intercooling a hot air

[garrett]

A couple of months ago I posted a thread about how I was going to attempt to use a 87 stock GN intercooler on my 84 T-type. Now I don't want to get into a arguement with anyone about why I'm posting this on a hot air forum. I figure others with hot air cars might like to improve the performance of their TRs with an intercooler. For me, my hot air car is my daily driver and the car I tinker with. It's also my test car where I try things. I have a highly modified 87 GN that is my pride and joy. So getting back to the thread; I put on 2.5 inch aluminum intercooler pipes that I fashioned from a universal kit. The intercooler was in the stock 87 location. I re-clocked the turbo and routed the return pipe between the intake manifold and to driver's side valve cover. Once it was completed, I noticed that above 7lbs of boost, the engine would bog down and lose power. I have plenty of fuel pressure and fat o2 numbers/ no knock. I have heard that other people who tried this have had the same problem. It has something to do with the throttle body not being on the post boost side of the set-up. Also, the hot air intake manifold is, in my opinion, horrible compared to the 86-87 intake. So now I'm going to put a 87 intake/ throttle body on the engine. I'm going to re-clock the turbo downward to it's original position and reverse the air flow through the pipes and intercooler. I have found, that in order to accomplish this and keep the turbo in the stock hot air location, I will have to modify the back part of the upper plenum/doghouse to make room. I will also tap my oil pan for a oil return. I have a few minor details to work out, like which tps sensor to use, 84 or 87. I'm sure there are things that I haven't thought of. I invite anyone who would like to offer advice or has concerns to chime in on the subject. I still think that if it works like I think it will in the end, it will be much cheaper than trying to do a full 84-87 conversion with all the brackets and pulleys.

[kenmosher]

Keep us posted! Interesting project ... and if you take pictures along with the narrative, we can postit on the site for others to reference!

[pfredricks]

Originally Posted by garrett

Also, the hot air intake manifold is, in my opinion, horrible compared to the 86-87 intake.

Yep, Jack Merkel said the same.

Originally Posted by garrett

I will also tap my oil pan for a oil return.

To return the oil from the turbo? If not, then what fer?

As Ken says, interesting project, and good for the hot air forum.

Thanks.

[garrett]

Yes, it's for the turbo oil. I could maybe go into the oil pan, passenger valve cover, or maybe into the deck of the intake and install the stock grommet from the 84 intake. I will take pictures while I do it and when it's finished. It will be interesting to see how fast the car will be. In theory, the car should be as fast as a 87 GN with the same parts. The only thing that will be different is more tubing, to and from the turbo. Some of the current upgraded parts are : ported heads,87 ecm with Turbotweak chip,electric fan, 30lb disc injectors, TA-33 turbo, cold air intake, Jet Hot coated exhaust.

[Keller]

Originally Posted by garrett

passenger valve cover, or maybe into the deck of the intake

Stick to the block, or the pan, I think. Going into the intake would heat the intake, and also flow right onto the spinning cam. Putting into the pan will give the oil a little cooling time.

Might even consider getting an oil cooler (the 86/87 cars have a tiny one in the radiator) plus a cooler adapter from an 86/87 car as well.

We have only oil to cool the turbo bearings, so keeping the temps down is a good thing.

Thoughts?

[garrett]

Your thoughts are appreciated and they make sense, but why do they dump the oil into the intake manifold on a hot air intake? Am I mistaken that it goes in there, is there something going on with the hot air intake that I'm not seeing?

[pfredricks]

Originally Posted by Keller

flow right onto the spinning cam.

Oiling the cam shaft is not a problem, but with the oil dropping down on the crank would be of some, albeit minor, concern. I know all the Engine Builders Challenge guys try to keep oil off the crank.

Originally Posted by Keller

Putting into the pan will give the oil a little cooling time.

I like that idea.

Another advantage I see is the ease of handling the turbo. It is a bitch guiding that return into the intake. I'm getting better at it, but I hate flexing that tubing knowing one day its gonna break off. It is also my usual suspect oil leak.

[garrett]

I'll try to see if my buddies at Aeroquip can figure out how to attach a hose to the oil drain hose so that it will mount to the turbo.

[pfredricks]

Originally Posted by garrett

why do they dump the oil into the intake manifold on a hot air intake? Am I mistaken that it goes in there, is there something going on with the hot air intake that I'm not seeing?

The oil is merely passing through the intake manifold onto the manifold gasket and exits at the slits at the ends of the gasket. There is no purpose I know of other than it's the cheapest path back to the oil pan.

[Keller]

Good point.