Polo GTI Intercooler Advice

[Stein]

Hi all,

I've slowly been improving my Polo over the last year and I'm at the stage where I'm looking into intercoolers. Everyone here seems to really know what they're on about so I'd hoped to pick some brains.

Currently I have and APR Stage I tune and a custom 2.5" dump pipe with a 100CPI catalytic converter. I'm yet to do the rest of the exhaust but it's something I'm looking into.

I've found a few intercoolers that are still in production, a Forge one, an Airtec one, a HF-Series one and a Bar-Tek one.

Initially I was pretty well set on the Airtec one but after talking to Airtec I wasn't super impressed by the installation required as it takes a fair bit of modifying to fit. I'm not against that, it just seems excessive when the other intercoolers are considerably smaller and easier.

Mostly I want to know what people with experience would recommend. I'm not at all against getting something custom made up either if someone knows of a decent place that I could get this done.

Eventually I'm hoping to get a GT28RS and supporting mods so I'm hoping to get an intercooler that'll still be suitable for that application.


Thanks heaps for any help in advance.

[sambb]

Forge was a neater fit yes but has a higher pressure drop than the Seat. Treadstone do a SEAT copy but its a bar and plate rather than a tube and fin so I would recommend it for a street car over the SEAT ie a bit more heatsoak proof in traffic. The other option is to get the Audi TT/S3 passenger side feed mani and then run a single pass intercooler and have the pipework come up on the batter side - have to relocate the battery though to pull that off neatly though I think.

[Stein]

Thanks for the quick reply sambb,

The Airtec sounds like the way to go then.

I was interested in the MAP adapters that are included with some of the kits, any idea what the go is with them? The Airtec doesn't have one and I'd they're so the ECU better knows the charge temperatures. If that's the case is it worthwhile making the same change with the Airtec unit?

Forge was a neater fit yes but has a higher pressure drop than the Seat. Treadstone do a SEAT copy but its a bar and plate rather than a tube and fin so I would recommend it for a street car over the SEAT ie a bit more heatsoak proof in traffic. The other option is to get the Audi TT/S3 passenger side feed mani and then run a single pass intercooler and have the pipework come up on the batter side - have to relocate the battery though to pull that off neatly though I think.

[sambb]

The stock side mount IC had the MAP sensor mounted directly onto the outlet tank. That's not done by any of the aftermarket IC peoples so you need one of the pipes that runs between the IC exit and the throttle body to have a MAP mounting boss in it. Some manufacturers have t as part of the kit, others don't. You can source the boss's separately but you'll then need that to be welded to the pipe (in a position that the stock MAP loom/plug can reach would be easiest).
The MAP sensor is manifold air pressure. It measures boost basically. The inlet temp sensor is in the throttle body on the plenum side of the throttle plate. Its definitely needed so look into the MAP sensor mounting side of things for sure.

[Grant]

I ordered the airtec kit from RS Shop this week (they are a local airtec distributor).... PM me if you're curious what they charged me.

Sent from my LM-Q610.FG using Tapatalk

[h100vw]

If you really want a gt28 don't be going with a twin pass cooler. I have a seat sport on my polo. It's going to be hard to fit much without carving up the front end to suit it.

[Stein]

Thanks sambb, I've contacted Airtec to see if the kit does indeed come with the MAP sensor adaptor.

The stock side mount IC had the MAP sensor mounted directly onto the outlet tank. That's not done by any of the aftermarket IC peoples so you need one of the pipes that runs between the IC exit and the throttle body to have a MAP mounting boss in it. Some manufacturers have t as part of the kit, others don't. You can source the boss's separately but you'll then need that to be welded to the pipe (in a position that the stock MAP loom/plug can reach would be easiest).
The MAP sensor is manifold air pressure. It measures boost basically. The inlet temp sensor is in the throttle body on the plenum side of the throttle plate. Its definitely needed so look into the MAP sensor mounting side of things for sure.

Cheers Grant, I've sent you a PM.

I ordered the airtec kit from RS Shop this week (they are a local airtec distributor).... PM me if you're curious what they charged me.

Sent from my LM-Q610.FG using Tapatalk

Interesting. I've not yet seen the work required for a Polo specifically, I just know that their were a few "Stage III" kits floating around that included one. How does a GT28RS affect a twin pass intercooler's fitment?

