Dale FZ1

Stop-start city driving between lights (not just sitting extensive idling) 500-550C Extensive idling 400 drops to about 350 Steady state rolling on/off throttle to stop, up to 80km/h not running big throttle 550-600C Highway running extended closed loop running 600-680C Climbing mountain range, mild boost 600-650C Flat knacker acceleration run 700C Thermocouple placed in split dump, main dump from turbine just behind O2 sensor.

Hats off once again, Sir. That is the cartridge spec that I was trying (none too successfully) to recommend. And you have photos!! If it is a HKS-only spec, then sorry Mafia, the 56T is the one that economics dictates should be used. If HKS are using it, then I feel a little justified in believing the 52T was going to be just that bit better. As always you can get pretty much what you want, but there is a price attached... cheers

There is a 0.50A/R comp cover that has a 4 inch inlet / 2 inch outlet as per the turbobygarrett product sheet. That combination should just crack the 270rwkW power target but it will take a fair whack of boost on a stock engine. Overall it will probably give a good result. Late edit: the -0023 comb is a 3071 ie 71mm compressor. Yes, I am talking about that unit using a 0.50 A/R comp cover with 4 inch inlet, and yes, I think it should hit that power target (only just, and running pretty hard to do it). But it should be streetable with good power through the range. Slide, this is your area of expertise. Any ideas? Clearly there is opportunity for business here. cheers.

Going on this spec page: http://www.turbomaster.info/eng/applicatio...ings_chraGT.php the -0007 cartridge gives a 52T comp wheel. It could be wrong though. Also the pics (if accurate) from Garrett here: http://www.turbobygarrett.com/turbobygarre...76_452159_1.htm suggest that the 0.54 A/R cover has a ported shroud. This feature has become something of a “must have” for marketing rather than engineering purposes, given that it is intended to reduce the propensity for surge. Point taken that it may in fact be a difficult cover to fit, but the impeller/housing combo actually seems to have a map suitable for Mafia’s needs with wide efficiency islands that are fairly upright on the left side (minimising the chance of surge as PR increases). What I liked was that it had published flow data. Definitely keen to see what comes up with the Isuzu-spec housings – anything I found was in Spanish or Italian and a bit vague in many aspects. cheers

Top effort Disco. Demonstrates the difference between A/R capabilities very nicely, and how/why smaller housings can result in both early power drop-off and possibly induce detonation due to back-pressure related scavenging problems. I'd suggest the 1.06 housing would be great for a dedicated track car (lowest buildup of back pressure) running full noise and consistent high rpm, but probably big enough to have a soggy bottom end. The 0.82 would give a happy medium. Something I've not been able to get squared away is how to derive what mass-flow exhaust we should be looking at for a given power output. Obviously the mass is reduced significantly. cheers

After punching the numbers in, I would suggest: 700177-5007 cartridge (BCI18 76mm 52T comp, UHP 60mm 84T turbine) 0.54A/R comp cover as used on the GT3776R (turbo # 452159-1) 0.82A/R GT30 internal gated turbine housing At the power levels targeted, a set of cams and inspection/tidy up of the ports would be desirable. The turbo specs should deliver the goods but improved volumetric efficiency for the engine would make it happen a lot easier.

Free breathing inlet/exhaust + higher than standard boost + standard ECU = rich + retard Do a search on rich + retard; it's Nissan's fail-safe.

In plain English, what are you actually asking?

Top marks for the pics. Saturday Sprints are on my to-do list for next year but I plan to be there for a bit of spectating if there is another round before Christmas. All I have to do is learn a bit (lot) of car control, and grow some goolies

How did it go? Event report?

Do a search on GT2876R. Jmac has this cartridge in his R34 high flow. Seems pretty happy with the results. Remember that spec has a higher flowing turbine housing (ie. larger A/R) than the R33.

Here's a pic shows relative size and measurements of the stock compressors for RB25 s.2 (nylon) and RB20. The comp housings are different sizes too; larger A/R for the bigger engine. None of the factory RB housings actually have adverstised A/R cast into them, and unless someone went to the trouble of cutting them up and doing accurate measurements it is a bit of speculation as to what A/R they are. This applies to turbine housings also, but there is some good discussion about RB and VG housing comparisons. Try doing a search on that one. cheers

Well the day was run and won by a VR4 Galant, second was a Eunos 30X. Traction and technique seems to be the key, and it's a real challenge to "read" the ground. It was really a fun day, and the weather held out - but for a short sprinkle at mid-afternoon to keep the dust down. I ended up running the Excel again (waiting for some wheels to arrive for the Skyline), and learned more about car control. Evidently there will be more events in the future, possibly with something run on a paved surface as well. This is really top-shelf fun at bargain basement cost, and is a great way to have a taste of motorsport. The only extra impost from running on grass is the cleaning/vacuuming to get rid of all the muck in/on your car.

That is the real key - the size of the valve is significantly larger; more bypass flow = better control.

