discopotato03

Well something to note is that a T04Z is a T4 P trim based turbo meaning it uses a T4 turbine housing and not a Garrett GT30 based one like GT30 and GT35 BB turbos are supposed to have . The manifold may have been designed for a GT BB turbo , anyway ask GCG because they should know . A .

Just to confirm , did someone mention you can use the std R33 throttle cable with this plenum ? Also one for Mercury , I don't suppose its possible to use the GTt runners and PM plenum on an R33 ? Would there be any gain or just lots of grief for no real purpose . Lastly , WHAT is the size of the R33 std throttle plate ? PM site shows a 66mm throttlebody as their smallest offering so whats the difference between this and the std R33 25DET throttle plate size ? Cheers Adrian .

My maths work like this . Area of a circle is Pi x radius squared so ... 2.25" = 3.976 square inches . 2.50" = 4.909 square inches . 3.00" = 7.068 square inches . Tube is usually measured in OD and last time I measured 2.25 and 2.5" exhaust tube had a wall thickness of ~ 1.9mm and 3" ~ 1.6mm . You're only going to get exhaust pulses one at a time from each dump so its not like a constant flow from both at the same time . A .

Personally I think the greatest gains are from being larger in the first 1/3 to 1/2 of the exhaust system . The gasses are pretty hot out of the turbo on full load so giving them some volume to expand into seems to work . The gasses cool and contract (increase in density) quite quickly and you can afford to go a bit smaller in tube size toward the rear half of the exhaust system . Usually the cat and mufflers are back there anyway so 3.25 or 3" mufflers should be reasonably easy to fit . Cheers A .

I had a looky here . http://www.plazmaman.com/shop/index.php?ac...m&itemId=17 Does anyone here have closer pics of the Plasmaman plenum , I'd like to see where the fittings and IAC assembly goes . I reckon if I got one I'd want it in innocent flat black . I did ask recently about what size the std R33 25T TB is but cant remember . On PMs manifold did your customers use anything larger than std and if so were there any negative results . Just for the record my R33 has porting/OS exhaust valves/approx 9.2CR/Poncams/740 Nismos/PFC and a GT3076R 52T 0.82 A/R IW turbo to fit . I like the sound of anything that improves an engines mid range so I'm all ears . With a pipe kit and an OE GTR intercooler I'd like to have a reasonably responsive 270+ at the wheels . Doable I think . Gotta salt the Woolafs tail , cheers A .

Interesting , I must have another look at Oyays RB25 plenum . I imagine its a lot less involved than changing the whole manifold over and more easily reversed if needed for any reason . For the record can the std throttle body be used in place of the pretty , expensive , one ? Lastly the real "Greedy" one is quite expensive so the PM one must be real expensive . I suppose you have to factor in the fitting antics of the GReady one so all up maybe similar ? Cheers Adrian .

I think the major concerns here are how much of either system you have now and how complex the system is later . The fact that you have the GT3076R and a waste gate means you're a manifold and dump pipe short of a single system . Should you decide you want to play around with things afterwards the single system would be cheaper and easier because theres one of everything and most of it is easy to get at . If you were only going to pull it down once and you knew your turbo choice was going to be correct forever for you then maybe the twins would be the go . "Response" is subjective because so much depends on the spec and condition of the engine as well as how well its tuned . Personally I'd be trying to get the engine build/spec the best it can be for what you want and add turbo/s as the afterthought . I don't know why but at times people like to think that there is some mythical magic turbocharger that is going to be supremely powerful everywhere and its not the case . The bottom line is you can't have boost at low revs and expect it not to run out of gas flow and choke off in the upper rev ranges . The problem is that GTRs are heavy cars and the low compression ratio 2558cc engine doesn't make sufficient torque at low revs to lug it around like say a 4+ litre V8 could . Turbocharging works but the limited capacity/mass means you need some revs to get it happening . In short , needs 3L so the engine can do more lugging before boost is made . For anything less size the turbos so the engine makes torque where its needed and accept it won't do moonshot revs . Also from what I've seen with single GT3582Rs and externals on RB26's you may need to rethink the 44mm gate . One fella I know found that once he put a free flowing 3 1/2" exhaust on his car the 44mm waste gate no longer coped and he had to have a 50mm one fitted to his 6Boost manifold . Your call but big pipes behind turbos at the front of the exhaust system is a must to have it spin up as soon as possible . My old L Series subaru made a huge difference when its turbo outlet pipe was changed to 3" and this is a turbo Garret rates at 260 Hp - 47mm turbine outlet hole . I would want a minimum of 3 1/2' if at all possible out of a GT3076R , it can step down in stages further back when the gas has cooled and "contracted" and you can do the muffling at whatever size you want back there . Very little if any sound penalty when the pipes are hugeish at the front only . Makes a significant difference turbine response and engine power wise . More coffee now , cheers A .

