Whats more restrictive, stock intercooler or stock head, 2nd gen 12v

C

ctk30

New member
Joined
Mar 23, 2013
Messages
19
I'm curious if anyone has done some testing

I have another engine that had the KDP fail out but the parts are good. My thought was to port out the head, and do a valve job. Reason being is that my truck has 325k and I don't want to worry about the stock head gasket, so I'm not going to swap a stock head on.

Background is my turbo took a ****, so that is where my oil consumtion issue was coming from, I am new to the turbo game and didn't look into the in and out play on my turbo and drove around with it till I noticed it started smoking, no failure though.

Moral of the story after much thought I talked myself out of a 62/65/12 and just pulled the trigger on a super b single.

I don't have high hp aspirations, but I do want something that is reliable and can hop in and not have to worry about it whether I'm towing or not. When I'm towing I'm pulling around 12k pounds with a good amount of drag


Now to the thread

Basically, I am wondering where the restriction is? Is the stock intercooler restrictive enough where porting the head won't make a difference in my case of towing egt's and lowering boost?

I plan on installing the turbo on my stock manifold and driving for awhile and then porting out my second manifold on and swapping it that on and seeing the difference

I've been searching quite a bit and really haven't found much that is relevant to my goals

edit: may have jumped the gun

Intercooler Field Testing - Page 2 - Competition Diesel.Com - Bringing The BEST Together
 
Last edited:
You're looking at it wrong....BOTH are restrictions, however the cylinder cannot change state, it will keep trying to flow whatever air it is given. The intercooler however can stop being as effective at intercooling, which I guess is the point I was trying to get at in the other thread.

I'm not trying to minimize the role head flow has to do in an engine, Shane Kellogg went from 1,800hp to 2,400hp by changing from a head that flowed 200cfm, to one that flowed 300cfm. That's 600hp, but it's also in a 5,000rpm diesel puller as opposed to a street truck.
 
They are both somewhat restrictive, but neither is much of a factor on an engine towing in the 2000rpm range with a SuperB. A little bowl work wouldn't hurt, but you don't want so much work that it slows the velocities in that low rpm range, or it will actually hurt you. The higher the rpms and the bigger the turbo(s), the more you will benefit from porting (first) and a better intercooler (second).
 
Yeah that was exactly the plan, just a little bowl work a valve job and gasket matching

How does the increase of volume from the larger intercooler affect velocities also though.

Also, it seems in the scenario you described the intercooler wouldn't be restrictive. The bowl work would help get a little more air in a lower lift
 
I forgot to reply to that old thread.

After upgrading to the BD intercooler from the factory one, I'd have to agree with the others and say the head is more of a restriction. I did see gains, but not as significant as I was hoping, however the biggest perk of running the BD is reliability and not having to constantly check for boost leaks from blown out stock units. Who knows how many miles I drove with boost seeping out of stockers.

I'd like to note that I've also got a little more fuel and air than your application, however I feel better head flow will make the engine more efficient everywhere in most setups. Compared to gains from an aftermarket intercooler that are directly related to engine modification level.

I've got a camshaft for my truck but I'm thinking about getting the head ported before I swap cams. These built 12v trucks are pissing through straws in my opinion.
 
Drothgeb said:
They are both somewhat restrictive, but neither is much of a factor on an engine towing in the 2000rpm range with a SuperB. A little bowl work wouldn't hurt, but you don't want so much work that it slows the velocities in that low rpm range, or it will actually hurt you. The higher the rpms and the bigger the turbo(s), the more you will benefit from porting (first) and a better intercooler (second).
Click to expand...

Just curious where you're coming from on the velocities. I have a decent amount of time (in the past) on a flow bench with gas stuff, and velocity is a big deal from the stand point of the fuel being in suspension (in the airstream), and wanting to minimize it falling out of suspension. On a direct injected, forced induction, diesel engine (or gas for that matter) that's obviously not a concern.

Have you guys out there with test equipment seen the VE go up with a certain port size or velocity range on a direct injected engine? Obviously you probably aren't going to quote any numbers, but curious about the general trend. Not saying anyone is wrong here by the way - just trying to learn.
 
I was kind of curious about that also, I'm not really sure about velocities and the such on forced induction, I imagine the least restriction as possible is best on it.

I can however see having physically bigger components affecting things, such as a bigger exhaust manifold, or the hamilton 12v head

But I'm still not even sure about that

I'm interested to hear more also, maybe I'll learn some info in my fluid dynamics class next year that will be applicable
 
bluthndr said:
Just curious where you're coming from on the velocities. I have a decent amount of time (in the past) on a flow bench with gas stuff, and velocity is a big deal from the stand point of the fuel being in suspension (in the airstream), and wanting to minimize it falling out of suspension. On a direct injected, forced induction, diesel engine (or gas for that matter) that's obviously not a concern.

Have you guys out there with test equipment seen the VE go up with a certain port size or velocity range on a direct injected engine? Obviously you probably aren't going to quote any numbers, but curious about the general trend. Not saying anyone is wrong here by the way - just trying to learn.
Click to expand...

ctk30 said:
I was kind of curious about that also, I'm not really sure about velocities and the such on forced induction, I imagine the least restriction as possible is best on it.

I can however see having physically bigger components affecting things, such as a bigger exhaust manifold, or the hamilton 12v head

But I'm still not even sure about that

I'm interested to hear more also, maybe I'll learn some info in my fluid dynamics class next year that will be applicable
Click to expand...

Smoothing things out will only increase your velocities, however, adding volume to the charge air track will slow the air down. This is why a huge intercooler will drop PSI over a smaller one. At the same time, you have to think about restrictiveness, and if your turbo can handle the added volume. Some people think that they have bottle necks on turbos because the compressor outlet is such a small diameter, but in reality, I bet they are that size based on flow characteristics that increase velocity without sacrificing volume too much.
 
CorneliusRox said:
This is why a huge intercooler will drop PSI over a smaller one.
Click to expand...
Is it possible that has more to do with the potential increased efficiency of the larger IC removing more heat from the charge-air thus decreasing the charge-air's volume?
 
BC847 said:
Is it possible that has more to do with the potential increased efficiency of the larger IC removing more heat from the charge-air thus decreasing the charge-air's volume?
Click to expand...

Not really. It's true that you cant calculate it for an engine as a closed system accurately, but in this case the volume doesnt increase hardware wise, and so the air has no where to expand, which is really what gives you your power when the fuel ignites and the air stays dense prior, and wants to expand more during.

On the other side of the engine coming out the exhaust, it makes more sense what you're saying. The further the turbo is from the engine is bad because the temp drops dramatically, increasing volume, lowering density, and spinning the turbo less effectively.
 
You must log in or register to reply here.
Top