Thanks Disco. All very accurate and correct observations/opinions. Definitely clears up some perceptions about the value (or otherwise) of various A/R combinations. I had been considering whether this housing would at last allow a suitably flowing/efficient driving bolt-on 71/60mm cartridge out of the GT3071 family, and also for those wanting something around 5-600hp but still internally gated (82/68mm?). It's almost like the different A/R is available so that we can use different cartridges according to the power:response balance being sought. Just a matter of determining the optimum compressor spec, then getting the turbine impeller + housing sized to suit (as per normal matching processes). I'd just like to gauge what it has been designed to mate up with, and if the range of options available to us has been opened wide up. It is a really good development and hopefully will satisfy a demand that has existed for a while now. Dangerman would you do us a favour and post up the CHRA number? Since you're one of the first (the first??) with this unit I'd just like to see what spec impellers it uses. cheers Dale

At the moment I'm a little ignorant of the cartridge/s that this turbine housing is designed to mate with. Hence the question about the CHRA - I want to see what impellers this particular baby has... Good work on getting the turbocharger part numbers. Pleasing to see that Garrett have brought out two A/R sizes; more options. Notice that the pics look remarkably similar to a HKS design with the divider cast between wastegate outlet and turbine discharge? Was there any solid/reliable info from GCG as to what sort of power rating or service application (ie road, circuit, drag) these things should have with a Skyline?

Is this the internally gated T3 housing that Garrett have been promising all year, and part of last? What is the used unit beside it? It appears to have a Garrett logo on the compressor housing too. And most importantly, can you post up the CHRA ID tag number too please? I'm going to be interested in the progress pics. cheers

That you have knock apparently well controlled is a good thing. I wouldn't be at all happy with the boost skyrocketing at the top end of the rpm range - recipe for a hand grenade under the right (read: wrong) conditions. So your 2871R is fitted to an SR20, uses a .63 A/R turbine housing? It's a stock, off-the-shelf Garrett unit fitted to a fairly stock engine and manifolds? What was changed that you went from boost falling away to boost running away? Main point of interest is if there are any lessons to learn in fitting a similar spec unit to an RB20. cheers

We'll stick on-topic here, but try www.turbobygarrett.com and read their tutorials; they are very, very good and easy to follow Turbochargers by Hugh MacInnes (if you can find a copy, will be in specialist bookshops). I have another text that was published early 90s and still on loan to my mate. cheers

HKS unit has comp .60A/R, turbine .63A/R. A carefully thought out high flow can work very well, but the apparent aims of factory engineering needs to be factored in when using factory-spec housings. In some respects I'm not massively surprised that kwazza11 had troubles with surge with the 56T comp and 2.4 litre capacity. My calcs for the RB25 suggested it would be borderline, depending on the power target. Using the VG30 turbine housing is a way of masking a technical mismatch and still getting a satisfactory overall performance characteristic. If the compressor is not excited as easily due to the higher flowing turbine, then it will not be pumping as much air at the middling engine revs, giving a marginally lazier transient response but eliminating surge - and also giving excellent high end power. I actually think it was a clever and practical way of making the turbo mate well - just not how I would have/did do it. If you are insistent on doing a Garrett GT2871R cartridge type high flow into RB20, depending on your exact objective then go either 48 or 52T comp, and use the RB20/25 turbine housing. If you can get some piping mods sorted, use the Garrett 0.60 A/R comp housing and have something close to a GT-RS. Just remember the more fabricating you have to do, then the financial advantages of going with this decision start to diminish. cheers

Any graph to view? The outright power figure is very impressive for the boost you've run. How are you finding the 56T / VG30 combination in terms of streetability and response with the 2.4 litre capacity?

I've had a few PM queries, so to answer most concerns or issues, will consolidate into a post: It's a non-speed club event (as opposed to championship), so passengers ARE allowed. I would recommend only ONE passenger per run. The runs are short, and there will be probably 12-15 tests for the day. Plenty of opportunity for passengers to experience the fun. You DO need the CTP extension paperwork when lodging entry. The insurer can fax it to you (assuming you have fax access) otherwise allow a few days for snail mail. They will need to know the event name, location and date. Aussie Super Springs Motorkhana Federal (via Cooroy) 17 September 2006 Event entry form and day license applications will be available there on the day. $20 entry, and I think (still haven't confirmed, sorry) the license would be about $20-30. I'm waiting to speak with the club treasurer on Sunday about that one. Anyway, turn up and fill out those documents, pay the fees (suggest cash, no card facility), present your CTP extension, and wait for the scrutineerining checks. It is a closed course, off road event, so don't even need a road drivers license. Junior competitors are welcome and encouraged. Scrutineering consists of BASIC safety checks. Presence of functioning seat belts, general condition of car, removal of all loose items, and (this will be mandatory) secure anchoring of the battery, and good insulation of battery terminals in the unlikely event of a roll or crash. Main suggestion I have though, is to source some tyres you can trash/thrash for the day on the grass/dirt. Don't bring any super sticky road tyres, and run some good pressures to keep the tyre carcass rigid. I would say about 38-42psi would be about right. If you have some stock rims and old shitter tyres, then fit them. Also make sure your air filtration system is good - it can get dusty. Do have a look at the club web page www.ndscc.asn.au for entry forms and supp regs. They are easily found. Hope that answers most questions, and be good to see some Skylines (or their owners) there. cheers

Suggest you locate the CHRA ID tag number, and post up that, along with any numbers off the housings. That may allow some cross-referencing to the Garrett catalogue and maps.

PM sent. Interested in BOVs.

Does the Z32 come with plug?