discopotato03

Thanks very much guys will look into this and ah also the minor fettling around the bucket bores , understand the Bridgeport not required ! Cheers and thanks , Adrian .

Thank you Pete , would have thought a bit more feedback from others . Did search , didn't have a week to go through non specific strings . Cheers A .

I would tread wearily with large valve heads on L20a's , my references show them as having 78mm bores and 38+33mm valves so 71mm across them . Late L24's use 42+35mm (77 across) in 83mm bore . L28's used 44+35mm (79 across) which is wider than the L20's bore even if they were touching in between . Cheers A .

Finally got around to having a look at my RB26 head last night and found more wear than I'd run it with in some exhaust guides . SK once said that this is not uncommon for these heads due to the Japanese refusing to change their oil . By the nature of these cars you'd have to say that most of them have had a hard life in the old country as well . I'm curious as to why a cam lobe over bucket valve train would allow enough side load to wear the guide (or valve stem) - are the std exhaust guides a little on the soft side ie some sort of exotic Hidural Bronze or some such for better heat conduction ? Can I take it as granted that K Lines are not an acceptable fix . The burning question is do these heads eat valve guides over time even with good maint/oil/bit of mechanical sympathy ? My previous experience of this kind of valve train ie FJ20/4AGE/7MGE is that the guides seem to live forever so this is new to me - though was told to expect it . I guess this leads into what makes these valve trains reliable long term . A good friend of mine (SC) who's been on the tools for ~ 30 yrs said that while hollow sodium cooled valves are good , if they hit anything they tend to break rather than bend . He was recently given two transverse 4AGE's , one of which had dropped a valve or seat and destroyed the chamber and daylighted the piston . Obviously no one intends for this to happen but I prefer bent valves to destroyed engine . Also while I'm here , some in the aftermarket are offering different buckets to go with reduced base circle cams for more lift and alternate material guides . Is this the way to go - dread to think of the cost ? Wish list includes highest lift ~ 260 cams but at what cost ..... Sorry so long but need all the facts , don't want to do it twice . Cheers A .

DR30 calipers are same as one of the Pathfinders and one of the local pad mobs does a 4x4 grade pad that works very well . Any pics of the late Z31 caliper and are pads same as DR30 ? Do the calipers interchange all else left std ? Cheers A .

I would be getting the 2835 repaired given a choise , they can be rebuit if its only bearings and seals . If its chopped out the piston ring groove on the turbine there is a Garrett cartridge that uses the same turbine with a larger trim version of your compressor (assumes yours is 52T) . Buy , swap compressor and run . When it gets here send me the turbo ID tag numbers and I'll see what is closest in the Garrett marketed range of cartridges . Cheers A .

People who talk about them say they chose the .81 for RB26's (HKS version) . The turbine is a TO4 P trim which is very common in the turbo world , Garrett do heaps of different a/r TO4 P trim exhaust housings in T3 or T4 mounting flange pattern and single or twin entry (split pulse) . Some are saying that the spanky HKS drilled compressor cover is unnecessary because that TO4R compressor is not prone to surge . If I was buying one I'd get the Garrett version because I cannot afford the extra ~ grand for HKS particularly since the cartridge/wheels are identical . Also I don't think these need the huge T4 mount flange pattern that HKS versions have . I have a couple of snaps of one with the TO4S .70 a/r comp cover and can't remember which Garrett exhaust housing . Cheers A .

Smaller Trim TO4E compressor will bring it on earlier . You are using a 57 trim so a 54 or 50 would be the next steps down . You could even look at usind a TO4B cover and backplate with the Buick Grand National compressor wheel which is actually a TA34 69mm 58 trim 7 blade wheel 410299-0004 that looks like 2/3 of a 60-1 map flow wise . There are 6 blade versions of the old TO4B compressors in 39/48/57/62 and 70 trims , 48 or 57 could work Ok . Several ways to skin the cat , mainly depends on price and availability of parts . I would NOT reduce the turbine housing a/r - anything that increases exhaust restriction is a big no no IMO . Cheers A .

