Does anyone know how big the air outlet size of a GT3540 with a .7 front housing is? The outlet part that goes into the cooler. Im trying to organise a reducer but the turbo is at home and Im at work and I forgot to measure it. Is it 2 1/4 inches? 2 inches? Cheers Dan

Hahahahahaha! Ive just been through this man, I bought the wrong size piece of silicone aswell....swapping it over as we speak, they had to order the correct size in. The comp outlet measures (external diameter) 64mm at the widest point (which is the lipped section right near the end), I think the 2.5" hose is 62mm I/D and thats what im getting, should squeeze over nicely. I had the 2.25" and that S T R E T C H E D over but would have split sooner than later. I dont have the internal measurements, are you planning on welding the reducer onto that comp outlet? Sorry if ive confused the situation, sounds like you are doing it slightly different to me.

Haha thanks mate. Im gonna have a crack at tacking up my cooler piping on the weekend so I'd thought I'd buy all the reducers and stuff today.

Cool, hope that helps, what are you reducing from/to?

Im just stepping up the outlet size to 3 inches for the cooler piping.

3inches works well and looks mad!

IMO.. 3" is not needed.. 2.5" is perfect.

I want 350rwkw and dont like doing things twice, would 2.5 be enough? Either way Ill need the reducer as the cooler has a 3 inch inlet.

Yeah go 2.5 off turbo and flare to 3 inch cooler piping if you want, im keeping my 2.5" piping on that side of the cooler, cooler outlet is 3" but reduces to 2.5".

i like morgo said 2 1/5 is perfect, less volume for the turbo to fill up to make boost which inturn makes a more responsive throttle !!!

You guys have a point, I think my cooler piping was only 2.5 all round on the AU. That seemed to work pretty good for 310rwkw at 14psi. I would prefer the extra room on that side so I have somewhere to put my filter, there is bugger all room as the cooler is upside down in the torry so the pipes are at the top of the engine bay. So does 2.5 on the hot side and 3 inch on the cold side of the cooler sound the go?

Yeah thats what i'll end up with mate, im putting a JD plenum on mine ATM so the 3" piece (on the cool side) is only going to be short anyway.

yeah, i'm going 2 1/2 from the turbo to the bottom tank top tank has a 3inch mandral bend coming of it, and is 10 inch into the throttle body

i did mine 2.5 on the hot side with a 3" to 2.5" silicone reducer at the cooler. and getting the 2.5" pipe through the guard there next to the light is hard enough let alone 3"

Your cooler is a bit bigger than mine isnt Leigh? Ive got a generic 600-300-76 core. I had a quick look and figured I could make 3" fit. Ill find out for sure on Saturday. Thanks guys, Ill definately go 2.5 from the turbo. 3 inch on the other side if it fits. Im running a rajab plenum and XF TB on my setup.

its same but 90mm thick. i can get you photos of the where the holes are if you like?

Nah its cool, they can really only go in one spot from looking at it. the outlets sit right against the metal. I was going to cut the metal so the outlets kinda protruded into the engine bay a tiny bit so the cooler sits a little further towards the rear.

i also had to cut the metal out from behind the cooler at the bottom. put the cooler in and bolt on that funny panel that sits behind the front bar(its shaped like the bar) just to make sure you dont have to do that aswell

Im not sure which panel you mean duz? Do you meant the thin piece of metal that is about halfway up the grill area? 2.5 inch was the right size too btw. The outlet O/D is exactly 2.5 inches. Thanks guys.

the bottom of the grille bolts to it