Cosworth is an off the shelf map designed for their systems, if you're going manifold then you'd want to get something tuned for your setup from the likes of Fensport, Tuning Developments or Abbey. Off the shelf would work just with the catback for quick and easy, but to make the most of it you're better off with a personal tune.

 

Ideally you would add all the parts before you get the tune as it will need to be tweakedif you have a map and then add more parts. Depending on location go to Fensport or Abbey, I couldn't recommend Fensport enough, really know there stuff.
Have you got in any intake mods? if not grab a panel filter also!

 

I'm in Lincolnshire so Fensport is closest...

But do I go for their cosworth package or their own ECUTEK?

Does the tune make a difference, just wondering if its worth it or not really.

 

I'm contemplating a remap at the moment and from what I've been told its best to decide if you want to get a manifold and over pipe or over pipe and front pipe assuming you have a secondary cat back system? If you lose the cat in the manifold you may struggle come Mot but if you lose the second cat you should be OK. Then if you want manifold do you go equal or unequal headers, EL for top end, UEL for mid range and boxer rumble. As for maps Cosworth is optimised for their staged mods so I'd go custom as others have said at fensport/abbey/TD.

 

Also if you price them up cosworth comes out by far the most expensive although may be better when you come to sell on.

 

For budget power gains (and completely reversible eg. prior sales) i'd add aftermarket drop-in air filter + OFT. +E85 fuel & appropriate tune.
Next step up would be adding some cheaper catless header.
Next would be adding forced induction, supercharger or turbo (in case of turbo, don't buy header. Turbo sets usually have own, and unlike NA or SC, "normal" headers are not usable).
If you'll ever think of FI, get Ecutek instead of OFT.
If you'll know at which bolt-on mod set you'll stop, to save some worth installing all of them and do custom ecu tune once, at reputable shops like mentioned in previous posts.

 

For budget power gains (and completely reversible eg. prior sales) i'd add aftermarket drop-in air filter + OFT. +E85 fuel & appropriate tune.

E85 is next to impossible to get in the UK though

 

Next would be adding forced induction, supercharger or turbo (in case of turbo, don't buy header. Turbo sets usually have own, and unlike NA or SC, "normal" headers are not usable).

There aren't many turbo options for RHD cars. The only one I know is Tuning Developments, and their own header is compatible with the turbo if you wanted to fit it later

 

From the Cosworth literature/dyno tests just getting a map on a stock car (with an air filter change, that's only £30) there's a bump of power towards the peak end of 10-15bhp with the remap and a more sensitive throttle which makes it all feel faster. With the addition of your exhaust you're basically at what Cosworth call 1.1 so it helps add some power lower down. A remap will help make the most of whatever mods you have fitted so you will see a gain with what you have now, but if you want more of a gain it's worth swapping one of the cats out for either a sports cat or no cat (depending on if more noise can be lived with).

I'm already remapped with 1.1, but looking at getting a midpipe and possibly manifold so I'd get remapped again to take advantage of the new mods.

 

Depends on the age of the car for that Steeps. Newer ones make less than 190 on a dyno due to maps so there's a "free" 10hp to go back to what the car should make.