Hi guys,

I have a 2004 5 speed manual xr8 ute with the boss 260 motor. Modifications so far are 3.73 diff gears, 25% underdrive puilleys, cai, cat back exhaust and flash tune. As most people I'm looking for more power still. My wish list goes in this order: short shifter, headers, hi-flow cats, billet oil pump and gears, supercharger, intercooler, injectors, cams. Like just about everybody in this world I'm on a budget and can't do all of these mods at once. I have a few questions for you as I don't want to do any modifications that will hinder further mods or become irrelevant down the track, for example I'm guessing that cams should be after forced induction as the performance cams set up for a naturally aspirated motor would have different specs to those set up for a blower, am I correct? Could you give me your professional opinion on what you think would be the best order in which to do these things? Also I'm aware that the boss 290, 302 and 315 have higher compression ratios than the 260 making them much easier to obtain high horsepower. what needs to be changed to get this from the 260? I might be wrong but I was under the impression that it was simply cams and pistons, do heads need to be changed too? Are these mods that I could easily do to my xr8? the k's are up there and I'd like to pull the motor out and rebuild it anyway for my own piece of mind which I feel would be a good time to change the pistons and heads before trying to extract serious power out of it with the blower. I would also know what peoples thoughts are on herrods helix spacer, is it any good or a gimmick? Will I need to remove the spacer if I buy it when I go to install the supercharger or would it be useful with the supercharger kit as well? What about throttle body, obviously in a supercharger kit I'll need to put in a bigger throttle body could I do this before buying the supercharger and use it in conjunction with the spacer for any noticeable gain while I'm still saving to buy the supercharger or will a larger throttle body just make it run like a pig? I've got the same question about larger injectors and also the fuel system like rails and pump should I upgrade before the supercharger or wait and do it all at once as I'd only need to go bigger again once I buy a supercharger? Any advice would be hugely appreciated.

Thank you,
Hamish

What sort of blower do you want Hamish, Positive displacement or centrifugal?
It's not worthwhile adding cams and pistons to your 260 engine. It's a lot of expense and when your k's are getting up there it just doesn't stack up besides, you can't just add the GT pistons to an otherwise stock engine you'd need to rebuild it. A better idea would be to find a 290-315 engine that's in good nick and bung it in.
The centrifugal blower is the cheapest option for good gains and better fuel economy to boot. funnily enough I just happen to have a capa Vortech SQ-trim, intercooled kit for sale if you're interested.
You could just bung this on and build another engine on the side or find that 290-315 engine to put it on later. The Vortech will get you mid to low 12's in street trim and 11's with the GT engine.

That's a really good idea xr9ute, That's something I never thought of before.

I'll send you a pm regarding the blower kit you have

I have a BA Xr8 with all the mods listed..

Dont be afraid of the CAMS. I put the crow cams 260 cams in, made 270rwkw N/A and over 400rwkw with the blower. These cams work with the blower so no need to worry.

To build a motor would cost a bomb, then supercharge it etc etc... big coin..

If your motor is in good condition, grab the centrifugal blower setup from member posted above (assuming good condition) and get it fitted/tuned properly. you should see easy 330rwkw non intercooled and upto 400rwkw intercooled. I have the large t trim blower though so maybe a little less kw for s trim.

Car roars and is a serious weapon.

what is your budget, they are fun cars no matter what your setup.

If you cant get supercharger, grab cams and you will see 6500rpm rev limit and more mid range as well. But nowhere near the gains of the supercharger.

Hi xr6turnip,

Where did you go for your cams? Herrod motorsport quoted me $2200 supplied and fitted which I thought was really cheap as I heard it is a motor out job.

Thank you for your input.

I appreciate all and everyones opinions and hearing pros and cons to different set ups. Everyone I have spoken too says the same thing... Go the blower!!! So it sounds like a plan now to just save the pocket money.

I don't sell junk mate.

Hi xr9ute did you get my pm. I don't want my offer to insult you its just all I can propose at this stage

Not yet but, it sounds like you've insulted me in it?

how much for the supercharger? PM me

Hey mate I resent the pm it said it was sent to you though. Can you pm me your email and I'll copy and paste it into an email? Or pm me your phone number?

Only issue with supercharging is getting an engineer to engineer it..

Sound proofing, body structure, emissions, db.. It's very difficult to get done and not cheap.

You can go without but then don't drive it like a madman, coppers will get you for it.