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Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 10:54 am
by Nd4SpdSe
Well, I figured I'd post here since there's alot of FI knowledgable people, and for the Xterra's, not so much, but this applies to both forced-induction systems, and most have experience with turbo systems.
For those that know, my Xterra is factory supercharged, and it's mounted to replace the intake manifold, so I can't pipe in an intercooler after it, so I was wondering, is there any benefit to having one to cool the air before the supercharger or turbo, whatever system it may be?
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 11:06 am
by onlytrueromeo
Based on laws of thermodynamics, and not actual experience, I'd say no. Incoming air will already be the ambient temperature, pushing it through an IC will not cool it further. (there is no "wind chill" factor")
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 11:11 am
by Nd4SpdSe
Ya, I was thinking the same thing....
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 12:39 pm
by wytbishop
Well the reason an intercooler is required on Turbo apps is due to the heating that occurs after the compressor compresses the intake air. You would need a way of cooling the air to temps below ambient, but if you could cool it prior to the compression of the SC it would deliver a denser, cooler charge to the cylinders.
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 12:45 pm
by onlytrueromeo
^Yes. The only way to do this effectively is to spray CO2 or NO2 onto the intercooler...an NO2 setup would give far greater yields if it was sprayed into the engine though, rather than just used to cool an intercooler.
For the trouble that it'd be, it's not worth it to have an IC before a compressor unit.
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 12:55 pm
by Daninski
Pressure and temperature are directly proportional. Raise one you raise the other. Install an A/C evaporator in front of your SC inlet. Run your AC system to it buy dividing the coolant line after the control valve then reconnect it to the system before it reaches the compressor. In saying that how many more ponies will you achieve verses how many ponies will it take to drive the AC compressor. My 5c
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 1:23 pm
by Nd4SpdSe
Ya, that's probably the only way. I'm not racing the truck, it's just that I'd like to put on a smaller pulley to raise boost from about 6 to about 15psi. Many people have done it, but some complain that the motor doesn't like it on hot days, but we're also talking about guys who live in the southern and mid US. It shouldn't be a problem, and it's not a race truck, so seeing 15psi wouldn't be often, but i'd like to benefit from more boost down low. A good CAI is what is recommended with that route, but it's typically a short ram. A low CAI wouldn't be good for off-roading to say the least, I'll turn into a straw for water crossings, lol
I'll probably just make a ram-style pipe that helps feed the sealed CAI, but I could close it off for off-roading. I've even e-mailed Outlaw Engineering to see if they could make some thermal spacers for the supercharger and plenum, but I'd need a body lift since there's no room beteen the S/C and the hood. I don't know if having a hood scoop (would look like a turbo diesel Xterra) to blow air onto the supercharger would all help to have the S/C cool down by a few degrees, so there would be less heat transfer to the pressurized air.
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 1:28 pm
by onlytrueromeo
A hood scoop would help if it fed directly to your ram air, but it wouldn't be a huge difference. Water would come through in intense rain though unless you had a bypass of sorts.
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 1:36 pm
by Nd4SpdSe
Ya, rain wouldn't be good, but there's worse things than rain, lol

Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 3:30 pm
by Daninski
You should concentrate on getting projector headlights for the Xterra first. lol
Hey is that the piece of property off the 403 (I think) near Hamilton that's clay and all the off roaders use it?
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 7:58 pm
by Nd4SpdSe
Nope, that's a trail along the Welland Canal. Went from Port Colborne to Welland
Actually, the headlights and foglights work great on the truck, but I think I'm going to try a set of Silverstars when I get a chance....but ironicly it seems that the kit I need is always sold out, and I checked at 2 CT's at different dates, but what the truck does NEED is 200 watts of KC lights mounted on the roof rack

, as well as a lift, some off-road tires and sliders
Re: Intercooler BEFORE The Turbo?
Posted: February 11th, 2009, 11:41 pm
by Ryan
Concidered heat sinks?
Re: Intercooler BEFORE The Turbo?
Posted: February 12th, 2009, 12:01 am
by Nd4SpdSe
Actually I have...but not sure how to go about that....
Re: Intercooler BEFORE The Turbo?
Posted: February 13th, 2009, 12:03 pm
by BuGS
If you are serious about trying to do something like that right, go with Water/Alcohol injection. That is how the guys around here do SCs to the extreme. Depending on where you could put the mister, but I would say just right in front of the TB would be a good spot.
Re: Intercooler BEFORE The Turbo?
Posted: February 13th, 2009, 2:39 pm
by projectzemx3
if you hook up a intake tube and route the air filter into a colder section of the engine bay, maybe even isolate it with some nice sheet metal. atleast the s/c will be sucking in some colder air for when you change the pulley.
i guess you could call it a cai!!!