Stage 1/2

http://www.MRCTuning.com - MRC Tuning Limited is based in Banbury, Oxfordshire. They pride themselves on their technical knowledge and ability to do all mapping in house. Dougal Bennet and Mihnea Cotet opened the UK business in 2005.
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FrazerD
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Stage 1/2

Post by FrazerD » Mon Aug 27, 2018 7:59 pm

Hi there,

I am curious for the future about your stage 1 and 2 maps and the differences.

My engine will be standard and after reading the details on your website, I’m not sure I would need a stage 2. I know it’s only £100 difference but if I don’t need to spend it then there would be no need. I’m also wondering if you could do either the stage 1 or 2 on s mode so the car drives normal with it off but mapped with it on? This is maybe what you do anyway but I wasn’t sure and it doesn’t say on your website.

Cheers :thumbs:

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MikeFish
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Re: Stage 1/2

Post by MikeFish » Mon Aug 27, 2018 8:13 pm

The S mode will still change throttle response as it does now, but the difference is much bigger. Once mapped the throttle response makes the car feel like a turbo car on boost in comparison.
The map affects both S and non S modes. They normally apply a linear throttle response to the non S mode and a much more aggressive one for S mode. When you switch from S to non S it fells like someone has stolen your engine (don't think it makes much difference to actual speed, just feels faster in S).
The difference between Stage 1 and 2 is that the stage 1 is a generic map, whereas stage 2 is a custom map that is better suited to modified engine (air filter, exhaust etc) but it also allows you to decide exactly what you want done i.e. remove cold start, remove secondary air injection, delete pre-cats, remove manifold flaps etc.

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FrazerD
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Re: Stage 1/2

Post by FrazerD » Mon Aug 27, 2018 8:37 pm

Thanks Mike. So the map will apply to both modes and the s will still alter the throttle response. If I was to get this done, at the moment I’m thinking stage one as the cold start and secondary air injection won’t worry me but now the pre cat delete and manifold flaps are interesting me. Will the pre cat delete add much power or just more noise? And what’s the idea between the manifold flap delete? Noob questions but learning.

Cheers :thumbs:

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MikeFish
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Re: Stage 1/2

Post by MikeFish » Mon Aug 27, 2018 9:00 pm

Pre-cat delete is one of few ways of adding power to this engine (short of spending £15k on a supercharger). The increase isn't huge but it is the most restrictive part of the exhaust and serves no real purpose. And it still leaves your car MOT compliant. The purpose of it is that manufacturers have to have low emissions from start up, and initially the main cats are not very effective when cold so the pore-cat does its bit to keep emissions down until the main cats are warm. MOT only measures emissions when the engine is at normal operating temp so not affected.
The OEM main cats are 200 cell, the pre-cats are 400 cell. Milltek sports cats come in 200 and 100 cell varieties so this gives you an idea of how unrestrictive the OEM main cats are (i.e. they are the same as one of the Milltek Sports cat options). The only downside is that your car might be a little more smokey for the first couple of minutes when cold.

Manifold flaps don't really do much but are a common failure point. When they fail they will throw an error on the dash. A lot of people have them removed when the head is off for a carbon clean and mapped out to save them getting the error a later date and having to take the head off again.

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FrazerD
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Re: Stage 1/2

Post by FrazerD » Mon Aug 27, 2018 10:32 pm

Thanks again, I think I would probably have to make my mind up nearer the time. At the moment I’m still thinking stage one as I think that would change the car enough for me to be happy.

Cheers :thumbs:

Quango86
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Re: Stage 1/2

Post by Quango86 » Thu May 09, 2019 4:41 pm

MikeFish wrote:
Mon Aug 27, 2018 9:00 pm
Pre-cat delete is one of few ways of adding power to this engine (short of spending £15k on a supercharger). The increase isn't huge but it is the most restrictive part of the exhaust and serves no real purpose. And it still leaves your car MOT compliant. The purpose of it is that manufacturers have to have low emissions from start up, and initially the main cats are not very effective when cold so the pore-cat does its bit to keep emissions down until the main cats are warm. MOT only measures emissions when the engine is at normal operating temp so not affected.
The OEM main cats are 200 cell, the pre-cats are 400 cell. Milltek sports cats come in 200 and 100 cell varieties so this gives you an idea of how unrestrictive the OEM main cats are (i.e. they are the same as one of the Milltek Sports cat options). The only downside is that your car might be a little more smokey for the first couple of minutes when cold.

Manifold flaps don't really do much but are a common failure point. When they fail they will throw an error on the dash. A lot of people have them removed when the head is off for a carbon clean and mapped out to save them getting the error a later date and having to take the head off again.
My car has has the milltek decat pipes and I noticed the bit more smoke coming out but I take it this is fairly normal on these running no cats then?

Fatneck73
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Re: Stage 1/2

Post by Fatneck73 » Fri May 10, 2019 9:21 pm

What sort of increase would you expect from a 1 or 2?

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WRS4
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Re: Stage 1/2

Post by WRS4 » Mon Jun 10, 2019 4:13 pm

I defiantly have more smoke since the stage 2/de catt was under taken but usually only when cold, once its warmed up the smoke is not too bad at all but I am led to believe these cars do burn a bit more oil than standard cars anyway. As for power increase I think I gained approx. 52 extra bhp on a stage 2 but its been 2 years now so it may have been a bit more or bit less cant actually remember exact figures.
Sprint Blue RS4 - 20" X 10J 3DSM Wheels - Carbon Front Splitter - Carbon Rear Diffuser - H & R Anti Roll Bars - Bilstein Adjustable Shocks - Milltek Exhaust System - De Catted - Valve Removed - MRC Stage 2 Re-Map - 480 bhp

welwynnick
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Re: Stage 1/2

Post by welwynnick » Wed Jun 19, 2019 5:07 pm

MikeFish wrote:
Mon Aug 27, 2018 9:00 pm
Pre-cat delete is one of few ways of adding power to this engine (short of spending £15k on a supercharger). The increase isn't huge but it is the most restrictive part of the exhaust and serves no real purpose. And it still leaves your car MOT compliant. The purpose of it is that manufacturers have to have low emissions from start up, and initially the main cats are not very effective when cold so the pore-cat does its bit to keep emissions down until the main cats are warm. MOT only measures emissions when the engine is at normal operating temp so not affected.
Deleting the pre-cats seems to be a popular option, but there's a popular misconception about why we can get away with it.

Modern 3-way catalysts work in two sequential stages - reduction and oxidation.

Reduction means converting oxides of nitrogen (NOx) to nitrogen (N2) and oxygen (O2), and oxidation means converting carbon monoxide (CO) and unburnt hydrocarbons (HC) to carbon dioxide (CO2) and water (H2O).

The reduction catalyst comes first, and is not required for the MoT because NOx are not tested.

The oxidation catalyst comes second, and it IS required for the MoT because CO and HC are tested.

Therefore if you remove the first catalyst, you'll still pass the MoT, but your car will generate NOx pollution.

That's the real reason why there are two catalysts (though some cars do have them combined in one case, and then they have a lambda sensor in the middle).

Nick

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