Air flow improvement

[porkopops]

All,

I have a FL 2017 RS3 with APR St2 maps, intercooler, milltek exhaust, forge turbo inlet pipe, hard pipe, a standard air box and intake with a K&N panel filter. But I'd like to improve on the airflow as it seems the weak point. But seeing as I've already dropped a lot of cash on the motor already and going on the cost of replacement intakes, which seem overly expensive, I doubt I'll be going down that route.

Would cone filters be a better alternative to the standard-ish setup that I have or are there other options?

Thanks

 

[8YARWY]

All,

I have a FL 2017 RS3 with APR St2 maps, intercooler, milltek exhaust, forge turbo inlet pipe, hard pipe, a standard air box and intake with a K&N panel filter. But I'd like to improve on the airflow as it seems the weak point. But seeing as I've already dropped a lot of cash on the motor already and going on the cost of replacement intakes, which seem overly expensive, I doubt I'll be going down that route.

Would cone filters be a better alternative to the standard-ish setup that I have or are there other options?

Thanks

I’m stage 2 and have been told my biggest restriction is the 3” Unitronic elbow .
The car is running out of puff in the higher gears
I believe Eventuri have launched a 4” Elbow for the RHD RS3 now so I may try that along with a D/P.


Sent from my iPhone using Tapatalk

 

[porkopops]

Cheers. Do you have a standard intake setup? I think that the hard pipe/turbo inlet pipes on mine are 3.5" but I may be wrong.

 

[CHRS3]

All,

I have a FL 2017 RS3 with APR St2 maps, intercooler, milltek exhaust, forge turbo inlet pipe, hard pipe, a standard air box and intake with a K&N panel filter. But I'd like to improve on the airflow as it seems the weak point. But seeing as I've already dropped a lot of cash on the motor already and going on the cost of replacement intakes, which seem overly expensive, I doubt I'll be going down that route.

Would cone filters be a better alternative to the standard-ish setup that I have or are there other options?

Thanks

Can I ask what makes you think your airflow is a weak point?

If you compare your dyno graph of your stage 2 map to a few others and you’re making roughly the same torque and HP output with a smooth curve then chances are your airflow is fine. If you’ve changed the turbo elbow and inlet pipe already then you should be good. If you can get a 4” inlet pipe to suit the standard air box I would go down that route but unsure if this is possible without a full intake as you’ll reduce back down at the air box outlet anyway, so will make very little difference.

These cars don’t run MAF sensors so you’re only sucking as much air as the turbo lets you, the only thing you can do is reduce the restrictions in place to allow for a quicker spool and better flow of air. Most of these fancy intakes offer very little gain over what you’ve currently got other that aesthetics and noise, the main gain is that they mostly widen up the inlet pipe and intake point to 4” allowing for a better flow. Most of them are carbon fibre as well which allows less heat soak in the material for a cooler air. The main intake which actually has proven gains is eventuri and this is mostly down to the venturi effect of the intake hence the name, but to get the intake and the turbo elbow to suit is around £2000 .

Unless you’re planning on upgrading the turbo and going for stage 3, investing in one of those intakes would see very little gain buddy.

 

[porkopops]

Thanks CHRS3. My concern is the power output which is not what I had expected (497bhp/485ftlb). I was expecting more seeing as I've seen people report 460hbp on Stg1's. So I'm searching for an explanation tbh, but maybe 497bhp is expected. The airflow is where I skimped (in not going for the expensive intake), so I was simply guessing that this may be the cause.
I'm not sure where people share their dyno charts, but I've attached mine in case anyone can see anything obvious and offer some advice which would be appreciated. One key point is that it was dyno'd on one of the hot days that we had in the UK this year, albeit at 0830am, nevertheless it was still warm at that time.
I've checked my car and the hard pipe and turbo inlet pipes are both 3.5". It looks like the air box exit is also 3.5" as there are isn't a 4" to 3.5" convertor I can see. It sounds like ditching the whole air box and replacing with a cone filter on the hard pipe is a waste of time.

 

[8YARWY]

Cheers. Do you have a standard intake setup? I think that the hard pipe/turbo inlet pipes on mine are 3.5" but I may be wrong.

