Need input from the team;
I am considering an intercooler for the 6.9 engine in my 86' f-350. There is a banks turbo on the engine now, the small turbo. The engine and truck have 151,000 miles on it. The vehicle is in great condition now. As an intercooler is somewhat of a expensive add I have these questions; Will there be a worthwhile h.p. increase? Will an increase in torque happen? Is there any fuel changes in mpg? Is this add even acceptable for an i.d.i. engine? I have encountered many opinions from people, now I ask the seasoned vets. Or, should I enjoy the vehicle as is and run it without this add. Thanks for the support,

Ososbill

 

Frankly besides a turbo an intercooler is one of the best mods you can do to these trucks, not sure on the mpg side of things but it should lower your EGTs allowing you to turn the fuel up and thus creating more hp and torque. Once I get mine running right (again) its getting an intercooler as well.

 

Thanks for the input re; intercooler. Maybe I can assist your questions down the road.

ososbill

 

Intercoolers are what makes turbo worth while in my opinion. Intercoers provid a compounding effect on the addition of a turbo. More are isn't always the answer it needs to be cool and matched to the fuel. So yes intercoers are in my thinking a must. Do it and post the project.

 

my opinion on this is for the amount of gains you will see, an intercooler on that 6.9 will be a waste of money.
if you were making over 15 lbs boost, it would be worth it. but for the 4-6 lbs boost your turbo makes it is not worth it.

 

you can add a intercooler to cool the air back down going into the intake that the turbine passed to the turbo for improved power and efficiency,however you can't crank the fuel up and keep the same size turbo,or you'll just be pushing the turbo outside it's designed place to produce,and you'll just be "spinning your own wheels".
if you want the same amount of boost as you had prior to intercooler install or even more,then just go all the way and upgrade to a larger turbo.keeping in mind,the larger the turbo,the more lag,the larger the cooler for the larger turbo,the more lag.before you know it,you will have lost performance down low but gained in the mid and upper.be mindful of your real world driving style and work duties first or you'll find yourself with a large laggy street turd,but a cool thing to show off on the dyno with peaks,of which you'll never use (unless under high load uphill all the time,or playing around wasting fuel.)


it's not a waste of money to add an intercooler either though because performance is found in colder air (back to ambient or close hopefully without wasted volume doing nothing but wasting spool up time,if everything is matched close) even without touching the fuel.
there are cons to just doing this,you will have increased turbo spool lag.you will have less boost,but higher performance which is what matters,but if your worried and focused on making boost,you could be tempted to over fuel and tax a small turbo bringing mpg down hard.
Tom is correct imho in that if you are wanting to install an intercooler for an idi turbo kit due to EGT's, then you already have the fuel turned up higher than you should.in ideal tune,the idi turbo kit will not suffer from high egt's.timing and or fuel settings are incorrect.people push the limits though and rather than turn the fuel down,they would rather push the small turbo's out of their work zone,hurt fuel efficiency and spike egt's right up to the max.in fact,despite the zones and cooler size,some claim all you need to worry about is the egt gauge.if exhaust temps are ok,then you can push a turbo right off the map.......of course this is incorrect thinking.

if you do add an intercooler and you plan to run the typical sized idi turbo kit,avoid these common mistakes;
1.too large of cooler and piping.
2.over fueling in general.
3.over fueling by cranking the fuel up to push the boundaries of the egt gauge.
4.over fueling by pushing the boost gauge to resemble the readings you had pre cooler install.
5.not being prepared financially with the next most important part of your drive train.the transmission and clutch need to be able to handle the increase in performance,or you'll find yourself with no performance at all.
6.expecting miracles.

9th gen f-series with 2nd gen banks turbo,intercooler install:
https://www.ford-trucks.com/forums/1...gen-truck.html

 

I disagree.

The volume of air of an intercooler and associated piping is very small in comparision to the amount of air an engine (and therefore, turbo) moves.

