Dale FZ1

Check the photos: Having just made these items and (almost) ready to install, I can tell you that it is time consuming, and it is difficult. There is a lot of judgement, time, and fabrication skill that goes into making one of these items. When you look at the Pro S design, there was little room for HKS to go other than with the dump pipe design they use. I've looked at the Garrett casting, and agree with comments from Cubes in a thread somewhere that a bell mouth design would work well with it. The main aim should be to let the vent act as a vent, not as a restriction. Pipe size and placement would play a big part in that, as Dave has alluded to. BTW Dave, I think your result looks quite neat. Interested to hear how it pans out.

Second the S15 option. Heaps of flow for the application.

Frankly if you are targeting 300kW as a minimum, you'd do well to head straight to a GT3582. I noted that your shopping list / parts list includes an external gate, so any of the GT28 series stuff won't be suitable or cut it from a flow viewpoint anyway. Suggest doing a search, using either GT30, GT35, or 300rwkW as key words for turbo specs. There are a few blokes who have exceeded 300kW but you have to make sure it lives a reasonably long life by giving it the right supporting systems. I hope your fuel system and engine breathing system is well thought out. If you're actually going to use that power (ie at a track) then cooling (radiator and oil) should be factored in. Get rid of the Walbro, use a Nismo in tank pump. Keep us posted with updates please, and good luck.

Fatigue, mechanical loads, elevated piston speed, and in most cases I would say knock due to poor tuning. Broken ring lands is normally the evidence to look for. I have heard of some picking up in the bores from heat, but that was of the out of coolant / engine overheating variety.

Overall engine height may be a problem, as BMW run their engines canted (leaning over to one side) to enable lower bonnet lines. I know that many blokes in the US shoehorn 6 cylinder BMW engines into the smaller chassis for a pretty potent result. Try searching here: http://forums.bimmerforums.com/forum/index.php Having said all that, run a tape measure over things. An RB might just fit with no real dramas - as far as engine conversions go.

There are three compressor trim specifications for the 2871. I'd say that for any of them the turbine would be the stumbling block from a mass flow perspective if you wanted better than 250rwkW. I'd say your HKS housing would provide a definite flow advantage. Buy a complete Garrett turbocharger, remove the T25 flanged turbine housing, and swap in the T3 flanged HKS housing. If you ran the 52 trim version, then you would have created a GT-RS. Without getting into any of the max power debates, the 2871 is a good unit, but a 48 trim may not be a massive step forwards from the HKS unit you're currently running. Also maybe not quite the right spec you'd want if chasing 280rwkW. Something out of the HKS Pro S range, or a Garrett GT30 IW based unit would be my preference for that type of output.

http://www.skylinesaustralia.com/forums/Gt...l&hl=GT2871 225rwkW @ 13psi. Responsive, torquey, easy to drive. Good upgrade, but I don't know how it compares to the HKS 2530 as I haven't driven a Skyline so equipped. Anyone who's driven mine is never unimpressed though. Best suggestion I would have if you went to the 2871 is to acquire the Garrett unit and transplant the HKS turbine housing onto it to make it all bolt on easily.

R34 has a larger comp cover, larger comp wheel made from plastic composite, and larger turbine housing. The similarities are in the centre bearing housing, and turbine rotor. Basically the R34 turbo is a higher flowing unit good for a few more kW at the cost of a bit less response. Blame the bigger turbine A/R for that one, but it would still go pretty good for a straight bolt up unit. Frankly unless you absolutely have to change due to turbine failure, I'd save more $$ and get a high flow or hybrid upgrade and side step the ceramic OE turbine.

Can you explain what is happening to lead you to believe there is a problem? ie. is there a sound of exhaust leaking at idle? perceived problem with rate of building boost? Also would you drop in a picture of the dump pipe design please. If it is a screamer I promise not to comment about that part of it. More interested in how it mates up to the turbine flange. Generally the only setup problem I see is insufficient preload on the valve so that it's not seated firmly. edit: On reflection it might be worthwhile to check how much play there is on the wastegate shaft. Perhaps the valve has just enough movement to contact the side of the housing and stop it settling nicely? In any event the guy who did the work on the turbo needs to have a closer look. He's a specialist, he should be able to see the cause.