So is std 33 RB25DET around the 65mm ? A .

Yeah fair enough , just thought I'd ask . Nissan really screwed us RB25 owners over with the different manifold pattern to RB26's . I got interested in RIPS RB25 to ITB 26 adapters but I don't want to lose the idle air control or cold start bypass . I'm also finding that GReady manifolds are serious money nowdays like probably enough to make some sort of 25/26 hybrid work if RIPS was asked for it . I think we all know what the preferable system is , ITB's . Cheers A .

Hi all , looking around for an R33 GReady inlet manifold and possibly a VH45 throttlebody . Cheers A .

I'm looking to get heaps done in the near future to my GTS25T and a GReady manifold may be on the cards . I did speak to SK ages ago about larger throttlebodies and he didn't think there was much it it even for a Modified RB25DET . I'm just thinking that a larger throttle wide open may do something for an RB25 to get from the pre to the post boost state . I don't know what the std TB size is on an RB25 or VH45 though I believe its 80 or 90mm . Out of curiosity is there anything suitable in between the RB25 and VH45 throttlebodies ? Also where do you get raped least buying the GReady manifold , hint 2nd hand ok too if clean ... I guess this may mean the 90mm MAF as well . Cheers Adrian DP03 .

I don't remember the dimensions of the ceramic turbines but if you can measure what you have and or post pics of the housing and turbine I may be able to identify them for you . I do have a std OP6 turbine housing I can measure possibly tomorrow afternoon . Actually I should have the VG30 single BB turbo it came off so should be able to measure its turbine as well . Cheers A .

PSI this is my opinion only but to get everything out of a GT3582R you need the T4 international sized flange on the manifold and a suitably sized TS turbine housing . You need two external wastegates on the exhaust manifold as well . ATP Turbo is the US are advertising T4 flanged TS housings machined to suit a GT3582R in 1.06 A/R and possibly 0.82 A/R . They also do "T3" flanged housings as well but I reckon you won't get enough exhaust gas through the largest ports it's possible to fit in the smaller flange . I think once your engines cylinders get much beyond 400-450cc you need the T4 TS flanges larger ports to vent the gas without a pressure rise in the system - this is to make serious power BTW not just tooling around power levels . Supra people often have 3L std and they don't muck around with "T3" flanged manifolds and turbos . I believe when you're talking about crank power levels of maybe 450 plus the T4 stuff is essential if you want the twin scroll type of system to function properly . I agree that big single scroll T3 flanged turbine housings can go beyond that figure but they do't have the divider taking up gas path space so their maximum flow potential would be greater than a "T3" flanged TS turbine housing . A .

SR OT but the interesting one to research would be the crank from a small KA engine , I believe thaere was a JDM KA20 in something and if it went into a KA24 with longer rods then it maybe possible to shorten the stroke and have a higher rev ceiling . The 89mm bore gives you more room for increased valve area and the direct bucket actuation is always preferable to rockers IMO . Shoot me I'm biased , had FJ20s in the past . Something for later , cheers A .

Well no doubt Geoff would have told you that the 0.78 GT32 housing is workable though no exactly in my mind ideal . It is comvenient in that it is twin scroll and has a "T3" mounting flange on it . I expect you would have read all the info at Freshalloy.com and it was a while back that Geoff noted that those GT32 housings do create a power ceiling based on their exhaust flow limit , its not what you'd call low but in a perfect world having a bit more flow potential would pay off . I also hope you noted what the Americans have gotten out of their KA24DE turbocharged engines , killer mid range torque starting 800 revs sooner than the SR20s in a similar state of tune . Arguably a better drift engine , iron block and a real cam lobe on bucket twin cam head as well . Many won't agree but I reckon a turbo engines turbine/turbine housing/exhaust manifold/exhaust are among its most critical components if you are to make super power reliably . Cheers A .

