without intercooler

[Lovesong]

do somebody have good results without intercooler? I have doubts that it was succesful but it is more cheap and easy

[nathan s]

I would say use an intercooler. Of course it is a little less money because you don't have to buy an intercooler, but you run the risk of having detonation and a bunch of other nasty stuff. Because of this you wouldn't be able to run as high of boost, thus you don't get as much of a benefit from forced induction.

[Matt Gignac]

There's always E85. Since it was such a high enthalpy of vaporisation, it has an intercooling effect

Matt Gignac
McGill Racing Team

[Denny Trimble]

Nah, nobody's ever done well with a turbo E85 non-intercooled engine...

except maybe one team...

[MikeWaggoner at UW]

E85 also has a slightly higher octane rating (100 to 105) than gas. I've also seen a successful car running Methanol turbo, but they changed the rule.

[jonnycowboy]

The effects of an intercooler are usually only beneficial at about 7-8 lbs of boost. Below that and the efficiency of the intercooler negate the effects of the boost of the turbo. It will reduce the temperature tho, but to be beneficial run more than 10psi boost, and use an intercooler or use only about 5psi without intercooler.

[powered by wattard]

Intercooler is bad news in terms of throttle response and driveability with all that extra volume between the throttle and engine.

We run 22psi boost at 6000RPM and about 12psi boost at 10000RPM with 10.5:1 CR with no signs of knock on 98 Octane fuel and no intercooler. Inlet temps are currently only about 60degC, reduced from about 120deg last year. Size your turbo and inlet and exhaust geometry right and temps should not be high, plus our intake system has alot of surface area and is made out of aluminium to disipate as much heat as possible.

Significant combustion chamber design and cylinder pressure analysis went into this to make it work. One major factor we found that will promote knock at any boost is high oil consumption from turbo or pistons. Solve the turbo oil issue and your problems will be signifantly reduced. Careful control of fuel and ignition is the key to making any package work.

Unless you have significant resources and plenty of time, don't even bother playing with boost. Plan on getting a reliable engine package together and a car to put it in first. You will find this a challenging task in a year.

Getting the engine to handle the boost is the next challenge as BMEP numbers will sky rocket. We see about 24Bar BMEP, measured from the gearbox output shaft. Getting motorcycle cast pistons and factory rods to handle this is highly unlikely as all motorcycle engine parts are designed on the limit. FSAE cars make less power due to the restrictor but similar peak torque numbers as the factory, this is what hurts factory components.

Good luck

Will Attard

[Daniel Hynum]

Will,

In your last statement it seems that you are insuating your team uses non-factory pistons and rods. Where are you picking these up?

[Denny Trimble]

They're running a non-factory engine. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[DanO]

There are quite a few people that make pistons and rods for these. Arias, Wiesco, Crower... etc.

Last year we had both custom pistons and rods in our car.