Forge inlet is indeed 3.5”.

As already said above, the less restriction you have the better the flow, there is a 4” elbow / intake system available, however they aren’t cheap and you’ll have to have your mapping tweaked to take advantage of the increased flow.


Sent from my iPhone using Tapatalk

 

[Count Drunkula]

Forge inlet is indeed 3.5”.

As already said above, the less restriction you have the better the flow, there is a 4” elbow / intake system available, however they aren’t cheap and you’ll have to have your mapping tweaked to take advantage of the increased flow.


Sent from my iPhone using Tapatalk

I've had my eye on a 3" unitronic inlet and forge hard pipe combo in preparation for MRC stage 1 around the end of April.

The Forge inlet is a fair bit less cash so would it be a more sensible choice?

I was leaning in the unitronic direction as I thought the cast material would allow less heat soak than the silicone forge setup

 

[8YARWY]

I've had my eye on a 3" unitronic inlet and forge hard pipe combo in preparation for MRC stage 1 around the end of April.

The Forge inlet is a fair bit less cash so would it be a more sensible choice?

I was leaning in the unitronic direction as I thought the cast material would allow less heat soak than the silicone forge setup

I like the Unitronic elbow but a lot do seem to fit the Forge 3.5”
Just be aware space is very tight once it’s fitted, some do report vibration through the pedals too.


Sent from my iPhone using Tapatalk

 

[CHRS3]

Thanks CHRS3. My concern is the power output which is not what I had expected (497bhp/485ftlb). I was expecting more seeing as I've seen people report 460hbp on Stg1's. So I'm searching for an explanation tbh, but maybe 497bhp is expected. The airflow is where I skimped (in not going for the expensive intake), so I was simply guessing that this may be the cause.
I'm not sure where people share their dyno charts, but I've attached mine in case anyone can see anything obvious and offer some advice which would be appreciated. One key point is that it was dyno'd on one of the hot days that we had in the UK this year, albeit at 0830am, nevertheless it was still warm at that time.
I've checked my car and the hard pipe and turbo inlet pipes are both 3.5". It looks like the air box exit is also 3.5" as there are isn't a 4" to 3.5" convertor I can see. It sounds like ditching the whole air box and replacing with a cone filter on the hard pipe is a waste of time.

I’ve done some research and your figures are absolutely spot on for the modifications listed. Even MCR custom maps are putting out pretty much the exact same figures as what you’ve stated with the same modifications. I just want to point out that 1. APR are generic maps so react differently to everyone’s car and 2. The figures they show are with all their own hardware including their full 4” carbon intake and matching turbo elbow to suit. The HP gains they quote include running cars on octane booster etc and even race fuel, so when they say ‘90-150’ HP gain this just includes all spectrums of fuelling and modifications available as everyone will make different power. A full intake is not needed, however will compliment the map and I then give slightly better gains.

If you do change the intake for something BETTER, you do not need to get the car mapped again, as I said above there is no MAF so the car will only provide the air needed quicker as nothing in the intake system to the turbo is calibrated when remapped. If you went back to whole standard intake and elbow then yes, the map would need changed as it won’t keep up with the airflow demand.

If I was you I wouldn’t go chasing figures, especially horsepower figures. Your torque (power) is absolutely spot on and your graph looks fine, yes there’s a few spikes but this is down to the fact of a generic flashed on map and will not be noticeable in day to day driving for how little they are. If you did change the intake and chase figures you’d find yourself disappointed in the 10-20hp difference as it would be barely noticeable, a simple 5degree drop in ambient temperature could see that HP difference.

Also, take dyno figures with a pinch of salt. You could try 5 different brands of dyno and your car would never make the same power on each one.

Personally I think your car has made great power, in colder weather it would be well above 500HP, and unless you’re going to a drag strip you won’t really notice any gain from an intake. However if you are chasing figures then a simple cone filter would not cut it, it would have to be a full 4” intake etc. If you do want to be in the 5** hp club, just go get your car dynod on a cold day mate it’ll easily do it.

Hope this helps.

