Dale FZ1

How did the day go, Jason?

So did you run with an adaptor plate, or have a stock Nissan housing machined to match? Was it a 56T or 48T compressor? Comment on overall results - driveability, what rpm does it start to flatten out, and any idea on dyno results?

Agreed. Top marks for having a go. I think this match will probably result in an effective rpm range starting at 3500 and running up above 7500. Interesting to see how it goes.

No, not a bad idea at all. A simple and effective path, but using OE housings has the benefit of fewer changes to associated pipework to get it fitted. If you're running an RB20 then a VG30 turbine housing is likely to result in a bit of top-end bias. Re the earlier comment on clearance if using a Garrett turbine housing, be aware that you will have to maintain some sort of air gap around it or risk cooking the loom and air-con fittings nearby. Nissan found it necessary to fit heat shields, so hopefully others would see the benefits of adopting that approach too.

Discopotato is pretty much on the mark. A 56T is going to be more sluggish in terms of response, compared to either of the little brothers 52T or 48T. It's not much good having a bit more power if you're waiting either longer time and/or more rpm for it to become available. An adaptor plate will work if you follow Cubes advice, but you may well find clearance problems between the fitted turbo and front suspension tower. A hi-flow using a Garrett core and factory Nissan housings will fit up much more easily but with a couple of its own issues to get all the oil/water lines and heat shields fitted nicely.

A little off thread Dan, but do you know the ID tag numbers off your hi-flow core? The guys from Turbo Australia are pretty good, just interested to see what specs they ran for your unit. I'd have a few concerns about the output, given I achieved 223rwhp with a stock turbo @ 7.5psi and other similar supporting mods to yours. Look at the tuning I suspect. cheers

Welcome, Callum. Surf around the forum and see what is posted. There is a wealth of knowledge amongst the owners, and plenty who are willing to share experience. Learn how to use the search function, it will serve you well. Re the cost, check the price that Slide is offering for a bolt-on plain bearing hi-flow. If he can sell them for that sort of money, then the workshop who quoted you is making plenty on the job. Nismoid is right.

Water injection is a long-proven knock inhibitor. The old school tuners used it years ago, before cheap effective intercoolers were available as they are now. My Dad ran a pretty potent combination in the 80s with water injection, worked like a charm. The comments about minimal carbon build-up is accurate too. Mafia's setup with alcohol mix should provide extra benefits, and I like the safety factors built in with anti-syphon and anti-blow back. I would like to see the kit come with a simple warning light for low water level, but if it's a simple one for one consumption ratio, just pull the bonnet each time you fuel up, and top up. Easy. Keep us up to speed with any dyno runs Mafia.

The 2530KAI is little modified from the previous 2530, other than a ported shroud comp housing. Specs of the rotating assembly is unchanged. Response ability should be unchanged. Normally the porting is done to control/reduce surge. The GT-RS has an upsized comp impeller 71mm vs 60mm for the 2530KAI. This will directly affect (reduce) its ability to respond quickly, but increase its power potential compared to the KAI. Hope this helps. cheers Dale

Suggestion: have a look at the stickies for dyno results on RB25 mods. This will give you a fair idea of the mods and end results for many people. cheers Dale

Some nice pics there Harry. Who ran the event? ie which club

I'm all for a return to something more aligned to the old Group E production tourers - mild modifications permissible and controls in critical areas. Tyres fall in that category I reckon. While the Nations Cup racing can be good to watch, it's all stratospheric prices that normal motorists can't ever aspire to owning. Class based racing can be a really good thing.

I take it the COMPARE inj map is values against the stock PFC default?

Spencer is definitely quick. Seems to have a bit of trouble with mechanical frailty but very impressive to watch. I've seen him at Jimna, and watched vision from Otago NZ. Worth following. Saturday's times before he DNF'd due to oil loss he was running pretty similar times to Dave Gaines in the Cruisin Auto Spares 240K. Dave is no slouch either and runs on the board to prove it. Another 2wd car worth watching for its pace was the Menzies Falcon. Guest's car seems more of a stop gap PR exercise for Ford this year until they get the S2000 specs sorted out. The Focus is a real work of art to look at, and seems very well engineered.

The Holden Sporting Car Club is also running a motorkhana in the carpark area starting 8am. I plan to enter that, then watch and learn how the sprint days go. A mate is running the sprints in a clubman car.

ECR33 stock turbo stock boost 7.5psi = 0.5 bar HKS pod filter + custom CAI Apexi PFC + Datalogit FMIC split dump 3 inch front pipe into 3 inch cat 3.25 inch Blitz cat-back system with 2.5 inch bolt-in baffle restrictor in place 98 octane Caltex fuel Splitfire coils result 223hp = 165kW sorry for the size of attachment don't know how to resize yet.

