only the 9 reverse rotation turbo gets the larger diffuser section and compressor housing standard . The larger diameter cast in back plate is the main difference in the centre sections . If you go back far enough at Evomnet you can read about the early 5/10 blade compressor in the "old school FP Evo Green" turbo . The modern replacement wheel is the HTA68 which makes a late "Evo White" turbo upgrade to a std Evo 9 turbo . It's supposed to give around 10% greater flow over the 16G with virtually no lag increase . Past this you get into larger heavier turbines starting with the SL2 etc and inertia is inertia . I can't remember which is the smallest FP BB turbo possibly the Green . A tuner I've used doesn't think some of these coloured turbos are much chop down low and reckoned they only really came alive around 4000 , not sure if that was bush or BB ones . Mick it depends on what numbers you want and how much lag you can live with . I'd like more torque in my 6 and getting that from a bog stock engine isn't difficult . If it was me and I was staying with std capacity I'd look at the larger turbine housing and the 68HTA in a 9 cartridge/comp housing . I think you probably want more than that so I'm going to say the BB HTA Green because it can be upgraded if it falls short of your expectations . A .

The thing is that many factory service intervals particularly with oil is longer than it's ever been and this is not because the engine necessarily likes it this way . Go look at the valve trains in all current engines and note the valve train systems used . Then do some searching on why engines from the 60s and 70's damage valve train parts when using current green oils , and BTW it ain't the viscosity doing the damage . Eco Nazis reckon that high levels of ZDDP shortens the life of cat converters (coating/poisoning) so it's been reduced in green oil . Automotive engineers know that high point loadings on conventional "sliding" rockers like say a Nissan L Series SOHC has need the high pressure additives so virtually all rockerised engines have roller drums on their rockers . 4G63s are a prime example , later EJ SOHCs do too . The pushrod V8s mostly have roller cam followers and I don't think the manufacturers did all this for fun . Turbocharger wise ball bearings are a win because they have hardened balls running on hardened races and cover radial and thrust loadings easily . The dramas occur when someone tries to run steel bushes in a conventional housing and supporting a shaft that was designed for non ferrous bushes ie Bronze Aluminium etc . Steel on steel doesn't play nice in high speed shaft bearings and as soon as they touch they need something like ZDDP in higher than Green concentrations to stop destroying themselves . I did searches ages ago on FP turbos and it seems obvious to me that they need you to run oils with high enough levels of ZDDP because they use non standard bearing materials so you go outside the manufacturers std servicing procedures . Now as to engines lasting longer , std ones , materials and clearances are often better and running at higher temps means greater heat stress . Engine controls are more accurate than they used to be as well . Diesels , have a look at their rods pistons cranks and heads and note how heavy they are compared to the same capacity petrol engine . Also have a look at their torque outputs at the same low revs , high torque means high cylinder pressures and power loads - higher loads on their crank bearings and gudgeon pins as well . Actually take a real good look at the size and wall thickness of those pins because they dwarf petrol ones . Manufacturers never add anything for nothing , take a look at RD diesel bits compared to RB petrol ones . As a bit of trivia LD28 diesels used reasonably beefy rods with big pins for the day and Nissan lifted these rods for use in later FJ turbo engines . FJs also had the larger diameter pins though with a lot less wall thickness . RD28 pistons weigh a tonne compared to FJ OE ones and would cost considerably more to make . For us ratbags some diesel oils are the easy way to affordably get the right additives which is why this is old news at all the US forums . I have yet to read anyone say that Rotella T6 screwed their engine or turbo and they much prefer the price compared to most performance petrol engine oils . At the end of the day I reckon the right viscosity with the right additives is what makes good lube oil . If the eco pricks haven't found ways to stop the oil producers using the good stuff in diesel oil then I see no shame in pouring it into a sparkler engine .

