Is this intercooler piping big enough?

[B0oStEr]

I've recently bought a Hybrid cooler in a group buy and I've been looking at piping options.

As I live in the country there is noone who specialises in performance fabrication.

The local exhaust shops dont even do TIG welding and one wanted $120 for a single 180 degree bend in 304 SS

I've found some aluminium tubing and mandrel bends for a very reasonable price at a place that manufactures aluminium gates and handrails etc and they can also TIG weld it for me.

The diameter is the same as the stock R32 gts-t piping (60mm OD- 57mm ID)

I know this is a bit smaller than most aftermarket kits use but I'd prefer to keep the piping as small as possible without it being too restrictive to keep it responsive and because it will fit better.

My power target for this car when mods are finished is about 160rwkws for everyday use and 200 rwkws for some occassional fun.

The next size up is 80mm OD- 76mm ID but it's a special order and can only be bought by the 6m length and the bends use a larger radius.

I've seen 80mm piping used on cars making 400+kw so is the 60mm piping going to be big enough for my modest needs?

[32vspecII]

go the 80mm

[B0oStEr]

go the 80mm

Why?

[hungry6]

Take it to an irrigation-pump shop where they do alluminium piping for farms, and those fellas can whip up the sort of bends a city exhaust shop can only dream of. One of the best exhaust fella in bris used to be a alloy pipe fabricator for a large turf farm. Now guess where i got my pipes done?

[awurth]

if it's before your intercooler you could use something the same size or bigger than your turbo outlet.

On my GTR the outlet of the turbo's are 38mm. so when I high mounted them I've run two 38mm pipes into a single 50mm which then expands into 3' this was just for a better fit. 50mm still has more surface area than two 38mm pipes so it will still flow more and then it runs into the 3' cooler piping. as long as you don't go smaller it should be OK.

[B0oStEr]

Take it to an irrigation-pump shop where they do alluminium piping for farms, and those fellas can whip up the sort of bends a city exhaust shop can only dream of. One of the best exhaust fella in bris used to be a alloy pipe fabricator for a large turf farm. Now guess where i got my pipes done?

Would you mind posting the business name and phone number so we can all benefit from his expertise?

Quote awurth

if it's before your intercooler you could use something the same size or bigger than your turbo outlet

What about the pipe after the cooler?

BTW

Quote awurth

50mm still has more surface area than two 38mm pipes

The cross-sectional area of 2x38mm is actually greater than 1x50mm

[awurth]

I don't know what formula i used originaly but your right. 2268 compared to 1963. as big as you can fit after the cooler

[B0oStEr]

I guess all I need to know is will 60mm piping flow enough not to cause a restriction at 200rwkw?

[dwhe009]

If its mandrel bent, then it will work perfectly. 60mm is just over 2 and a quarter OD. This size is used by alot of intercooler kits. Some others use 2 and a half (63.5mm), this is only a 24% increase in cross section. Guys use 2 and a half inch for up to 400kw easy. It will easy flow well.

Another point, if your total lenght of intercooler piping is around 4m (mine is),

times this by cross section and you get volume of air in piping (4*pi*(.03)^2)=.011309m^3. Now a 2ltr motor uses 2ltr of air per 4 revolutions, or 2000ltr (2m^3) per minute at atmosphere pressure. at 15psi @ 4000rpm = 4m^3 per minute=0.0666m^3 per second.

So now a 2ltr motor at 4000rpm @15psi will be swallowing .0666m^3 per second, so to fill your intercooler piping (one aspect of lag) will take .16 of a second. ha. crap all. if you do these calulations for 3" pipe it is quite similar (.26sec).

You will find that most lag is the turbo having to spin up although you can feel that fraction of a second if anyone has run a motor without any intercooler at all.

(these calcs did not include filling the intercooler up with air, (another .2sec approx)

The 60mm piping will be exactly what you want.

[dwhe009]

As for restriction, it is usually the intercooler that causes a pressure drop.

Most guys with the norm, 2.25-2.5 inch piping+ say 300*500*50mm intercooler will only see around 1psi drop at 15psi. big deal.

[Zahos]

it shouldn't

I used piping the same size as the stock R33 pipes, which i think is the same

I dyno'd my car with cooler, exhaust, boost (9psi) and SAFC2 (A/F ratio's at a perfectly flat 12:1 all through the power band), and achived 200rwkw.

If all stock intake pipes you wont be changing are 60mm, why would using larger pipes just before/after the cooler make a difference?

The 60mm should be more than adequate for your modest needs.

[Birnie]

You should check this out.....

http://www.skylinesaustralia.com/photopost...500&ppuser=8870

[Bass Junky]

You are really limited by the size of your throttle body and turbo outlet.

No point in going any bigger than those sizes and they are the bottle necks.

[B0oStEr]

Thanks guys, 60mm it is.