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Read further on now, sounds quite a serious spec !
If MRC can do Motec then get it checked over as you can have the spec in the world but if the guy mapping it isn't sure what he's doing then that may be your problem.
Plenty of people can map Motec though, where in the country are you ?
Hmmm.... if the cams are made to give top end power (much like the 7A exhaust cam), it may be quite unresponsive at the low end and then give out all the power, eg. after 4500 rpm.
I take it this is the engine in the S1 Gary? Like has already been said if you are happy with 450-500 then a gt35r is a bit wasted there. You would be better off with a gt30 at that power level. The compression seems a little on the high side if you are only going to be using super unleaded. If you run it on race fuel then its about right. To get more responce out of it I would take it for some mapping looking at the cam and ignition timing.
Oversized valves are only of use if the correct port work up has been done otherwise it can be a negative effect. As for the statement regarding redtop valves yes they are pants once you get to the high end of the EGT range.
As a ball park reference for desired powerband.
Proper headwork with stock valves and valvetrain, h-beam rods, stock pistons, stacked headgasket (8.7:1 compression ratio), standard AAN exhaust mani and GT30R with 3" system sports cat and 2 box's, stock airbox and MAF setup at 0.96bar base running in map made 420hp and 410ft/lb on the SRS audi south dyno day at surrey rolling roads.
Whereas on the same day another AAN with 3071 turbo on stock head with RS2 mani made 410hp @ 1.4bar
So looking at your power figs the low torque will be from the late spool of too big a turbo and the low hp is either from incorrect headwork (I've seen professionally ported heads flowing less than stock). Or incorrect mapping.
^^ it was all the line of an experiment, tweaked the collector of the manifold getting rid of hotspots, once it was turned up to 1.4bar the car kept up with a 447hp (dyno'd same day) passat with 2.7t and a6 quattro running gear.
But this lasted approx 1 day before the compressor oil seals let go, diagnosed as the stock MAF airfilter box setup physically not allowing enough air into the turbo for it's requirement so instead of sealing under pressure it physically drew the oil out the centre cartridge from suction under boost trying to get air from wherever it could.
One turbo rebuild after less than a 1000 miles and a wagner direct replacement exhaust mani, relocated MAF and mushroom airfilter later, just awaiting a live map this month.
I'm running 2.5 stroker. Ported head with 0.5mm oversize valves. Mech cams with 254deg duration@ 0.1mm and 226@ 1mm lift. T66 turbo and running E85 fuel. 584hp and 520lbs/ft @wheels (mustang dyno) with 1.8bar boost.
I'm running 2.5 stroker. Ported head with 0.5mm oversize valves. Mech cams with 254deg duration@ 0.1mm and 226@ 1mm lift. T66 turbo and running E85 fuel. 584hp and 520lbs/ft @wheels (mustang dyno) with 1.8bar boost.
Do you have any action videos of that car of yours?
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