Polo GTI Intercooler Advice

[h100vw]

Vr6 mk3 golf is the wrong maf. Needs to be the early s3 or tt

[Stein]

That's fantastic, I'll see if I can grab one from the S3 I got the brakes off.

Is there anything else useful that I should try and grab while I'm at it?

Vr6 mk3 golf is the wrong maf. Needs to be the early s3 or tt

[sambb]

the K04 turbo, exhaust mani, and oil/water lines, injectors and fuel pump and then you can have S3/TT power in your polo from the word go!!

[Stein]

I was under the impression the manifold from an S3 isn't suitable because of the longitudinal engine layout?

the K04 turbo, exhaust mani, and oil/water lines, injectors and fuel pump and then you can have S3/TT power in your polo from the word go!!

[sambb]

no the early S3 with the 1.8T is a transverse engine just like ours. It has the BAM designation (ours is BJX). So the S3 exhaust mani, oil/water lines for the K04's CHRA and injectors and fuel pump will all swap straight into our car. The K04 will obviously bolt straight onto the mani - only snag is you will need a slightly different dump pipe made than you would for a K03, the K03 is a down exit from the turbo but the K04 is a side (towards drivers side) exit. No big deal, each would be most likely custom made anyway its just that its different. Also the normal Forge style TIP you would buy for the K03 wont fit as the K04 has a bigger compressor inlet. Most guys just make one out of the appropriate sized 90 degree silicon pipe from super cheap running up into a joiner section of aluminium and then into another 90 degree silicon pipe that mate s up with the 3in S3 MAF housing. Or you can buy a couple of china knock off TIP's for K04's and K03's and mixed in with the right sized joiner find a good combination of the inlet and exit diameters you need and all the right take off points for DV and PRV etc. Again straightforward, just a little different to K03, not as plug and play but will work. Some guys on here have made there own aluminium hard pipe top section TIP's for K04 compressor housings.
All you then need is an S3/TT type file to run what is essentially S3/TT hardware but with a dump pipe. Stock S3/TT mk 1 is 225hp (versus our 150hp) so with the dump and an appropriate tune you are obviously looking at a much more solid setup than a K03s stg 2. In the light Polo body you are looking at a seriously rapid little sled. There are a million ways to skin a cat but thats the 'mimic the S3/TT' solution for a Polo 9N3 Gti that uses all factory parts, made for the same engine (more or less), except for the additional benefits the dump will give - has to be a dump as the stock S3/TT dump wont work in our different engine bay/firewall/crossmember arrangement.

[Grant]

Isn't there an issue with the S3/TT turbo exhaust side interfering with the ABS module in RHD cars?

Sent from my LM-Q610.FG using Tapatalk

[sambb]

The mani interfering or the turbo? The abs module is passenger side of engine bay below/ behind the air box. It's on the opposite side of the engine bay to the master cylinder. The dump that would come off the turbo aims itself towards the master cylinder so it wouldn't be a problem in that respect.

[Grant]

I was reading it here but maybe they're referring to LHD cars.

K04 Turbo - UK-POLOS.NET - THE VW Polo Forum

Sent from my LM-Q610.FG using Tapatalk

[sambb]

looking at your engine bay, the comp housing will be on the right above the ABS module, the exhaust housing will be on the left - same as K03s. Its just that the K03s housing curves downward whereas the K04 one sits sideways so its the dump itself that needs to curve downward. There are lots of K04's, transverse longitudinal, ones where the exhaust itself is a continuous piece with the exhaust housing etc etc. I believe K04-022 or K04-023 is the transverse S3/TT one.
Seperately there is also a K04-001. That was something ECS tuning dreamt up I believe. It is packaged in a K03 turbo basically. It uses a K04 compressor housing, yet uses a compressor wheel smaller than our K03s, maybe a basic golf mk 4's smaller comp wheel? But the exhaust housing, while still our downward facing one houses a K04 exhaust wheel (maybe the one out of a K04-022/23?). It is entirely plug and play. If you want a proper one get it off ECS tuning in the states. Don't think that something advertised as K04-001 is the legit ECS made one as the Chinese are ripping them mercilessly.
K04-001 will hold boost longer giving more use after the midrange hump the tuned K03s gives us. But being a smaller compressor wheel still doesn't move a big amount of air so isn't going to turn what a proper K04-023 can. The K04-022/23 has a bigger exhaust wheel and a bigger comp wheel and the housings around them are bigger so are more efficient at air in/air out. Therefore it has an extended top end and pushes more air overall so will make more real power and will do it with cooler inlet temps because it will be more in its efficiency range when its doing its thing.
So in power order above our K03s go K04-001. Step above that would be borg warner K04-022/23. Step above that would be a hybrid K03 (small frame yes, but they bung big wheels in them). Step above that would be a K04 hybrid. Anywhere along that line you could ditch K0 turbos altogether a go Garret, IHI etc. If you want virtual plug and play then K04-001 (it says K04 but its still a K03 frame) or K03 hybrid eg, custom, BBT, TTE, Franken F21 etc. If you want to mildly stuff around but still run factory gear then K04-022/23 or K04 hybrid eg BBT, TTE, franken F23 etc. If you want to change absolutely everything inc lines, mani, turbo, dump, inlet angles etc etc then go Garret kits etc.

[simon k]

argh, too many numbers...

If you want a proper one get it off ECS tuning in the states. Don't think that something advertised as K04-001 is the legit ECS made one as the Chinese are ripping them mercilessly.

exhibit A ?

K04 K04-001 for VW Audi 1.8T Turbocharger Turbo Charger K03 Upgrade Replacement 6941324411490 | eBay

[Grant]

Thanks for that explanation, Sam.

Sent from my LM-Q610.FG using Tapatalk

[seangti]

I'm running an ebay sourced k04-001 and have been for nearly 4yrs I reckon. Had a conservative tune done and running a forge wastegate actuator instead of the supplied one.

It's been fine and done more track miles than most polo's will do in a lifetime. Realistically, in my current state of tune it's making marginally more than a maxed out k03s, dare I say I'd be around the 150kwatw at 17psi boost. I was having a few dramas with the car back in the day and this was a temporary fix to get me running and setting up the rest of the car. If it fails, I'd probably just replace with another to save retuning. But yeah, a high power turbo these are not.

[sambb]

oh ok I didn't realise your was a K04-001 Sean. I thought it was a bit more of a bigger K03 hybrid.

[seangti]

oh ok I didn't realise your was a K04-001 Sean. I thought it was a bit more of a bigger K03 hybrid.

The car originally had a k03 hybrid, but it failed (for a 2nd time) and the builder couldn't explain why it kept failing. Gavin also had his fail twice if I recall correctly. Yet my ebay turbo has lasted longer and been faultless.. touch wood. I'd otherwise have gone back to k03s at the time cos I wasn't overly bothered with power.

[h100vw]

K04-023 will fit with a change of downpipe. Done in the uk. It's also bigger than a -001 in respect to power output. For something over a k03s, a decision needs to be made on budget as rods come into tje equation if you go too big.
As we know traction is a big hurdle too. Given my time over I reckon a bbt k280 would do the vast majority of what I need without opening the engine.