I need a book about turbocharging.

Boost_Crazy wrote: In reply to Keith Tanner: In theory, tanks on the long sides should be a better design for the same core size. The cores have the same mass, and should be able to absorb and shed the same amount of heat. The air should spend an equal amount of time in either core. Small side end tanks have a longer core, but the air travels through it more quickly. The air charge in a long side end tank I/C would have a shorter path to get through the core. But the charge moves through it more slowly, so it should take the air charge the same time to get from tank to tank in both I/C's, and they should both have the same opportunity to give up their heat. The difference is that the long tank I/C should have less pressure drop because the air charge is moving more slowly over a shorter distance through the core. But the reality of it is that the end tanks of the long side I/C are harder to design in a way that allows more equal distribution of the air charge through the core. They also are usually orientated "wrong" on the front of a car, requiring an extra 90 degree turn in and out- take a look at the pictures you posted, you will see what I mean. To be apples and apples, the first I/C would need to be mounted 90 degrees. And it would then stick out the hood of the Miata, which demonstrates why the short side method usually works better in the real world on most cars. But that's not the same thing as the original principal being wrong. It's just harder to execute, and not really that big a deal overall.

We've done testing on radiators - having the tanks on the short ends gives lower outlet temps. Double pass work even better if you can package it. The efficiency of our turbo kits went up with tanks on the short ends. So I'm not buying the theory.

I'm quite familiar with the packaging problems of the long tank ICs, we used to sell that thing in the pictures. Corky is also good at proving things with theory that don't pan out - he once proved to us mathematically that the heatshields in the kits were strong enough to resist any vibration. They kept cracking anyway.

In reply to Keith Tanner: So you are saying bells intercooler theory is proven wrong by your radiator testing? I don't think that applies to intercoolers and a different fluid.

The two intercoolers pictured have a good deal of difference I see. Is that what you tested? If not I would love to see more. If so doesn't look exactly like a back to back comparison. Looks like more bends in the tube just leading up to the core.

Personally I bought into the more tubes ic design so I would like to better understand it's downsides.

In reply to Keith Tanner:

The efficiency of our turbo kits went up with tanks on the short ends. So I'm not buying the theory.

The efficiently of your kits most likely went up because you replaced a compromised long tank design that had an extra 180 degrees of turns with a design with less turns and better designed short end tanks. You came up with a better solution for the application, but that doesn't disprove the theory. But you make a good point- designing a system to work best with what you have will often be better than forcing choices that are "best practices" on paper that lead to other compromises in reality.

Radiators are a different animal, as you are moving a fixed volume of a non compressible liquid through a system. I won't pretend to have any idea on why side to would work better than bottom to top, so I'll take your word for it.

Radiators and intercoolers are heat exchangers of very similar design and purpose. The fact that the coolant is incompressible doesn't seem to be a fundamental difference to me. We were measuring the temperature at the inlet and the temperature of the outlet at a given flow rate, which seems to be a very good comparison to an intercooler at a given moment.

But whatever. I've had too many direct dealings with Mr Bell to blindly accept his proclamations, and my experience - while not adhering to the strict science fair requirements of this thread - is that he's simply wrong in his IC design suggestions. And he has apparently decided the same thing.

In reply to Keith Tanner:

That makes me wonder more about the effects on the engine of more volume vs cooler temps. Maybe that is what part of the benefits. In a radiator volume and pressure doesn't matter so much, who cares what the rate of flow for the coolant going in a loop is (as long as it's cooling the motor)

Now with a turbo that volume,pressure matters as does the temperature.

The testing was just the radiator, isolated. It doesn't matter how much coolant there is or if it was going in a loop. All we measured was temp going in and temp going out, and there was a greater delta across the core with the short tank, long tube design. We could have been doing the same thing with air and we would have seen the same behavior.

I get that you want your choice to be the best design. If it's in your car right now or you've already got parts, it's the best design. Go with it. Chasing another 10% will mean you never get the car finished.

I appreciate all the design considerations going on in this thread. I got my Max Boost book today and will read the IC and cam sections with maybe more than a grain of salt. Maybe closer to a tablespoon of salt.LoL

I have both Mark Warner's book and Corky's Maximum Boost - I learned a lot more from Warner's book. Maximum Boost was good - at the time - because people didn't know better, but time has shown much of it is actually feelings stated as fact. The sentence I had to read a couple times to make sure I wasn't seeing things was him stating that a smaller exhaust is better than a large one for a turbo engine. Huh? No, no, no. And as others have said, his advice on ECU control is so outdated, reading it is more harmful than helpful.