This myth of increased spool times because of an IC comes from the past of using way too big of a turbo on too small of an engine, that already has an issue with lag... A laggy engine is a laggy engine, no matter what. As if that isnt bad enough, people attribute the way their boost rises on a gauge to "lag", when thats not necessarily true either. Just because your gauge was at 4psi on its way up, pre-IC, and now its at 2psi on its way up post-IC, doesnt mean you arent pushing the same volume of air... Cooler air is more dense, and it takes less pressure to deliver the same amount of volume... The pressure drop post IC isnt due to the IC being a restriction, its due to the IC working and cooling the air like its supposed to. If you have a wastgated turbo, you can take advantage of this by adjusting your wastegate to where your boost was before (As long as your fuel is there to drive it)...

I actually am a fan of relatively big IC piping, because on a diesel, it works the same as increasing intake plenum volume, and that provides more of an air cushion for the intake charge so you get better cylinder filling under boost... Off of boost I believe its better as well, because its closer to "atmospheric" conditions than having a small plenum right after a compressor wheel.

The Turbos that are normally on diesel trucks are pretty small in the grand scheme, so the idea that lag is an issue by adding an IC, just doesnt hold any water, its just a myth, thats all.

 

And BTW.... An IC is totally worth it even for 4-6psi... Like F250 said, the closer you can get the air to ambient temp, the more power your engine will have with the same amount of fuel... 4-6psi at 250* is less air than 4-6psi at 100*.... Now whether you think the 20hp you gain is worth it or not, thats up to you I guess... But thats a subjective thing.

 

Wow I just read my previous post and sorry for all the spelling! It must have been really late ha. But at operating temp with egts in the 700-1000 degree range charge air temp can be as high as 365 degrees. Maybe even higher it depends on load and a few other variables but that's high and if you think cooling that **** down isn't important than you need to educate yourself on volumetric efficientcy and thermodynamics at least to more clearly understand heat soak and what affects that has on an engine and its ability to make power. Most of my friends that are mechanical engineers laugh when they find out my 6.9 has a turbo but no IC.

 

It really boils down to simple as cooler air is more dense and therefore has more oxygen for a given volume. Air is heated when it is compressed, so cooling it back down while maintaining pressure is a good thing. You ultimately need more oxygen in the cylinder, and intercooler is the way to achieve that. Higher boost does give more oxygen, but if it is hotter air, the increase is not as effective. 10 psi at 250 F is not twice as much as 5 psi at 150F.

To be technical, it is related to what is called ideal gas law: PV=nRT, P = pressure, V = volume, n = number of moles (think quantity), R = gas constant, and T = Temperature.

So if you can lower the temp and the number n is the same, then P or V has to decrease. BUt since a system has close to equal pressure throughout (after turbo and up to intake valve), this means that volume reduces. Less volume means denser air with more oxygen.

End result without getting too technical, is that intercooler is good.

 

Racin what you said reminds of this ricer dummy out at the track. He bought a 3" DP to put on his car, his boost fell a couple psi. He even said himself, it feels like it has more power and spools sooner, but because his boost fell he put the 2.5" back on.... FAIL. I tried to explain to him that it was just the turbo not working as hard because it can breath.. might as well talked to the car.

Intercooling is great if youve got the spare cash / time to do it. Been waiting for someone to build some pre-built IC kits *cough *cough

 

The way that I talked myself into putting one on my next build, was the turbo is a big heat exchanger, you have hot air on one side and cold on the other, when hot meets cold they have to even out the best it can, there is around 300F diffrence on the exaust temp in front and behind the turbo, that is way you want your pyro in front of the turbo That 300f has to go some where not all of it gose back into your 6.9, but if you ever pulled the same load on a 80F day and a 20F, with my truck it's normaly a gear higher when it is colder. That might give you an idea what 60 degrees can do

 

I smoked two pistons wich had me rebuild my IDI twice.
Now it has an intercooler and it has made it past 10,000 miles
without smoking a rear piston like before without using an intercooler.

The power is much better the engine behaves much better and
my EGTs are below 1000F when running it hard.
My actual psi went from 12psi MAX to over 15psi I need a 20psi gauge now.

But driving it is easy to get the power I need at about 12/14 psi.

Intercooler=less engine damage


Javier

 

has anyone tossed around the idea of insulating the intake manifold?

 

I don't see how that would help, you could wrap insulation around it, but it is still tied to the hot block, the heat will travel through the metal