Ecotec single pass to dual pass

[Heywood-Yablowme]

Materials required: 1/2"npt street 90 elbow,1/2"npt to 3/4"hose nipple,teflon tape.  Tools required: 1/2"npt, 5/16" drill,3/4" drill bit and a drill.

This is how the laminova tubes should look using a dual pass setup..center two have the small outlets facing you,end tubes big holes...

       [img width=800 height=600]http://img218.imageshack.us/img218/4661 ... ere008.jpg[/img]

 Drill using small bit first,follow up with the 3/4",then tap with the 1/2"npt...

    [img width=800 height=600]http://img340.imageshack.us/img340/5113 ... ere011.jpg[/img]

 Done!   [img width=800 height=600]http://img594.imageshack.us/img594/9462 ... ere010.jpg[/img]

Intake manifold MUST be removed to relocate laminova tubes,and to get the end manifold off to modify. There is an 8th bolt on the intake manifold,underneath, that has to be removed to get the manifold off.You will also have to remove the two studs to get it to clear the frame.An E7 socket will be required for them.

Thanks again,brammo...

[DarthChicken]

I dunno, I think you may have overcomplicated things a bit. 

[Heywood-Yablowme]

Just call a plumber..they will have it done in 30  minutes...    

I was going to buy one all done..but I figured I'd wait and see what all the fuss was about..and it's actually so easy,a caveman could do it..like me!

I can't believe how many things I need to.."fix" on Doc to bring it up to a performance level I consider minimum for track use. Uprights and brakes are done..next the springs.(shocks have been revalved) I'm swapping Max's old blower/injectors/ECM on to the car as well. With an actual operating intercooler setup and the 3" exhaust,it should make better power than it did on Max.   Very tempted to try the Harrop on Doc..but I will wait till Max is back in action..just in case....    (I have decided Max is going full turbo,with no Lam-mee-nova crap)

[WorkingOnIt]

What is the current vision of the distinction between Doc and Max?

ie. are they different methods to achieve similar end function, or do you envision them having different proficiencies - eg. better at autocross vs. road course?

[DarthChicken]

One is a four cylinder, the other is a 3.5 cylinder

[Heywood-Yablowme]

I won't push Doc up the hp ladder..very far.No need to really, for my track day needs. Max will probably stay Ecotec..but it will be a turbo.I'm  trying to get an LNF to drop in and if not, I'll do an air/air intercooled turbo. Same goals..just different paths. After all,it is the journey...

[silver]

there is quite a bit of data that supports a single pass is actually better at getting heat into the coolant....soooooooooooooo..maybe all of what you did is for not.

[Heywood-Yablowme]

I don't see how passing the same coolant 4 times across the same heat source is better than passing more coolant through 1/2 of the same heat source. (more flow and less restriction in a dual pass setup)

GM tests have shown the dual parallel configuration to remove enough additional heat to be able to make more HP with the stage 3 setup.Lower ITS's=more HP.GM still reccomends a dual pass configuration on a stage 3 kit.

Where is this data you are looking at? Do you have any links? Is this GM information? I have learned not to trust the Cobalt community for the most accurate information.Some of what they do is not exactly "scientific".

This is right from GM,in reference to stage kits used by GM LSJ equipped cars,in competition,on road racing cars:

"The Time Attack car uses the Stage 3 pulley and 2-pass intercooler. It has a different
calibration, and has been upfitted with additional components such as aftermarket pistons,
neutral balance shafts, and high-speed valve springs. It also has a short header, large
exhaust, and dry-sump oiling system. The Grand Am Cup Cobalts have used the Stage 2
kit in the past, along with the 2-pass intercooler. However, revised rules in the series
have made the smaller supercharger pulley illegal".

Tough to argue with that.

[silver]

when you do the dual pass you're not allowing the heat to get into the water in the first place......so no matter how good your intercooler is, it doesn't do much good if the coolant isn't hot.

Although I don't think it makes much of a difference.

CpnRob and myself are currently outfitting our magnusson intercoolers with fans/ moving the 5/8' side mounted bungs to the back for better plumbing, and he's adding a 1.5 gallong inline tank to increase the volume of the system.  We'll test his set up versus mine then if his is proving to work well, since I have individual seats I can add a 3.75 gallon tank where my ebay intercooler currently is, I don't think it's doing much to reduce my IAT2's as they get up to 160 pretty easy in this texas heat.

[Heywood-Yablowme]

"when you do the dual pass you're not allowing the heat to get into the water in the first place"

Why?? Explain that statement?   Each pass through the heat source is going to get the same slug of coolant hotter,and it will absorb less heat as it passes through 4 tubes..vs. the same coolant only having to remove heat through two tubes, through the heat source,and back out to be cooled.  I don't see the logic in saying 4 times through the fire is better than two...

Why does GM use the dual pass on its performance applications,and reccomend it be used on all stage 3 setups?

[silver]

if you put a pan on the fire does it get hotter if you leave it in for .2 seconds or 2 seconds.

there's your answer.

you've cut down the time the air has to heat up the liquid by 50% thus the liquid isn't able to remove the optimum amount of heat b/c it wasn't in the chamber long enough.

You are assuming the liquid can extract optimum heat if it passes through the laminova top and bottom tube, I'm assuming that if you leave it in through all 4 tubes it would get hotter thus allowing your intercooler to remove more heat out of the coolant.

we'll see.

I bet that contributed to you never seeing high IAT2's and now I'm going to laugh my ass off if you made it worse..............of course you're only making the same as the rest of us so I have to laugh at myself too.

[Heywood-Yablowme]

The difference is..you are NOT removing the "pan" in a dual pass application. You are passing more coolant that is COOLER across the same working surface.There is never a time when the laminova tubes are empty (hopefully..)

The object is to remove heat energy from the incoming air,not boil water. The greater the temperature differential,the better.

[Speedytec]

Simple cooling dynamics: For max heat transfer you need the biggest temp difference you can get.
It's not about heating up the coolant; It's about cooling down those cores as best as you can!

And yes, the increased flow will make that you need a more efficient radiator to cool things down quick enough.
Some Cobalts/Ions have changed to a single pass (4 parallel cores) and report even lower IAT's than the dual pass. Expensive/difficult to make though...

Edit: To slow... 

[DarthChicken]

Sorry silver, what you are saying doesn't mak sense.  Take kitchen knife, and heat it over a burner.  Lay it on a small piece of ice, and hold
still on that ice until the small piece of ice is gone and turns to water.  Now take that knife and touch your tongue.

Now take the knife, heat it up, and slide it across multiple pieces of ice.  I'm betting the knife cools off before the ice melts all the way.  Just because the larger qty of ice hasn't melted doesnt mean it's not absorbing heat.  It's just spread out over more ice.

Also - the idea of using a larger resevoir has the same affect.  More liquid to absorb the heat.

What our cars need is better laminovas with more surface area

edit:  ok, I see what's going on - this is a misunderstanding on what the stock piece does.  The stock piece recirculates water
through four time.  What max has done is make it so it only goes through twice.  And... Single pass can be done
for even more improvement. 

[silver]

ok gotcha, I think the misunderstanding is when I read single pass, that would mean that the liquid only passes one core before returning to the intercooler,

so I interpretted single pass as stock, which y'all are saying............is not.


stock would be called quad pass, because you make the liquid pass through all for cores before being cooled back down.


so.............we are in a consensus that a large resevoir that's INLINE would be a great addition?


I think my ebay intercooler behind the seats is what's really NOT helping my system, no air flow, and not a quality core so it's cooling properties are probably below spec.