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Curtthrasher01

Is remapping nessecary if installing uel header?

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Been looking into going with unequal length headers but was unsure if a remap is absolutely necessary straight away. Will the cars ECU get confused? Can you run the car reliably for a while with uel's on the stock map? I understand that a map will give gains and help with overall performance and I do intend to map it eventually. Just a big lump of money to do the two at once. Any help is appreciated.

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It will not give you gains but give you the boxer rumble, if you change your exhaust too. With OE exhaust and a UEL without a tune, you get very minimal gains. So do it if you want to but not expect gains or save up and do it with a tune. Tuning development links on this site will show you examples of people who fitted the manifold themselves and later went for a tune. Their dyno will give you before and after.

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Can't add much to what's been said already, other than you can get the Tuning Developments NA kit for about £1500 and it includes the manifold (EL and UEL options) as well as fitting and mapping. It's a good chunk less than you'll pay if you buy a manifold, pay someone to fit it, and then pay someone to map it later. Plus if you ask Mike nicely he might give you a passenger ride in their turbo'd 86 while they're doing the work!

The improvement in the way the car drives once it's been mapped is huge and you will wish you'd done it sooner. Lots of people on here have gone the TD route and I've never heard an owner say something bad about it.

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It'll probably throw a CEL from o2 sensor (assuming it's catless manifold you're looking at) and then you'll lose cruise control but not sure if this can be cleared with torque app each time. Also heard risk of it running slightly rich if not mapped but don't think this is a big deal short term

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21 minutes ago, willclarke said:

It'll probably throw a CEL from o2 sensor (assuming it's catless manifold you're looking at) and then you'll lose cruise control but not sure if this can be cleared with torque app each time. Also heard risk of it running slightly rich if not mapped but don't think this is a big deal short term

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You can, I did it that way. CEL will come back on the next time you start the car, but I flash it for the cruise control. And it does run a bit rich to be fair, car pops now

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Another problem I'm about to run into - Fitted the TD Manifold, exhaust etc myself just getting things slowly in place to book in with @Mike@TD.co.uk for a turbo install in the new year, didn't want to pay for a remap only to have to pay again in a month or 2 when I get the turbo.... Problem is as mentioned the CEL comes on every few days - not usually a problem except I'm now due an MOT and it would be a fail if it comes on during the test. Just going to have to cross my fingers it stays off.

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It can take a while for the CEL to come on. I used to find a long motorway journey always did it. Resetting clears and reactivates the cruise control fine, but the car always runs like crap for the first few miles each time you do a reset.

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I ran mine for a while without having a remap. With the overpipe I did see slight performance gains (was pulling away a little from my friend's stock BRZ). I have an 02 sensor spacer on mine and didn't have a CEL for the month or so I ran it. I probably covered about 2k miles that month. Enjoyed it much more after a remap obviously.

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Still having cats in aftermarket parts, or usage of O2 sensor spacers will only reduce chance for CEL to pop up, or increase mileage between them appearing, but certainly is not sure way to eliminate them. In some cars O2 spacers also may ill-affect fueling strategies by ECU. Hence imho not worth bothering with spacers. Disabling cat readiness checks in tune (alongside tune changes to work better with changed/upgraded exhaust/intake parts) is the way to go.

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Just got of the phone to the garage who have failed my car for emissions running the TD UEL - will a remap help with this at all, are the emissions worse with the engine running rich?

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1 hour ago, Adam9 said:

Just got of the phone to the garage who have failed my car for emissions running the TD UEL - will a remap help with this at all, are the emissions worse with the engine running rich?

Is it running rich or is the second cat not quite cutting it? 

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4 hours ago, Lauren said:

Is it running rich or is the second cat not quite cutting it? 

Both I believe, getting some lovely pops and crackles at the moment! I have it booked in Saturday to a 'friendly' garage.

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I wonder whether putting it into the 95 RON map would give it some extra headroom on emissions? Mine had its first MOT this year and was very close to the limit, I wouldn't have the first idea how to find a friendly tester.

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2 cats are there from the manufacturer for a very good reason. Taking one out could help you pass for the initial years but as the cat ages and wears out with mileage, is destined to fail. Finding a friendly garage is a nice way to make something illegal, legal for cheap. Not my way of thinking but hey ho.

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5 hours ago, BRZ-123 said:

2 cats are there from the manufacturer for a very good reason. Taking one out could help you pass for the initial years but as the cat ages and wears out with mileage, is destined to fail. Finding a friendly garage is a nice way to make something illegal, legal for cheap. Not my way of thinking but hey ho.

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The car is fitted with 2 cats for EURO6 standards not those of the MOT. Our cars should easily pass on either of the factory cats. If the standards of the MOT were that strict most older gen cars will fail it.

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1 hour ago, Varelco said:

The car is fitted with 2 cats for EURO6 standards not those of the MOT. Our cars should easily pass on either of the factory cats. If the standards of the MOT were that strict most older gen cars will fail it.

A few points here and let me try to be specific -

1. If it were easy pass, people above are stating that they scraped through or even failed for a header change aka first cat removal. So our cars do not easily pass MOT. It is a tight pass and there is a bit of get your cat hot theory applied (or a friendly mechanic).

2. Older gen cars have different criteria. Please check page 176 of emission protection from DVLA, which is what MOT testers use and each and every make and model is listed. TVR Griffith/Chimera being older cars are just below Toyota in alphabetical order and hence prove this point. Over a period of time CATS are bound to fail and removal of a CAT and a DPF ( in case of diesels) in itself is a MOT fail, 

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/676700/in-service-exhaust-emission-standards-for-road-vehicles-19th- edition.pdf

I am talking of principles here of having a CAT is to reduce emissions. Removing it is counter intiutive, though not illegal yet like a DPF removal. Every one has a right to his/her own decision, which i do not deny but "long term" cars passing MOT with only one cat is dicey. Short term issues keep surfacing now and again anyway.

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Makes sense. Primary cat in header is in such bad to performance place close to cylinders exactly so it can heat up to working temps sooner, thus improving cold start emissions.

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