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Exhaust and remap

Posted: Fri Dec 18, 2015 7:13 pm
by AlanH
Evening all. Just a bit excited, going to get my milltek catback that I bought off shearermax fitted tomorrow. Then on Tuesday I'm going to Midland VW to get a REVO map put on it. Will hopefully be able to put some power figures of the before and after. I've managed to get the last slot to take advantage of the 25% discount


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Re: Exhaust and remap

Posted: Sat Dec 19, 2015 1:02 am
by blower
Nice - be interesting to see what you can get out of it :)

I've gone the APR route but their stage 1 map is so aggressive in the mid range (340nm, 1.6 bar of boost) that I have had some ignition issues (misfires) at WOT so been doing some upgrades - waiting for R8 coils and adapter plates to arrive from Greece. Although I have changed the sparks (again) for a different type and misfires look to be gone for the moment.

If you do post dyno figures, please post WHP as well as BHP - so many tuners exaggerate their BHP figures with 'corrected' values, WHP is best comparison and multiplying that by about 1.13 will give you a more realistic BHP estimate.

Re: Exhaust and remap

Posted: Sat Dec 19, 2015 1:11 am
by AlanH
I've done a bit of research, as well has having previous cars mapped too. I've read that the APR map is a little aggressive low down, whereas the REVO is s little smoother and I don't think quite as much power.
We'll wait and see.
Is it worth telling them I run it on momentum 100, performance panel, and I'd assume they'll notice the exhaust. Wonder if it'll make any difference?


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Re: Exhaust and remap

Posted: Sat Dec 19, 2015 1:43 am
by blower
The exhaust will gain you a little in the upper end, even with a stage 1 map but we are talking a few BHP here. A cat back is more about noise than performance.
A sports cat and bigger down pipe would give you the biggest gain in the upper end - but its not recommended on the stock turbo as it imbalances the oil seals (they require a bit of back pressure) and you could end up with a turbo that leaks oil.

The Revo BHP isn't quite as much as the APR - the upper ends are similar but a lot less torque in the low-mid range....but tbh its the safer option, not so much from a engine reliability point of view but just so you don't get misfires - pushing 1.6 bar boost is right on the limit of what the ignition setup can cope with.

The APR map favours boost and high fuel over less boost and leaner to get its power - this is great for keeping exhaust gas temps under control, but no good once ignition craps out.

Tesco Momentum is 99 (unless there another version I'm unaware of)...any map they put on will be a 98 ron minimum map.

Re: Exhaust and remap

Posted: Sat Dec 19, 2015 11:00 pm
by AlanH
I did mean the momentum 99. A Freudian slip with the 100.
I've had the exhaust fitted today, it's not OTT, just gives a slightly deeper burble at idle and a little more roar on acceleration, it's subtle
Looking forward to the remap on Tuesday, should be an interesting drive back.
Will I see an improvement in MPG? When I had my Audi 1.8T done I saw very good improvements with that, my GTi returned 3-4 mpg more....
What about the twin-charged?


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Re: Exhaust and remap

Posted: Sat Dec 19, 2015 11:20 pm
by blower
You will get a slight increase in mpg if you are not too heavy with the throttle - primarily because the extra torque will allow you to sit in a higher gear without changing down.

The map will probably run a bit leaner to get some of its extra power so that will improve mpg - but only slightly as most of the power increase is just from running more boost.

Re: Exhaust and remap

Posted: Sun Dec 20, 2015 4:29 pm
by AlanH
I've just re-read and I'm surprised APR even go close to 1.6bar. That's 23psi of boost. Usually remaps tend to be around 19/20psi iirc.
I'm not 100% but don't these run around 14/15psi as standard?

I've had a look at the graphs from the APR map and the torque is huge low down isn't it...


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Re: Exhaust and remap

Posted: Sun Dec 20, 2015 6:59 pm
by blower
The stock map hits 1.2 bar / 17psi of boost, which is pretty high as it is.
I believe APR were concerned about exhaust gas temperatures and hence burning exhaust valves and overstressing pistons.
To keep the temps down they ran more boost (and more fuel) to get the power, rather than just run leaner with less boost.
The K03 turbo in the twincharger packs quite a punch, unfortunately this much boost on the remap is running into an issue with ignition.

And yeah the torque in low to mid range is huge - when I hit the sweet spot on a kick down man I do feel it, car feels noticeably faster than a GTI due to that huge amount of torque low down, it's diesel levels of torque.

Re: Exhaust and remap

Posted: Mon Dec 21, 2015 12:32 pm
by AlanH
The K03 is not a big turbocharger in relative terms, but it's a big turbo to bolt such a small displacement engine. I hadn't really done my homework when I bought this car, so was surprised when you said it had a K03.
It packed a punch in my GTi, so it's definitely going to on this one.
Looking forward to getting it done tomorrow now!!!


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