discopotato03

Remember that 70's cars didn't use the zero scrub geometry and hub offsets are different for this reason . To get around this you may need to cut and shut your control arms with the inner section from the Z . S12 stuff may be worth looking into (same era ) . Import Bluebird 910 with power rack could go close . Thats what I have and will use if my rally fabricator runs out of work . He once fitted manual Bluebird steering to an MR30 but can't remember which X member he used . The control arms were I think Skyline outer and Bluebird inner (cut and shut) . The steering arms were shortened Bluebird .

That first turbo is NOT a propper Garrett GT3071R . That thing is what ATP Turbo call the GT3071R "wastegated" , HKS call theirs a GT2835 . The one pictured uses a GT28 turbine housing with a T25/28 mounting flange . The real GT3071R uses a GT30 turbine and exhaust housing with a T3 flange and non gated .

Some bad news peoples , R30 Pwr Steering Boxes no longer available nor worms or sectors . Drag links are still around early and late type (changed around 10/83) but expensive at $458 retail . The race cars used one off special internals to suit that application .

Area to radius ratio is difficult to measure without sectioning (cutting up) the casting . These Hitachi housings never had the ARR size cast into them like Garrett's housings do . My impression looking at all three is RB20 type = miniscule , RB25 type = small , VG30 type = huge . They really do have a lot of volute area inside them but remember they were designed to not choke a three litre V6 . Cubes do you intent to run the complete VG30 turbo or some kind of bitza thing . Cheers A .

I spoke to Peter from Sydney Suspensions (Heasmans) and he said that there is a high point in the worm sector interface and it should be adjusted to have no freeplay there (in the straight ahead position). The trouble is the further away from this point either way you go the more the freeplay there is . I can jack my car up and have about a quarter of an inch of movement in the offside wheel at full lock . Is this normal with these cars and this type of steering system ? I very much doubt the GRP A cars were raced like this . Can anyone with experience in dinosaur era steering systems offer any solutions . Cheers A .

I spent an hour removing one of these from an 85 MR30 lift back this afternoon and paid $ 50 for it . Does anyone know if there are rebuild kits for these and if the worm and sectors are still available . One other thing I noticed was that all three MR30's at the wrecker had worn joints on the nearside (idler arm) end of the drag link . My DR's steering box has a shocking amount of freeplay that can't be adjusted out . I dread to think what Nissan would want for a new one , if there's any left . Any help appreciated , Cheers A .

Is anyone using these and what do you think of them . Cheers A .

Cubes , have been very interested in this topic . Is there an Apexi PFC for the VG30DET or VG30DETT ? If so it would be interesting to know their reference tables particularly as the airflow would be based around 3 litres . Also probably impossible but are Z32 ECU's electrically similar to R32's ? Cheers Adrian .

I fitted a pair of Noltek bushes ($12.50 Trade) and was surprised how much less vertical movement there was in the idler arm . The std Nissan bushes have three grooves in their bores for either soft spots or grease retention I guess . I noticed that the Nissan bushes are slightly countersunk at the flange outer face meaning that the tapered section is not compressed into the arm properly . The Noltek version fits much better so steering should be more accurate . Cheers A .

I know it sounds silly but make sure you'r not pumping into the return line (hoses wrong way round) as the injectors will be on the wrong side of the regulator .

Congrats Bullant on a good result for the cash outlay . Can you tell us if the spool revs moved up with the larger ARR housing . I'll stand with Corky Bell when he says turbine inlet pressure is an evil and should be delt with accordingly . My rantings only , cheers A .

Its been said that a couple of cable ties around the rear damper pistons will move up to show squat height when under maximum acceleration or power load . This is where you need neutral camber and toe to put the most rubber on the road ie largest contact patch . Once this is known I suppose enough bags of cement in the boot at aignment time should re create it .

