Turbo addon

coke · Post by **coke** » Thu Dec 30, 2010 3:42 pm

Toying with the idea of adding on a Turbo to my 1.6L NA for the pure economy gain. Not looking for a powerhouse, which means I'll be using my NA pump.

So I'm thinking what I'll need is turbo, manifolds, oil pan, filter flange (for the turbo oil line, right?) and some piping. I'm fairly certain some of you have done this before but I can't remember.

Having problems locating decently priced used turbo motors, which was my first idea, but it is still an option. What do you folks recommend for a turbo and what other custom modifications might I have to make?

I wana get rid of the AWY transmission too. It screams at 65-70. Looking at the old gear/transmission calculator, looks like the possible candidates are the ACH and the AGS. Both should fit, right? Anyone replaced an AWY with something different?

How about the ACN? I know its for a gasser, but I didn't know if the gasser ratios would be ok for a Diesel.

Vincent Waldon · Post by **Vincent Waldon** » Thu Dec 30, 2010 7:39 pm

Probably a good idea to scare up the oil cooler as well... particularly since your block won't have oil squirters.

coke · Post by **coke** » Thu Dec 30, 2010 8:15 pm

Yeah, I had that in my mind just forgot to translate it into text.

79 300sd · Post by **79 300sd** » Thu Dec 30, 2010 9:28 pm

Working on the turbo install this weekend. Don't forget the down pipe, new exhaust, air filter, and piping for the filter. I chose a t3 turbo from a mercedes 300sd because I had a good spare one laying around, and bought an exhaust manifold for an 8v 2.0 like this one.
http://cgi.ebay.com/ebaymotors/VW-2-0L- ... 35ab57a7ea

I'm thinking I read that a smaller turbo would have been better to get some boost at lower engine speed. I think that thread I read suggested that boost would start at around 2000rpm.

I have the ACH trans and like it ok. I'll know better in a few days when the new used engine is in. The old 1.6 never felt like it had the power that it should. If it still loses too much speed on the hills on the interstate then an AGS would solve my biggest complaint. Couldn't get over 55 uphill in fourth and couldn't maintain speed uphill in fifth. The taller fourth in the AGS would make it a lot easier to drive around here.

coke · Post by **coke** » Thu Dec 30, 2010 9:30 pm

I'm trying to get less RPM at high way speed. Around town doesn't really matter. My tuned up pump really puts out the power. Lower rpm equates to lower fuel consumption at interstate/highway speed. My little 84 Jetta had a beautiful 5th gear/final drive combo.

The ACN would be even less, but its a gas transmission and I'm not entirely certain it can be used. I'm sure it can but not quite sure about the expected results. I just want something less than "sounds like the engine is gonna explode" at 70mph.

What kinda RPMs did your ACH turn at high way speeds?

79 300sd · Post by **79 300sd** » Thu Dec 30, 2010 9:40 pm

Yes, but the AGS has a taller fourth and would solve my complaint about the hills.......if the new motor doesn't. Just a little more speed in fourth, or enough power to stay in fifth would make a world of difference. I'll know for sure in a couple of days. Hope to be driving it this weekend.

coke · Post by **coke** » Thu Dec 30, 2010 9:45 pm

Transmissions and gear ratios confuse the hell out of me. I can punch numbers on the Gear up! calculator and figure out my engine speed at a given rpm with the final drive and gear ratio but thats about it.

Now, the ACH turns more in 4th at a given speed than the AGS does, so wouldn't the ACH be more what you're looking for? Or are you trying to build up more speed in 4th with the taller gearing in order to climb the hill?

How was your ACH highway speeds? My AWY is horrid. It revs about 34-3600 at 60-70 mph.

79 300sd · Post by **79 300sd** » Thu Dec 30, 2010 9:49 pm

I don't know what I read that prompted the last response...lol

I don't have a tach in the car, but the ACH seems like it is geared right to drive at 70 or 75 without winding it out to much. In fact I wouldn't want a taller gear unless I come up with a LOT more power.

The 81 dasher I used to have would sound like it was going to explode on the interstate, but would keep up with traffic pretty good.

With a lot of power, maybe an AGS with a .71 fifth could make a great highway cruiser.

Maybe somebody has an ACN and could let us know how it is. I would be worried that is is geared too tall.

coke · Post by **coke** » Thu Dec 30, 2010 9:53 pm

The ACN has a 3.67 final drive and a 0.75 5th. Gearing between 1-4 is the same as the ACH. It'd be about 2800 RPM at 70 mph vs the 3600 I'm at now.

The AWY is a 3.94 final drive with a 0.89 5th.

DanHoug · Post by **DanHoug** » Thu Dec 30, 2010 9:58 pm

i've got the AWY in my 91 also and it revs at hwy speed. i wonder if VW reasoned (right or wrong) that this might reduce head gasket failures if the engine was kept at higher rpm - lower combustion pressures.

the noise bugs me but at 340k miles, the high rpms don't seem to be a longevity factor. might even help. ya drive these motors on rpm as we all know.

it would be interesting to know the MPG effect of lower gearing. one would ASSUME it would help but it is a complex relationship between engine load, rpm, and efficiency.

-dan

79 300sd · Post by **79 300sd** » Thu Dec 30, 2010 10:00 pm

With the ACH I run out of rpm in fourth before I have enough speed to use fifth. This has only been a problem uphill. It works good on level ground. I think if the problem persists, then the smaller spread between fourth and fifth will be what I need. I used to think that the ACH was just geared too tall, but now I'm leaning towards the engine being worn out and not having near enough power.

Not sure about the rpm cruising, but I had it up to 90 once down a long hill. It would have revved up some more, but the little car scares me at that speed.

The lower numerical gear ratio means lower engine revs for a given speed. You can multiply the final ratio by the ratio for a given gear and come up with a number. Compare that number with what you already have/know to kinda judge what you want.

coke · Post by **coke** » Thu Dec 30, 2010 10:04 pm

Yeah I plug all my numbers into the calculator for gear ratios and tire size and whatnot. The ACN definitley has the final drive and 5th I want, but there is some difference between the other gears (1-4).

Probably not enough so I'd notice a huge difference, but I do some highway travel and the less RPMs at highway speed in 5th, the better.

Looks like the AGS would do me well too, only about a 250 rpm difference between 65 mph with the AGS and ACN.

79 300sd · Post by **79 300sd** » Thu Dec 30, 2010 10:12 pm

I just punched in my numbers and came up with 2820 in fifth at 70mph, and 3873rpm in fourth at 70mph. I could do 70 in fourth on lever ground, but that is all it would do.....I thought the rpms would have been a little higher than that in fourth.

coke · Post by **coke** » Thu Dec 30, 2010 10:19 pm

Yeah sounds about right. All I know is I want something different. Either a turbo, or a transmission, or both. But like I said it depends on availability come 2nd week of February as far as parts and stuff.

79 300sd · Post by **79 300sd** » Thu Dec 30, 2010 10:22 pm

If you really have a lot of power, and are more concerned with highway than around town, then the ACN could make a great highway cruiser.

If I replace mine, I think the AGS would be my first choice. I like how 3rd and 4th are a little taller to reduce the spread getting into fifth.