A blow off valve would replace the stock bypass valve. The stock one is a recirculating valve which is made of plastic and liable to leak. You can replace it with a performance recirculating one made of metal, or block the location off and install a blow off valve instead, which is an atmospheric dump valve. The Forge FMDV004 is popular, as is the Bailey 0026. Either way it must be a dual piston valve. The performance gain is not much - smoother gearchanges on boost, and a nice whooshing sound when shifting, but that's about it.
The FPR all depends on the other mods you have, but the stock one should be fine for a while. If you are in the US you have an SPG, not an Aero (same car more or less, different name), and it will be the 2.8 bar FPR I believe. You can change it for a higher rated one if you are running lean but not much point before.
3" downpipe is held to be a very worthwhile mod that frees up quite a bit of power. Minor drawback is that you'll have to relocate the battery, usually to the boot/trunk.
Lots of people sell upgraded APCs. It is apparently very easy to do the mod yourself, by turning up the P and F pots and maybe replacing resistors. Many on here have done the work themselves, or got the specs and had it done by a local sparky. The place to find out about APC tuning is on
www.900aero.com .
The best way to find out about these mods and others is to do a
search of this forum, as that will give you many more replies than you will ever get in one thread.
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24-02-05
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