K14 or K24 - help me decide

[burn_your_money]

Ok, I have both turbos and I don't know what would be best to run.

The car:
91 Passat sedan w/ 4 speed auto
Engine - stock AAZ

Goals:
Acceptable power for a grocery getter/family hualer
Excellent fuel mileage

I'm torn between the two turbos. Anyone have experience with the auto? Whatch y'all think? I might run an IC, but I have AC so it would be a bit of a pain.

[libbydiesel]

Are joining the Dark Side?

IMO you shouldn't run either turbo above 15 psi without an intercooler.  If you are planning less than 15 psi of boost, then the K14 is the clear choice.  At that boost pressure there is no downside to the K14 unless you PREFER lag with no top end benefit.  If you are planning on running 15-20 psi max boost then it's a toss up (I'd still prefer the k14 but the smaller size is noticeable).  Above 20 psi the K24 is the clear choice.

  

[burn_your_money]

Are joining the Dark Side? 

rejoining... yeah...since I have to

IMO you shouldn't run either turbo above 15 psi without an intercooler.  If you are planning less than 15 psi of boost, then the K14 is the clear choice.  At that boost pressure there is no downside to the K14 unless you PREFER lag with no top end benefit.  If you are planning on running 15-20 psi max boost then it's a toss up (I'd still prefer the k14 but the smaller size is noticeable).  Above 20 psi the K24 is the clear choice.

From a power perspective I understand what you are saying. However I have a theory that the smaller turbos get worse mileage. I've always found that the 1.6s got better mileage than the 1.9s. Now I know there is a lot different between those 2 engines. Even more is different when we consider the mileage of the AHU and it's tiny turbo.

At this point I see no reason to run above stock boost pressure.

[8v-of-fury]

If you are sticking with stock boost.. I am a severe advocate for small turbos! Too bad you do not have a K03, they are a mean turbo on an turned up AAZ. Me and my bro push an easy 15 out of both of ours and they run it great.

There has been a lot said that higher boost pressure whilst cruising is more efficient. I believe it. My brothers AAZ took the place of a 1.6TD. The only thing that changed was the engine, and he now gets better overall mileage. Trans, tires and driving habits remained the same.

Sso because you do not have a ko3.. K14 it is for my vote. You will love the lower spool in town and stock boost will be no feat for it.

[RabbitJockey]

the smaller turbo is obviously the better choice just for getting around, it will be more efficient in the normal driving range and obviously spool faster.  between the stock vw t3 and k24 i like the k24 better its a good turbo for a lightly modded 1.6td.

[starrd]

I run the K14 - tried my rebuilt K24 around the block once and pulled it.  Would spool and had good power, but the below 2500 rpm performance was terrible (although no large downpipe).  Also, just a thought, but you should be able to rig up an intercooler from a Passat G60.  There was a knockout in place by the battery for the upper intercooler piping on my 1993 Passat and the G60 intercooler bolted right in - just have to rig up the piping to the turbo.  My Passat has A/C, but the intercooler is in the left wheel well so it fits fine although not the best intercooler.  I may look to see if the 1996 Passat TDI intercooler will work because I hate the oval lower connection on the G60 intercooler.  The TDI one and a lot of the piping should work even better than the G60 one.  I have the TDI parts so some day I will have a closer look.

One other comment - I have the TDI CTN tranny installed, so that made a big difference due to the low revs.

[burn_your_money]

I just checked my tranny ratios and it looks like at 100 on the highway I'd be spinning 2900 and at 60 in town I'd be around 2300.

Does anyone have experience driving a 16v with a 5 speed and an auto, preferably in the same car? I know that the 010 is a real dog behind the 1.6na in a mk1, but with a 5 speed the car is a whole different animal. I'm not expecting miracles with the auto, and I am expecting it to be putting more load on the engine which is why I am leaning more towards the K24.

I have a B4 TDI so I know that that IC would work pretty easily, I'm just not sure how efficient it is. Plus I hate turbos because of all the extra junk in the engine bay, LDA, turbo, air box, oil feed line, I don't know if I want to add a bunch of IC piping on top of all that.

Actually what I really want is a K16, if anyone has one

[RabbitJockey]

Check Porsche forums for k16 expect to exchange a few limbs.  U could come up with a similar turbo from the Garrett family.  I didn't think my auto was any slower than any other na car I had, it just sucked sooo bad on the highway

[8v-of-fury]

Which 4 speed auto do you have? 096? or 01M? What code??

[theman53]

My vote is K24. You don't have to lift to shift, so that will help you boost 50% better I would guess. You won't loose the boost between shifts plus the added load you are talking about. Plus I like the smooth power better than the instant boost feel...personal preferance, call me silly, but whenever there is snow and ice a little area between idle and full power is nice. Hate that in the TDI.

[Alcaid]

Daily driver, auto, 15psi or below - easy choice! K14!

[theman53]

I also have a Giles pump and a 3" exhaust, so my k24 I bet spooled more closely to a K14 than a normal k24. My point is it did not come on instant and I liked that. Easier to get traction in all kinds of environments.

[burn_your_money]

I also have a Giles pump and a 3" exhaust, so my k24 I bet spooled more closely to a K14 than a normal k24. My point is it did not come on instant and I liked that. Easier to get traction in all kinds of environments.

Excellent point, thank you. Giles switched from a T2 to a T3 or something like that when I worked there and I really did not like the way that the boost came on with the smaller turbo. Given that this is my mom's car, she'd probably hate it even more.

The K16 came on the 5 cylinder TDI euro vans didn't it? I'm not too serious about getting that turbo...

By looking online I think I have a 096 APE with the following ratios    2.71    1.55    1    0.68    -    4.22. Haven't checked the actual gear box for a code.

[Blocksmith]

I've got a brand new k16 I could let go of, if you're interested.

[R.O.R-2.0]

with an auto?

K24, easy choice..

bigger turbos get better mileage too..

i LOVED the K24 on my Audi 5kTD... it had an auto..

spooled quick due to the auto trans, and being able to flash right past the stall speed of the tq..