GTI Forge TWINtake air intake - Review....

[QD MBE]

There is only a certain amount of airflow that the intake pipework can handle, and the velocity of that airflow is entirely dependant on the Turbo's ability to effectively utilise the airflow.  Assuming there is an element of 'Ram-air' due to the forward motion of the car.

If you have a Y piece then at the point to two airflows join an area of turbulence will be present,  this will effectively stagnate the flow.  I am assuming that Forge have tested this.

The extra airflow will however have some element of cooling the whole shebang down. 

The angle of incidence of the 2 airflows will have a tremendous effect on the amount of turbulence present.  The forge is about 90 degrees between the 2 airflows, this is quite a difference in flow directions. 

Interesting.
 

....As I understand it, the 70mm piping will only flow a finite volume of air regardless of the number of filters used. Higher flowing air filters, however, provide for a reduction in effort required to draw air through them due to a decrease in flow restriction. A larger surface area through which airflow is introduced, provides for the least possible restriction in flow.

Okay, so just before this less restricted airflow has arrived at the 'Y' junction it passes through a velocity stack - Vanes moulded into the delivery end of the filter's cannister. This also has a bearing on why the Twintake orientates its cone-shaped filters the opposite way to usual practice.

Without having very in-depth discussion with Forge to explain it further, the airflow sucked in at the 'Y' doesn't suffer from stagnating. I'm told by Forge that they have thoroughly tested this and also a version with just the one forward facing filter cannister (which gave less gains).



I'm sorry if I can't be more help in answering your questions at the moment. I may be able to post some answers another day though.

Interesting.  Do you have any pics of the velocity stacks?  I am interested in understanding why and how things work.

[Janner_Sy]

So the conclusion at this stage is that the Forge TWINtake gains very similarly to the EVOMS when fitted to a K03 car, namely about +15 bhp. Logically, as the EVOMS has been seen to add about +20 bhp to a K04, one would expect the TWINtake to perform very similarly and hence matching the K04 performance of the ITG intake.

i actually thought the evoms made about 8-12bhp on a k03 from people who have had them and had their car rolling roaded.

look forward to seeing some maf readings etc.(will that increase or decrease with more or less boost??)  your fuel trim would be nice to see as well

what settings is your revo on RR for the before and after runs,

your old 245hp dyno plot you had @JKM seemed about right for a stage 2 with oem airbox, but your before dyno plot prior to fitting the twintake seems below what i would expect of  a stage 2 K03.

[jonnyc]

Susan Boyle is a bit of a fitty 

jonny what the f*** dude?
 

Well.. What can I say.. 

[RedRobin]

Interesting.  Do you have any pics of the velocity stacks?  I am interested in understanding why and how things work.

....Without dismantling a Twintake filter cannister I don't have any pics. A conventional 'velocity stack' is usually trumpet shaped (as I'm sure you know, Dave, but other readers may not) and straightens and accelerates the airflow and makes 'breathing' easier.

Here is a pic of another different stack vaned cap - The cap is shown unattached and upside down to show the vanes:-



As far as I can see, the Twintake has a curved rotary set of open ended vanes (or fixed internal ribbing) moulded into the cannister's cap at the delivery end and consequently enhances airflow characteristics. But, this doesn't necessarily answer your earlier question about the shape angles of the 'Y' junction. If I can find further info I'll post it. I do know that Forge have spent a lot of time designing and testing their TWINtake.

[RedRobin]

i actually thought the evoms made about 8-12bhp on a k03 from people who have had them and had their car rolling roaded.

....JKM have seen up to +15 bhp on a K03 and up to +20 bhp on K04 on the 2.0T FSI platform.

look forward to seeing some maf readings etc.(will that increase or decrease with more or less boost??)  your fuel trim would be nice to see as well

what settings is your revo on RR for the before and after runs,

....As previously posted, I'll post such info when known but am reliant on others with appropriately loaded laptop etc.

Revo settings info already posted in the review.

your old 245hp dyno plot you had @JKM seemed about right for a stage 2 with oem airbox, but your before dyno plot prior to fitting the twintake seems below what i would expect of  a stage 2 K03.

....Hence why no rolling-road should be entirely relied upon regarding bhp numbers. What you may "expect" and what is aren't necessarily the same. I've never seen 245 plotted anywhere on my K03 GTI while I had a oem airbox - Only with a Carbonio and also anything from 235-245 according to which Revo stage map, its settings, and conditions on the day. Superchips' Maha rollers said I was running 273 bhp on the Carbonio! (@ them, not you).

That was the whole point of this Twintake vs Carbonio dyno exercise: To see the relative gain regardless of max bhp numbers.

The result of my totally independent test on a K03 GTI was +15.5 bhp and some torque. I want to dyno my car at JKM again just to see how the plots shape up after a few hundred miles.

[QD MBE]

Thank you Robin.
 

[RobH]

Robin whats GTI backwards - enough said.

[RedRobin]

Robin whats GTI backwards - enough said.

....And your point is?

[jonnyc]

Lol, fan boy.. 

Well, the Twintake will be getting probably its biggest test shortly, as ill be using it on my BSH 3076R turbo.. Wouldn't choose anything else..

[RobH]

Ha fan boy, was just a joke, everythings getting rather serious on this forum recently so ill just leave!

[jonnyc]

Ha fan boy, was just a joke, everythings getting rather serious on this forum recently so ill just leave!

It was a joke mate! lol.. Dont be soft 

[Janner_Sy]

i actually thought that was quite amusing. Not quite as amusing as RR getting the hump there though. banter is good,

[KRL]

Great review Robin 

In JKM's experience on the K03 turbo, the EVOMS offers the greatest power increase of about 15 bhp on the K03 and closer to 20 bhp on the K04. They are somewhat unimpressed by the cheaper BSH.

Interestingly when the BSH was released about a year ago it was the same price as the EVOMS in the US and has only fairly recently gone down in price while the EVOMS has remained the same.  What was it that JKM were unimpressed by with the BSH?

[RedRobin]

^^^^
Not sure of the detail, KRL, but Jim made a face and said that he wouldn't rate the BSH as highly as either the EVOMS or VF from those he'd seen IIRC.

Generally JKM tend to prefer to stock products they think are good rather than just on price.

[RedRobin]

....

Thanks to the generosity of GTIjames (or is that jamesGTI?), I now have an EVOMS engine cover. Not fitted yet because it needs repair but looks like it will fit alongside the TWINtake, albeit with minimum clearance of the filter cannister.

Will post pics when completed with carbon centre strip attached as well.