DR30 struts should be easier to get . Calipers/pads easy to get and I think disks are same as 274mm Z31 ? . Struts are not common but I may be able to locate some . I have a complete spare set (no dampers) but keeping till my DR30 is sold . I did know of another bare set . Cheers A .

Back again , discovered you mean QR25 not RB25 and wish to keep your turbine housing and dump pipe . Garrett has released five new Ball Bearing cartridges designed to replace everything between the housings for some bush bearing turbos . Over your way there has been a huge craze over TB31/TA34 + TO4E hybrids . Garrett has decided to use the 76 trim TA34 turbine (stage 3 in US speak) and match it with one of four TO4E compressors , ie 57 and 60 trim in the 75mm or 2.950 O/D . The second two are 50 and 60 trim in the 76.2mm or 3" wheel version . My lists of TO4E compressors is not complete but I would lean toward the 50 trim version because it will spool sooner for the given turbine shaft power . My list shows the 76.2mm 50 trim as 53.9mm inducer and 5.2mm exducer tip height , wheel number is 448048-0004 . Garrett part numbers for these conversion cartridges are 757179-2/-3/-4/-5 for the respective compressor options mentioned above . The 757179-1 I left out is a TO4 PTrim combined with a TO4B 60-1 compressor . From memory QR25's are long stroke engines so sizing the compressor to support beyond safe revs is pointless . Probably need a 3000 to 6500 rpm range which the 50 trim should handle and not overwhelm the turbine or integral wastegate . As for boost pressure the best gauges are absolute pressure type which read zero as zero (total vacum) instead of those silly things that only read sea level pressure as zero . Sea level pressure is 1 bar absolute so at 5000 ft it will read something less . If these read 14.7 lbs of boost it will be 1 bar at sea level , 5000 ft or 20,000ft because its pressure above absolute zero . Often with aircraft turbos are there to maintain sea level manifold pressure to their desired service ceiling so that lower atmospheric pressure does not sap performance . Cheers A .

Gurov , the easiest and cheapest way to get earlier response is to use a smaller trim TO4E compressor wheel which will also need another compressor cover . TO4E's go down below 40 trim in 76mm or 3" diametre . I went to a lot of trouble some years back to get a TO4E 50 Trim from turbonetics because the map looked so good . You should be able to get some turbo shop over there to do this for you cheaply and easily . The std Hitachi's on RB25's are badly short changed in the turbine and housing dept so I would not seek one if it had something easily available . Actually I think Garrett has released some Ball Bearing T3/T4 conversion cartridges they're calling T3/T4R CHRA's . Getting nagged by the kids again so back with more info later , cheers A .

Tried searching no good , anyone ? Cheers A .

Bluepoint make a nice plastic tool for the job if you have access to a Snap On dealer . Wooden block workes fine .

Yep confirm this , did it to my Bluebird with DR30 IRS though the diff mount was one off with nolathane bushes which creaked . Otherwise great mod . Cheers A .

The only R30 I ever saw with a rack used Bluebird (modified) struts and cut/shut Bluebird/R30 control arms . Steering was HEAVY though it did have shorter steering arms . I have import Bluebird cross member and power rack but the DR is going on the market after rego in a couple of weeks so wont happen with me . I would have also cut/shut the control arms to suit the respective cross member and caster rod/ball joint . S13 geometry is different because they used larger diametre springs and have less bump travel . You may find on a Bluebird or R30 that the bump travel is insufficient and droop travel excessive . Setting a reasonable ride heigh is only half the job . You can get better geometry from nearly std bits - need adjustable caster rods .

See an auto sparky .

This may sound silly but is there enough meat in the head casting to drill and tap alternative stud holes ? I'd really like to know this myself because RB20/25 HKS cast low mount manifolds are easy to get compared to the rare RB26 version and I want to use the 26 head . Long shot I know but sometimes these things work . Cheers A .