OHR-30T yes in time the plan is R32 RB26/31 DET . ATM I'm living with the DR30 (which is OK) and trying to correct any niggly probs . A clean car that responds nicely to driver inputs is a pleasure to drive and sells itself . Also refuse to be beaten by minor technical hitches . The plan for the back is to find its squat height and align the semi trailing arms to have zero toe and zero or just a tiny bit of negative camber . I want to make the best of what I have and apply the results to later cars with more sophisticated factory suspension . If Fred and the boys made respectable racers out of R30/31's we should be able to make reasonable road cars of them . Cheers A .

There is a chance that the S13/14/15/ R32 front cross member/rack/lower control arms may work . I would be measuring the lower control arm length to see if their similar length to R30 . It seems that other Nissans of the 80's with racks used shorter control arms and their inner pivots further appart than the R30 with its conventional steering . Its probably a case of having a rack long enough to allow suitable travel that forces the inner pivots to be further out necessitating shorter arms . The conventional system can work IF the pitman and idler arms work (pivot) only in the intended arc . It would be a large undertaking to put S13 rear suspension into an R30 . The body would have to be strengthened in the mounting point areas for the cradle and it would be sheer good luck if the dampers lined up properly . The track width needs to be right and who knows what happens with roll centres , hight etc . Nothing is impossible but the S13/R32 is probably cheaper to buy standard and have (the R32) more potential . Cheers A .

A lot of people look into this idea . SK costed out the cams buckets springs etc to mod a R33 25 head , buying the GTR head and manifolds is far cheaper . I'm not disputing that Nissan made it difficult to fit GTR manifolds to any other RB head , but when comparing them too many things get in the way to make it practical . Obviously the RB20 pattern came first and the GTR type later . It looks impossible to fit the GTR inlet on the alternate pattern because there would be no access to the fasteners . The exhaust stud pattern has the same dramas for the same reason . The two flanges would have been changed to give access to the nuts and washers around the twin turbos . Bang for buck using the complete RB26 top end (turbo/s optional) is best from a performance viewpoint if you can afford it . Being non VVT it solves the oil drain problems as well and another reason why I bought mine . Cheers A .

OHR-30T , thats interesting about the 180B idler arm fix . Did the machinist turn up two taper walled bushes or bore the arm section parallel walled for a cylinderical bush ? Also what material was the bush made of ? I was under my car yesterday afternoon pulling up and down on the idler arm and watching the nearside wheel toe angle change markedly . This is with a new genuine idler arm assembly (1 month old) , the arm rocks on the tapered bushes which is totally unacceptable . The offside doesn't budge on its end of the drag link because the power steering box and pitman arm are robust and rigid . It appears that the idler arm vertical movement is the weak part of the system and a workable fix should not be an engineering feat . If I can get my rally specialist interested (very busy ATM) , if enough people are interested he may be persuaded to do a short production run of something that works for an acceptable cost (economies of scale) . I aim to fix this one way or another otherwise the vehicle is useless to me . Cheers A .

I asked ghostrider this ages ago to which he replied no the mounting pads are further apart . Also the R31 lower arms are shorter (pivot points different) wich is a disadvantage for camber change . I was talking to my Nissan rally specialist and he believes its all in the idler arm bushes , even genuine (new) they're too compliant . I'm going to try and machine some bushings up out of a special acetyl material to get firmer ones . Cheers A .

From a convienence point of view the HKS version wins hands down . The housings are designed to fit in like the standard ones . As has been said before labour charges in Japan are horrific which would be why HKS's kits come with everything to make the turbo fit - quickly . If they had to pay for all the fiddly one off bits to make generic housings (turbo) fit the car the labour charges would be huge . Back here at Cactus Island labour is cheaper and many of us will try a bit harder to make the generics fit to save a quid . Power ratings and turbos - HKS set out to market turbos that would work ok at pressure ratios beyond what the OEM's wanted . No rocket science here , specing a turbo with a more open bladed turbine that wakes up a little later , and with less restriction when the compressor's pumping 1.3 bar boost , is very easy . Its just an alternative combination of bits from other Garrett turbos . Some suppliers sell HKS exhaust housings separately which is good because it can be the most difficult part of a conversion to get right . I haven't seen their compressor covers separate but occasionally a second hand OEM one will work . Its really not that difficult to adapt the bolt on flange type to barb type or vise versa , this is done all the time with rubber/silicon hoses and elbows or custom pipe work . Cheers A .