There is oxygen in some of this . Diesels are often low revving high torque engines for their capacity so it stands to reason that you can't use eco Nazi grade oil in them . Getting late emissions compliant petrol engines to survive on green oil was all about valve train changes because this area is where you get the highest point loadings in a petrol engine . Things like roller rockers and roller cam followers in pushrod engines were done specifically to make valve trains survive on green I love cat converters "oil" . Because diesel engines have high bearing loads at low speeds the oil has to be able to form and maintain a reliable film to stop components eating each other . Because the eco Nazis are attacking diesel emissions of late you can expect them to change as well . Take it to the grave , eco oil is about cat life in petrol engines end of story . Because the Nazis do emissions tests I believe yearly in the States they're changing cats and probes more often than we do . Now synthetic oil , the properties good ones have are more than just living longer than dino oils . Flowing better at lower temps has nothing to do with longevity nor standing up to higher temps . If your engine runs clean and doesn't contaminate it's oil then yes it can live longer but if it doesn't then the only way to ditch these contaminants is to ditch the oil . I like some diesel oils because to get the good anti wear additives at a sane price it's hard to go past them . Synthetics are creeping in to them and that's not a bad thing either . I run Rotella T6 5W40 and have no problems with it . A .

Does it still have that hateful 4 link rear end with the diagonal top links ? Semi trailing arm rear end from SSS 910/200BSSS/DR30 solves the problems but adds weight . Mine had the DR30 R200 stuff with a Nismo LSD - eventually . H190 Detroit lockers make them open up the rear seams too . A .

Some patent stuff on Virtual Flex Fuel Sensing . http://www.google.com/patents/US7921704

I agree , any engine built and tuned to run low octane fuel never gained anything out of better juice and went backwards on alcohol fuels consumption wise . The sad fact is that Joe Average buys the cheapest fuel he can get and the manufacturers are well aware of it . It's beyond the scope of this thread but IMO the sooner we get a consistent lower blend like 25 to 40% the less the general public would fear ethanol . Most people I speak to , performance people aside , tell me how it burns out your seals and engine and are aghast when I tell them about using 70% for long enough to know better . The problem is that people know that E10 is cheap and not very fuel efficient and assume if 10% is bad more must be worse . The other sad fact is that EPAs the world over wanted Ethanol (E10) for failed f**kwit green reasons and all it ever did was make in theory emissions content look a smidge cleaner . I don't see too many manufacturers lining up to make E100 engines and as long as ULP engines are the norm you'll always get a consumption penalty burning high ethanol blend fuels . To get the best of both for volume sales setting the bar at the effective knock limit percentage means better consumption per litre and that's the thing people care most about .

We don't have United E85 in Hobbitville yet but there are two Eflex outlets so that's what I run . For street only I think Eflex is a little more user friendly in some ways and still better turbo tucker than 98 PULP . A while back a few here did tests to show the power difference between E70 and E85 but I can't remember if it was that much of a difference . Someone else said recently that the knock resistance with ethanol flattens out at about 40-50% so if that's true the benefit of more must be extra evaporative charge cooling . That aside I didn't realise the General had given up on flex fuel and it would be interesting to know why . A .

I mentioned to SK when the new "Yagoona" United servo got E85 and he reckoned that a while back when the price of all fuels was really high in Sydney the dough was going into new tanks that are ethanol compatible . I agree it's easy enough to tune for E70-E85 and the only disadvantage is you'd use more fuel with the higher petrol contend mix . If you were tuned to run exclusively E70 and the light load and cruise mixtures were set for economical running it's real easy to bump E85 up to E70 . Assuming they are 15% different that's a whole 8.25 litres of petrol in a 55L tank so if you were dry adding that then filling with E85 is no drama . Close enough to 2L per 1/4 tank . I was reading recently that late flex fuel cars don't use these sensors and if that's the case they must have really sophisticated oxygen sensing and knock sensor systems and the ability to self learn really fast . A .

I'm curious to know what the car will be used for though it sounds like a top endy drag app . Always with long period cams the dynamic CR drops because the trapping efficiency is poor at low engine speeds , valves open too early and close too late to get much effective compression happening . Raising the static CR means what air the valves seal in is compressed more so you get higher compression pressure . Also your call but big cams make for lots of reversion (inlet air going in and partially back out of the inlet valves at lower engine speeds) and having a throttle plate per inlet port helps here . If I was contemplating a high horsepower RB26 and not using twin turbos or ITBs it may have been worthwhile researching turbo Neo heads with the RB26s valve train . Reasons being you get smaller chambers for less heat absorption area and you can have higher compression ratios without raised piston crowns which screw up breathing to a degree . Also the basic but useful variable inlet cam ability is not a bad thing either . IMO the value in a GTR head is it's valve train and manifolds , beyond that its just another RB TC head that started out in 1989 . From memory GMS had the CR around 9.6 but that changed when CAMS tried to rein in the GTRs power wise , I think they had less boost with a higher CR to minimise the power loss .