Josh what I mean is for the same effort a better and simpler solution may be had . I'm not against people trying things that may not have been done before but for me the end result needs to be good to justify the effort . For me the drama with RB20's is that good torque is difficult to achieve without a peakier power curve than I want . I reckon the cheapest RB to buy is an RB30 SOHC and the ET exhaust manifold is (should be) easy to get . For power and torque on a budget a second series NA RB30 is hard to beat - depending on the expectations . Turbos - could be an expensive suck it and see debacle . If I could find them the G11 Charade could be worth a look . Otherwise maybe Garrett T2's or small T25's . Garrett T28's off a GTR with smaller trim compressors may bring it on in similar fashion to a GTR . These use exhaust housings of compact dimensions because this set up is rather crowded on an RB26 . If you can use these housings and dump pipes it would save lots of time over custom fabrications . Twins will have a weight penalty over a reasonably sized single . Gotta go , cheers from Goulburn A .

R32 GTS TT , I'm not sure for the cost that a TT RB20 could give you any advantage over a larger engine with a reasonably straight forward single turbo . Nissan sized the GTST's single turbo for 2000cc so in theory doubling the turbine /housing area would also double the boost threshold rpm . Each turbo only has half the number of cylinders and exhaust energy to drive it . Sounds silly but the turbos designed for a three cylinder 1000 would probably be better for a 2000cc six . I would not be in any hurry to use a balance pipe on a twin parallel turbo straight six . The reason why they work GTR style is the firing order and exhaust manifold/turbo sequence . 153624 , front back front back front back with no interference . Short three leg manifolds will have less internal volume than the 6 into 1 or 2 . I reckon a split pulsed single manifold ie the cast HKS would be easier to package and suitable single turbos are around . With the Hitachi turbos its doubtful if you could get small enough a/r turbine housings and if you could I reckon the turbos would surge . Factory engineering is often hard or non cost effective to beat so if I really wanted to do twins I'd use the GTR manifolds (don't bolt straight up but cheap) and turbos such as GT-SS's as they spool earlier than R32 GTR turbos . Bottom line , TT RB20 not cost effective .

Similar to a 2835 in that it has the same series of turbine and compressor wheels . ALL of the GT2835 HKS's and GT3071R's are GT30 turbine based turbos , ALL of them use 71mm GT35 (BCI-18 series) compressors . The turbine is cropped in all of them except the propper GT3071R cartridge 700177-0023 . Most of the HKS GT2835 series use the 52 Trim compressor though I have a table of HKS turbos that shows a 48 Trim compressor version rated at 380ps . 52T rated at 400ps , the 56T 410ps and the 56T Pro S at 420ps . Garrett has a bad habit of only offering the largest trim compressor version in the turbos they market . CHRA's 700177-0002 Cropped Turbine 84T + 52T comp 700177-0003 Cropped Turbine 84T + 56T comp 700177-0004 Cropped Turbine 90T + 56T comp 700177-0023 Uncut !!! Turbine 84T + 56T comp I suspect the 48 trim compressor version is 700177-0001 but unconfirmed . The middle two of the list above are what Garrett is fobbing off as "GT3071R WG or wastegated " . You are getting ripped off big time if you buy them or any of the HKS GT2835 series with the T28 flanged GT28 integral gate exhaust housings as the combination of GT28 housing and GT30 based turbine is a flop . Also to save confusion , you will notice the first three have a cropped version of the GT30 UHP (Ultra High Pressure Ratio) turbine . Its major diameter is 56.6mm where the uncut version is 59.9mm . So the 84 and 90 trim versions of the first three are based on a smaller diameter than the last which is an 84 trim 59.9mm . HKS/Garrett turbo unit numbers for the above cartridges or CHRA's 700177-0002 = 700382-0002 , 700382-0006 , 700382-0018 700177-0003 = 700382-0003 , 700382-0007 , 700382-0019 , 700382-0024 700177-0004 = 700382-0004 , 700382-0020 , 700382-0021 Turbo unit numbers vary because of differences in turbine and compressor housing style and a/r . The last one (-23) is only sold by Garrett as a cartridge that you can select a number of housing options for . ATP Turbo (US) sell them as a unit with .63/.82/1.06 a/r GT30 turbine housings + .50 a/r TO4E compressor covers . Cheers A .

