discopotato03

For what you buy an Evo or GTt for they are better value for money than more current exotics . The average person isn't even going to consider the above .

Bogun racing out here consisted of people who could not believe that the big Aussie Ate Olden or Ford were so out classed by the other brands . Nissan and Ford Sierras were living proof that cars with shitty little ingines and shellas hair dryers were blitzing their big dick extensions . Hence the bull shit bull shit at the mountain back in 92 (beerish for bo gun bo gun) .. Production based racers are a double edged sword because mainstream models that make manufacturers money are not race like at all . The vast majority don't like cars with race traits because they are not comfortable easy relaxing things to drive . Most tarted up performance cars today are "sporty" rather than sporting - there is a difference and the GTt Evo thing is a good example . Lets say you get the best standard sport spec Gtt and then grab the equivalent era Evo and go belt them around Mt Panorama . They have on paper the same power (206 Kw) and probably similar weight , Gtt possibly a bit heravier than a 6 GSR . Assuming the same driver and the same conditions I think the 6 would lap faster than the Gtt on the same tyres . I reckon the Gtt would cook up faster than the 6 because of its more modest intercooling and oil cooling . The Gtt would be harder on its tyres and the 6 I reckon would go a lot deeper under brakes because they are larger . So there you go , one is a tamed down rally basis and the other is a warmed up road car . More people would prefer the Gtt as a daily road car because that's what it was designed to be . I think more honest track day users would prefer the Evo because that's more towards its intended purpose . I'm sorry if this offends but serious drivers who are focused totally on performance and handling prefer cars like Evos because the comfort compromises are an annoyance to them . They are bent on pure function and a small minority amongst all road users . The hectic skids and using more than one lane to aim the boat down the river is something else again , Evos aren't as good at that and if its important auto V8 barges probably do it best . A .

I reckon whats happening there is that a more fully opened throttle again a load that isn't allowing the engine speed to increase (high gear) means better cylinder filling so more heat energy to drive the turbine . If you had your car on a hub dyno and could load it so it couldn't accelerate in any gear the result should be the same . Against a light load an engine accelerates easy with less throttle and not as much energy to the turbine so it accelerates more slowly - lower boost . A .

The manufacturers loved it because they never made money out of the special production cars anyway . Not so good for petrol heads . It allowed the change to Bogun spec-tater racing because beer swilling knuckle abuser isn't interested in the details , it looks like his Falcadore so as long as its wiping its arse over the neighbours heap of shit he can hold his head high above the pie all down his chest . Tater money is what finances this "motorsport" and without money all motorsport stalls . A .

HKS did non gated T25 flanged GT30 turbine housings in 0.61 0.73 0.87 1.01 and I think 1.12 . I guess this proves that the port through the T25 flange is big enough not to be a greater flow limiter than the volute passage . The thing is that little flange wouldn't work too well if it had 6 runners merging into it . Years ago someone in the States had a GT3037 52T in a HKS T25 flanged 0.73 housing and the tubular manifold was quite involved . Being in a FrWd Sentra B13 with an SR20 the manifold had the turbo out over the boxes bell housing and the ext gate was between the merge and the turbine housing inlet . HKS housings had better formed passages and nozzles than Garrett production ones and looked more like the Tial ones of today . Also people the "GT35" turbine housings are really machined out GT30 castings , the only GT35 turbine housings I've ever seen were diesel spec ones and they were probably GT40 housings with enough meat to take the smaller 35 wheel . Bitzer - GT3540 . A .

You can ditch the AYC for the RS mechanically simpler lighter stronger mechanical LSD . Just keep the pump for the ACD in 7/8/9 . The Americans cry because USDM 8s and 9s only got the non active centre and rear diffs . I think they did get RS model 8s and 9s with mechanical rear LSds , don't know what their GSRs got probably viscous rear . Funny actually , Mitsy turned the LSD plates around in their RS cars so they basically don't work . If they don't chatter they don't attract complaints in dealerships . 9s got a larger fuel tank and possibly some 8s as well . 4/5/6 were Grp A homologation models and they were trying to keep them light , racers no doubt used a fuel cell anyway . The 7s just saw a dabble in WRC class but they gave up trying to compete with the kit cars WRC rules allowed . GT4 in a Corolla anyone ? WRC killed off production based Rally cars just like "Nascar" here killed off production based tarmac racing in Grp A . A .

