discopotato03

Finally reached the end of this thread . Also now on the alky wagon but need a tune off Scotty at Insight . If he can get the old PFC to do it great but the Evo will probably get a ViPec plug in if Eflex works out well in the Skyline . Need more outlets here in Sydney , cheers A .

I ended up starting with the internal cooler or Eflex . I pumped the remaining 98 out into a fuel container via the rails return tube and a couple of meters of fuel hose . I poured a bit of Eflex in to stir up the remains and ran it until I heard the pump start to "sing" . Then it was in with 5L and jack the injector trims up 30% . With a couple of primes it fired up fine and idles better than I think it ever has with the PFC on ULP . I've been round the block a few times and it appears to drive fine so I'll fill it up later on . The cold start tomorrow will be interesting but warm it fires first time every time . I know the intercooler won't cope but that will be replaced in time . Cheers A .

Or http://www.capa.com.au/xr6_accessories.htm

I think the focal point here is that lower charge temps help reduce combustion temps and its high combustion temps and pressures that help promote detonation - depending on how well developed the engine is to start with . A . I can't remember the exact chemically correct AFR for petrol E85 and methanol but I think it comes out something like 14.7:1 / 8.8:1 / and ~ 6:1 Whatever fuel has to vapourise because most fuels as a liquid don't burn too well . Throwing in approx 1/7 of the total charge mass as a vaporising fuel would make methanol a virtual freezer compared to petrol . E85 would be almost 1/10th the charges mass and petrol approaching 1/15th . I'd say the greater the charges fuel mass is the greater the evaporative cooling will be provided it changes state to a vapor that is .

I don't expect people to agree with my reasoning but no i don't like those return pipe things . Can't see the sense of having a return pipe when a tank can have dual roles . The reason I dont like bar and plate IC cores is because I don't think the air flowing through to the radiator get an easy time , round edge tubes are a better compromise I think . I doubt a Trust turn flow is going to magically fall in my lap but there are a few alternatives to look into . I was looking at Datalogit software with SK yesterday afternoon and he thinks the easiest way to increase the fuel injected across the board is to change the injector settings on the LHS of I think the injectors setting page from 48 to I think 62.4 . I think the logic is that 740s are twice the size of the std 370s and the compensation in my case was 48% . 48 times 1.3 = 62.4% . This is probably a crude dirty way to go about starting the Eflex experiment but I can't think of an easier one to start with . I just need to buy a length of low pressure fuel hose so i can connect it to the low pressure side of the reg and pump the 98 out into fuel containers . I've two 10s and a 5L container of Eflex to play with so if I can tip 5 or so in and get it to start and run I can pour in a bit more and see how it drives . If its not workable I can pump it out again and revert to 98 and the current "livable" settings . I also asked him about AFR vs lamda and he reckons Tech Edges can be switched between the two . I guess its getting my head around E85 being something like 8.8:1 instead of petrols 14.7:1 . I can see where lamda cuts the confusion because the ideal ratio is always 1 not matter what the fuel is . Working today so probably no time to get into this till Wednesday or Thursday . A .