While I'm here is there a way to remove the slop in the Idler Arm assembly . Mine is new (whole unit) and it still moves up and down taking the drag link with it and making eratic steering . I have visions of ball race bearings or even a gutted steering box on the other side . I have to say that steering dramas have been the most frustrating part of my time with the DR30 . Cheers A .

Trust me the compressors and turbines in the HKS spec cartridges contain no more kryptonite than those marketed by Garrett . Years ago HKS had a technology agreement with Garrett and could obtain combinations that no one else could . I suspect with monolopy laws being what they are this situation has ended , if the likes of the FIA and CAMS can't have monopolies why should HKS ? What you need to remember is that Garretts bread and butter is OEM turbos for volume sales and economic survival . HKS being aftermarket sells in much smaller volumes and small production runs of specific cartridges would be expensive . HKS want you to believe that their badge engineered Garrett turbos blitz everyone elses ET's with a single whoosh - to separate you from your dollars . If you can get the same results for less money its a win in my book . I should also mention that some cartridges now sold by Garrett can have better results than any in the HKS range because R/D is an on going thing . My opinions , cheers A .

Can anyone tell me if R30/31 front lower control arms are the same . The R30 type have non replacable ball joints and Melbourne is fresh out of new ones . If R31 ones fit it'll give me the option of replaceable ball joints but , the bush to ball joint length needs to be the same and the caster rod drillings as well . Cheers A .

Sorry Dale , been away with work . I don't really know what a drag turbo is as its not in my sphere of interest . If your using production gearing you need a power curve to suit its spacing and speed range (final drive) . A power curve that starts half way through the engines speed range and hits like locomotive is useless with wide (std) gearing . To me good turbo power starts with modest boost that can be run to the redline as often as desired without hurting anything . It should wake up about a third of the way through the usable rev range and be progressive (controllable) as it climbs onto boost . I think Roy mentioned the power out of corners thing as being more important than the guided missile down the straights idea . As I mentioned before I prefer the method of least possible back pressure and most turbine torque coupled to a compressor of just a little above the required flow capacity . What this gives is a rotating assembly that gets spun pretty fast at times but not outside its design criteria . This is why all the R/D went into Garretts GTBB turbochargers , low innertia wheels spun faster than the bush bearing designs to create high efficient airflow . Compared to T4's the GTBB turbines appear small and open bladed but generally pass more gass with less restriction at higher speeds . The rolling element ball bearings are there because bush bearings cannot reliably survive the shaft speed and thrust loadings , and the oil shear with the high surface area of bush bearings creates unnecessary drag . The GT3071R has it all , the GT30 turbine with its wide range of turbine housing ARR's and a propper high RPM capable GT compressor wheel that will put good transient response and oomph into the mid range . I doubt I'll ever own an RB25DET but the GT3071R would be my choise . I think the rod stroke ratio and the weight of an R33+RB25 Skyline require a sensibly sized turbo to make it a nice package for road and the odd track day . For the record I don't think HKS market the GT3071R but it is in the current Garrett catalogue PDF . My rantings only , cheers A .

A much cheaper easier option would be to repair your own box , same syncro rings as Bluebird/240K etc or get an MR30 Skyline box in good condition and bolt it in . RB71C gearboxes take a fair bit of expense and work to fit , much more than removing and repairing your own .

That turbo already has an integral waste gate .

GT28RS has the T28 flange . A good option could be the Garrett GT3071R with the .68 or .87 ARR HKS T3 flanged GT30 exhaust housing sold separately . Brett at GCG says he can get them as I'm sure others can . Going this way gets you very little exhaust restriction and an efficient turbocharger . Avoid the GT3071R "wastegated " its really a GT2835R with a T28 flange .