1.6 TURBO vs 1.9turbo and intercooling options

[Anonymous]

hey guys,
i was out comparing the difference between the 1.6td and the 1.9tdi, and noticed that the tdi's turbo is watercooled!!!!!! not just intercooled!

it's definately a night and day setup from the 1.6td.

I also noticed that my 1.6turbo was extremely hot just after only a couple of mins. driving.... and this was the intake side of it.

I have an intercooler off an audi 1.8t that i'm thinking of using to bring the temps down.....

anyone else intercool their 1.6td and notice the temps go down tremendously?

david

[fspGTD]

The transverse-mounted 1.6lTD intake manifold is prone to heat soak due to the turbo being located right near it.  Luckily, it seems to heat soak worse with the car sitting still, hood up than it does with the hood closed and driving.

An intercooler will help to cool down the compressor-induced heat, but only works when there is boost pressure.  It won't help with the heat-soak issue.  There isn't a whole lot of compressor-induced heat at stock boost pressure but it still doesn't hurt.  The compressor-induced heat goes up as you adjust the boost pressure higher.  Make sure whatever intercooler you add has good flow characteristics and good cooling ability or you run the risk of doing more harm than good with it.

PS - another effective way to cool down the motor more is to enlarge the exhaust system.  The stock exhaust makes a lot of backpressure at the turbine outlet, which also backs up to the turbine inlet and all the way into the motor.  Relieving the backpressure by going to a large-diameter exhaust (such as 2.25+" diameter) will cool down the turbine inlet and outlet temps considerably.

The stable operating temps of the motor will primarily be controlled by the thermostat.  The stock thermostat of both the N/A and turbo 1.5/1.6 diesels is set quite high!

Hope that helps and good luck

[BlackTieTD]

jake: an exhaust system is only as good as its most restrictive bottleneck...so if i'm not mistaken, unless you fabricate a downpipe in 2.25" or larger, the largest exhaust you'll be able to get on a 1.6TD will be by modifying the 1.9TD downpipe to work, which has an inner diameter of around 2.125" or something close.

so technically, you wouldn't really benefit from going any bigger than 2.25" without a completely custom downpipe, would you?

(i'm about to do the exhaust on my car   )

[dieseltech]

i put a 2.25 from turbo back streight pipe no mufflers custom mandril bent at my shop on my 86 jetta td.

WOW   it was like a whole new car. i did that a year ago. its not that loud but you can hear that turbo, sound like a tractor trailer, and it did cool the temps down a bit when climbing steep hills. also with the stock pipe the best psi out of the turbo i could get was about 15 now with 2.25 i can get 35 psi!!, i never run it that high but i was playing one day just to see how high it would go!.

[fspGTD]

I can see the logic in your theory...  It's possible that further enlarging post-turbine outlet is helpful, but I agree that it's not really well-tested or established yet.    What kind of flex-joint are you planning on using?  Let us know how it works!

My system enlarges smoothly from 2 5/16" to 2.5" at the balljoint between the upper downpipe and the lower downpipe.  Here's a shot looking up into the upper downpipe where this transition happens:

Lower downpipe:

More pictures:
http://home.comcast.net/~vwgtd/downpipe.htm

Dad's '84 will also maintain the 2.25" exhaust currently on it, when we turbo his 1.6l.  Haven't figured out what we'll do for the downpipe yet, might just throw the stock one on there because it's easy, although maybe we'll figure out something.  IMO, someone should make up abatch of performance downpipes for these cars IMO...  Dad would buy one.  

[AntonUK]

hi, does anybody know how restrictive the exhaust on the 1.9TD is?? Iv not really heard of anyone saying they are?

thanks guys!

[VWRacer]

I don't know about the 1.9, but the downpipe on my '85 Quantum is pinched right after the turbine outlet down to something like 1"...I mean really bad! :shock: