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PROJECT R32 - DYNO RESULTS 2/04/02 - The starting point for my R32 GTS-t 4 door manual (for pics click here) with around and about 72k mls (116km) under it's belt, came with standard downpipes attached to a GTR 'middle' exhaust section, with De-Cat pipe, to a single custom made SS rear box, finishing in a 3 1/2" (90mm) tailpipe. In addition it has the standard air filter housing with a TJ ? 'sport' panel filter, the only other known mod is a 'simple' turbo bleed valve, with a 2.5mm restrictor venting to atmosphere (ummm, crude ??), running on Super Unleaded (RON 97 octane) So lets see what we got then.... 27/04/02 booked in for a 'run' at Tuning Japanese, their 1000bhp 4WD rolling road is generally taken to be the 'benchmark' for UK Skylines and they do some major works on a few too.... handy also, as I'm only an hour of nice country roads away too :-)
Anyway the 'run' turned into four !, as it transpired.... RUN 1 - With the car as it arrived, very 'erratic' curves produced, Tim dismissed them so I won't quote the figures here, boost 'spiked' at 0.8 bar then tailed off quickly RUN 2 - (see sheet below) - with the turbo bleed valve sealed, curves 'smoother' figures - 249bhp/216lbf-ft, boost peaked at around 0.78 bar Notes - Had to add text and arrows to graphs as I have no colour scanner :-( , Yeah I know the dyno sheet shows 26/04/02, but is was/is the 27th and the clock was wrong too :-), low speeds due to the car being shod with 225/40-16's, all 'runs' done in fourth gear
RUN 3 - Restrictor enlarged to 3mm (from 2.5mm), but a minor misfire (again !) at high rpm - 254.5bhp/225lbf-ft, no printout so boost unknown but probably similar to RUN 4 RUN 4 - (see sheet below) - Tim 'That misfire, I suggest new plugs'... me 'what you got ?, nothing to fancy now :-)'..... 'GReddy Iridium's eh!, how much, umm! good price, go on stick 'em in then', no more misfire :-) So out with old (nice and clean eh!!).......... and in with the new (fancy eh!!) :-)
Well there you have it, after some expert 'fine tuning' by Tim, I have a more 'stable' - 254bhp @ 6010rpm and 226lbf-ft @ 5640rpm (stock figures 214bhp @ 6400 and 194lbf-ft @ 3200), boost peaked at around 0.95 bar (and quite stable too, bleed valve crude maybe, effective ?). Now I'm no expert at these graphs, but Tim is and he seemed satisfied with the result, well for a 12yr old R32 GTS-t at least.... and that's good enough for me, well pleased :-) Curves for the runs above put together, for easier comparison, seem to be very similar apart from the boost levels (a lot more boost but little gain) and the point of peak power (around 300rpm different), as I said I'm no expert with dyno sheets, so what to make of them then ?, comments ??..
All that was left to do, is for Tim to give it a 'serious' road test, whoooaa !!! well serious mate..., cheers Tim ;-), I'm now a few millimeters nearer changing them 'budget' tyres, it came shod with, for some 'proper' rubber :-) Conclusions (well my non techie one's, at least :-), firstly considering the known mods I am somewhat surprised, but very pleased nonetheless, at the good levels of power produced over 'stock', maybe some other mods yet to be uncovered... 1. Bleed valve - made only 5bhp/10lbf-ft difference, from RUN 2 to RUN 4, although peak boost rose from about 0.78 to 0.95 bar, so worthwhile ?... probably not 2. Plugs - NGK Platinum changed to GReddy Iridium, well no change power wise but the old plugs were a little 'tired' and the Iridium's did cure that high boost minor misfire, so worthwhile ?... yes I feel and only a few pounds more than the Platinum's 3. Car - a good cheap buy ?... yes definitely 4. Fun ?... loads !!! :-) Written by Ron 27/04/02. Any comments or thoughts, please email alex@skylinegts.co.uk |