 

[Count Drunkula]

I like the Unitronic elbow but a lot do seem to fit the Forge 3.5”
Just be aware space is very tight once it’s fitted, some do report vibration through the pedals too.


Sent from my iPhone using Tapatalk

Guessing that the forge inlet won't have the same small amount of adjustability the unitronic inlet does.

I've got an 034 motorsport billet upper and lower dogbone insert to fit to alleviate some of the movement to minimise the chance of vibration

 

[8YARWY]

Guessing that the forge inlet won't have the same small amount of adjustability the unitronic inlet does.

I've got an 034 motorsport billet upper and lower dogbone insert to fit to alleviate some of the movement to minimise the chance of vibration

I don’t have an issue with the 3” Unitronic.
Same here with the upper / lower dogbone inserts, as the engine will rock back quite a bit when you hit that pedal.


Sent from my iPhone using Tapatalk

 

[porkopops]

I’ve done some research and your figures are absolutely spot on for the modifications listed. Even MCR custom maps are putting out pretty much the exact same figures as what you’ve stated with the same modifications. I just want to point out that 1. APR are generic maps so react differently to everyone’s car and 2. The figures they show are with all their own hardware including their full 4” carbon intake and matching turbo elbow to suit. The HP gains they quote include running cars on octane booster etc and even race fuel, so when they say ‘90-150’ HP gain this just includes all spectrums of fuelling and modifications available as everyone will make different power. A full intake is not needed, however will compliment the map and I then give slightly better gains.

If you do change the intake for something BETTER, you do not need to get the car mapped again, as I said above there is no MAF so the car will only provide the air needed quicker as nothing in the intake system to the turbo is calibrated when remapped. If you went back to whole standard intake and elbow then yes, the map would need changed as it won’t keep up with the airflow demand.

If I was you I wouldn’t go chasing figures, especially horsepower figures. Your torque (power) is absolutely spot on and your graph looks fine, yes there’s a few spikes but this is down to the fact of a generic flashed on map and will not be noticeable in day to day driving for how little they are. If you did change the intake and chase figures you’d find yourself disappointed in the 10-20hp difference as it would be barely noticeable, a simple 5degree drop in ambient temperature could see that HP difference.

Also, take dyno figures with a pinch of salt. You could try 5 different brands of dyno and your car would never make the same power on each one.

Personally I think your car has made great power, in colder weather it would be well above 500HP, and unless you’re going to a drag strip you won’t really notice any gain from an intake. However if you are chasing figures then a simple cone filter would not cut it, it would have to be a full 4” intake etc. If you do want to be in the 5** hp club, just go get your car dynod on a cold day mate it’ll easily do it.

Hope this helps.

@CHRS3 - I really appreciate the effort you've gone to here and it certainly puts my mind at rest knowing that the figures I'm seeing are expected, so there's no problem with the car or the work done on it. Phew. Many thanks.

 

[Ross_T_Boss]

You will have a flow restriction on the stock airbox, but what you have there is a pretty good "half way house" for money vs gain.

As as has been said, take dyno figures with a pinch of salt, I've never bothered with it but run alot of logs and Dragy times which are a better "real world" viewpoint of how the car behaves on the road. A car that has stood idling for 10 mins after a fast run and heat soaked will drop a good 50hp, and running in the best weather conditions vs worst probably 20hp, so these numbers can really vary.

If you have access to logging (I use my Unitronic cable and datalogger, but have done VagCom which isn't bad albeit about 4Hz) then you can track your boost values to evaluate how much theoretical gain you have: "Charge press. ctrl", "Charge press. actual" and "Charge press. specified" makes a good graph of how hard the turbo is working vs. target boost vs. actual

So to give you an example, on Stg1 swapping the IE intake for the stock airbox and rear pipe only, dropped the "Charge press. ctrl" which was at 80% by 8 points... that is pretty significant. But, the "actual" was matching "target" and Dragy confirmed in the numbers; my best run on each setup were 1/100ths apart.

