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I had my R33 Gtr Dyno tuned at 310 AWKW recently and found out had detonated piston so had rebuild with Forged pistons, head work, metal head gasket, N1 oil pump, N1 bearings, new belts, new crank and blue printing. Had car re tuned and found only 2KW increase in power.

Is this normal? I would have thought it would have increased around 20 kw but still happy with overall power just thought this was interesting. I guess that power just safer with stronger engine now.

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maybe the headwork took you backwards and the extra power from increased compression and the rest brought it back upto your previous power? its abit strange, though ive heard of people not making any extra power from doing a fresh rebuild.

Generally if your engine is in piss poor condition, after a full rebuild it should run alot better, make better power with less inefficiency due to everyting being returned to factory spec or better.

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Did you lower compression ? What kind of head work did you do? Is the engine still very new and very tight ? Piston to bore clearances? Do a comp and leakdown test then you will see whats going on . The dynos can make a lot of difference even if you used the same dyno .

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Forged pistons won't increase power.. just your capacity to do so...

yeah but i think he means the car was dynoed with a busted piston and with new ones (not leaking pressure) it should probably produce better power. Plus with the engine cleaned up like new you'd think you'd get a little bit.

Was it the same dyno??

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Sorry can't say much. It was at same dyno and engine build all arranged through UPI in moorabbin. I know they sent it off to get done and because of christmas break only get the car next week. Sorry don't know much technical terms yet am learning form reading in here though. Thanks for all replies. Car only had 34K on clock and maybe they are genuine as no difference in power after re-build. If so obviosly very happy with car. Get R33 GTR with probaly now 40K in newish mods, very low K's for little more than mods would have cost. Also only charged fo rparts in re-build as upgraded parts involved, just wish had the money at time to do cams and rods. Maybe a future thing and get T04Z or similiar in a few years time.

I read on here that 400+rwkw is the new 300.

Edited by gdogzgtr
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yeah but i think he means the car was dynoed with a busted piston and with new ones (not leaking pressure) it should probably produce better power. Plus with the engine cleaned up like new you'd think you'd get a little bit.

Was it the same dyno??

Ah my bad :) , true it should have made a bit more power over the busted piston... Not a lot tho..

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Hang on... metal head gasket should decrease compression, right? Thus giving you more potential to boost it higher.

Headwork... if you had it shaved down to increase compression, then you're right back where you started in terms of manifold volume. (due to the metal headgasket increasing the volume)

If you didn't have the head shaved, then it's still the same, and whether you did port matching and so on or not... if the head wasn't maxed out in terms of flow, then porting and polishing shouldn't actually do anything.

You've got a stronger top-end, which should put up with the power you have. I'd be happy with that!

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