In reply to Keith Tanner:

All we measured was temp going in and temp going out, and there was a greater delta across the core with the short tank, long tube design. We could have been doing the same thing with air and we would have seen the same behavior.

That most likely is fine for testing a radiator, as it's job is to remove heat from the water. Doing the same thing with air is not a good test. Air is compressible, and compressing it heats it. So a restrictive I/C may cool the air well (inlet temp Vs. outlet temp), but the turbo has to work harder, and heat the air more, to achieve the same manifold boost pressure. You could end up with a net higher charge temp Vs. an intercooler that cools less but flows better, because the air charge leaves the turbo at a higher temp.

get that you want your choice to be the best design. If it's in your car right now or you've already got parts, it's the best design. Go with it. Chasing another 10% will mean you never get the car finished.

I think that is one of the fun things about turbo system design. There are so many options and variables. Each one probably won't make it break you, but the cumulative effect can make a big difference with the same engine. But you are right, it won't matter too much if the car is sitting on jackstands. I should know, I'm a three time bench racing champ.

I'm kinda lost on what you point was... If you literally meant that turbos don't run on heat alone, you are correct, but I don't think anyone would ever say that and you are misunderstanding what they are actually saying.

Maybe my post would have been more clear if i had just pared it down to the last sentence:

to me it's not that heat has no place in the discussion, but it's aggravating that people talk about it in half-ass ways that drown out discussion of equally or MORE important aspects of how the system works.

Which, based on this sentence:

designing a system to work best with what you have will often be better than forcing choices that are "best practices" on paper that lead to other compromises in reality.

.. I think you actually agree with.

It's just been my experience that most people who get too deep into talking about heat energy end up making the perfect the enemy of the good.

I hate to use myself as an example because i literally take zero pride from my E36 M3ty turbo cars, but my minivan has slightly over TRIPLE the stock power, on a stock (non-turbo) bottom end, on a highly NOT-ideal setup. It works, it's fast, it's hilarious. If i knew absolutely nothing about turbos and was trying to build it, people talking about heat retention would probably not have helped me in any practical sense and half the people saying anything would have been totally or substantially wrong anyway. People can't even get the relationship between fuel pressure and volume right and that's a topic that's WAY more practically applicable to keeping a homebrew turbo setup from breaking your engine.

In reply to kb58:

I appreciate all the design considerations going on in this thread. I got my Max Boost book today and will read the IC and cam sections with maybe more than a grain of salt. Maybe closer to a tablespoon of salt.LoL

Maximum boost is a good book, but keep in mind that it appears to be written in the context of building a turbo street car. Much of the criticizim leveled at it does not take that into account. Many of the things that are "obviously wrong" with it are wrong because they are not ideal for a race car. If you want a guide to build a challenge car- probably not the best. Cams, exhaust, etc., there is no "best." There is best for your intended purpose. If anything, my biggest gripe would be the title- It should be "Not Quite Maximum Boost" - How to turbo your car with minimum impact to driveability, NVH, and emissions.

Keith Tanner wrote: I get that you want your choice to be the best design. If it's in your car right now or you've already got parts, it's the best design. Go with it. Chasing another 10% will mean you never get the car finished.

I based my choice on the what was around in 2004 so if there is something better around before I rebuild the car around it.

I do get that this is a nerd fight but I don't know anyone in person that even knows what an intercooler is

Anyway boost crazy more than covered anything else I could have come up with.

Boost_Crazy wrote: That most likely is fine for testing a radiator, as it's job is to remove heat from the water. Doing the same thing with air is not a good test. Air is compressible, and compressing it heats it. So a restrictive I/C may cool the air well (inlet temp Vs. outlet temp), but the turbo has to work harder, and heat the air more, to achieve the same manifold boost pressure. You could end up with a net higher charge temp Vs. an intercooler that cools less but flows better, because the air charge leaves the turbo at a higher temp.

I'm gonna file that under "in theory, there's a difference between theory and practice; but in practice there isn't". The difference in flow restriction between the two designs is not enough to cause the turbo to move to a dramatically different efficiency range. Yes, you can build a wildly restrictive intercooler, but we're assuming a reasonable amount of competency of all involved.

For a book it depends on your starting knowledge. You can read up on how an engine works, how a turbo works, etc. But reading the beginner FAQs on the various boost related forums probably hits most of the up to date salient points.

I too remember reading the theory behind the long side intercooler tanks and it made sense to me. But ^ here we see it doesn't necessarily pan out. It's equally important I think, as being able to understand a lot of the theory, to recognize the proof in the pudding and not lose the forest for the trees so to speak. Sometimes people overcomplicate or oversimplify things when explaining theory, but recording the temperature on the car is the ultimate test no matter what a theory might suggest.