My idle with 740s on 85 is around 0.91-0.93 L which is ~ 13.5:1 . I haven't yet tried to go leaner idle or cruise (~ 1.01-1.03) on United yet . I think a bit higher than standard base pressure would help if the injectors aren't too crudely made and close in flow . Rolls option is EV14s but 740s are alright on E85 IMO . I was told to avoid Nismo SF550s like the plague because their short pulse performance is supposed to be terrible , worse than 740s not better . A .

The only way to solve the Evo Skyline debacle is to buy one of each and see which one you spend the most time in . My bet is the Skyline will do more miles but you won't want to part with the Evo ... A .

I think you need to be serious enough money wise to justify the GT30/35 HTA turbos , at a certain gas speed the standard manifold will become a problem and the larger the engine is the more apparent that would become . Costs would escalate faster with header manifolds and gates and stealth dies a quick death . Hard to say what size turbo (turbine size) is the limit on the factory manifold . Be interesting to see a 3076HTA and the 0.82 GT30 IW hanging off the standard one . I think it's impossible to say that the GT30 turbine limits an RB30 because no ones ever tried one in the largest 1.06 IW turbine housing AFAIK . Again back to questionable turbine maps but the GT30 1.06 combination is vaguely similar to the GT35 0.82 combination . I reckon GT35 turbines are fine for driving 82mm compressors and maybe even the GTX76mm one but the GT30 doesn't do too badly on the 76mm GT or HTA compressor wheels . If Mick o screwed 330 wheel wasps out of his RB25 with a 0.82 GTX3071R we know the stock manifold is at least that good . We don't know what a 1.06 GTX3076R or GT3076HTA would be like with this manifold on an RB30 , it may do even better . Actually , RB30 would lift the turbo up off the engine mount with the HKS cast RB20/25 manifold . Mmm interesting possibilities and I got me one of them . A .

Injector Dynamics short EV14 850s . They are intended to be an alternative for later Chev alloy V8s amongst other things . I wanted something in between 740 and 1000 and since Anthony ran his 740 side feeds out at I think 360 RWKW on his RB30 I figured 850s should be fine . Anthony it would be great to get up to Newie and talk tuning , I'm interested to know if it's still possible to get an RB2530 past the emissions test to make it legal and insurable . I don't do social networking like facebook or twitter but other members of my family do . I have a bit of time ATM if your health is up to a run on the rollers . Will PM soon cheers Adrian .

True Scotty but in this day an age (better computers/injectors/E85) I rather have an RB26 with a 9.5 static CR than the standard 8.5 . It wouldn't turn it into an RB30 but if the quench zones were done properly it should make more part throttle torque all else being mechanically equal - on E85 . A .

Last time I asked Gary he said the Evo spec Bilsteins from some 8s and 9s are pretty good valving wise . A certain 7 is doing well with them though you do get side load problems if you use concentric lower spring seats on the front ones - which would include pretty coilovers . A .

The dynamic CR is the important one not the static (measured) CR . All else being equal an engine with long duration cams generally has a lower dynamic CR because the valves trapping efficiency is lower at lower revs . The less charge air you trap in the cylinders when all valves close the less you have to compress so the dynamic compression ratio is lower . This is why nice street turbo engines have short duration cams in them , higher lift versions allow better breathing but without the reduced dynamic CR caused by earlier opening and later closing valves . The only useful thing long period cams do is allow better cylinder charging at high revs but you lose in the low to mid range area . The way to get back some of what you lose with long cams is to increase the static or measures CR , it works because the less air ingested is compressed into a smaller space so the dynamic compression pressure loss isn't as much . Broadly speaking increasing the CR of an engine with not particularly responsive read big turbo/s will help the bottom end because of the above reasons . The thing is that FI increases cylinder pressures and temps too so when on boost the forced dynamic CR is the one to watch . High temperature is what generally finds the detonation threshold . Other things like throttling contribute , ITBs generally have less restriction than singles and allow better cylinder filling in most circumstances . The theory is the best filled cylinders make the most power (torque) provided detonation or thermal overload doesn't destroy things . And heat has to be able to escape easily at the end of the cycle . A .

