Re-map. When Is It A Must Have?

[Richie Cross]

Hi folks,

Thought I'd throw this out to the forum before I do something daft!

Basically, my car started with the PPP exhaust and so far I've been to Meercat and had the

Snakehead downpipe with a sports cat.

I'm planning to go back to get their straight through centre section and was talking to Wullie

about their up pipe. He described it as being more rally without using flex? Two parts that

fit together loosely but expand in the heat and make a tight fit?

Probably the worst description in the world!!!

So, I wondered if I could safely do this without needing a re-map? Will I cause overheating?

Am I ok because I've kept the sports cat?

From reading old posts, I kind of got the impression that I would definitely need a re-map if it

was a fully decatted system?

I was hoping to get a re-map through the group buy but £460 is quite a lot to think about and I

e-mailed Andy who said I'd only see a gain of about 20bhp, but if I was going to do any damage

with the exhaust changes I'd either get the re-map or not do the changes.

Cheers

Edited September 4, 2007 by Richie Cross

[~ ~ Cal ~~]

What you are doing is exactly what I have done.........

At work :- so will type later.......... but answer is get a remap asap OR wait till you install more mods to avoid having 3 remaps ( like I did)

Cal ( see the link below for my car spec.)

[~ ~ Cal ~~]

Remind me to mention your EGT sensor which is pre-cat in the up-pipe ..............

[Richie Cross]

Mmm, should I leave it with the downpipe for now then or could I at least get the centre section done

as well??

I've had the Walbro uprated fuel pump put in already. I guess I was just wanting

to get as much out of the car as I could for the least money!

I thought, "£140 for a centre section....why not!".

The cost of the re-map is obviously a different matter rather than £140 here and then

£90 for the up pipe later. Mind you, I guess it could be more expensive if things go

wrong...............and then I'd have to explain to my wife!!!!

I'd planned to spend the potential re-map money on front/rear arb's and droplinks first

because again I could get them over a couple of months before getting it all fitted at

once. decisions, decisions

I always tell myself...."It's the fastest car you've ever driven....YOU DON'T NEED IT TO

BE ANY FASTER!!!!".............but I never listen!!

Edited September 4, 2007 by Richie Cross

[thewelsho]

I always tell myself...."It's the fastest car you've ever driven....YOU DON'T NEED IT TO

BE ANY FASTER!!!!".............but I never listen!!

Haha! I used to think like that! It might be the fastest you have ever driven, but not the fastest you can ever drive... on a private road or track of course!

[scoobyiain]

You need to think about what other changes you might want in the future because as cal has said there is no point in getting multiple re-maps over a year or so. Best keeping it the way you have it and once you have bought all the mods you want get them put on then go for a re-map. I wanted a re-map too when i got a cat back system but andy said it's would not be worth it.

[martin_allen]

You need to think about what other changes you might want in the future because as cal has said there is no point in getting multiple re-maps over a year or so. Best keeping it the way you have it and once you have bought all the mods you want get them put on then go for a re-map. I wanted a re-map too when i got a cat back system but andy said it's would not be worth it.

I'm doing the remap and have a full scoobyworld system, including centre section and cat pipe on the way. Also going to get a Y pipe for the turbo and then that's it for power mods, i need a reliable car!

I was going to get all the whiteline stuff off Cusco Kid and i still will do, it just costs exactly the same as the remap and i'd rather put up with some body roll than blow the engine.

Andy told me to keep the car off boost until he's mapped it if the cat pipe is fitted so i'm not having that fitted until the day before it is mapped as i don't want to risk any damage!

5t.

[~ ~ Cal ~~]

Okay dokey.........

Here was my journey :-

http://forums.sidc.co.uk/index.php?showtop...p;hl=thundercat

The Samco Y tube is a must when whacking up the boost and helps air flow too. Decat centre section & straight through section is best but not really necessary tbh. I would have told you to get your turbo ported but your Sports Cat is already on. You have the Walbro which is great. Stock injectors are fine for a WRX on a TD04 too.

You deffo want an up-pipe and I would recommend not getting a flexi one but other opinions may differ. I think mine is an HKS one but any up-pipe from a classic will fit your car. Again perhaps port the opening of the up-pipe ( & turbo as you will have the chance to do this again when the turbo/ exhaust is easily accessed)

At this point you need to ask yourself what you want from the car ? For me I wanted 300bhp and great handling. I have both now but the brakes would be next ( already have a good set-up but I want some 6 pot jobbies at some point)

Hope this helps.........I went up to a VF35 turbo from an STi. This is something else you may wish to consider ( or Andy F TD04 Hybrid)

Also you might wish to install a STi intercooler ( I havent got one though)

If I was going for more power then I would need an Sti8 IC and STI pink injectors

Drop links and the ARB will make a HUGE difference ( just ask MadMonk ( RB5 PPP) who tried to follow me on a recent country road !

Good luck and keep us posted !

Cheers

Cal

[fai17]

Meercat is talking about the 3 sleeve slip joint that he use on the up pipe

[Richie Cross]

Meercat is talking about the 3 sleeve slip joint that he use on the up pipe

Cheers Peter, that's obviously what I meant! Could you not tell!