In effect Gary, the cause of the extensive/expensive failure you documented here was a car poorly specified/upgraded for track use? It gives clear warning to those wanting to do some track work that a suitably enlarged/baffled sump is a must for engine life in that environment. I can't ignore that regardless of whether he had a turbo failure, a rooted big end was going to mean the end of day and engine out repair job. It just so happened that his overall engine spec meant there was a multiplication of failures (and expense). I agree that the BB construction offers service life superiority - my understanding from literature sourced in the early 90s was THAT was the primary reason Garrett sunk money into the technology. Performance benefits were evidently viewed as an added bonus rolled into the package. We should consider that manufacturers involved in rally use turbos sourced from companies other than Garrett (eg. Mitsubishi, IHI) and those running Group N production class would be using series production plain bearing turbos as per their homologation papers. Turbocharger reliability does not seem to be a problem in that competition category. FWIW, my money is with a BB upgrade, but I have no experience with Slide's product. I'm not sure if Slide has made any claims that he will equal the overall power/response ability of BB units, just that "normal use" (my description) reliability is assured provided that full flow/pressure oil supply is given to the unit. That stands to reason given that the assembly is really meant to be floating and spinning in a film of oil without metal-metal contact. Technically very different to the BB core. I would like to see Slide accept the offer of a back-to-back test; surely an interesting experiment. I suggest that it would be something of a Dutch auction if turbos with big differences in spec were compared, but Slide should have a reasonable idea of the rated capabilities of his product (as do other sellers). Take up the offer, Slide. If a typical GCG (or other) unit is rated @ 420 - 450hp then surely you have something equivalent? At the prices you have secured a nice little piece of the market, and good for you. It appears there is an opportunity to cement that position. cheers

Search on VG30 R34 turbine will show a larger A/R (numbers unknown) than R33. Adds to more high end flow, less response down low. cheers Dale

Looking at the ski-jump profile of the graphs, I reckon all the chosen turbos are track refugees. And straight-line tracks at that. Willall Racing are into dragging as far as I can tell. The shape of the torque curves would be interesting - nearly vertical I would think. It would make for some interesting driving if you come on/off boost rolling on/off throttle on the road. Even on a drag strip they would need to look at very tightly stacked gearbox ratios to factor in the effective speed range(s) of the chosen turbo(s). I do find it interesting to see their results from an academic viewpoint, as it highlights the ability of one setup to generate significantly more power across the range, if not the biggest outright number. GT-RS looks the best in that regard. Also, comments made beg the question for the HPI exercise - do you match the turbo to engine, or choose a turbo and then work out what spec the engine needs to be? cheers Dale

I still rue the go-slow decision route I took when buying my turbo R33. The extra power definitely puts smiles on faces more frequently, but for forgiveable handling due to the Atessa 4wd, the GTS4 is a great value machine. The secret to getting good performance is to make them carry speed into/through bends with the engine rpm wound up! Brake spec is lamentable, but cured with turbo-spec transplant. Not a race-car but provides good fun when the price difference is factored in.

My understanding is that the larger the impeller, the slower it needs to (or can) spin. It's about the speed of the wheel at the blade tips. The larger diameter, the higher the tip speed for a given rpm. All existing literature I have seen has mentioned a critical tip speed of Mach 1. The turbobygarrett.com site will allow you to check compressor maps of different sized impellers to highlight what I'm suggesting. Garrett have provided a large amount of information and it is well worth the read. Inertia is a function of mass and diameter of the impeller, so larger, heavier wheels take more to get going - shows itself as lag. It's comparatively easy to choose a turbo that generates X amount of power; getting one that responds well across a wide range of engine rpm is harder - keeps engineers gainfully employed. cheers Dale

Sorry, work commitments put the skids under my plans. Will be interested to see/hear the results of the day. cheers Dale

Top effort. I'm surprised the tyres lasted as well. In fairness it is a horsepower circuit, but there is some heavy braking and tight turns. How grippy/abrasive would you rate the track surface?

Are you planning for just 3 tests on the LVMA? What sort of time limits (start/finish) apply to that venue? Myself and son are interested in motorkhana, but why untimed tests?

Difficult to directly compare the specs of those two units. OE Nissan unit has larger comp + smaller turbine impeller vs the HKS HKS unit has significantly different housings vs the stock Nissan stuff. The result for both is fairly responsive units, but known frailty with the OE ceramic turbine if you boost it. I suspect that but for the frailty, a stock Neo RB25 unit would outflow a 2530 by a small margin. There are a number of places that can do a high flow of OE turbo - and the bolt-up cost benefits are worth considering. Check the stickies for RB25 upgrades, and use your search function for a few ideas. cheers.