Actually that was his quote not yours . I'm not sure if he ever ran the 0.82 housing on the 25 before it became a 25/30 . Has anyone ever done a back to back on the same RB25 with the same everything except turbine housing - both being Garrett GT30 IW ones ? Interesting how he says that with the 0.82 housing on his RB30 and I assume the same turbo RWKW didn't change just the torque - from 720 to 850 Nm . Since most peoples dick rulers have RWKW graduations on them I guess that says something . The fella with the GTX3067R has to decide if the current set up with probably a higher rated actuator gets him what he wants . If that's a torquey responsive engine than doesn't need WOT and a smokes worth of "forplay" waiting for boost then the path is obvious . Only he can know , A .

Short ID850GMs . A .

Yep pyrometer not a bad idea . Changed to straight United E85 at the bottom of the last fuel price cycle because the next tune will be on this fuel . I paid 1.30.9L and at the same time 7Eleven P98 went up to 179.9L - screw that . When I change fuels I drive it till it starts stumbling and throw 10L of the new whatever in , and do again to get the residual down to SFA . Then fill to the top . In the 10L stages I tune for the new brew which starts with the master fuel trim - from -12 to +5 in this case . My car was originally tuned on E70 nearly two years ago so master set a 0 isn't too far from what E85 is . It just needed a fiddle with accel settings and cold start stuff . I have a feeling that the consumption is going to be better than I thought it would be possibly because my tuning is better than it used to be - or I stumbled upon better settings . I don't often make changes to my timing table but the corrections get moved around a little . My current challenge is to get up around 375 out of a tank of E85 because that's three quarters of my best efforts on E42 - 500+ km . Tuning with E85 is a pleasure because its such a forgiving fuel , it can be a fair way out and still run with a few hick ups . To be fair my SF740s cope better on E85 because the low down pulse widths are wider and that helps keep things a bit more accurate .Once the EV14s go in it should get better again and with enough pump the target 300 wheel wasps should be easy to achieve . I'm lucky that I can buy E85 close to work and stash a bit so I don't run out . I would like to see more servos in southern Sydney selling E85 because my next closest is Minto . Cheers A .

Yep most people seem to agree that a higher poundage actuator will go towards keeping the gate shut if has been leaking or blowing open . The plus is that its the cheaper of the two alternatives and you probably need it regardless of housing size . Dale the greatest failing of waste gates in principle is that most are regulated by boost pressure - often with little regard to hot side pressure/flow . Something else to think about is that those Garrett turbine housing maps are very likely generated using non gated housings so total flow through the IW ones probably isn't common knowledge . The MHI thing is a different story but the parallel is that to make the power they wanted in a limited rev range they used smallish compressor wheels in relation to their turbines - not unlike a GTX3067 in some ways . Many Garrett competition TR30Rs use miniscule looking compressors for their 60mm TR30 (Ns111) turbines and their turbine housings aren't exactly huge . Its all about making the turbine spin the compressor wheel fast enough to make the turbocharger boost in the desired part of the engines rev range . As for race like , at this stage of life I doubt my car would ever see a race track and I'm not sure if Mafias ever did either . If you drove in such a way that you never saw less than 3500 plus revs then yes a 0.63 housing wouldn't be very useful on an RB25 with a GT30 turbo . Mind you you wouldn't be looking at much less than a GTX3071 or GT3076 either . Also I notice you mention that Mafias car went off at 6000+ but made 700Nm of torque to 7000 - possibly 6800 . With that available from 3100 why wouldn't you change up at 6-6500 and wind it up again ? I can only see the extra revs making a not real close ratio gearbox harder to swap cogs with . I guess Evos get a leg up here because turbo lag , which they don't have std anyway , is less of an issue when the revs don't drop as far between gears and you're less likely to fall off the turbo so to speak . A .