Also, as Cal said, it wasn't the flexi one!

With regards to what I want....I'm 'pretty sure' I won't be getting an uprated turbo or headers

done etc as my wife would know about this and it would be a lot of money that I couldn't get away

with spending.

Andy F had mentioned a turbo upgrade but it's not a financial option.

I'm looking to spend a wee bit here and there....ie £140 for the centre section...£90 for the uppipe etc.

As far as the exhaust goes, I had thought....centre section then uppipe and that would be that. Keep

the sports cat on.

So, would having that done, and only that, warrant a re-map/cause potential damage?

I can't plan ahead due to cash etc so if in a years time I did fancy more, I'd have to worry about that

at the time.

Good answers as always. Cheers folks.

[Green Hornet]

As far as the exhaust goes, I had thought....centre section then uppipe and that would be that. Keep the sports cat on.

So, would having that done, and only that, warrant a re-map/cause potential damage?

Short answer is yes. Put simply if you run full decat or sports cat only you'll be allowing much more flow through the engine. As your current boost profile and fuel map aren't set up for so much unrestricted extra flow, you run the risk of boost spiking and lean fueling. May not happen but you'd be walking the high wire without a safety net IYSWIM.

If you're determined to set the exhaust system up this way you really need to remap or potentially face repair bills down the line which could dwarf the cost of a remap.

Leaving the up-pipe alone means you won't really need the remap but this will pretty much limit any power gains to what you currently have. The up-pipe cat is quite restrictive.

On that note though, don't just get hung up on the potential peak power figure.

Dont' forget that remapping will see you gain engine efficiency across the board because it's car specific - all aspects of boost, fuel and ignition maps will be tailored to your car and choice of fuel. Don't underestimate the effects this can have on performance.

You will probably see a much improved torque figure and importantly, torque spread. This is what will make a big difference to response and driveability of the car which (IMHO) is everything if it's an everyday road car. Imagine quicker shove out of bends or away from roundabouts and quicker overtaking with an improved midrange . Reckon if you have a search through old threads you'd be incredibly hard pressed to find anyone who didn't come away from Andy F with a car that simply performed better (regardless of whatever power figure it made).

Another common effect of remapping is that mpg actually goes UP! I kid you not. (Note: I think you have to do in XS of 150K miles to get back the remap costs though but it's a nice feeling not to have to visit the petrol station just quite as often.)

So you see - peak bhp is only part of the remap story!

I can't plan ahead due to cash etc so if in a years time I did fancy more, I'd have to worry about that

at the time.

Don't think you're alone there fella but bear in mind that subsequent visits to Port Seton will only cost £200+VAT . Additional map tweaks cost a lot less as you'll have already taken the hit for the license (if you go ahead on the discounted group buy).

Something to maybe factor in and consider for 'down the line'

Hope this helps a bit.

Cheers,

Stewart.

BTW if you're determined to change the up-pipe, another option to the classic pipe is the STi slip jointed pipe. Either can be got 2nd hand for much cheapness. As Cal advised - worth porting, so too would be porting and wrapping the exhaust headers. A WRX prepped like this and remapped would probably make 270bhp - maybe more on 99RON fuel - with very quick spool. Some lucky WRXs make over 280bhp but this is exceptional and not really a 'take it to the bank' kind of figure.

[Richie Cross]

Stewart,

Great answer. Cheers. Looks like I'll leave the up pipe for now then. I'm not really

mechanically minded so didn't know how restrictive certain parts are etc.

I was just thinking....mmm, only £xxx ....I could afford that!!

Looks like I'll get my arb's/droplinks first while I do more overtime and get the up pipe/re-map

in quick succession!!!

I guess I was indeed getting hung up on the power gains rather than all round driveability.

I don't know figures I expected to get from Andy.

As far as lean fuelling goes, I've had the fuel pump uprated so should be ok there.

Thanks for all the answers guys and gals.

[Green Hornet]

I was just thinking....mmm, only £xxx ....I could afford that!!

Yeah - with you there! There's definitely something about kids, sweetie shops, Impreza owners and mods......

Looks like I'll get my arb's/droplinks first while I do more overtime and get the up pipe/re-map

in quick succession!!!

Suspension and brake upgrades are well worth doing - good set ups can be worth 40-50bhp on the right roads in the real world.

Having the power is one thing - being able to fully exploit it's a whole other ball of wax as they say. Get some of that factory understeer removed and some better body control back and you'll be very pleasantly surprised by how much speed an Impreza can carry

Cheers,

Stewart.

BTW:

As far as lean fuelling goes, I've had the fuel pump uprated so should be ok there.

Word to the wise , having the uprated pump fitted gives you the potential to flow enough fuel on a modded car. It doesn't automatically deliver that fuel to the cylinders. Don't forget fuel pressure is regulated and you haven't altered the injector pulse width or duty cycles beyond the factory map so you aren't physically adding extra fueling - you would still run lean without being remapped. Edited September 5, 2007 by Green Hornet