Well these are my theories but yet to try my combination out . Bit better exhaust/cat/front/dump/turbo/IC/head/cams/MAF/filter element . Should be a bit less restricted everywhere than standard so should get more in and out than Nissan did . I think the value in high ethanol content fuel is twofold . Firstly you're injecting 1/4 to 1/3 more liquid and the greater volume has more capacity to cool the charge air - evaporative cooling . Secondly yes it is a slower burning fuel so better control of the combustion event should be possible . Sort of start the fire earlier and time the pressure rise so it occurs at the most advantageous point . People say you can run leanish mixtures at times with pumpE85 and not get detonation as easily as pump98 sometimes does . There are pros and cons burning a lower heat value fuel because its generally the heat and pressure that causes detonation in the first place . The balancing act is getting enough heat to develop the cylinder pressure to make good power and some peoples theory is if you don't get enough heat you add more fuel . With too much heat and or pressure pump ULP wants to detonate and you have to find ways to manage the heat and sometimes pressure to limit detonation . The simplest way is to retart the spark ignition timing (fire point) so that combustion event starts when the pistons are further past TDC on the power stroke than you'd like . The combustion pressure/temperature will be lower and below the detonation threshold - if the timings retarded enough . I like Corky Bells ideas and I think he got it right when he said the greatest dramas with forced induced engines are thermal ones . Basically you are taking a given engine and increasing its power output by generating higher cylinder pressure - and heat . There are lots of ways to control temperature and generally it starts with air or charge temperatures . Cold air intakes intercoolers maybe some insulation . Evapotarive cooling is significant and the more the better IMO . Cool air is more dense and contains a greater weigh of oxygen but I reckon the important thing is that cooler charge leads to lower combustion temps and thats the thermal management part of reducing detonation . Air fuel ratios play a big part in combustion temperatures and if you get cooler burning and a detonation resistant mix it has to be all good . All of this is mainly an advantage in an engine that wants to detonate at or at less than the optimal charge firing point and since detonation is destructive you have to retard the timing to avoid it . Most people know that advancing the ignition timing beyond the point that best torque occurs is pretty pointless so why go there . My feeling is that this "wobble" thing people reported when they first started tuning seriously with E85 may have been because the combustion was srarted with the piston and rod too close to TDC , and the thermal pressure rise from the burning charge was trying to compress the piston and rod because the crank pin wasn't far enough past vertical or TDC to act as a lever . In my case I need a tune anyway and my fuel system should cope - 740s and a GTR33 pump . I'm getting ~ 400-420 to the tank on Ultimate and this thing is not in the best state of tune but it is livable . I want to give Eflex a go because its about the closest thing you can get at the pump to race fuel and its a way of getting around the emissions dramas as well . I'd prefer to change to a better fuel while this car is in a pretty mild state of tune because it should open doors later if I want more performance out of it . Like when my old dinosaur Subaru changed from effectively FrWD to AWD this is a toe in the water and if it works out out well then the Evo may get it as well . We know AWD is generally all good and I expect the Eflexto have its advantages as well . If the running costs are same or cheaper I can't argue with that either . Gotta run , cheers A .

I'm not having a shot at anyone who bought a GTX3076R I just think the reasons behind their release were market based . Bit morer bit blinger bit laggier . That aside I spoke to SK this afternoon and he thinks I should give Eflex a whirl as it is meaning with the R34GTt SMIC . It would be an interesting experiment providing the boost was kept sane meaning possibly one bar . He also found another Eflex servo not far from me which is a bonus . I'm tempted to go grab a small amount in fuel containers and have a play with the datalogit and Tech Edge . I don't do much tuning and I need to see if I can globally up my fuel table by 25-30% and see what happens . If I can make it run acceptably I can get it to Scotty at Insight and have him tune it properly . Better intercoolers can come later and a slightly bigger turbo if I think it needs it . SK really likes Eflex and their finding is that it actually works out cheaper once tuned than Ultimate PULP . They reckon you use about a third more Eflex by volume so if you use $1 a litre as the cost basis and add 1/3 $1.33/L looks better than $1.46 plus for Ultimate . So initially should owe me a tune and see what happens , I'd expect it to go better everywhere though it will show up any limitations moreso than it does now . Hope it smells as good as United E85 , cheers A .

Lith I know you don't believe it but no one will ever run any form of GT3076R to its full potential without the largest available turbine housing , the jump in exhaust flow is considerable 0.82 to 1.06 and if either side of the housing can handle the gas flow rates volumetric efficiency has to climb with it . A lot of people seem to think 1.06AR turbine housings are GT3582R territory when they were in fact designed for GT30 turbine wheels . The reason you get them on 82R turbos was because there is nothing else available (speaking Garrett here) , they just copied what HKS did with GT3240Rs (cropped turbine 54T GT3582R) but with non cropped GT35 turbines . I personally think GTX wheels are a bit of a crock and blind Freddy knows they need larger bulkier compressor housings . Not going to happen . Also aftermarket wheels like HTAs often work better . Anyhow all that aside the 76R 52T I own and it would make more than enough power for any road only car IMO . A .

Yes I gathered that .

GTRs used an aluminium upright or "knuckle" in the rear and the foot style of shock absorber is different . GTRs have an inverted fork where GTS25Ts have a conventional rubber encapsulated eye for a single bolt . GTRs had larger heavier axle joints and brakes so needed to save some weight somewhere . The aluminium would not reliably support a single bolt so they had a rubber bush with a crush tube pressed into a thick section of the aluminium to spread the load . The fork straddles the bushes crush tube and locates with a through bolt and nut . Possibly a bit late now but you may have been able to space your std calipers out with adapter plates so they fitted over GTR sized discs , its an easy conversion if suitable safe plates are available . A .

