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Discussion Starter · #1 ·
I've produced this write up to answer some of the myths surrounding TIP's for the 1.8T. Please note the install section is provided as-is and I take no responsibility for any problems you may have as a result of following it. Like me, if you have any doubts about fitting the Forge TIP yourself, please seek the advice of a professional. In this case I chose Awesome GTI to fit the part.

Enough with the disclaimer - lets crack on.

The Turbo Inlet Pipe (or TIP as it?s known on the scene) is what connects the air box to the Turbo Inlet (yes, you guessed it, it's a pipe!). The standard stock pipe is a two piece item. The upper section is made of rubber, with ribbed sections to provide flex during engine movement. The lower section is metal, and is 'L' shaped (also called elbow due to its shape) providing a bend around some of the coolant and other piping. It's this bend that produces the biggest problem with the stock TIP and is the main reason why air intake can be so restrictive. Performance wise, the stock TIP can shift around 150 - 160 g/s (Air flow measured in grams per second). This is based on remapped figures; in standard guise expect that figure to around 130 g/s.

There are a few aftermarket solutions available to get around the issue of the standard TIP being restrictive. Early on in the 1.8T's life some companies chose to replace just the 'L' shaped section of the TIP, using a larger bore inlet. Of course space was restricted so the inlet could never be large enough. Plus with the pipe being made of metal it did complicate things further.

The other main alternative is Silicon piping. This is better suited all round, due mainly to being flexible and heat resistant. It can also have a larger bore and flow capacity due to thinner wall construction and flexibility. All in all it's the obvious choice, really!

With this in mind I chose to go for Silicon based TIP. There were a few different variations around, but I chose to go for the Forge Motorsport TIP due to its superior construction and ready availability.

Install.
The following is a brief install. It shouldn't be used as a defacto guide. If in doubt seek the help of a pro....

Car being prep'd:



Old TIP removal:





With the stock TIP removed a placed beside the Forge item, we can see the difference in neck size:



Forge TIP nearly installed - just the bracket bolt to install. This proved to be the most difficult part to screw back in! :



All done:



More images can be seen here

Graphs.
To show the comparison between the two TIP's, I took a handy bit of advice from Doug @ MRC Tuning. By using VAG COM to log block 003 to record Air Flow, I could measure both TIP's and compare differences. It did prove difficult to try the various runs using different gears, and after playing a little I settled on 5th gear as it did produce a longer, more readable, curve for plotting. The following are the results I found.

Stock TIP - 5th Gear run (duration around 15 seconds)



Performance wise, the stock TIP is peaking at around 159 g/s. The graph above shows the peak at around 5100 RPM. This is to be expected and was consistent over numerous runs.

Now let?s look at the graph for the Forge TIP.

Forge Motorport TIP - 5th Gear run (duration around 14 seconds)



We're now seeing an increased, smoother, flow rate, that now peaks at approx 179.5 g/s, much higher in the rev range. This has been verified over a couple of runs. Also spool up and power delivery are noticeably improved. Result!

Conclusion.
Well the figures speak for themselves. Apart from the problem of hesitation I have during early acceleration, peak air flow through the uprated Forge TIP is up by around 18-20 g/s or, an average of 10-15% over the stock TIP. This is certainly felt during acceleration, with top end performance certainly being improved. Delivery even feels smoother, which is echoed in the graph above. It's amazing just how much difference changing the restrictive TIP can make. I would certainly recommend this to all 1.8T owners, both stock and remapped, as it will provide a noticeable gain.

Links and acknowledgements.
Massive thanks to Forge Motorsport for their speedy service in getting their TIP to me. Top service as usual! Also massive thanks to Awesome GTI, in particular, Mark and John, for fitting the TIP and allowing me to document the install - hope I didn't in the way too much.

www.forgemotorsport.co.uk
www.awesome-gti.co.uk
 

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I didn't think you would be disappointed! But I have to ask something about the graphs.. How is plotting airflow against time useful? Surely airflow and rpm's would have been better? As you cant really compare the 6 second mark (for example) with 6 seconds on the other graph, as the rpm's could have been entirely different? Or maybe you have some reason for this? Either way, the gains are there to be seen! (And felt)

Also, im curious, what did you notice sound wise?

