260DET Posted January 15, 2012 Share Posted January 15, 2012 After being distracted for a year by a mirage engine, the DET is back in the Z and better than ever. Its performance affecting specs are - custom rear entry upper plenum with single 90mm throttle body, Tomei Poncams, Tomei cam wheels, GTRX3582 divided housing turbo, Tial wastegate, custom 3.5" dump with 3" exhaust and two mufflers, Motec M600 ECU, M&W CDI ignition with Mercury coils. The standard exhaust manifolds are retained. So onto the dyno to see what this circuit orientated setup has. The whole idea as far as I'm concerned is to have a useable 3000rpm power band orientated towards controllable corner exit acceleration, the top line by itself is irrelevant. There remains only a couple of problems, the Tial wastegate needs a slightly heavier spring so the engine can run more boost which the turbo is entirely capable of, eg 18psi @ 4000rpm previously. The second is streetability. With road tyres wheelspin around town is difficult to always avoid even at relatively low rpm, there is no traction control. Notes on the dyno sheet below. 4000rpm - boost 13psi, 230hp. 7000rpm - boost 17psi, 420hp. The engine is easily capable of handling over 20psi boost which it looks like the turbo will deliver but let's do some track time first, the car is probabily faster than I am as it is. So I am going to stick with this engine. By modern standards it may be a bit heavy but my race budget can be better spent than chasing the ultimate engine. Torque curve starts off highest of the two curves. Quote Link to comment Share on other sites More sharing options...
johnc Posted January 16, 2012 Share Posted January 16, 2012 Looks like you hit your goals. Lots of torque from 3,500 to 6,500. Quote Link to comment Share on other sites More sharing options...
260DET Posted February 17, 2012 Author Share Posted February 17, 2012 Had the Z back on the track the other day, mother of my god, scared the s**t out of me after a year off. Comment from a following driver as I lined the Z up through the straight entry corner, 'I saw a puff of grey exhaust smoke, the back of the Z sat down and you disappeared, bastard'. Got out of the car and I was shaking, with power comes great, err, difficulty Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted February 17, 2012 Share Posted February 17, 2012 Cool! What's your boost threshold? Looks like 3k RPMS or a bit after. Quote Link to comment Share on other sites More sharing options...
260DET Posted February 18, 2012 Author Share Posted February 18, 2012 At 3750rpm its on zero, at 4000 its boosting five pounds. Boost can be adjusted on the fly, for street driving it's set at six pounds which is the lowest possible but still quick enough for all legal purposes Obviously the turbo is a good match but it seems like the divided housing really works even though the stock manifolds are very cramped in design and no doubt limit outright power. Quote Link to comment Share on other sites More sharing options...
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