I never intended to use a GTRS on an RB30 , as for on an RB25 the only thing holding up the show is the RSs 0.64 AR turbine housing . HKS really should have had a 0.86 AR version of that turbine housing made because I reckon you'd get closer to 0.68 2835 type performance out of them . I did once look at the turbine maps for the GT28 NS111 turbine in 0.86 housing flow rates and compared it to GT30 ones in various ARs . Anyway an RB30 really needs a GT30 based turbo and probably at least a 0.82 turbine housing on it . I still have my 0.82 GT3076R 52T on ice and if I ever went RB30 I'd use that . At this stage I'd like to try E85 or similar on my 25 and I think the ViPec or Link G4 plug in sounds good . Goes into factory ECU box so a bit more stealth at a glance . I have to read more of Guilt Toys experiences with these and another thread I found here of when these plugs ins first came on the market . I need to speak to Scotty at Insight because I know he has done flex fueled Evos with V88 computers and seems to have the flex thing worked out . I think PFCs are alright for what they are but later faster boxes seem to do all the crunching in real time so have a bit finer hold on the engine electrics . I think these have an auto tune feature and it would be real good if it was tuned on E85 and then the auto function could make changes to an ethanol percentage correction table . Also its not impossible to look at RB30s later but a flexed 25 may well be all I need and that gets around the engine number and insurance dramas . Anyway SK Garys sold on E85 and will get to see him soon to talk options . Yes I will need a better intercooler and no I don't want non std plumbing in the engine bay so that means something like those rare Trust turn flow intercoolers . I did see a similar kind of thing locally made though it had a bar and plate core which I won't have . Someone here makes another single sided XR6 upgrade cooler and that could be an alternative too . So basically cooler computer sensor and tune . A .

Yeah I think 260-270 would be plenty and a GTRS looks so innocent compared to a GT3076R . Everyone reckons the Link/Vipec runs an RB25 a bit smoother than a PFC and that auto tune thing looks intersting Will talk to SK and Scotty K soon . A ..

Can you get at it from underneath the dash or does the cluster have to come out ? A .

A very rough quote to supply a complete RB30 short with better rods pistons and collar was around five grand , in your lap BTY . Not sure about R/R and anything needed to make it happen thats not a straight bolt up/in . Cost wise throwing in say a Link/ViPec plug in with any wiring/sensor work and turning probably adds another dunno 2-2.5G ? The PFC and Datalogit can be sold to offset some of this . I like the idea of not having the ethanol variation hassle and being able to find a performance/consumption trade off would be great . Can run the highways on PULP and use the grog when its available . The only downside I can think of for E85 or Eflex is the 15-40% petrol they add - 91 octane powere Kero I suppose . Shame its possibly not easy to get E100 and throw in your own PULP . I hear that good tuners can get you emissions compliant with a reasonable cat too . GTRS , interesting to see what these would be like on a cleaned up 25 with jungle juice . Should make some reasonably fierce low to mid range torque and maybe top out at say 270 Kw if the exhaust and intercooling could manage it . A .

Yep that was my thoughts and reversing it just means using 98 mapping . Thinking about it even changing to an ECU that can do flex fueling properly is cheaper/easier . Can the Vipec or Link plug in do this or only V88s ? Cheers A .

Hi all , I'm weighing up the E85 (Eflex anyway) on the existing RB25DET vs going the RB30 route in my R33 . I've being reading through Guilt Toys E85 thread and he does make it sound reasonably easy . 740 Nizmos I'm running with a 33 GTR pump and the dryer is a GTRS . Intercooler is a GTt SMIC that needs upgrading but as always I don't want the constabulary breathing down my neck . Have to run ATM but its obvious the jungle juice 25 is much easier and no doubt lots easier to fly under the EPA radar with . I think Eflex is available at Heathcote and Tempe servos so not too far away Back later , cheers A .

Pilot Super Sports on the water and lock bar fitted today . They found a few things loose in the nearside rear links but the front was spot on five years and 14k after being fitted . It feels different without Hicas steering the rear , I think it tried to make the driver feel that these cars were agile without necessarily being agile . I have an old copy of Wheels or Motor kicking around that had a write up of Jim Richards first drives of the R32 GTR roads cars that I think ended up as racers . From memory he said that Hicas made the cars easier to drive but not faster . I just wanted my cars inputs to be mine and if I can lose a bit of weight and have it predictable so much the better . Function is everything , cheers A . Actually must search for a DIY of how to get at that HICAS dash light and make it mind its own business . I dont suppose the wiring can be doctored at the Hicas computer to make is go away ?

