hey i have a ef xr6 manual with a herrod short shifter, redback cat back exhaust, and k and n filter and not quite sure what he next step is to modify my car! i was also wondering if a ba xr6 growler intake box would fit into the engine bay? thanks!!

get some extractors and a high flow cat if you haven't already.

IMO and experience you're better off going for cam THEN J3 chip with custom tune THEN extractors and cat - better would be all of that in one hit - and IDEAL would be all that plus proper timing of the cam (adjustable gear) and J3 chip tuned to the car on dyno. Of course if the cam timing is good just fitted with the std gear then an adjustable gear won't be needed - ie. pretty sure Wade cams end up fairly close with straight up fit? And I'd caution against getting too greedy and going too big with the cam - you can end up with maybe better max figures but much worse overall performance.

Freeing the exhaust up is definitely a priority from stock - and cat back does that - but altho also having extractors and hi flow cat will of course yield optimum results, the std manifold and cat section flows quite adequately for decent performance improvement which won't fall DRASTICALLY below the ideal.

I've recently proven that a cam fitted to my EF with completely std exhaust (that's std manifold and cat and press bent 2 1/4 pipes etc.) worked FINE. And with 3.4mm of EXTRA shimming in each lifter that's not exactly a mild cam. It gave an immediate and very gratifying improvement across the board over stock and was reaching the rev limiter up to 3rd gear (fine in 1st and 2nd but indeed close to just thrashing in 3rd).

It comfortably matched std AUIII XR6 everywhere except top end - where the XR6 was clearly breathing happier.

That's fixed now with a 2 1/2 cat back and interestingly enough it was slightly better again with 3 inch cat back... - ie. evidently there's reasonably decent overhead for performance in the std manifold and cat.

My point is that IMO a cam is the way to get your best improvement straight up - then the rest is optimising that.

extractors and highflow cat> New cam> then J3 tune.

+1 for the above.

Do your intake, exhaust, extractors. Make the engine breath. Needs to get the air in and exhaust gases out. You won't need a tune with those mods. Do a cam and use a vernier gear. Better if you also get some port work done on the head as well. Then if you want get a J3 and get it tuned.

What type of j3 chip do I use as I have looked in eBay and there is many different types

use whichever one you want. but jase at tiperformance.com.au is cheap and he can get the tune pretty close if you supply a dyno sheet showing afrs

Go and speak with Paul from CVE performance, he has a heap of know-how with the E series and offers great bang for your buck packages.

Otherwise, you probably need to look at porting and polishing, can to suit, inlet manifold modification, designing a free flowing exhaust to suit and upgrading the ECU with J3 or even wolf V500 depending upon mods.

If you look into the above you can reach 200rwk BUT it is an expensive exercise!