Honda Car Forum

tools and parts from the others types of engine's recommended without any special branded tools

NOS and chip, but even though you'll get more p/f torque and doubled HP, you will use up the engine that much faster.PS, if you intend to street race it, don't race a GN, you'll loose your ride.

This engine already produces a very impressive output for the size - increasing further starts to push limits more than "lazy engines" which are producing a lot less than 100+bhp per litre.To get this level of power is going to involve either a turbo, super charger or nitrous - otherwise I cannot see how you can possibly force the amount of air you need at atmospheric pressure other than increasing the rev limit frightningly.Portnig / gas flowing the head is all well and good - and will make a little difference here - as will removing the cats (replacable for MOT of course) and improving the air-intake. But all of these mods are "little bits" that are not going to add upto 120bhp in a month of Sundays.Turbos are one way - and folks seem able to run 9psi with some degree of stability - but this is not going to take you to 300bhp. I am guestimating that you would need more like 15psi - 20 psi to reach the sort of power levels you need - and to be honest you are starting to get VERY close to the outer limit of engine integrity at this point. You also need to think about space for intercoolers etc.ECU is likely to need piggybacking here - as you are going to need some new fuel maps when running high pressure from the turbo - it is likely you will need to upgrade your fuel pump too. Depending on the design of the air metering (AFM?) and how close it runs to the limit now, this may also need upgrading.Ditto with a supercharger.A much easier way of doing some of this - and at least the bulk of your investment could then be taken with you (boosted cars harldy EVER get anywhere near their investment back when you sell them) - would be to consider nitrous oxide.If you go this route, with an engine as stressed as yours already is, then I would suggest a progessive controller is essential - as would be using a kit from "Highpower". Crap name but they are the only folks in the business who have solenoids which do NOT end up leaking when pulsed. The american ones (HolleyNos, Zex, Nitrous Express etc) all use modified (or standard) industrial solenoids - they even sell "solenoid repair kits" which kind of tells you something too.A progressive controller, starting at perhaps 30% and raiding to 100% over a few seconds will allow you to use around twice as much as an equivalent "direct hit".You will also need to uprate your fuel pump.It has to be said, that at the power levels you are talking for the physical size of the engine, you may need to think about strengthening rods. Pistons should be fine with nitrous if you run a little rich and with a progressive controller. If risking a cheap american kit, then get forged pistons and double-up on the solenoids so when one leaks you don't run lean.Incidentally, if you do fit nitrous, don't waste money on a chip (nitrous should run a little rich for safety - when the chip wants you to run a little lean) and don't waste any money on performance cams - again stock cams tend to work best with nitrous.You will also learn with nitrous the BIG difference between torque and BHP. You can have a 200 BHP car being thrashed all over by a 150BHP nitroused engine - because the 150 is available almost instantly and at a rev-band selection. the 200 bhp engine will be at at (typically) max revs only in a specific gear - at all other times it will be producing less than 200bhp.For more info http://www.mark.lineisp.co.uk/nitrous.htm

NOS

T3 turbo 2 stage nitrous