Assuming a logical approach to building / rebuilding a 30DET, what hidden costs are there? I did note the previous experience you had with the oil pump and drive flange, but otherwise? I understand the sentiment. Sounds like there has been a costly learning process in your case, but what of SimonR-32 who wants to transplant a freshened 30 bottom end under his existing head/turbo/manifolding? The information you've dropped into the thread would be invaluable in terms of getting it "right" from a reliability viewpoint for either a 25 or a 30 build/rebuild. I'd say Simon's target is to keep within existing rev range and pick up response. I don't think there is any question he would achieve that. Reliability will obviously be down to the degree of care/preparation to achieve tolerances, and the type/quality of parts necessary for his application. My questions, based on your experience Gary would be Rods. 7200rpm, 280rwkW. Retain stock items? Pistons. Inspect for cracks/defects/bore clearance and reuse stock cast pistons? Or just accept new slugs as a necessity and get something of reasonable quality? Oil pump. Assuming the restrictors and return mods are done, why not reuse a stock item? Hopefully Simon could get the results for the application (and do so reliably) without costing a fortune I appreciate the knowledge and hands-on experiences you blokes have, so it's a learning exercise just to listen to you both.

What pistons do you plan to run, and what static compression ratio? Also what sort of rpm ceiling? I may be slightly wide of the mark, but it seems that mild 30DET builds often produce similar maximum power figures to the donor 25DET, but at lower rpm. Their advantage is in torque, and with your spec 3071, I would say rapid response. Bigger torque would turn tyres easier, but is there any problem if you run out of revs?

Take the boost controller out of the equation and run it that way. Less boost = less mass air flow = ECU operating away from the rich/retard failsafe. Taking your plug gaps down might have some effect, as coils could be getting a bit tired. At this stage you'd be lucky to be hitting 180rwkW, so it's not like you've got massive amounts of intake charge to be ignited that are blowing the spark out. Start saving towards replacement coils and some sort of ECU that will get you around the factory failsafe. Plenty of reading is available via the search function as pointed out already.

With that tag number, it is actually a GT3082R, aka GT3040R, aka GT30R. I'd originally suspected it might have been using the 7 bladed TO4S compressor, but it's bigger than that. There is plenty more left in the turbo, but you'd want to be mindful of surge if you crank too much boost into it. A turbo that size if able to pump more boost at middling rpm should be able to easily outflow the engine's breathing capacity. Shape of the curve is smooth, and AFR looks well controlled - nice consistent mapping and I'd say some time spent getting that looking nice. I hope your drive impressions are good, and it performs well on-road? Got any pics with good detail of that exhaust manifold?

Agreed. WI would be very highly desirable (essential) if you want to run to higher boost levels and keep the thing away from knock. That then places a big demand on system reliability, and fail-safe protection. Some systems offer flow blockage indicators and boost control interface to help keep things safe if you do encounter water flow failure. The off-boost torque, and potential fuel economy difference is definitely a +ve for this configuration, but it's worth grasping the whole picture for high comp + forced aspiration. You might make another 20 or 30 rwhp with higher boost, but pushing it towards the edge of sensible limits. Getting really good results beyond that 300hp is going to take some thought and careful tuning. I've looked very carefully at the 25DE piston design, and my opinion is that there are some little sharp edges around those valve cut-outs that are not knock-friendly. The other issue I'd be aware of is what Nissan did NOT put into the DE - oil squirters under the piston, and the dinky oil heater/cooler. They obviously felt it necessary to do something to remove heat from the piston crowns in the DET version in the name of reliability. WI would take care of that to some extent, but just be wary if you pushed the DE+T too hard, too long. Very good streetable combination, but you'd need to know where its weaknesses are when leaning on it for more. Edit: that dyno sheet shows power at the wheels.

