A Question About Turbos

[VW_Commuter]

I've tried searching for this information but haven't been able to find an answer.  I'm looking for a listing of turbos for our VW diesel's that ranks them based on either flowrate or power increase.  I know that the K14 from the ECO-Diesel model boosts efficiently to around 15PSI and has low lag due to it's size but where do the other models such as the K24, T3, etc. lie in relation to the K14?  If this has been previously posted a link to that posting would be great.  I'm even thinking that a chart with boost on the vertical axis and lag on the horizontal axis would be quite useful.

Thanks

[nathan_b]

lag cant really be measured because it is relative and there is no official measurement of it.

[RabbitJockey]

imo tho bigger is always better, na cars scoot around ok with out a turbo at all, i'd rather have a huge hit of power at higher rpms than worry about quick spool up... only to a certain point obviously tho.

[nathan_b]

I disagree. Depends on what you are after. I think k14 and k03 are fantastic turbos for idis. k24/t3 can have higher power but are laggy. and by laggy I am talking no power in first gear. but balls to the walls by 3rd. Not a good daily driver combination. lol.

[8v-of-fury]

I have to agree with Nathan on this one. What's the point of having the big hit of power at higher rpms when we are driving diesels that max at 5500ish. You want your power to only come on at 3750+? And be disgusto laggy until then?

I think the k14 is actually perfectly suited to the smaller 1.6idi's in the fact that it will spool quickly and still be able to flow the air uptop. I mean the small ko3 can flow 5000 rpm on the 1.9 AHU.. And its marginally smaller than the k14.

[RabbitJockey]

i think that the smaller turbos are best for a daily driver only car, but if u want a cross between fun and daily, a larger turbos going to be far better,  what i am saying is, u don't really need that quick spool up down low cause they already get moving just fine, the big turbo will give u more peak power, and make merging on to the highway far easier, na cars just don't have much *** after 45-50mph, so u still get the extra power when u really need it, and far more peak power, when u really want it

[burn_your_money]

Plus a smaller turbo will wear out faster than a larger one. And it's my opinion that the smaller turbos hurt mileage. That said I would go with a K14 from an AAZ since the cold side is a bit bigger than the 1.6 version IIRC.

[8v-of-fury]

Trev, having a smaller turbo will make that power available way lower in the power band. Why do you think the AHU makes 150 ft.lbs at 18-1900 rpm's? Because of the k03 that is strapped to the back of it. It makes the high torque because it is a 1.9 tdi, but if it had a T3 sized or bigger turbo it wouldnt make the torque until much later. This can be seen when you add the bigger turbo's to the tdi's and the torque peak jumps up significantly on the power band.

Tyler, a smaller turbo will only wear faster if it is run above its ability. For example 20+ psi regularly will destroy a small turbo. Physics says that the smaller turbo (to a degree) should improve mileage. Not with all out race settings though.. If the turbo is cruising at a higher boost pressure and there is more air in the cylinder, and thus a more efficient burn then there should be more gotten out of each unit of energy.

I do agree with the AAZ K14. I feel the k14 will do wonders on a 1.6 for daily driving and a little fun on the weekends.

I am still toying of putting my tdi's k03 and inter cooler on my 1.6 NA with a TD fuel pump.. I think max boost at 2000 would be very nice seeing as how i do %90 in town

[damac]

I got an acn tranny in my 85 jetta td with a t3.  We don't beat on it and cruise on freeaway mostly at 70mph.  Lower gears are fine, but at that highway speed it seems it just starts to pull.  So no good for us if you don't want to get a speeding ticket.  I want to get a different turbo myself but not sure what bolts up easy to my other stock parts.

[vanbcguy]

Jezzie's K24 has absolutely nothing until I'm about to gear up to 2nd.  Beating people off the line doesn't happen, but as soon as I grab second I've got good boost.

On a highway run with the turbo spooled up nicely I have 10+ PSI as low as about 2100 RPM but I definitely don't hit my current 15 PSI max until more like 2600.  For stop and go driving it really isn't the most ideal turbo but once you're moving it works great. 

For the way I run my car currently a smaller turbo would be better.  Having some lower RPM boost would be fantastic, plus I'd be able to get to peak boost a lot sooner.  That said though once you get used to the larger turbo and know how to keep it spun up while driving you do just fine.  My longer term plans include getting up in to the low 20's boost-wise at which point the K24 is pretty much being used to its full potential.

[burn_your_money]

Tyler, a smaller turbo will only wear faster if it is run above its ability.

The smaller turbo will be at higher RPMs more often than a larger turbo, thereby increasing wear and shortening it's life, assuming similar driving styles of course.

[nathan_b]

Tyler, a smaller turbo will only wear faster if it is run above its ability.

The smaller turbo will be at higher RPMs more often than a larger turbo, thereby increasing wear and shortening it's life, assuming similar driving styles of course.

this is assuming that a turbos life is directly related to the number of times it rotates, and I do not think this is correct.

[burn_your_money]

this is assuming that a turbos life is directly related to the number of times it rotates, and I do not think this is correct.

What would you say dictates the life expectancy of a turbo?

[nathan_b]

oil quality, balance condition, abuse (overboost and run with improperly functioning wastegates, barking it ect), filtered air quality.

these sort of things.

[burn_your_money]

oil quality, balance condition, abuse (overboost and run with improperly functioning wastegates, barking it ect), filtered air quality.

these sort of things.

I would consider those things to be abuse, not normal wear and tear. No big deal though