Hi all , just curious to know if anyones used this intercooler in an R32 or R33 GTST . CAPA also do one for a BA-BF XR6T and will post link later . Cheers A .

RB25 and possibly RB26 heads have a minor problem in that the ratio of exhaust to inlet valve size falls a little short . I don't remember the exact numbers but I think Gary (SK) told me that the sort of ideal was the exhaust was supposed to be ~ 73% of the inlet valves area and I think std 25s and 26s are about 69% . This is really easy to fix with a set of (I think) 1/2mm oversized exhaust valves which Ferea and one of the other manufacturers make . They are not expensive in the scheme of things and better than OE Nissan ones . All the machinist needs to do is remachine you std exhaust valve seats and then in like std ones they go . His R33 and mine both have these and with 256 Poncams work really well , lost nothing anywhere . Their R33 used a GCG OP6 Hi Flow so turbo wise it was conservative according to some people . Scotty at Insight tuned that one and was impressed that the power didn't fall away at the top end of the rev range . Both engines had their springs tested and went back in with minor shimming more to suit the boost pressure on the backs of the inlet valves , and obviously set not to coil bind . I would do this (exhaust valves) to any 25 or 26 head because its so easy , valves are not really a bolt on like cams are but can improve breathing without going too far . Personally I would do this and experiment with cams later and the thing to remember is that the more you do to an engines top end cam and spring wise the harder it works things mechanically . Big cam lobes springs and revs is where wear and potential destruction lives so if you can get breathing improvements with a low stressed valve train so much the better . If you can have better breathing with no loss of torque and drivability anywhere thats a real bonus IMO . People here are telling you that you may not need to over invest in your top end to get the results you seek , if you go too wild it will cost you power and drivability at around town revs and speed and that makes cars not nice to drive . You introduce increased wear and tear and maint issues because of it . Just my thoughts cheers A .

There are some advantages to mounting external gates off turbine housings and being able to remove the gate with the turbo/turbine houing makes life easy . Also the ducting to external gates on fabricated manifolds means they sometimes have to take packaging into account at the expense of gas flow into the gate . A turbine housing is basically a collector and provided the passage at the mounting flange is large enough to pass all the exhaust , inc the gates volume , its no problem . Now because the collector "tapers" so to speakits its a good place to vent exhaust gasses because its slightly upstream of a potential pressure rise point . If you can angle the gates entry to face the exhaust manifold you can benefit from the gasses partially directing themselves into the wastegate . If its at right angles to the gas flow you can have problems getting the gas to change direction and flow out the gate - especially when the gas speed is high . There is a picture of something like this in Corkys book Maximum Boost . Wastegate vent direction is the reason that some integral wastegates aren't the most effective in a high gas speed high output turbo engine . The old Sierra type turbine housing and some European IHI IW housings are a bit better in this area . I wonder how a big T4 flanged twin entry turbo would work with two external gates mounted off it ? A .

Yes there are good reasons and they mostly come back to the fact that engines are designed and built to suit many different applications . The one that trips many people up is the old adage "the best exhaust behind a turbocharger is no exhaust" and that would be fine if noise was not an issue and the engine ran in a boosted state all the time . Noise is an issue and turbo road cars can't be loaded up all the time for obvious reasons . They have to be able to get around at part throttle and light loads and normal speeds - particularly in built up areas . All the things that apply with too much exhaust on a road NA engine also to a surprising degree apply to a production based turbo road engine . For the millionth time everyone please delete all notions of backpressure is good because its BS , the value in passages/pipes that carry exhaust is to maintain adequate gas velocity to ensure the engine scavanges properly in the valve overlap phase . A turbo engine is just as vulnerable to reversion as an NA engine is if not more so - most likely because exhaust manifolds are short and the turbine housing and turbine form a restriction NA engines don't have . Plus often the static CR is lower but that is changing nowdays . Back to the tube size vs velocity . We know tha as hot gas cools it contracts/shrinks/increases in density . If the pipe size is constant the gas will slow down and there no benefit in that . If this was a race engine that never used less than 4000 revs sure maximum flow is everything but we are talking about a road car engine . Road car engines can't be driven flat out everywhere and more often than not they run around at part throttle and low to no boost . To have an idea what an engine that is loaded most of the time is like look at semi trailer truck engines . Forget that its a four stroke low reving diesel for a minute and note that they run on boost most of the time . Everything including the exhaust is sized for the specific engine running in a full power full boost mode . By comparison road cars are very overpowered and don't need their full output just to drag themselves around - meaning lots of off boost light load running . Anyway I think its enough to say that an exhaust thats beyond making good power for an engines state of tune achieves noting other than more noise more bulk more weight . I reckon if a real good 3" exhaust is good for 270 odd Kw on an RB25 or 30 its overkill on a 210 Kw RB20 . I remember years ago a GTST coming into a workshop I used to use lots and it had a Jap metric 3" exhaust (more like 80mm) and it was silly loud and drony . That shop basically changed the rear section to 2 1/2 inch and the car was much quieter and lost zero performance . A rear exhaust change doesn't have to reduce in size right behind the cat and if anything you need to keep it up a little way behind the "cooker" because of the temperature rise . I honestly can't remember where the last joint is in a Skyline but if its down around the axle somewhere its not difficult to experiment with a smaller size from that joint to the last muffler . If that muffler flows real well for its size and the transition is gradual you might be surprised at how much performance id doesn't lose . Something else very few people think about is how much a big bore exhaust rings like a bell . The larger diameter tends to make the tube a LOT more rigid and at times they transmit a lot of mechanical and combustion noise into the body/cabin . If you can get them those spring loaded carbon ring flex joints they can help isolate the engine roar from the exhaust and if fitted possibly in the exhaust behind the gearbox hanger it takes the car length "engine steady" part out of the exhaust and can at times reduce the echo chamber effect . Your calls , I'd just be a little conservative with exhausts and play around with the rearmost section . A .