Well going from the std tiny turbine and housing to the GT28 ones in a 2530 is a reasonable step up . The only smaller turbine thing they had was the 2510 and finding one of those in the T3 flanged turbine housing could take time . A .

The Minister of RB20dom Roy has been researching this stuff for ages and there are lots of threads here to read through . I don't think there is a "perfect fit" , to owners taste not spanner stuff , for an RB20 because everyone's expectations are different . Half the hassle is getting a different turbo in and running and then liking/living with the results . Only you can know what power curve suits you and simply setting a number isn't much of a guide to your likes . 220 wheel wasps should be easy peasy for an RB20 but the $64 question is how much headroom do you expect beyond that . If you don't need any then sure a HKS bolt on like a 2530/2535/GTRS should get you there easily enough . The GTRS would go a bit further too . The real questions to ask yourself are 1) budget 2) how standard it has to look 3) how far you're going with this engine/car 4) best power curve to suit YOUR driving style . Physically the hardest part to get right is the turbine housing because it has to suit the turbine/the manifold/the dump pipe/boosting characteristics . The HKS turbine housing does a reasonable job of all these things in that power range but they aren't often cheap and easy to get . Sometimes the go is to buy someone's trashed turbo cheaply and use its housings if they are undamaged . The best thing to do is go for a run in other peoples GTSTs and see what drive characteristics you like best . A .

That answers a lot of questions , I gather when it was removed the fuel pressure was a more sane number and that your reg then operated as it should ? A .

At the end of the day an RB20 is what it is , short stroke smallish bore 2L six based on the dimensions of the old L20A . It's never going to be a stump puller that revs like a turbine , Nissans answer was a larger bore with a longer stroke topped by a head with larger ports and valves . 2.5 litres is simply far better use of the RB blocks real-estate than 2 litres . In real terms the only simple answer in an R32 with a RB20 is to make the car as light as possible and make the gearing suit the engines power curve . Revs aren't a problem if the gearing is suitable because you stay in the usable rev range . Roy what would happen if you used Evo RS gearing ie a 4.875 diff and a close ratio gear set ? Actually you mentioned R31's and it would be interesting to find out what gearing the Grp A R31s used especially as some of that stuff was made here in Aus . Some of it may have been a carry over from the DR30 era as well and they may have used Rally style direct 5th five speeds . A .

Roy those HKS 0.64 T3 flanged turbine housings can be hard to find but std RB25 ones wouldn't be . They can be machined to fit Garrett BB cartridges with the turbine you want . Maybe kill two with one if you can find an affordable GTRS . Always going to be a challenge with an RB20 and I'm not sure trying to force high cylinder pressures into them at sub 3K revs is the answer . The problem is small capacity cylinders ie 330 odd cc compared to a four cylinders ~ 500 cc , so the SRs pots are ~ 1.5 times the size of the RB20s . The RB would no doubt rev better than the SR so power at revs is probably the way to go . The other side of the equation is to make the Skyline as light as possible to improve the power to weight ratio . Every kilo equates to a tad more torque when you think about it so be ruthless and strip every avoidable bit of weight out . A .

