hey fellas... this is going to be my first topic, and i was hoping you guys would be able to give me some info on various different mods for my x-reg vectra. It's actually turning into a very long post... so if you cant be bothered reading it all I'll summarise all the questions i have at the bottom so you dont have to read all the garbage 😃

Basically... I'm wanting to know what the best mods are to be done which will give the most power gain without too much harm done to my wallet.

I was originally thinking of the following:
Exhaust (cat-back since you guys seem to think de-catting causes more problems than it solves?)
Air filter (not sure if i should go for a cone filter or panel filter? K&N is most likely either way...)
Chip/Re-map

I was hoping this would give me a reasonable increase in power and performance without being too costly and without having to mess around with the engine itself too much. However:

I took my car down to work today to do a service on it (changed oil + filter, fuel filter, spark plugs, pollen filter - not that that's even imporant here)... left air filter since i'll be fitting a K&N (not sure panel or cone yet) filter anyway.

Anyhow... its been using about 1/2 a liter of oil a week so far, so once i'd done the service i revved it up to check for any signs of blue smoke (for burning oil)... nothing really noticeable at all from the exhaust... so assumed it must be down to the oil leak(s) on the engine... first port of call being the rocker cover gasket which i plan to do next weekend.

anyway... after i'd done all this, i switched it off and left it stood while i was busy doing other bits and pieces... came to drive it out and when i started it up the engine was missfiring really badly. took spark plugs back out and found cylinder 1 full of coolant. I assume this will mean the head gasket is on its way out... but i've had no other symptoms until i did the service (other than the heaters blowing warm shortly after engine started... even from cold... is this normal?)

I left it running while i put it through the car wash, then switched it off when i went back inside for about 5 or 10 mins... came out and it started up fine... drove home fine... no smoke, no lack of power, parked up for about half an hour and started up fine again. Seems strange that it was full of water that one time, but now seems fine.

anyway... the main point in all this is that if i do have to replace the head gasket, i'm wondering if it will be worth putting a pair of cams in while i'm in there... since it would all be stripped down and ready...? are there any other bits and pieces you guys would recommend while im in there which aren't too time consuming to do before it gets built back up?

I'm obviously gutted that I've found this 2 weeks after buying the car, but atleast it might motivate me to do a little more than first planned to tune it up a bit.

Heres the list of questions :roll:

1) Is a cat-back exhaust my best bet, or should I de-cat it, or get a sport cat? Basically... what exhaust system will be best?
2) Air filter... unless you guys know any better... I'll go with K&N... but should i get a panel filter or cone filter? I've been told panel filters seem to be better on normally aspirated engines...?
3) Is it normal for the heaters to blow warm fairly soon after driving off from cold compared to other cars? somone told me vectra's have a pipe from the exhaust manifold to allow the heaters to warm up quicker, is this true?
4) If I'm in there doing the head gasket, is it worth buying a set of uprated cams and doing those while im in there?
5) Any other bits and pieces which i should do while I'm in there doing the head gasket? (not too costly or time consuming).
6) If cams are a good idea while im in there... can anyone recommend which cams to get and from where?
7) I've been wondering about Nitrous Oxide and while talking to a friend of mine i dismissed the idea... but i read a thread on here which has begun changing my mind... is it a good cost-effective way to increase power?
8) I read about a 250bhp threshold on these engines... what does this refer to? is it how much you can squeeze from them before having to up-rate the pistons or what?

Sorry for the mega-long post and loads of questions :lol: