Intercooler in engine bay????

[Iain H]

Speedwheel,
Nope, I left the guides as per factory. I know everyone has their opinions, but I never saw any guide erosion whatsoever( nor did Dave Becker, who bought the engine from me after 5 years and improved on the concept dramatically). I won't speak for Dave(who regularly dragged, hillclimbed and circuit raced his car) but as a daily driver I drove that poor motor like I hated it.
My opinion is if you do everything you can to keep your combustion and exh. gas temperatutes in a sensible range-(read tightly controlled mixtures, efficient intercooling [water OR air],turbo-compressor working at or near it's maximum effeciency "island" at high/max boost levels(do your research, get the compressor maps, do the math!!), well conceived cam specs and compression ratio, optimised ignition timing and maximised air cooling....phew) you shouldn't see any problems with your street motor.
Of course, full-on racing where every last morsel of ET/MPH/HP is sought,(generally at the expense of longevity) is another matter entirely.
Iain

[This message has been edited by Iain H (edited 11-22-2001).]

[speedwheel]

How effective would an intercooler inside the engine bay be???

thanks

[effvee]

Where in the engine bay? Mine took some thought. If you louvere the deck lid like I did it would help, reverse the louvere direction (point the opening up) that should aid to some degree. Now what I did was behind the back seat inside I cut a hole and fabed a box of metal and with a speake tray none will see. From this point I bought two NACA duct to install into the rear side windows for ram air inlets, now this will help. I also will have a secadary electric fan to aid when needed. The botom line is air and lots of air in a air to air intercooler is needed so whatever way you plum it get that air in and out. Here my attempt at intercooling at this point I will be runing maybe Feb/2001

[Searoy]

Water to air or air to air?

For air to air to work you need cooler air going through the intercooler than is being cooled by the intercooler. The cooler the air the better. Therefore, inside the engine bay of a Beetle is not the best place for an air to air intercooler. They also tend to be larger than water to air intercoolers.

If you want to use an air to air intercooler a better place might be under the package tray in front the engine on the passenger side, opposite the starter.

A water to air intercooler is a little more difficult to plumb, since oyu much plumb the air and the water and the water heat exchanger (radiator). The water to air exchanger can be in the engine bay since they tend to be smaller adn are not really affected by the temps in the engine bay (not much anyway). But the heat exchanger for the water (radiator) dhould be placed where it can get the coolest air possible. This might be under the package tray, or it might be all the way up front behind the bumper. In a super beetle behind the front vents is perfect.

You might wat to read up on intercooling to find out how they work and why they are needed. That will help you decide what kind you want and how to configure it.

------------------
*** Teach a Man to Fish ***
Searoy

"I tend to lean toward a tighter gap and a
looser skirt....a little slap never hurt." -- Joe of the West

[Iain H]

In my opinion on blow through or fuel injected engines any intercooler is better than no intercooler at all, but the whole point of an intercooler is to increase the charge density by maximising the temperature difference between your charge(turbo-compressed)air and the cooling medium(I'm assuming ambient air as this is an air cooled motor forum). The cooler you make the ambient air conditions the more heat can be transferred out of your charge(boosted)air by the intercooler and the more dense(read horsepower!!)your charge air becomes.
Given that the air cooled VW engine bay is subject a considerable amount of radiant heat from the crankcase, you may not get as dense a charge with your intercooler in the engine bay as in you might in other high airflow areas such as the RHS of the gearbox, for instance.
Hope this helps,

Iain

[speedwheel]

I was thinking of having an air to air intercooler inside that engine bay and maybe running stand-offs? what do you think? cause if i run the intercooler on the starter side of the tranny, the plumbing would really be difficult as my turbo is located on the left side of the rear apron. I was thinking of fabricating an intercooler the size of a doghouse cooler and attach it to the pipe going up the carbs (the T ) and maybe run stand-offs? what do you think and any suggestions would be greatly appreciated.
Thanks!

[Iain H]

Building an air cooled turbo system is always going to be a compromise. Limited available space and the need for maintaining the air cooling system integrity as well as functional constrains like whether to go gravity or scavenge with your oil returns all add up to some sleepless nights and funky plumbing. The important thing is to get your main priorities clear in your mind early, as a bad decision in the beginning of the project can mean you are compromising the rest of your installation.
Notwithstanding what I said in the last e-mail, in my books an air-to-air I/C the size of the doghouse oil cooler would be too small to really effectively drop your charge temperature and this needs to one of your top priorities in terms of horsepower vs.engine longevity.
I wouldn't hesitate to move a turbo and all it's attendant plumbing in order to maximise the location of a correctly sized air to air intercooler.
Good luck with your project.
Iain

[speedwheel]

thanks Ian for the inputs.
Ok, for example I have a good sized intercooler mounted in the engine bay, would putting stand-offs and getting ram air do the job?

[Iain H]

Are we both talking air cooled type 1 engine bay here?
Remember how little room there is in there, even with stand-offs(which aren't to my "stock looking" liking but, hey, whatever blows your hair back!!)
Even a "compact" air to air I/C is too big to go into a T1 engine bay. Water to air will, but there is added water plumbing issues associated then.
Iain

[speedwheel]

thanks dude. yup its a T1 engine in beetle. anyway, i have another question, which produces more heat a blow thru(w/o an intercooler) or a draw thru type of setup?

Thanks again

[Iain H]

When you say "more heat" where do you mean?
In the engine bay? or the inlet tract? In the combustion chamber? or the turbine?
(this could get complicated and technical, and I have a sneaking suspicion we may open up the ol' blow through vs suck through can of worms!!)

Iain

[speedwheel]

I guess i'm concerned about heat for the whole system, engine (mainly). although I know that turbos will surely generate heat, but what I would like to know is what setup produces less heat? (w/o the intercooler for the blow thru). i'm sorry if ur not getting the point, cause i'm really new to this stuff... thanks!!!

[speedwheel]

yeah, well i guess the question goes as well for the combustion chamber =)

[Iain H]

Don't be concerned about being new to this stuff. The trick is to keep asking questions of as many people as you can, read everything you can find on the subject then come up with your OWN opinions on what to do.
There are many different views on blow through vs suck through and the pros and cons of each.
I am a blow through advocate.
I intercooled my first blow through turbo VW motor in 1985 after talking to a lot of people here in Australia and asking lots of questions, then began looking at how OEM factories like Porsche,Audi,Volvo,Maserati and Saab were doing it. Without exception they all blow through and intercool.

Good luck
Iain

[speedwheel]

Hey thanks man! well at this point, I already have the turbo in my beetle. Its a blow thru but w/o an intercooler yet. Where did you put your intercooler man? my friend said that if i put the intercooler far (RHS of the tranny) this would cause me to hardstart and possibly flood. because he said that the air would be travelling much longer on start up since the intercooler is located far (my turbo is on the left side under the apron). Which I see is possible. So where did you put your I/C? is your turbo also in the left side (near 3 & 4 cyls)?