I now think there's a bit more to fuel pressure regs than meets the eye . Obviously the OE one is designed to suit a factory std car as in std turbo/boost/cams/injectors/fuel pump inc the high low voltage system . From what I read in here you ending up tossing most things on say an RB25det because externals like the AFM/injectors/pump etc aren't good for much extra power - fuel flow air flow etc . So you reaches for the bigger fuel pump and do the direct battery rewire , add larger injectors a Z32 + PFC and tune . If you don't have a wide band and gauge etc you never really know what's going on AFR wise and you take the tuners word that everything's apples . Then you throw a wide band in and you find things the tuner couldn't get around like say that learning business with PFCs and maybe injectors that aren't as modern as current good ones . Things like mixture control at light loads and cruise aren't brilliant and you can't seem to piss off that rich spike you get when backing off from part throttle . Fuel consumption can be pretty average around town too . Recently I was into the ViPec again and tried a different approach to the cam switching and pump low/high maps (neither based purely on revs BTW) and found better cleaner running . The real surprise was finding how much easier the low/cruise mixtures were to get right by having the pump at low voltage meaning less pressure/flow for the injectors to try and work with . Just so you know I'm running a 33GTR pump 740s and 256 Tomeis , fuel pressure reg is std . Scotty asked me recently if I was "over running" the std reg and at the time I said I didn't think so but now I think differently . Obviously those Nismo 740s aren't up with EV14s and when you're idling at about 1 ms IDC they need all the help they can get . Maybe it's better accuracy that makes EV14s a tuners best friend because they don't have to screw around with all kinds of things to make older injectors play nice . The point of all this , IMO anyway , is that once you fit higher capacity fuel pumps and direct wire them the std FPR probably won't cope too well if and may struggle to regulate fuel pressure properly at short injector pulse widths . I think Scotty said somewhere that the std reg has a quite small bypass passage so with a big pump running at full voltage it can't open up enough to prevent the pressure rising under those conditions . It probably won't be an issue with the revs up a bit and a some engine load and that's all some people care about . So , with big pump full voltage the only simple way to make the fuel system run in regulation (base pressure + manifold pressure) is to use an aftermarket fuel pressure reg that can bypass more fuel than a std one can . If you can find a way to keep the high low voltage system that will help but getting the std wiring to cope with current draws like that E85 Walbro can drag at times won't work . A . Oh and BTW EFI Hardware is doing this nifty gadget to adapt a std FPR to aftermarket billet fuel rails . Handy . http://www.efihardware.com/image/2358/regulator-and-adapter-alloy-fuel-rail-end-8-o-ring-port-to-Nissan-regulator_2358

I ended up in the back of my GTS25T yesterday chasing the standard fuel pump wiring so I know where it all goes . The upper rear seat was already out and I removed the firewall access panel as well . It goes like this in a 96 S2 . The fuel pump relay switches power to the pump via a light blue wire with silver bands . It runs into a common loom with the large power feed wires ie White , White with red trace , and red which feed the fuse block under the parcel shelf in the boot . This loom runs behind the top of that access panel hole on the boot side and is taped up inside a split black plastic insulating tube from near side to off side . It then runs into a tall shallow white plastic insulator gadget that the access panel overlaps . I opened up the white gadget and found three light blue wires with silver bands so I then opened up the above mentioned loom to confirm that the single wire had branched into the three inside the black plastic insulator tube . I taped it back up with the fuel pump wiring separate from the large power feeds . Now those three light blue wires , the first runs into the boot and down the loom until it branches towards the fuel tank lid - pump power feed . The second runs down the inside of the firewall in the main body harness heading towards the front of the car on the drivers side . I believe this goes to the air regulator under the inlet manifold that heats up when the engine warms up . The last light blue wire runs up the inside of the firewall to the top RHS corner and back into the FPCM . I then started to follow the pale grey wire from the pumps loom back towards the boot side of the firewall and to the inside at that white rectangular gadget . Inside there is a pair of pale grey wires and if you trace them back towards the pumps loom they both join under the insulation in the boot . Actually where they are joined the second wire is noticeably smaller and they run inside and up the firewall where the thicker one heads back to the FPCMs plug . The thin one goes back into the boot and into the loom that runs across the back of the boot under the trim . I'm 99% sure this reappears at the loom side of the dropping resistors plug . Now for the body earth/grounds . As mentioned in an above post there is a bolt into the rear firewall with two brass eye terminals and from memory five or six black wires running to the drivers side and back into the main body loom . There is a black wire at the FPCMs plug and it runs back to this earthing point . In roughly the same area as the above mentioned thin pale grey wire heads back to the boot and a thin black one appears and runs to this body earth terminal/bolt . Again I'm 99% sure this is the earth return from the dropping resistor . So the system must work like this . ECU switches on the fuel pump relay which powers up the pump , the cold air bypass reg , the FPCM . The earth return from the pump is permanently connected to the dropping resistor via the thin pale grey wire , after the resistor the circuit is connected to ground via the thin black wire . Off idle the ECU sends a signal to the fourth wire on the FPCMs plug switching its fancy electronic switch to basically connect the pale grey wire to the black one earthing the pump and bypassing the resistor . Now the OP mentions below his third pic , of the resistor , than Nissan used quite thin wire to and from the resistor which concerned him . If you think about it at idle inlet manifold pressure is low (in relation to atmospheric) so the vacuum signal to the FPR will also be and the load on the pump at low pressure will be low . The current draw from the pump would be low so Nissan obviously thought light wiring was all they needed . Off idle the FPCM uses the slightly larger pale grey pump earth return wire and the larger black earth return wire to ground . Now if you choose to use heavier wire it's easy to replace the section between the relay and the fuel tank cover though I'd still have power to the other pale blue wires . It's also reasonably easy to use heavier wire between the pumps earth return (pale grey) and the FPCMs plug . Ditto for the black wire from that plug to chassis ground . Once you know where the dropping resistor is it's simple enough to replace the thin black lom plugs wire with a heavier one to earth and the pale grey one back to the fuel tanks cover/plug . There's really only two questions now , can we buy the terminals for the Nissan plugs which all look the same BTW . And can the FPCM handle the higher current draw of larger aftermarket pumps . A .

