Polo 9n 1.6 n/a project

[NachoBides]

Hello, my name is Thanasis. I'm the owner of a polo 9n 1.4 bby 75hp.


Right now I'm proceeding with my project. The plan as of now is:

1. aub complete head (Reprofiled oem or aftermarket cams. Looking for options except dbilas 252-10)
2. 1.6 pistons, rods, crankshaft
3. aub intake manifold ( I would like to have an aftermarket one, but the only one I can find is from dbilas and it's really expensive. If you have any suggestions they are welcome!)
4. aub injectors
5. aub throttle body (I've found a slightly bigger vdo throttle body that is p&p, so I might use this)
6. BMC CDA airbox
7. R8 coils
8. 4-2-1 exhaust manifold
9. 55mm exhaust

I would be glad if someone could guide me, or link a topic that can be helpful. I'm looking forward to your responses! Stay safe!

[Sydneykid]

You are going to spend a lot of money for not a lot of gain. If you don't have any particular reason for sticking N/A then I'd suggest you consider buying a front half of a turbo model and swapping over the mechanicals. A better result in the end, with much more scope for development, at a lower cost.

Cheers
Gary

[sambb]

I don't know much about that engine eg whether it has a street tuners/motorsport sort of capability. I'm assuming the head you're looking to run is DOHC. If not then are you sure its going to be capable of flowing the required air even with cams/valve work/porting to be able to make good relative power for the dollars you'll spend to try? Not knocking your idea - a mate of mine runs a Renault fuego 3 valve per cylinder head, spark plug in the wrong spot, weird combustion chamber - emissions era car and with A LOT of work got it revving to 9000rpm and making 150hp atw and it is a really fun car. It took him a over a year and triple his budget and a standard 2.0L SR20 would still probably beat it because its not cammed to rev to the heavens to achieve the same power figure.
If you had your heart set on NA then even a 1.8T high comp'd with a pair of cams and nothing else would work better for less $ and you know it and a box will fit.

[NachoBides]

Thanks for the replies! Appreciate all the opinions. I know a 1.8t conversion would be more logical and has better results for further development.

Thing is that with this setup the car is going to be ~150hp (seen dyno and drove car with same setup), with room for improvements. I bought everything I need for 600 euros. Checked head (valve stems, guides, seats, lifters etc.) as well as all the parts and they are in great condition. A 1.8t complete swap would cost me at least 2500euros + labour to get it on the car, with an engine and gearbox of unknown condition that may need to be rebuilt soon.

My plan is quite solid as it is and I know I will be happy with the results. What I'm looking for is the details that can make a difference.

Cheers

[sambb]

Hey just out of curiosity is that 1.4 block the same family of block as the 1.2TSI and CAVE 1.4TFSI twin charger. If so you might have DOHC options?

[NachoBides]

1.2 tsi is completely different. 1.4 tsi has the same bore and stroke (76.5x75.6) as well as other similarities, but the head I'm using is already DOHC and one of the best flowing as well. So there isnt something I could use from this engine for N/A application.

[sambb]

oh ok so it is DOHC. Wasn't sure - I thought it was a single cam. Well I for one will be very keen to see how the build goes. If you don't run this as a build thread on this site, please pass on a link to wherever else you may blog it.
Sorry I dont have more to offer. If it was me I'd be paying a lot of attention to diff/gear ratios, keeping the rotating weight crank, flywheel, wheels, brakes package) as light as possible as well as the pulling weight out of the car itself.
The intake you mentioned is that a single throttle body?
What we can definitely help you with here is 9N chassis setup for when you have the engine sorted.
What is it wit the Greek scene - you guys do some really cool stuff over there.

[NachoBides]

I will keep this thread updated. My gearbox is not the original, I'm using a shorter ratio from the 1.2 version. You can see the ratios here:


The stock ones:


Intake manifold is a single throttle body one, but has bigger ports and plenum than the stock one. Here are some comparison photos:







Also stock throttle body(45mm) and the bigger one(54mm). The one from renault megane is even bigger(59mm). I will upload a comparison photo of the 3 throttle bodies when I have one.:


In the greek scene we have a polo 9n3 gti, which is one of the fastest fwd (if not the fastest) in its category. Here is a video of it with the old setup. Right now it is almost 900hp.
[YOUTUBE]Y3FNW54VuYc&t[/YOUTUBE]

[simon k]

yep, sounds like we'll learn more from your build than you can learn from us... twiddling numbers and fitting bigger turbos is the cheaters way of making power

I've seen that video you posted before - that car is crazy

[NachoBides]

yep, sounds like we'll learn more from your build than you can learn from us... twiddling numbers and fitting bigger turbos is the cheaters way of making power

I've seen that video you posted before - that car is crazy

It's a joy for me to share experiences with other people. Also I know I could just buy a gti and build from there following the numerous guides for 1.8t but for me building something different is what makes me happy and keeps me learning. I don't have big expectations, I know where I'm going. I know I will be happy with the result, as I am attached emotionally to this car with this engine. Either way 150hp for reasonable money in a car which weights sub 1000kg with some simple weight reduction (removing spare wheel and rear seats- 5 minute job) can be really fun.