Well the issue aside from the time and costs involved , splitting hairs I know , would be grinding the bead off the inside of every weld to maintaain boundary layer flow . A mandrel bend would be easier cheaper and less heat stress into the material . May not look as pretty but when function is everything ... I wouldn't know at TRD level but 7MGTEs are known for headgasket sealing probs and people who used to race them could tell by the witness marks left by the fire rings how many times they really let them have it . Again don't know about noise issues but you'd think they would have ovalised the outlet rather than form a collector to three short pipes . Just my observations , cheers A .

I'm going to suggest (for a 210 kw 2L six) a mid muffler and consider going down to 2.5" at the back . Most here won't agree but the "signature" 3" exhaust is not the be all and end all because different apps are different . I've no idea what size exhaust an RB20 gets std and I think 33/34 RB25s were a metric 2.5" , and GTts made 206 kw ? 3"' at the front where the gasses are hottest and wanting to expand should be Ok but as they cool and shrink the only way to keep the velocity up is to reduce the pipe size . In a perfect world 2 3/4 (70mm) tube and mufflers would still be available but the cap on backwards brigade wouldn't be told 3"s too big in some circumstances . The do know better smarter exhaust fitters gave up on 70mm because they couldn't sell it even though it can be better in some apps . A .

Unless there were specific regs dictating its design I wouldn't view that pipe as you beaut . It looks like 500 short sections welded together and thats not required these days to get good pipeforms - if you have money . My problem with the second small pipe is exactly that , its small and wouldn't have a lot of volume for expansion . Also note how it rejoins the pipe down the back , same scenerio as the IW type turbine housing debacle . I also have issues with mobs that start the gates vent pipe out as a holesawed hole through the flange plate when the gates outlet hole is not round . Where I agree with some carefully made twin dumps is when they are made firstly to be a turbine outlet pipe and second a wastegate outlet . Its all the same deal with Evos and if you can find some pics of the American Megan Racing firms Evo dumps you can see why they work . What they do is form a slow expanding taper (elongated conical tube if you like) that curves down to run the exhaust back under the engine . They have a "shell back" section that vents the twin wastegate (twin scroll) and it comes back into the main tube after its diameter has increased in size . The findings with Evos is that 3" outlets don't seem to work any better than 2.7" ones even though the front pipe is 3" . I think at the end of the day it depends on the engines state of tune and ultimately its use . Obviously if you have a GTRS on an RB25 you're not looking for 500 Hp so most reasonable dumps should be adequate . If you are super serious it'd be a GT30 or larger using an external gate . I have that RS and dump and I wouldn't bother spending good money on a split dump because I don't think the returns are there . An open collector is much simpler and easier to form and if the turbine housing is a good design it won't fire the gates gasses sideways into the turbines outlet . All the race tech thinking is fine on a race car thats mostly driven flat out , road cars mostly aren't so the full load time is short/small . A .

I think the big issue is the Multinationals have made a habit of charging more to their Australian agents . If retailers pay more they have to charge more and guess who gets the damage . With "shipping" the drama seems to be air freight and if you get stuff sent by sea it appears to cost less . A .