aw11 intercooler upgrade

**EVO 747** · 12-08-2009, 03:14 PM

Hello. First of all i have had a look for this and with the abundance of infomation on here its very easy to get lost so i thought id just ask!

My mate and i have just purchased an 86 aw11 with a 4agze for track work. We dont want to spend millions of dollars so i am basically going to upgrade to an sc14, smaller pulley and a decent intercooler and see how we go from there.

What is the most common intercooler upgrade for the aw11? I was thinking something along the lines of a late model sti top mount as they are fairly cheap and efficient, but im guessing airflow is the problem?

**MR22ZZ** · 12-08-2009, 03:20 PM

yep, either an ST205 water to air, or a Subaru water to air intercooler is what most people use.

for a heat exchanger, most people remove all the A/C junk and the front and put a heat exchanger there.

If you search 'AW11 water (to air)* intercooler' there is a ton of information.

* the terms 'to' and 'air' are too short for the search engine so will not be searched so don't need to be there hence the brackets

**011** · 12-08-2009, 03:29 PM

Hey mate
I have a Subaru W2A core for sale, if you want.

PM me if you're interested.
Thanks

**EVO 747** · 12-08-2009, 03:36 PM

another thing i should mention is this is purely a motorsport car. So i dont have to worry about putting along at 50kph or sitting at traffic lights. Is w2a still the best option, keeping in mind i am trying to get the weight down as much as possible

**X kyle X** · 12-08-2009, 03:49 PM

roof mounted intercooler..

check out

ADSPORT on here... he has a roof mounted cooler on his SC14 aw11...

**mullett** · 12-08-2009, 08:16 PM

For a motorsport application, I'd box an air-air cooler in, probably in the boot, and feed it with a couple of bloody big scoops in a high-pressure area (one on each side of the boot lid, picking up from the side or top of the cab would be good) and a big outlet vent in the rear panel, between the taillights, to remove the hot air, as this will be a low-pressure zone when the car is moving. You'll want to keep everything fairly lightweight, use a medium size core, but very thin (50mm would be nice), and 2in aluminium piping. While you're there strip all the un-needed stuff from the rear of the car, and the weight shouldn't change much. Also gives you much shorter piping, less top-heavy weight (like a roof mount) and much better airflow (to my mind).

What kind of motorsport do you intend to do? If it's short-distance stuff, like motorkhana, hillclimbs, etc, where there's a lot of low-speed corners, I'd go with the SC14, and a heavier intercooler core (for better heatsink properties, especially with the low airflow at low speed)

If you're going to be doing sprints, circuit work, etc, I'd ditch the SC and go for a turbo, the lag will be minimal at that power level, it'll breath much more efficiently and rev out a lot cleaner (SC14 doesn't like revs, especially with an overdrive pulley). You'll also remove a lot of weight from further back in the car, and replace it with less weight further forward. You also have the advantage of much easier parts, shorter distance from the throttlebody to the intake (important for throttle response), etc etc. Cost will also be comparable to using an SC14 (they're getting expensive now!). I'd use a WRX turbo, and the boot mount mentioned before, or if you're after more power, a GT28.

The other option, if you want to be creative, is the Eaton M90. It was used on the supercharged commodores, along with heaps of other applications, and is very cheap and easy to get now (cheaper than SC14!) It's a far superior supercharger, much more efficient, happier to rev, and would make more power, more easily, while draining less to drive it. That would be my personal choice, but it would be a lot of fabrication, and could prove a headache as it's a fairly un-trodden path.

-RM.

**the_random_hero** · 12-08-2009, 08:57 PM

Nice twin screw charger would blow your budget out a little, but totally be worth it. I'm planning on mounting a W2A core in the boot and making an intake manifold with the throttlebody facing the opposite way, piping should be very easy (in one side and out the other of the boot).

**EVO 747** · 12-08-2009, 09:29 PM

Originally Posted by mullett

For a motorsport application, I'd box an air-air cooler in, probably in the boot, and feed it with a couple of bloody big scoops in a high-pressure area (one on each side of the boot lid, picking up from the side or top of the cab would be good) and a big outlet vent in the rear panel, between the taillights, to remove the hot air, as this will be a low-pressure zone when the car is moving. You'll want to keep everything fairly lightweight, use a medium size core, but very thin (50mm would be nice), and 2in aluminium piping. While you're there strip all the un-needed stuff from the rear of the car, and the weight shouldn't change much. Also gives you much shorter piping, less top-heavy weight (like a roof mount) and much better airflow (to my mind).

What kind of motorsport do you intend to do? If it's short-distance stuff, like motorkhana, hillclimbs, etc, where there's a lot of low-speed corners, I'd go with the SC14, and a heavier intercooler core (for better heatsink properties, especially with the low airflow at low speed)

If you're going to be doing sprints, circuit work, etc, I'd ditch the SC and go for a turbo, the lag will be minimal at that power level, it'll breath much more efficiently and rev out a lot cleaner (SC14 doesn't like revs, especially with an overdrive pulley). You'll also remove a lot of weight from further back in the car, and replace it with less weight further forward. You also have the advantage of much easier parts, shorter distance from the throttlebody to the intake (important for throttle response), etc etc. Cost will also be comparable to using an SC14 (they're getting expensive now!). I'd use a WRX turbo, and the boot mount mentioned before, or if you're after more power, a GT28.

The other option, if you want to be creative, is the Eaton M90. It was used on the supercharged commodores, along with heaps of other applications, and is very cheap and easy to get now (cheaper than SC14!) It's a far superior supercharger, much more efficient, happier to rev, and would make more power, more easily, while draining less to drive it. That would be my personal choice, but it would be a lot of fabrication, and could prove a headache as it's a fairly un-trodden path.

-RM.

thanks very much this was very informative! From what i have read though, doesnt turbocharging the earlier AFM 4agze cause major dramas with tuning?? Also with regards to manifolds, does anybody do a decent quality off the shelf one?

I am also interested to hear more about the twin screw supercharger

**wasfishing** · 12-08-2009, 09:49 PM

speed source do a bolt on turbo kit quality is good but very exspensive, i wouldnt knock the sc14 its a great upgrade and im very happy with mine with w2a setup, perfect for motorkhanas and lapsprints.

**mullett** · 12-08-2009, 11:32 PM

SC14 is great for motorkhana etc, but to my mind it gets very breathless at higher RPM, and produces quite low power for the amount of effort it takes to spin it. The torque is fantastic, so great for low RPM 2nd gear corners in motorkhana, but I didn't really enjoy the experience on longer, more open tracks (like barbagallo)

With regards to the ECU, the AFM ECU is great for turbocharging, although an interceptor like an SAFC will give you much more power, the ECU goes very rich. I'd still go aftermarket, like an Adatronic, but factory ecu should be fine up to 12-14psi.

I've seen a couple of manifolds, but it was a while ago. Keep in mind that a lot of the 4AGE ones aren't suitable. Have a chat to AJPS about these: http://www.ajps.com.au/parts/kelway_turbo_manifolds.asp they're made on a one-off basis, so maybe they can make it to suit.

-RM.