Check out this little guide High compression forced aspiration cars are a little (lot) more fussy when it comes to making them detonation proof. That high effective static compression ratio indicator shows that a 10:1 engine will probably take a LOT less timing across the entire range of on-boost load. So in some respects what's being gained through the compression is being lost through comparatively retarded timing when looking at the 9:1 DET spec. That's what it is all about. I agree, and while it may lack a bit of the bling etc, if it works effectively and you suffer no driveability or reliability at this level of tune then run with that manifold setup. Not how I would do it, but that's just my view. FWIW, below is a graph of my DET with light mods and small-spec high flow. 300hp, with boost peaking at 13psi and tapering to 12psi. If you have 10 minutes, plot the points from one graph to another (yeah, I know, not directly comparable...) but you can pretty much see the difference. Same sort of max power number, but the 9:1 engine has bucketloads more from 3200-5800 where you drive it. That is a function of the mass flow capacity of the turbocharger at differing pressure ratios - the high comp engine just won't let you pump too much in before it reacts with knock. Hope that adds constructively to your setup and understanding differences.

Slightly off thread from a 2835 , but I share the interest. I'll back it in that there would be little to separate that unit from The Mafia's similar unit running a Garrett 0.63 A/R housing.

I believe the larger snout and associated trunking would just give the impeller a better quantity of air to "grab". Probably a bit of potential for increased flow and power. Not much, but a bit. Be sure to get the correct spec with the larger 60mm turbine. I understand skylinecouple is very happy with his results. Hopefully you can update this thread with impressions on the delivery yours provides after tuning.

I think that's a MHI product, not Garrett. Trust have some retail rights over specific product, much the same as HKS do with Garrett. I've got some limited info about Mitsubishi turbos that I can try to dredge up. Meantime, perhaps a search on this forum and via Google?

Quite a reasonable outcome. Torque curve below 4500rpm would be more pleasing if it was filled out a bit more. Stock 25DET turbo fitted? What boost level? Sounds like the exhaust is relatively de-restricted too; noise levels not over the top? There's a little bit of literature out there about high compression and forced aspiration that guides on effective static compression. Basic outcome is that there is a boost level at which your 10:1 engine will see a rapid increase in "effective" compression and head towards/over the detonation threshold. Be careful if you want to push further.

Nobody said it's low. 360 odd rwkW is plenty. It was more the case that the turbo's potential is not really being tapped. Fair enough for a built engine to come into the equation later on.

Being a plain bearing unit, expect that it will have some movement both end-to-end (thrust), and side to side (radial); more that you would experience with a BB unit. In operation it rides on a high pressure film of oil that takes up a lot of that play. If there appears to be a genuine problem with your rebuild, then the best advice is to get in touch with the servicing agent for a warranty claim.

Searching the forum before posting this question, I found posts from several of the more respected SAU members http://www.skylinesaustralia.com/forums/Rb...rods+in+rb25%2A http://www.skylinesaustralia.com/forums/Rb...rods+in+rb25%2A So I know the issue of higher reciprocating mass has been (sort of) discussed. One thing that wasn't resolved was how to counter it. ie. did Nissan do anything about it with the basic engineering of the RB26 crank? and do I do anything about it while preparing to put 26 rods in bed with a 25 crank? It's one thing ending up with stronger internals, but if the engine doesn't rev as quick or sweetly then I wonder about the value of the upgrade. This really does need comment from people who've had their hands in the bowels of a few RB engines, so I'm calling for a response from GTRgeoff, Duncan and Sydneykid please. Also Security, who has more recently stuck GTR rods into his 25. thanks in advance EDIT: the same principles should apply for people doing mods including forged pistons and rods, due to the changes in reciprocating mass, so I don't see the question as relating solely to the cheap upgrade I want to do.

Here's a question for any experienced RB engine builders: Apart from the slight difference in stroke, is there any difference in weight, balance/size of throws, or construction between the cranks in RB25 and RB26? There are various people who've fitted 26-spec rods into their 25-spec engines, but no indicator as to whether they required any work to the crank to deal with the heavier (by around 50 grams each) GTR conrods. Are there any/many experiences in this area please?

Oil pump bought and paid for. PM sent Brendon.

Check the link for some good detailed pics of a VH41/45 bottom end. http://forums.nicoclub.com/zerothread/288890 Other than for the John Holmes award (Longest Schlong) I don't see the point of fitting them up with those massive snails. With the capacity advantage in either the 1UZ or VH45 - and some intelligent turbo matching - they would pull like a locomotive. Awesome road car. A bit like the kit that's available for the Gen 3 Commode.