k-14 or k-24?

[kooch]

I am finishing up a rebuild of a 1.6td Solid Lifter longblock that I am going to put into a 1981 Caddy that I will pretty much turn around and sell (too many cars so I've got to get some done n gone) Anyway, I also have a 1.6td hydro from a Eco-diesel which I plan to someday rebuild and pump up a bit to install into my 86 Westy Weekender Syncro (which I will NEVER sell)...So having said what I have and where it is going, which turbo should go where? I understand the k-14s are pretty desireable, but I've also read some good things about the k-24, is the k-14 too small to put on the Westy? I live at about 5,000 feet and so I want as much power as possible since I will be going to a diesel from my current installation which is a Turbo PG motor from a Corrado (fun, but sucky fuel mileage) Please let me know your thoughts. Also, what kind of power could I expect from something like a AHU/1Z running a mechanical pump? Just wondering in case I come across one. Thanks

[bbob203]

K14s are great I have 2. One from an aaz on my tdi and 1 on mk2.

[TylerDurden]

AIUI, generally, the smaller turbos spool earlier and have less power gain in the high rpms, the larger spool later and have more mojo in the high end.

Depending on your driving pattern, one size may be more desirable.

[kooch]

Any idea where the k-14 runs out of steam? Obviously the Diesel Caddy has the appropriate gearbox, but my Westy is awaiting a gearbox rebuild at which time I will have the 3rd n 4th gears changed out for Diesel appropriate, but I'm sure that I will still be in the 3,000 rpm range at 70mph, but I don't want the turbo to be living on the top end of its range. With this post I'm really looking to find which turbo to keep for the Westy as I'm pretty confident that either one will work great in the Caddy.

[bbob203]

Im not sure when they run out of efficient steam but If you get one from an AAZ the top end is better because it has a higher flowing hot side.

[kooch]

That would be great, but as you probably know AAZ's are pretty hard to come by. Heck I still occasionally look for a AAZ turbo manifold because I wanted to put on on my PG motor in place of my flimsy aftermarket manifold, plus I wanted to test the different turbos, but those AAZ'z are pretty much non-existent.

[bbob203]

That would be great, but as you probably know AAZ's are pretty hard to come by. Heck I still occasionally look for a AAZ turbo manifold because I wanted to put on on my PG motor in place of my flimsy aftermarket manifold, plus I wanted to test the different turbos, but those AAZ'z are pretty much non-existent.

They pop up on vwdiesel.net now and again. I have some canadian contacts that may be able to help you out if your really interested. I have on for my tdi its getting rebuilt right now though it didn't need it i just didn't want to put a grungy looking turbo on an otherwise clean motor.

[Dakotakid]

From my real-world use of both turbos in stock form: the K-14's benefit is well-gone by 3,000 (or even sooner) rpm. And when it signs off....it is annoyingly GONE.

The stock K-24 is just beginning to live at 2,800 or even later. And the wait for THAT boost is damn annoying as well.

You honestly have a tough decision and any decision you make will be (at best) some sort of compromise. Lately, I have this undying postitive affair with my gas engines!

[kooch]

Thanks for the rpm info, i guess I'll likely use the k-14 for the Caddy and keep the k-24 for the Westy...but for this one I may have to research a VNT installation. Thanks Again.

[libbybapa]

I don't know what Dakotakid is talking about. I think he's confusing the K14 with the K03. There is no high-end hit for the K14 vs. the K24 unless you're running more than 15 psi or so unintercooled and doing so is not wise in a vanagon.

I have always preferred to have more boost in the lower rpms in order to help get the big box moving. I don't tend to rev it high and so having the boost at lower rpms is important. The other factor to consider with the vanagon installation is whether or not the turbo interferes with any of the engine mounting components and what work is necessary to eliminate that interference. There were basically 5 different turbo-chargers used on the 1.6TD and 1.9TD engines and provided the appropriate manifold is used, will all bolt up to the cylinder head. They were the T3, K24, K14, T2, and K03. The mounting interference issues of the K24, T3 and K14 can be eliminated using the Quantum/Vanagon exhaust manifold, but that approach introduces other issues with oil drainage and intake plumbing and so is an approach I do not favor.

The T3 and K24 have the same boost characteristics and are both just plain too large for the 1.6TD in a vanagon. Boost doesn't start until about 3,000-3,500 rpms and you can literally get stuck in 2nd gear on moderate grades and even if you rev it to the limit, you cannot shift fast enough to be above the boost threshold in 3rd and without any boost you cannot accelerate. This effect is most apparent at higher altitudes, but those turbos are irritating even at lower altitudes. The K24 and T3 also both severely interfere with the driver's side mounting bracket.

The T2 and K03 are the smallest of the 5 turbos and share the same boost characteristics as each other. Their boost threshold is below idle and so you will see basically instant boost when letting the clutch out. Full boost is developed by 2,000 rpms. They don't ever give the punch of the larger turbos because they are always developing some boost right from idle. They do restrict the exhaust more than the larger turbos and so comparatively hurt high-rpm power some. The K03 when used with the 1.6TD has a very slight interference with the driver's side engine mounting bracket which is very easily eliminated. The k03 does not have any interference when used with the 1.9TD. I have not personally used a T2 in a vanagon, but saw someone else's install on a 1.9TD and it appeared to clear the mounting components without issue.

The last option is the K14. It is middle-of-the-road as far as size is concerned. It is a much better turbo than the K24 and T3. It flows as well as the larger ones at higher rpms and yet spools at least 1,000 rpms sooner. There is some lag, but you definitely feel the boost kick in more than with the k03. The K14 flows better at high-rpms than the K03. The K14 is a significant interference with the driver's side mounting bracket and requires significant modification to the mounting bracket."

The overall performance of the K14 is my personal preference but the installation is definitely more difficult. IMO, the easiest way to eliminate the interference with the K14, is to chop the nose off the aluminum mounting bracket and then bolt a piece of 3/8" steel to the bottom of it with an appropriate bend and hole. Then drop the front of the carrier bar 3/4" by adding a spacer, and the engine geometry remains the same as it was. The slight interference with with the k03 mounted to the 1.6TD can be eliminated by grinding or cutting the mounting bracket slightly.

To sum up, if you are planning on using a wastegated turbo on a 1.6TD in a vanagon, DO NOT use a K24 or T3. Use either a K14 if you don't mind a little lag and can do the fabrication necessary or use a K03/T2 from an AAZ with matching manifold for fastest spool with a little loss of top-end but an easy installation.

[avocado]

Very helpful, thank you libbybapa.