Intercooler size?

[Rich J]

Just ordered a HKS intercooler 400x260x65 and was wondering what sort of gain I could see with this over the standard one?

Also got a HKS FCD, Blitz DSBC, and a HKS superdragger? Is this a good setup? Got the bigger intercooler coz or running slightly higer boost and the FCD to aid and the zorst the aid more clearance of gas?

Any pros and cons?

[Rich J]

Any views at all?

[rev210]

Bigger Intercoolers are cool! (pun).

The con with intercoolers is they need to have a size appropriate to the flow dynamics of the air passing through them.

the what? I hear you say.

Well, basically the larger surface area of the bigger intercooler allows for greater heat exchange (keeps intake air cooler for longer than stock) but, there is a point at which the longer and wider pipes will cause unhelpfull turbulence. This is most obvious at low or no boost level but can extend right through the power band if poorly matched.
It's like shooting a .22 bullet through a .44 barrel, the air rattles around and loses flow speed.

A lot of design can go into producing just the right size for your engine combo and driving style.

This bigger intercooler will not give you anything over the stock intercooler's power peak until you are pushing more than 350HP or so of air through it.
However it will lose less power than the stock unit if you drive on full boost for longer than 60 seconds or so. I don't know many people with large intercoolers who do this, so the rest have wasted the money for the time being. Most owners give short bursts of power over a quater mile where the run is less than 20 seconds.

anyway, go dyno your car now before you fit it and then after you fit it do it again, without changing anything but the intercooler. A bag of carrots says you are on the same power or less. (Note; don't do the run at the same place you buy things, the operators can fiddle the dyno to make it look good).

Last bit of advise; go buy yourself a light flywheel for $450 ,you will pick up far more power than you did for the intercooler and half the other things you have bought.

[Rich J]

Thx for that mate, boost wise I won't be running anything silly, thats the reason for getting the cooler incase of bigger mods, thought it be a good place to start.

Flywheel, well with the car being an auto i have the disadvantage there plus the extra weight!

Thx for the reply. What sorts of mods is your car running then m8?

[gtr33m]

Rev210,

Some great info, thanks mate!

What about clutches with integrated flywheels? Same gain?

Any one gears/pulleys give you the same benefit?

I assume the same applies to wheels.

[rev210]

Ahh... automatic. a beer in one hand and a steeringwheel in the other.

The lighter pulley setup is worth a couple of horsepower, but is most often chosen in conjunction with a different sized pulley setup.

The water pump and alternator pulleys are often chosen to be replaced in order to accomodate higher and more frequent reving (usually race track).

The frequent high revs of some driving styles can cause water cavitation in the case of the water pump and premature failure of alternator bearings, so the size change.

The idea of decreasing the weight of the bits attached to the crank is an old one. You can lighten the pistons,rods,crank,front pulley and flywheel to good effect. These are all the most primary of components to lighten to increase power directly in the motor.

As a really rough guide every kilo you can shed off the crank assembly is worth more than 1 kW, in an engine producing 200kW it is probably closer to 3kW or 4kW (maybe more it all depends).

The wheels are far less critical in terms of weight reduction for power, light ones are always good and so is not having two fat bastards riding in the backseat.