The TS system allows you to use healthy cams particularly if you go bigish on the TS turbine housing . The point a lot of people miss with a properly functioning TS system is that the turbine housing A/R needs to be big so that you get high flow rates with less pressure driving the gas . To not get a pressure rise/restriction the passages need to be large . This is also the reason why serious TS systems use the larger divided T4 international sized flange on the turbine housing and manifold . Examples would be the HKS cast manifold for RB26's and the turbine housing footprint on HKSs T04Z turbine housings/manifolds . Yes I know those HKS Z turbine housings are not twin scroll but they would not have gone part of the way for no reason , cheaper to make a single entry housing than partial twin entry one . I believe ATP are now offering twin entry T4 flanged TS turbine housings for the GT3582R and maybe GT3076R as well . http://www.atpturbo.com/mm5/merchant.mvc?S...tegory_Code=GTH Too late this time but for those interested Geoff probably does T4 flanged manifolds for SR's and has been for RB25/26 for some time . Like all smart people they make the flanges suit both RB25 and RB26 stud patterns . http://www.full-race.com/catalog/product_i...roducts_id=1640 A .

As I've said in the past the people with the smarts in the States really liked the 52 trim GT3037/GT3076R , and that was in single scroll form . Just make sure the cartridges ID tag says 700177-6 or 3037-52T . For the 56T 700177-7 or 3037-56T . A .

If you have a look at ATPs site they are now selling twin inlet GT30 turbine housings in from memory 0.82 and 1.06 A/R ratio . If I was going to do another turbo I'd think about a GT3076R and give consideration to the 52T version . You don't necessarily have to use the port shrouded compressor housing on a 2L four cylinder particularly if the turbine housing ratio is up there . I don't remember what size your exhaust was off the turbo but if it'll fit 3.5" would be good - need big pipes for the first meter or so off these turbos IMO . A .

The thing you have to like about big Gs bearing cartridge , not CHRA cartridge , is that they are so easily fitted to a housing with a simple hole machined through it . These things have been around for a while now and it may pay to find out who supplies the bearing pack for Gs units . I think we're going to find increasingly more parts available for Gs BB cartridges just like it has been for plain bearing center sections . Have you thought about importing G's cartridges from overseas and doing your own thing with housings ? A .

Hi Roy , I think this one may have those bits if they don't fit the Turbosmart and I don't think they do . The fella is on this board and I'll be with him again in an hour or so . Can you PM a mobile no please . Cheers A .

If it makes any difference the Metal Cat and Catco metalic one sound ok ? A .

I really hope this doesn't degrade into some sort of war , just some personal experiences please . I know someone who recently did an exhaust for an RB26 and used a 100 cell cat from Liverpool . I've been searching for info about metalic core cats but nothing seems to be conclusive . Would like something low restriction and have some life out of it . Cheers A .

Timing Roy , I know someone that just took a TiAL 44 of a 6Boost manifold on an RB26 and wants to sell it . He went to a larger Turbosmart because the 44 wasn't big enough when the exhaust was increased to 4 and 3.5" . Stay tuned , will be with the owner in a hour or so . Cheers Adrian .

This business of welding external gate mounts to the std RB exhaust manifold raises one more possibility , welding on two mounts and keeping the divided nature of these manifolds intact . ATP are advertising twin entry "T3" flanged turbine housings for GT30 and GT35 BB turbos so that would solve the what to hang it off issue . I'm not sure what the worst flowing section of say an RB25s exhaust manifold is but possibly the most significant choke points could be where each set of three runners merge into the turbos twin exit mounting flange . If each of the gates could communicate with the front or rear three runners you may coax a bit more than 30 out of a 25 with a GT3076R . Not as good as a purpose built manifold but food for thought . Cheers A .

This is what Garrett call it . http://www.turbobygarrett.com/turbobygarre...9R_707160_9.htm A .