Oh, and I too noticed that performance was smoother. Picks up noticeably better, even at part throttle.
 

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Discussion Starter · #3 ·
Good call Paul, changed the graphs above. I was in a rush to get the info up so decided to plot time against air flow as knowing both runs were done using the same gear, starting the at the same speed, they should of been similar. Fist time I've done comparisons like these so I'm on a learning curve lol! [$]

The sound has changed slightly, spooling sounds quicker and sharper? (if thats a way to describe it)
 

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now that you've plotted it against RPM the forge TIP doesnt really seem to be much of an improvement? If you compare the 2 graphs like for like on RPM its pretty similar, the forge looks better top end cos the stock TIP graph ends too soon...
 

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Mark,

Good writup.

Your car could be pinging due to too much boost(the spike and drop in airflow could be becasue of that), and that is causing the hesitation.

Log boost and block 20 and we'll see what it is doing.

I'll get my logs to show with and without the forge TIP this week - and a home modified TIP.

Doug
 

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i thought that the standard tip on a aum is not as restrictive due to
vw changing them?? i was looking in to getting one until some one told
me that its not worth it. is it really worth it as i would be
interested in getting one of these?! cheers

myk3
 

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i thought that the standard tip on a aum is not as restrictive due to vw changing them?? i was looking in to getting one until some one told me that its not worth it. is it really worth it as i would be interested in getting one of these?! cheers
myk3
They might not be as restrictive but they still get sucked closed - anything over 210bhp ish and you get an improvement by changing or modifying the TIP - especially in high gears, high revs.

Run your car so it is upto temp, and then put your hand round the standard intake hose and feel how soft the rubber is.

Some aftermarket intake kits (especially some with small bore cold air feeds) can make the problem worse due to more of a restiction before the hose.
 

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Just looking at the plots again - you are getting similar ish air flow at the same revs - but it would be interesting to see the 5000+prm plots of the original hose - if the flow goes flat or even drops sharply - that is when you collapse the hose - and the car feels like it doesn't want to pull - that is really bad for the turbo!
 

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Discussion Starter · #13 ·
It could have an equivelent internal flow capacity, similar to the Silicon TIP, as it is wider at the neck but, I'm definitely seeing a performance gain with this TIP over the stock item.

It would be interesting to see what Doug's figures are like to compare.
 

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I don't see how this bend can't be restrictive!?
Me neither, I didnt feel any difference in performance when changing from my stock TIP to my Samco TIP.

I should have listened to Wilko as he advised me it was a waste of money changing.

It was a whole different ball game with the older very restrictive non-dbw TIPS.
 

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I don't see how this bend can't be restrictive!?
Me neither, I didnt feel any difference in performance when changing from my stock TIP to my Samco TIP.
I should have listened to Wilko as he advised me it was a waste of money changing.

It was a whole different ball game with the older very restrictive non-dbw TIPS.
this is what i was told, think ill save my money then.
 

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I don't see how this bend can't be restrictive!?
Me neither, I didnt feel any difference in performance when changing from my stock TIP to my Samco TIP.
I should have listened to Wilko as he advised me it was a waste of money changing.

It was a whole different ball game with the older very restrictive non-dbw TIPS.
Gary.

I saw no difference in logged boost levels or peak airflow with the samco silicon tip.

But tabs logs show that the forge one on his car has seen a worthwhile gain.

The bend on the forge one looks futher from the turbo inlet, and the whole thing looks larger in diameter.
 

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I can't see a difference here, Mark only took the plot of the Stock TIP
to 5Krpm (Forge to 6.5Krpm) and saw VERY similar figures so why can't
we assume that figures over 5Krpm wouldnt be the same as the Forge TIP?

Approximate figures from above graphs taken after the hesitation spot.

Stock TIP

3500 - 120

4000 - 124

4500 - 142

5000 - 158

Forge TIP

3500 - 119

4000 - 124

4500 - 140

5000 - 159

5500 - 170

6000 - 176

6500 - 177
 
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