It's a bit off topic but I've seen that there's K03 Hybrid turbos available like BBT's K300 that I'm now very interested in. If anyone has any info on how they go I'd love to know.

If you really want a gt28 don't be going with a twin pass cooler. I have a seat sport on my polo. It's going to be hard to fit much without carving up the front end to suit it.

[sambb]

I think Gav has one? Yeah BBT and TTE seem to be the guys doing the best K03 hybrids. Definite attraction is they are plug and play except for needing a bigger TIP to go onto the comp housing snout.
The reason for holding off on a twin pass with a Garret is that the orientation of the comp outlet lends itself more to single pass. Have a look in Louis19's build thread on about the last 10 pages and you'll see what I mean. If going K03 then double pass more suited.

[Stein]

That's fantastic, a hybrid K03 sounds like the way to go. Looks like BBE sell a larger inlet pipe so that, some injectors, maybe a fuel pressure regulator and I think I should be set.

I've gotten some brake calipers off an Audi S3 1.8T for really cheap but I'm yet to check if they'll actually fit. Anyone got an idea before I go pulling wheels off?

I think Gav has one? Yeah BBT and TTE seem to be the guys doing the best K03 hybrids. Definite attraction is they are plug and play except for needing a bigger TIP to go onto the comp housing snout.
The reason for holding off on a twin pass with a Garret is that the orientation of the comp outlet lends itself more to single pass. Have a look in Louis19's build thread on about the last 10 pages and you'll see what I mean. If going K03 then double pass more suited.

[h100vw]

I have a BBT K300 and I dont consider the twin pass adeqaute. Maybe in a cooler environment it can hold it's own. If I ever get time the Seat Sport is coming out and I'll do a proper front mount welly cooler and S3 inlet manifold.

You need injectors, fuel pump and MAF housing to go bigger than the K03s. All 3 are limiters in their own ways. Dont try and miss one out, that wheel was invented moons ago.

Also have a think about rods!

S3 calipers fit under stock wheels, you need the brackets too.

Have a read of Gavin's cheapy thread, lots of stuff in there for you.

[sambb]

Gav whats the advantage of S3 claipers. They are still single pot arent they? Is it just tht they carry a bigger pad? Are they the same as TT Mk 1 caliers?

[h100vw]

Same as TT, use 312mm discs.

[sambb]

thanks.

[Stein]

Cheers for all the info. That's a fantastic thread you've got there as well, I've been soaking up as much info from this forum as I can.

I've seen that the MAF housing off a VR6 should fit without too much drama. Any recommendation on where to get OEM bits like that? I also need a few miscellaneous things, the previous owner looks to have taken a buffer to the passenger side mirror and both interior reading light switches are busted.

I've been thinking hard about better rods. Definitely know I should but I wanted to do some more looking into it as it's something I've never even had to consider before. If you've got some recommendations I'd be happy to heed them, I've really got no idea.

If I get some time tomorrow I'll have a look at the brakes, I got the carriers and everything so it shouldn't be a problem. I've been holding off until I can do a proper rebuild of them.

I have a BBT K300 and I dont consider the twin pass adeqaute. Maybe in a cooler environment it can hold it's own. If I ever get time the Seat Sport is coming out and I'll do a proper front mount welly cooler and S3 inlet manifold.

You need injectors, fuel pump and MAF housing to go bigger than the K03s. All 3 are limiters in their own ways. Dont try and miss one out, that wheel was invented moons ago.

Also have a think about rods!

S3 calipers fit under stock wheels, you need the brackets too.

Have a read of Gavin's cheapy thread, lots of stuff in there for you.

[sambb]

I didn't realise you had the Seat Sport Gav, I always thought you had the bar n plate versions of it. Yeah I've not found it to be fantastic either even on my K03s. Fine if you are howling around with lots of airflow but really prone to heatsoak and doesn't seem to want to cool down afterwards very quickly even after you get going. Dave Howletts been looking at my tune again and was surprised by how far above ambient it was running on my logs. At his recommendation I'm going to put water injection back on to take care of inlet temps when its heatsoaked. One day ….water to air.