If you build an engine that makes acceptable torque down low mild turbo lag isn't as much of an issue so think engine first . Mechanically speaking only three things increase an engines performance , capacity CR and revs . Forget revs ATM . Capacity is in theory the easiest way because for the same state of tune ie cylinder temps and pressures because you have have a greater volume of charge to burn . CR helps because you compress the charge volume more increasing its density . Go back to 1988/89 and look at how Nissan went about making power with RB26s . Lowish CR with big intercooler (for the day) and big lungs in multiple throttles - good throttle response here . Turbos were on short three branch manifolds so short path to turbines and light ceramic turbines . Turbos had modest sized housings on them . Twin turbos with twin integral gates is effectively same as twin scroll single turbo with twin gates , but TS single manifolding won't be as good . Two fold advantage with E85 , better evaporative charge cooling and chemically less detonation prone . This allows you to use a high static CR and suitable pistons can have better quench so even greater detonation resistance . Cams , generally short timed big lift cams are good in engines that need torque early on . They work because big lifts open valves further to fill the cylinders but the limited off seat time means you keep/maintain good trapping efficiencies . This means you don't charge the cylinders and lose part of what you got by it leaking out either valve because of extended durations . Long duration cams are great at high revs because the engine events are happening so fast that the gasses don't get enough time to leak back either way . Shorter duration cams have less overlap timing because the emphasis in on getting best scavenging at less than telephone number revs . Turbos , if there is a modern update to what you have performance wise now I'd look that way with twins on a std capacity RB26 . I'd look at the maps of your turbos and see if there is say a GTX equivalent that has a more efficient compressor ie possibly GT2860R . Valves , some people think big bore RBs like 25 and 26 didn't have an idea valve size ratio inlet to exhaust with the exhaust being slightly smaller . I don't know about RB26s but you can get slightly OS valves for RB25s and they go straight in with just a bit of seat work to the existing seats . I think you can look at closing up the low down turbo engine torque hole two ways , better or smaller turbos vs better engine itself performance . Raise the static CR better quench and cams with better trapping efficiency . These lead to higher cylinder pressures down low and that means more torque . Smaller turbos tend to have smaller passages which increase gas speed in relation to engine speed , GTSSs are like this . Sometimes same size as existing turbos but with lighter forged/milled compressors help because there's less inertia for the exhaust energy and turbines to accelerate . Better aero wheels can add a bit too . Tuning/fueling . IMO the best injectors you can get your hands on should help down low for two reasons . Modern ones like EV14s have much lighter internals so they are faster acting and more accurate withy fuelling . Good spray patterns help too and you can't forget that accurate well atomised fueling can make a considerable difference to how much torque an engine makes at low speeds and light loads . Also a tuner with the smarts meaning strategies to make the fueling and timing give the best everywhere . My 2c cheers A .

Go back to the site and look in the Lancer Evolution/Diamond star or Subaru sections and open the FP Turbos section in any of these . You'll see pics of these turbos with FPs "84mm FAP" or flow advancement port covers - comp housings on them . They still claim 59 pounds a minute air flow but I'd say they fit more easily in the engine bays of Evos Rexs Diamond stars and DSMs . If it works for them I can't see any reason why it wouldn't on a Nissan RB engine . I can't see why you can't order these turbos with any GT30 turbine housing you like or without if you have your own already . A .

Yep dunno if the SK Bilstein Whiteline kits are still around , I think he said some of the springs may not be available . However , the SK re rated Bilsteins are and that is a good start . He said you can do a coil over conversion on them (threaded sleeves on circlips) and use small diameter springs in the right rate . Really all the bling lookin tops with spherical bearings do is give you grief on a Skyline . Also he organised some years back an adjustable Silvia stut top that solves some of the lack of compression travel issues . If genuinely interested I may be able to contact him , cheers A .

AFAIK if you can fit a GT3582R on the standard manifold you can fit a GT3076 HTA because dimensionally they are the same . FP have an alternative compressor housing which you can see if you go to their site . I think its based on a TC06 housing and is port shrouded . If serious email them and ask if it makes any notable difference with this housing . A .

As far as I know the waste gate flat valve or disc is a bit larger and the hole it covers . Group A rally engines of the 90s . They tried all sorts of things to make a usable power range with the air restrictor which limited them to about 5500 revs . Mitsubishi had quite a few variations of their TD05s and they went reverse rotation and twin scroll when they turned the engine around in the Evo 4 . The first TS housing was 9cm in the 4 with an optional 10.5 in the 5RS and most 6s . The 6 TMEs had an optional smaller 15G compressor to make them boost even lower down . I don't remember which Evos first used the 9.8cm TS housing but they were standard on most 7s and some 8s I believe . Evo 9s had a different head with variable inlet cam timing and improved cooling passages , smaller diameter plugs as well . The VCT helped pull up the bottom end and let them use an updated 10.5cm turbine housing , sort of a bit like Neo RB25 enhancements . I can't remember the build numbers but Evos 4 5 and 6 weren't made in huge numbers , I did read all up there were 7000 6s built . 8s and 9s were sold new in the States and here in larger volumes than the earlier cars . They were never going to be main stream because most people don't like real performance car characteristics . Back to today and GTX turbos . As part of the range they do a "Rally Potato" GTX28 turbo which has a modified compressor wheel , its intended to work within the limits of a given restrictor size and available on special order . A . BTW this site won't let me edit my posts so please excuse the silly spelling mistakes .