[NachoBides]

Some updates for those interested. Regarding the intake manifolds, I've found that the ones from the 6n/6n2/lupo gti with engine codes AVY/ARC are the best flowing among the OEM options.



VS the 1.4 aub one I'm using right now.



I need to get one from the gti in hands to compare it, apparently for some reasons its flowing a bit more than mine. Fortunately there is a friendly spare shop in my hometown, so when I get there I will visit it.
Now regarding aftermarket ones there aren't many options obviously. The most popular is the one from dbilas, which is tested and is flowing quite well.

Flowtec Saugrohr VW, Seat, Skoda 1,4 16V mit 74kW - dbilas dynamic
Quite expensive at 800euros, I'm not willing to dispose that kind of money. If only I could find a used one.

Another option is one from a greek fabricator, used in Greece in various setups both N/A and turbo. It's also tested with good results. Reading older topics in a greek forum, the price was around 450 euros. If I'm not mistaken this is the correct photo.


I also found this one on youtube with the brand name Auto Art. It looks similar to the above one. But I couldn't find any further info. Go to 0:20 and you will see it.
[YOUTUBE]Qs02fzljvVY&t[/YOUTUBE]

This one comes from Vw Motorsport Polo 9n S1600, but I think it was never available for the public.

http://www.vwmotorsport.com/vwpics/Images/9polo%20s1600%20ii%20engine.jpg

This one also from a greek Polo 6n2 S1600



The cheapest option is ofcourse the OEM 1.6 gti manifold. I can exchange my aub one for it, in case I won't find a reasonably priced or a used aftermarket. More updates regarding the head and bottom end coming soon.

[sambb]

As well as flow you need to consider the correct runner lengths that will mesh with your chosen cams rev range. ie the length from plenum wall through the runner to the back of the intake valve matters big time if resonant pulse tuning will work or not. From watching mates engines go together I know the builders spent lots of time on calculating all that kind of stuff before selecting (or making) the intakes.

[NachoBides]

Solid advice! That's the reason I'm trying to discover all the available options and find the best for my target, always listening to the advice of my tuner and mechanic.
If I'm not mistaken, shorter length runners help for better results on high rpms and longer ones give better response down low. If you look on the photos above the 1.6 gti manifold has shorter runners than the aub I have. That's the reason it gives better results in cars with aftermarket cams and mods that help them rev higher.

[sambb]

I'll be keen to see how it plays out. A mate of mine with a Renault Clio RS w172 went through what you are doing now. His cam wasn't big enough (we do sprints and hillcimbs not circuit stuff so much) for quad throttle bodies, so he tried all the different Renault sport iterations of each NA inlet and also some apparently aweosme aftermarket carbon trumpet ones as well. The impact they had on the car was enormous forcing cross the board timing and fuel changes. For the cam he had ( a W182 clio inlet) the Renault sport long runner beat all the aftermarket ones and still had the best top end? Results were sometimes counter intuitive so like you are doing you need to consider everything. He's changing to a W182 head now (same cams) and because they have different inlet port angles/lengths they are going through it all again re intake selection - incidently they've modded the megane 59mm throttle body you showed and taken it out to 60mm with new internals.
Same was true of the exhaust too. The supposed better 4-2-1 extractors weren't as good as the 4-1 that everyone said to get rid of. The calcs said go with 4-1 and they did. On inspection they found that the union of the 4 pipes at the collector didn't have one of those spear head pulse guides things and the mech didn't like the angle at which they arrived into the collector. So they cut the collector open, welded a pulse guide in and made the preferred extractors even better.
Have you seen the tissue paper test of extractors that you do with compressed air? - our mechanic guy demonstrated a bad set of aftermarket extractors versus a good set of OE ones. You place a tissue covering the extractor port of what would be the next cylinder in the firing order ie the one that would pulse down to the collector next. You then give a little burst of compressed air down the extractor port that would fire before it. If on that burst the tissue over the other port gets sucked straight down and flies out the main pipe then collector scavenging/timing is decent and back pressure isn't bad. They did it on some bad extractors and the tissue would fly off into the air in the opposite direction = back pressure at the collector etc etc and other likely problems. Its a non scientific but apparently a very easy way to quickly weed out what is utter crap and what might be designed well enough to consider further. could help

[sambb]

Here's the pulse guide they made to enhance what was already there before welding it back up again. Last pic is with it all back together looking into the end of the collector.