Surge

I bought myself a 13BT series 4 engine for my VW bug conversion and have a noob question regarding the intercooler.
I understand that the intercooler cools down the compressed air coming from the turbo before it enters the engine thus making it denser and thus increasing the amount of fuel that can be burned in the combustion cycle.

However I'm looking at the intercooler sitting on top of the engine and I can't figure out how it actually cools anything without any air passing through the fins.
Is there a fan or something on the RX-7 that forces air through the intercooler?
If not then how does a "radiator" with static air sitting between the fins actually cool anything?

Thanks

phoenix7

The air still goes through. The bottom plate on the IC doesn't seal the IC. At higher speeds the hood opening allows air to be shoved in. What car is this motor going into?

rotaryracer1

iTrader: (1)

he is asking "how does the intercooler cool the air going through it when there is no outside air passing over or thru the intercooler?" like in the back end of an older VW Bug.

Surge

Hmmm ... so it basically has little to no effect at low vehicle speeds.

It's going into a 1974 VW Beetle which means that no air will be forced through it.
I'll have to make a plan to get some air flowing through the fins and then maybe use a water based intercooler later.
Thanks for the reply.

phoenix7

your turbo shouldn't be pushing hot air when it's not boosting. Boosting = higher speeds = hotter temps.

https://www.rx7club.com/showthread.p...ight=Bug+turbo
https://www.rx7club.com/showthread.p...ight=Bug+turbo
https://www.rx7club.com/showthread.p...ight=turbo+bug
https://www.rx7club.com/showthread.p...ight=turbo+bug
https://www.rx7club.com/showthread.p...ight=turbo+bug

Searched the forum for turbo bug. Find out how the turbo bug guys are mounting their things.

phoenix7

I always wondered about those air cooled VWs. I'm sure you can get an aftermarket custom unit to work. Myabe mounting it parallel to the ground with it's own air supply from under the car or something. Kinda like the oil cooler setups Mazda Competion used that I'm always talking about.

slo

iTrader: (1)

I removed my intercooler in preperation for replacing it with water/alcohol injection after seeing a thread in the AI section of the forum. I have been lightly driving the car around dataloging (haltech e8) and have come to the conclusion that an intercooler isn't needed on stock turbo cars running 8psi boost or less. I am using stock 13b-rew twin turbos, currently non seq, (no boost controller, wastegate control only) and after sustaining 8 psi for 30 seconds the intake temps never climb above 40 degrees over the ambiant temp.

The ambient temp at the time was 65 deg F and the max temp was a little over 100 F. As read from the haltech temp sensor.

8 psi is well within the efficiency range of the turbo, so I'm sure it will get much hotter with more boost, but perhaps you should consider water/alcohol injection instead of an intercooler. It can be done for nicely for less money, and there is the added bonus of a much better throotle response and slightly faster spool.

wackaloo13

iTrader: (3)

i would custom an intercooler setup. im not sure how much space you have but if i were you id build a duct from the bottom of the car and use a fan to suck air and blow it through the core. can you post some pictures, these projects are always fun to look at.
good luck

phoenix7

there is a guy with a 13B-T porsche 911. I'm sure he had the same issues with his car. I don't know his name so you'll have to search.

marK's

just make an intake system like mr2's and nsx's

phoenix7

old bug with rotary turbo having fun!! sick bug!!

NZConvertible

No air-to-air intercooler will, no matter where it's located.

I would concentrate on that now instead of wasting time with a stock IC. If aftermarket W/A intercoolers are out of your budget, you could jacket the stock IC like this. There's lots of interesting info on custom and DIY W/A systems all over the internet.

phoenix7

i remember that thread. I wanna say 88integraLS but that's just a wild *** guess.

Just search for it

hurleysurf24

iTrader: (3)

id imagine you would need an intake scoop like you see on Mister Two's

phoenix7

pics or ban.