It generally never does . And there we have it , the user wants GT2835 Pro S like performance but with something available off the shelf and as compact/stealthy as is reasonably possible . We know that you can hide a GT3076R 0.82 reasonably easily and the only non std bits needed is an inlet tube like Scottys and a spacer plate . This assumes you keep all the standard airbox and snorkel - and the airflow metre . If you get creative with a turbine housing and dump shield most people won't see too much out of the ordinary . Hiding a GTX3067R should be easier because from memory you don't need the manifold spacer and the compressor housing is smaller . The inlet boss is smaller , I think 3"/76mm vs 4"/100mm) . The AFM from memory is 80mm so not much bigger than the turbos inlet . Dale you must have been one of the few who had the larger Pro S turbine housing on your 2835 Pro because I believe they came standard with the 0.68 housing - in kit form . Now of all the GT3071Rs , 2835 was the HKS handle for cropped GT3071Rs , their Pro Ss gave the best all round results and I put that down to their turbine housing (both sizes) being GT30 format and their comp housings being port shrouded . I suspect the people with full sized GT3071Rs and Garrett housings (both ends) tried and to a degree failed to get good all round results because they were trying to fix issues bcaused by lack of port shrouded compressor housings . This can really easily cause surge and boost control problems and changing turbine housing AR size (generally larger) often isn't a complete fix . It bleeding obvious , to me anyway , that HKS found the problems and fixed them before they became grumbling customers dissatisfaction . HKS didn't always use big or even medium sized turbine housings but most of what the marketed worked - remember the tag states Power and Response . Some early efforts like GT2540s and GT2510 were superseded by GTRS and GTSS but that's another story . To keep this close to home ask Wolverine what he thinks of his GT2835 Pro S in 0.68 AR form on an RB25DET . I'll suggest nobody had boost control or surge issues with these turbos using the smaller 0.68 turbine housing , very few people changed to the larger 0.87 turbine housing . I have a fleeting memory of someone doing this 10 or more years ago here and I think it typically moved the power range up evenly but not by a huge amount . It got them closer to their target number which was the point of the exercise . I think the GTX2867 and 3067 are aimed squarely at being GT2871 56T and GT3071 replacements , one for one . Most GTXs of similar wheel size to the earlier GT versions are intended to make more rather than the same power more efficiently , X67 wheel is (base diameter anyway) 4mm smaller than the GT71mm wheel it's replacing . I think the comp maps even show similar flow rates GT71 to X67 compressors . With Evolution Lancers yes Ralliart and MHI were trying hard to make a two litre engine perform like a high torque rev limited diesel . All the manufacturers were hard pushed to turn in some cases like Ford with their RS500 Sierra engine a rev donk into a torque one . The restrictors forced they to use everything they could think of to make them boost from nowhere and haul within the restrictors flow ceiling . Dragged away for domestic bore now , back soon cheers A .

FP does an alternate compressor housing for the 3076HTA , I think its a Mitsubishi based one they use when the T04S one is too big . I was under the impression that turbos with the S or "GT35" compressor housing fitted if you use enough spacing on the standard manifold . Isn't someone running around with a GT3582R on a std manifold RB25 ? Happy to be corrected but that's what I thought . A .

Well I'd like to hear what Mr Maffia thinks because his results largely fly in the face of what many here think . Maybe the laws of physics are different in Mackay . I don't see how anyone can reason that a big trim turbine in a reasonably big housing is gonna spin a modestly sized compressor fast enough to boost properly in a car that doesn't get many opportunities to stretch its legs . 4000 rev boost threshold on a 67mm compressor - piss off . How f**ked would an Evo be if it did that with the 67mm compressors they have - factory ...