Just a little overkill and hopefully reliability . I think I know a way to parallel the std high low system using the original relay and FPCM to trigger a heavier duty system . From what I can tell the only thing stopping us from rewiring the std system is the current carrying ability of that FPCM which is a glorified protective (for ECU) switch .<br /><br />From what I gather R33 GTRs have the twin FPCM/resistors in a single assembly and they are famous for overheating and failing . The GTS25T has the single FPCM in the same place but the resistor (heat) is near the std jack .<br /><br />A .

I think the white nylon spacers with the O rings top and bottom may be threaded though anyone's guess how neat a fit they are on that bolt . I suppose a very light smear of a suitable sealant may stop tank pressure feeding up through the threads . For an R33 you don't need it to be insulated because the tank lid and ring aren't metallic . A modified brass or stainless bolt could probably be made to work with a dowty seal . Jamb nut to clamp it up and some means of fitting an eye fitting to the head . I've been looking into Britax relays - R4-1280R is an 80a on/off with 9.5mm terminals and 6.3mm coil spades . They have a resistor in them to protect computer circuitry whatever that means . They doing a mount base with brass non insulated terminals as well Pn 99025 . A .

I stumbled on these insulated bulkhead power terminal bolts to get higher current reliably into your fuel tank . http://www.efihardware.com/products/1593/submersible-pump-bulk-head-terminals I searched long and hard for this kind of thing a few nights back without success . A .

I searched the SX ones and they claim to have better diaphragm material to suit alternative fuels like ethanol . I didn't see any pics of them in Skyline engine bays , do you have any of yours Scotty ? Really the way forward looks like doing the top feed conversion to EV14s then the reg and pump and sort the pumps wiring . Scott would you go with Xspurt shorty 740s / XS reg / DW300 pump in a GTS25T ? I doubt I would see more than 340 or so wasps at the wheels just to give you a number . Cheers A .

If you have to resort to a higher flowing FPR which are the better ones ? A .

This is a link off the above Evom thread that goes into overrunning the standard FPR . http://highboostforum.com/forum/showthread.php/28719-TESTED-Stock-Evo-8-9-FPR-Capabilities? Fuel systems get deeper and deeper . Not sure if there is an easy answer to regs if you don't like glitzy looking aftermarket ones . I was wondering a while back what would happen if you ran a second OE style FPR in the line before the rail and spliced it into the standard return . In theory both would close up as manifold pressure rose but have double the flow arera of the std single one . Also in theory not all the supply runs through the warm rail . That aside looked at Britax large spade 80a relays today and need to find a supply of non insulated 9.5mm terminals and insulators for them . A .

Not that I know of but I'm running std GTS25T wiring and an R33 GTR pump , have set the pump voltage change at about 1300 revs . Would have looked into the reg business but had a train to work . Do the Nismo ones flow more or are they just adjustable ? A .

Hi all , I found this link when looking into DW300 turbine pumps and fuel pump rewires . http://forums.evolutionm.net/evo-engine-turbo-drivetrain/590352-fuel-pump-wire-high-low-voltage-circuit.html The aim I believe was to avoid "over running the std FPR" when using high volume fuel pumps . I found it before starting work this morning and have only gotten a couple of pages in . The thread may be of interest to those with an advanced understanding of volts n amps a so forth . Enjoy , A .

A big thanks to J_Red33 for showing me where the fuel pump resistor lives in a GTS25T , I would have found it eventually but you showed us where to look . Man they go around that boot and rear fire wall looking for places to hang the fuel pump control system , I suppose the resistor needed to be away from the fuel tank filler for crash / fire reasons . I'll be curious to see how hot it gets cheers A .