In reply to Keith Tanner:

I'm gonna file that under "in theory, there's a difference between theory and practice; but in practice there isn't". The difference in flow restriction between the two designs is not enough to cause the turbo to move to a dramatically different efficiency range. Yes, you can build a wildly restrictive intercooler, but we're assuming a reasonable amount of competency of all involved.

So what would you attribute the difference to? Your findings are that the short side version out performs the long side version, and I don't doubt your findings. You don't think end tank design or the extra 180 degrees of turns would make a difference, but you believe there is that there is a measurable difference simply from short side to long side chance alone- contrary to the expected result. Are there any other differences between the two? Same core size and thickness?

You would be surprised how easy it is to build an overly restrictive intercooler. O.E.'s have been doing it for years. And that doesn't even mean that they are bad intercoolers- some have a lot or research and $$$ invested- and work very well within their design parameters. But they show their weaknesses when asked to do more. I've got one of those on one of my cars- a stock EVO 8 intercooler on my Galant VR4. It has a realatively large core that is very efficient at removing and shedding heat, and nice 2.5" inlet and outlets. Looking at it, you would think that it's a very effective intercooler. And it is, up until it becomes a choke point due to it's extruded tube core. My car would make more power with a no name eBay I/C with a tenth of the engineering that went into the Mitsu unit, but it doesn't mean the EVO I/C is bad. Just not optimal for my application.

In reply to Vigo:

.. I think you actually agree with. It's just been my experience that most people who get too deep into talking about heat energy end up making the perfect the enemy of the good. I hate to use myself as an example because i literally take zero pride from my E36 M3ty turbo cars, but my minivan has slightly over TRIPLE the stock power, on a stock (non-turbo) bottom end, on a highly NOT-ideal setup. It works, it's fast, it's hilarious. If i knew absolutely nothing about turbos and was trying to build it, people talking about heat retention would probably not have helped me in any practical sense and half the people saying anything would have been totally or substantially wrong anyway. People can't even get the relationship between fuel pressure and volume right and that's a topic that's WAY more practically applicable to keeping a homebrew turbo setup from breaking your engine.

I think I completely agree with you. While all of this theory and best practices is well and good if we were designing turbo systems from scratch budget be damned, most of us here aren't doing that. We can't control every variable, sometimes we need to work with what we've got. But I'd argue that's why we need to pay extra attention to the things we can control. If you are limited in the choice of turbo available, paying attention to other details could reduce the impact of compromises those choices lead to. All the little things that we can control add up. But at the end of the day, I think we could agree that any boost is better than no boost.

Boost_Crazy wrote: In reply to Keith Tanner:

I'm gonna file that under "in theory, there's a difference between theory and practice; but in practice there isn't". The difference in flow restriction between the two designs is not enough to cause the turbo to move to a dramatically different efficiency range. Yes, you can build a wildly restrictive intercooler, but we're assuming a reasonable amount of competency of all involved.

So what would you attribute the difference to? Your findings are that the short side version out performs the long side version, and I don't doubt your findings. You don't think end tank design or the extra 180 degrees of turns would make a difference, but you believe there is that there is a measurable difference simply from short side to long side chance alone- contrary to the expected result. Are there any other differences between the two? Same core size and thickness?

You don't agree that the radiator testing is valid and applicable, but I think it's an illustration of the efficiency in design. End tank design is definitely a concern when it comes to long tanks, but in the radiator testing we were testing radiators from multiple sources. We were also testing core designs - fin density turned out to be more important than core size, which isn't how the usual marketing push goes Interestingly, BEGi used to supply intercoolers with a variety of cores on each delivery, so at the time Corky didn't believe the core design was more important than the supply of the parts.

Anyhow, on the actual implemented turbo kits and air/air intercoolers - the core size was almost identical between the old and new setups. Yes, the path was much improved with the new one and we had much better designed intercooler pipes as well. I'm sure that was a factor. So we have a more efficient design that can be implemented more efficiently - sounds like a win on both counts.

In case Maximum Boost doesn't work for you, we have Sport Compact Turbos & Blowers by Joe Pettitt (Cartech), TURBO: Real World High-Performance Turbocharger Systems by Jay K. Miller (Cartech), Turbocharging Performance Handbook by Jeff Hartman (Motorbooks), Turbochargers by Hugh MacInnes (HPBooks), and Street Turbocharging by Mark Warner, P. E. (HPBooks) in stock ready to ship from Autobooks-Aerobooks in Burbank, CA. We also have the Corky Bell book as well as most of Keith Tanner's books.