A GT3071R , (real one has 84T 60mm GT30 turbine + 56T 71mm GT35 Comp = CHRA No 700177-23) would not be the most responsive thing on an RB20 . Works better on 2L four ie 4 ~ 500 cc pots . The HKS GT2835 Pro S in .68 a/r turbine housing would be a little better with its smaller 52 trim compressor but the kit is not cheap . All in all I reckon a std (ceramic BB) turbo Hi flowed like GCG's or a model specific HKS GT2530 sounds good for the road . You can go bigger but its getting not nice for a street car at typical street car revs . Cheers A .

Adam when I stripped the Bluebird I had 4 good 205 50 16's to use up but was eternally greatfull to go back to 205 55 16's for more height and a more compliant ride . Depending on how you see it the increase in tyre diametre did sort of fill the front arches a little more but this was not the no 1 priority . I would never deliberatly buy 50 series tyres again at least in 205's or 215's . Most cars of that era look nose high if the rails are parallel to the ground but thats because the body slopes forward not the floor pan . Also because the front end has the engine/auxilaries and transmission to support it needs to have more travel than the rear . When there is a rapid downward surge of all the front end mass there needs to be sufficient suspension travel for the spring and damper to control it . If the car is lower generally it hits the bump stops before the spring/damper can do its job . In my opinion you don't need to lower it to get it to handle . There are plenty of $100,000 + sports minded cars out there and they dont sit close to the ground . Just for the record any strut that has the coil spring over the damper is a "coil over" . I would not be in any hurry to use Tien etc S13 bits and the spherical strut tops are a pain in the ass . Like I said , neutral camber , lots of positive caster , zero toe and you'll run rings around the doof doof wallys with 205 rubber . Wide tyres , low height and screwed up geometry - particularly with the wrong wheel offsets - doesn't work . Highly amusing rounding up some sickmobile with a standard appearing car . The bonus is its easy to live with on a daily basis and doesn't chop tyres out . Have you cake and eat it . Cheers A . Edit : What width rims and aspect ratio tyres do you run ?

To each their own but bent cross members and holed sumps don't do much for handling . If this is a look thing I don't want to know . Cheers A

I wish it was as simple as buying another compressor wheel and fitting it . If one was very lucky and came across the remains of a damaged turbo and good compressor it may be possible . Generally 2nd hand wheels are the only spares for the BB's but the situation may change next year . I've no idea if there is any back spacing difference between the TO4S and 76mm GT wheels . The GT wheel would almost certainly have a different cross sectional profile and tip height so the housing would need to be re machined to suit and anyhow its a TO4S where the 76mm GT wheels use TO4E housings . Even if you got that far the turbine is the cropped version so only HKS do exhaust housings in T3 flange to suit . Garrett do a factory bored out (bodged) GT28 integral gate housing that fits but it won't work much better than that bored VG30 and it has the wrong (T28) flange . Sorry , wish I had some good news , A .

Do you have alternate wheels in the short term ? Or do you have enough std bits to get it back to std ? If either is the case I'd pull the turbo /dump pipe off and try to sell it - trouble is you're selling someone your problem . Sell it with the oil and water fittings as they probably won't suit the next turbo and sweetener for the buyer . If you can wait till March there is supposed to be some real T3 flanged GT30 integral gate exhaust housings coming onto the market at long last . This should solve most of these dramas with GT30 based turbos . Little late I know but I wish the bastards would stop selling those turbos to the unsuspecting . Anyway if you can turn the sow's ear into folding stuff its a start . Cheers A .