Tuning my Cupra TDI (PD150) - Remap, EGR, DPF and Mufflerectomy

Soldato
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dynos mean very little. you can twiddle a few knobs and make it read whatever output you want, dont pay attention to it unless unless there is a known calibration car used for before and after runs if you want to be that specific haha
 
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MrSix, where in warwick are you from?

I got my custom decat made at Custom Chrome in Nuneaton, as I go to a dub meet in coventry which they attended, and their work looked great.

Great company, with great experience, prices and lifetime warranty (which transfers over, even when the car is sold on, which normally doesn't happen).
 
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dynos mean very little. you can twiddle a few knobs and make it read whatever output you want, dont pay attention to it unless unless there is a known calibration car used for before and after runs if you want to be that specific haha

Im talking dyno run > oil change > dyno run. No fiddling, they didn't care if they got more power, but were very surprised they did!
 
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A new paper filter is often as good as the aftermarket ones (aftermarket one in original air box, not a cone filter above the exhaust manifold!). However as I understand it, paper filters get dirty and the flow rate drops. This happens significantly less with say a K&N.

Plus the aftermarket ones can be cleaned and reused so it doesn't work out that much more expensive!
 
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A new paper filter is often as good as the aftermarket ones (aftermarket one in original air box, not a cone filter above the exhaust manifold!). However as I understand it, paper filters get dirty and the flow rate drops. This happens significantly less with say a K&N.

Plus the aftermarket ones can be cleaned and reused so it doesn't work out that much more expensive!

K&Ns dont filter anywhere near as well as paper.

its called an air filter, its function is to filter. its not worth the 0.4bhp gain.

cleaning is a ball ache. you need to purchase cleaner and oil which is dear

a new filter is £10 and you just swap it and bin the old one
 
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I run a dynatwist on my TT. I made 9bhp more than a stock airbox with pipercross filter in!

Read into that what you will. But teh dyna twist staying on at the min!

but yours is miles from standard with miles more airflow than a standard blower would flow
 
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K&Ns dont filter anywhere near as well as paper.

Dyno result on my car suggest otherwise. May be car dependant.

its called an air filter, its function is to filter. its not worth the 0.4bhp gain.

A dirty filter can have way more than a 0.4bhp impact! 5 bhp on my test between a 4,000 mile old Pipercross and a new K&N.

cleaning is a ball ache. you need to purchase cleaner and oil which is dear

And needs to be done every 30,000 miles or so?

a new filter is £10 and you just swap it and bin the old one

Changing the filter takes an hour on my car! :(
 
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Like been said, you shouldn't have a DPF, only on mk2 leon's.

I got a 1.9tdi 110 Bora (non-PD) and I got a decat (well technically not a cat, but what they call it) and it made such a difference IMO, feels freer flowing, better response, and pulls quicker.

Is it an ASV? Did you ONLY replace the cat section? I decatted mine and lost torque, somehow?!
 
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The car is going in today for the first lot of work - we'll probably manage the air filter test and mufflerectomy today and relevant power runs and then complete the EGR delete and remap on Friday.

I'll post back the results when I get them.
 
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Right then, yesterday I took the Leon down to Thor Racing in Coventry for it to be tuned.

First of all we had the standard car on the dyno (which is a hub dyno, so figures are at the wheels rather than at the engine).

The standard car made 130.7bhp and 236.9lbft at the wheels which equates to roughly 150bhp at the engine - pretty much bang on the manufacturers stated power.

We then ran the car without an air filter to replicate the very best airflow to see if fitting a high flow panel or cone filter could potentially make a difference. Over four power runs the car made identical power (within the tolerances of the dyno). Thus bringing us to the conclusion that on these PD150 engines, as standard an aftermarket filter offers absolutely no performance gains whatsoever - the only difference was a more noticeable induction note.

We then had the car back out in to the workshop and performed a "mufflerectomy" which involves cutting off the backbox just after the exhaust pipe runs over the rear beam. The backbox is then repaced with a straight 2.25" pipe and a new tip (i'm running a Cupra R style oval). We were all very surprised at how little difference in sound there was once the backbox had been removed. On startup there's now a slightly lower growl but on idle there is no audible difference between stock and no backbox - the difference comes when changing gear and you can hear a slight "chirp" from the turbo from outside the car (which I quite like). Inside the car you wouldn't be able to tell if it had been done or not and there's no droning on the motorway either at any speed or RPM.

The car was then put back on the dyno to see if the mufflerectomy had made any difference to the car's power and we were quite shocked to see that by this simple £60-£100 mod had actually made 6.2bhp at the wheels and 8.4lbft of torque. Over four more dyno runs we saw the power figure staying at a consistent 136.9bhp and 245.4lbft torque which equates to approximately 160bhp at the engine.

Now that the car was clearly breathing better, we removed the air filter again to see if an aftermarket high flow filter would make a difference. But once again the dyno results showed no gains in power. Leading us to the conclusion that the standard induction system provides sufficient airflow.

2dwbvo9.jpg


Conclusion
So all in all a very good days work having leveraged an extra 6.2 wheel BHP and 8.4lbft torque from just a simple, cheap modification. The added benefit was that I saw my average MPG increase by 6-8mpg on the motorway run home.

The next stage is remapping the car and I'll report back on Friday with the results of that.
 
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We then ran the car without an air filter to replicate the very best airflow to see if fitting a high flow panel or cone filter could potentially make a difference. Over four power runs the car made identical power (within the tolerances of the dyno). Thus bringing us to the conclusion that on these PD150 engines, as standard an aftermarket filter offers absolutely no performance gains whatsoever - the only difference was a more noticeable induction note.

i dont think that proves that at all. no air filter doesnt strictly mean "most efficient".

any form of airbox has aerodynamic characteristics, some better than others which effects power output
 
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i dont think that proves that at all. no air filter doesnt strictly mean "most efficient".

any form of airbox has aerodynamic characteristics, some better than others which effects power output

Bonnet up, airbox lid off, cold air cascading over the intake and engine bay in general. Argue all you like, but it's good enough for me to be sticking with my standard paper filter.
 
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