I haven't repeated that on Stg2 but I'm at 98% Charge Pressure Control (wastegate duty) and it's still about 50-100mbar below requested at the top end. So there is still a handful of horsepower on the table that I may never be able to get (even with a 4" turbo inlet - I will get hold of one and test it some day!) From the results I've seen moving from similar to yours to a full intake it's ~70mbar gain, about 10hp ish, and that was running Ethanol so as extreme as you get.

For me it was worth it, but I have really been wringing all I can out of the stock turbo, just for fun. But it's not great value if that is what you are after, you have a really good balance with your current set up.

 

[porkopops]

You will have a flow restriction on the stock airbox, but what you have there is a pretty good "half way house" for money vs gain.

As as has been said, take dyno figures with a pinch of salt, I've never bothered with it but run alot of logs and Dragy times which are a better "real world" viewpoint of how the car behaves on the road. A car that has stood idling for 10 mins after a fast run and heat soaked will drop a good 50hp, and running in the best weather conditions vs worst probably 20hp, so these numbers can really vary.

If you have access to logging (I use my Unitronic cable and datalogger, but have done VagCom which isn't bad albeit about 4Hz) then you can track your boost values to evaluate how much theoretical gain you have: "Charge press. ctrl", "Charge press. actual" and "Charge press. specified" makes a good graph of how hard the turbo is working vs. target boost vs. actual

So to give you an example, on Stg1 swapping the IE intake for the stock airbox and rear pipe only, dropped the "Charge press. ctrl" which was at 80% by 8 points... that is pretty significant. But, the "actual" was matching "target" and Dragy confirmed in the numbers; my best run on each setup were 1/100ths apart.

I haven't repeated that on Stg2 but I'm at 98% Charge Pressure Control (wastegate duty) and it's still about 50-100mbar below requested at the top end. So there is still a handful of horsepower on the table that I may never be able to get (even with a 4" turbo inlet - I will get hold of one and test it some day!) From the results I've seen moving from similar to yours to a full intake it's ~70mbar gain, about 10hp ish, and that was running Ethanol so as extreme as you get.

For me it was worth it, but I have really been wringing all I can out of the stock turbo, just for fun. But it's not great value if that is what you are after, you have a really good balance with your current set up.

Thanks Ross_T_Boss. I appreciate the detail in your reply. I think Im pretty convinced now that it's not worthwhile for me to progress this avenue of investigation and Im happy that what I have is expected. I'm very happy with the car, just in case it comes across than I'm not. I was also told that the 4" inlets don't fit onto RHD cars, so I'd be stumped even if I wanted to try.

 

[8YARWY]

Thanks Ross_T_Boss. I appreciate the detail in your reply. I think Im pretty convinced now that it's not worthwhile for me to progress this avenue of investigation and Im happy that what I have is expected. I'm very happy with the car, just in case it comes across than I'm not. I was also told that the 4" inlets don't fit onto RHD cars, so I'd be stumped even if I wanted to try.

Eventuri fits.

It’s a route I’ll be going to increase flow into the turbo.
My Tuner then will tweak my boost control once fitted.


Sent from my iPhone using Tapatalk

 

[porkopops]

Thanks T-1000. I was wondering if anyone would pick up on that. TBH I dont fully trust the tuner who gave me that feedback.

 

[RS3 FUN]

Thanks CHRS3. My concern is the power output which is not what I had expected (497bhp/485ftlb). I was expecting more seeing as I've seen people report 460hbp on Stg1's. So I'm searching for an explanation tbh, but maybe 497bhp is expected. The airflow is where I skimped (in not going for the expensive intake), so I was simply guessing that this may be the cause.
I'm not sure where people share their dyno charts, but I've attached mine in case anyone can see anything obvious and offer some advice which would be appreciated. One key point is that it was dyno'd on one of the hot days that we had in the UK this year, albeit at 0830am, nevertheless it was still warm at that time.
I've checked my car and the hard pipe and turbo inlet pipes are both 3.5". It looks like the air box exit is also 3.5" as there are isn't a 4" to 3.5" convertor I can see. It sounds like ditching the whole air box and replacing with a cone filter on the hard pipe is a waste of time.

Just for comparison my car produced 496 ps 696 nm on stage 1 map and on stage 1 with octane booster it produced 520 ps 740nm.