ock in the qood ol' doys,tuninqwos simple.YoJ po*ed the heod, ttt'ot.hud ond theports,ond. the'monifolds whqckedin o lumpycom.A quick zry ond chonoe e of corb ietsond o re-curveddiznt produced'oodles you'J lesof powerwithout you' J produced.'ood ruinini driveobility. lfls not so eosyony more.Most cors now systemto run somesortof enqinemonoqement o, keepcontrolof spoftsond fuelling,.onJ of soonos vou storichonoinqthe mechonics usedby the how theLngineworks,"the"mops monoqement systemwill be wronq. Mois? Well'weexploinedsomEof thiso coupleof issuesbock (seeFostCortogrophy, FasiCor November),but let'siustrecop.
svstemqoesone sfepfurther. full monoqement mop' therewill be o ln odditioi to this'iqnitio"n 'fuelmop' whichtellsthe computerhow much fuelto iniectundero qivenseiof conditions. Fuelond oduonceEquiredwill chonqe of the whenyou oltertheoirflowchqrocteristiis com,for enqine- bv fittlnqo performonce So the fomputerwill be usingthe "^Jrplu. wrong volues,ond the enginewon't run right. Worse still,thereore now'odoptive' which 'leorn'oboutthe monoqement systems enginJthey'retontrolling,ond groduolly to qet the bestoui of it odiustthemselves will differdue to beorinoin mind thot"enoines norrol'productiontolerlnces.Puto different com in one of theseenqinesond thecomputer will recognise o differeice,but ossumethotthe differencE is becouseone of moreof iis sensors run lt'll therefor:e hos siortedto molfunction. leornt theenoineusinqvoluesit hospreviously to be oboutriqF'iwhichwon'i do ot oll.' So it's cleor"thotif you fit o differentcom profile,you needto qlterthe ignitionqnd/or system. luellinqmopsusedbv the monooement hovegot Whicliis why Piperond Superch-ips together,to ofter.completepockoges, in benefitinqfrom theirexperience engine p"rfor*o"n.ecomsond're-progrommed chips,respectively. monoqement of o chip ond To iheck out ttre'combinotion pockog. com,we triedthe Piper/Superchips on o Mk3 WV Golf GTI usedby Mork Hororeoves. our tometiminqmon lrom Dot[n. Aport from o tostyit of Borbetwheels thecor wos wroppedin PirelliPZeros, stondord. completely Thiswosn'tiustq motterof fittinqthe bits, thouoh.becousePiperdon'tyet do-o com for theMkS 2-litreenqine.so Piper'sTechnicol DirectorJohnCro6b brouqhitheirMk2 Golf com ond hopedit would fi'tond be somewhere neorthe riqhtprofile.And of coursethere wosn'to SJperchipmoppedfor thecom, so we hod to siortwiih the stondordMk3 Golf Superchipond olterthe mop to suit.
As we'veexploinedbefore,o,mopped iqnitionsystemstoreso setof volues- o mop o"fiqnitionodvonce.Thesystemhosenqine dotl inputs(usuollysp""Jond lood)frim which ii con decideon the rightvolueto use.A
New Piper cam was timed in using'OT' marks on the pvlley and cam box, which give the TDC position, Superchips usedtheiremulotorsystemso theyi:ouldolterthe mop, ond topp6dintothe outpulfromthe cor's lombdosensorto monitor thefuellinq. Firstwe"ronthe cor usinothe emulotorwith the doto from the stondord"Golf Superchip. Thisnormolly.increoses.ignition odvonce' -udegrees, moybe.less (usuollyby slightlylusuoily srrgnfly by 4-8degrees, moybelessot ot certoin points in the rev ronge) ond richens the
ffi
mixturewhere needed Superchips' JomieTurveyron the cor up on the rollinqiood to checkthe fuellino. monitorin"q exhoustCO ond the ouioutfrom the lombd"o sensor.Bosicollv the fuellinqwos oboutright,thouohot idle (*h"r" the cim hos too mucf,overlop"ondisn'tiillingthe cylinders very efficientlv)the mixture*os"prouin'otoo ric6.To correctthisthe fuel mop'woschonged
Managemenl system revealed - the 'chip'is the smaller of the two black obiects al the bottom left of the board.
to reducethe omountof fuel iniected.Thisolsohod the side effectof reducinoidle emissions. At wide openThronle the ionitionneededodvoncinosliohtlv ' o"tthe top ond the bottom-oftlie rev ronqe.while in the middleit needed-reto rding slightlywhere thecomwos ooerotinoof its best. At port throttle'olittlelessodvonce wos neededin the low ond mid ronoesto ovoid the onsetof pin['inq.Butbeorin mindthotoll ihit *o"t bosedon thevoluesin the Superchip, not the stqndordGolf mop, so in oll cqsesthe enginewos