Turboing my NA Diesel

[vwmike]

So, I'm new here on the board. I've had tons of VW's and currently own 7 plus one Audi, and a Mazda. Anyways, my fast car is a Callaway Rabbit GTI that puts down 200hp/229 ft/lbs to the wheels so you can imagine how insanely slow I feel driving the NA diesel.

I'm working with an 81 Rabbit diesel truck, and wish to turbo it. So far I've heard the main differences to the longblock are oil squirters and the head is slightly different. I ran a JH (no squirters) for years and had no issues so I don't think this is a problem so long as you don't keep it in boost for long periods of time. If you've had experience with this though, please let me know.

So far I've managed to scrounge up a few parts that I think will help this thing go faster. I was just planning to hack off a toilet bowl manifold and weld on a garret flange. With the low EGT's of the diesel I figure this should be fine. I then have a turbine off a volvo with the diesel regulator and a good center cartridge with a .42 compressor. I also have a .60 compressor but something tells me that's just too much. I have an MX-6 intercooler that's going to be retired from the Rabbit and now I just need to come up with an injection pump for proper fuel enrichment. I've heard a peugeot injection pump is a good candidate.

So, if you guys think I'm crazy for some reason, or maybe I'm forgetting something, let me know. I'm mainly posting here hoping to hear someone elses experience with what I'm about to do. Thanks

[AntonUK]

Hey vwmike you just need the LDA of another pump you dont need to change the whole thing (maybe thats what you meant anyway?). Anyway sounds like a good conversion hope it goes well for you!

Just a question, whats this diesel regulator on your volvo turbo you mentioned?

[vwmike]

Hey vwmike you just need the LDA of another pump you dont need to change the whole thing (maybe thats what you meant anyway?) . Anyway sounds like a good conversion hope it goes well for you!

Just a question, whats this diesel regulator on your volvo turbo you mentioned?

Thanks for the reply, that's good news on the injection pump. The diesel regulator I was referring to is just the diesel style wastegate on the turbine housing. The Volvo turbine housing has it on there (came off a 6cyl diesel - VW engine ironically).

[VWRacer]

Mike, back in the 80's I considered adding a turbo to my n/a Rabbit. There was a ***in' Callaway kit for them that pumped them up to 60-plus hp (from 52... :cry: ) and gave them quite a bit more torque as well. Unfortunately, the kit was out of my price range and I never did it.

In any case, IIRC the kit left the internals untouched...no squirters. It added boost and a modified pump, that's all. My point here is that I suspect converting an n/a diesel to TD would be a piece of cake, and that the engine would not suffer unduly. If you have the pieces, I say go for it.

Too bad, but I watched a complete used Callaway kit go on eBay a couple of months ago for about $250. They were really nice kits, and I'm sure would be a real conversation and nostalgia piece.

Good luck! Stan

[racer_x]

<snip>
I ran a JH (no squirters) for years and had no issues so I don't think this is a problem so long as you don't keep it in boost for long periods of time. If you've had experience with this though, please let me know.

There's a fundamental difference between diesels and gas engines. Diesels don't have throttle plates. They always take a full load of air. So diesels always run in boost if the engine RPM's are high enough to generate boost. They do generate more boost when the injection pump is injecting more fuel, because there's more post-combustion expansion in the exhaust manifold as the last of the fuel burns. But you'll find that turbodiesel engines run in boost a lot more than gas engines do.

So far I've managed to scrounge up a few parts that I think will help this thing go faster. I was just planning to hack off a toilet bowl manifold and weld on a garret flange. With the low EGT's of the diesel I figure this should be fine.

Do a search for "EGT" on this message board before you jump to conclusions. Diesels run lean, so EGT's can get quite high, especially when operating in boost under moderate to heavy loads.

I then have a turbine off a volvo with the diesel regulator and a good center cartridge with a .42 compressor. I also have a .60 compressor but something tells me that's just too much. I have an MX-6 intercooler that's going to be retired from the Rabbit and now I just need to come up with an injection pump for proper fuel enrichment. I've heard a peugeot injection pump is a good candidate.

So, if you guys think I'm crazy for some reason, or maybe I'm forgetting something, let me know. I'm mainly posting here hoping to hear someone elses experience with what I'm about to do. Thanks

Personally I think you're crazy.

It is possible to turbocharge a normally asthmatic VW diesel engine. With a lot of work and a lot of expense, you can get one up to 65-70hp. Going much beyond that is asking for reliability problems.

If you start with a VW 1.6L turbodiesel engine, you'll have that amount of power out of a completely stock configuration. And if you make a few mods, you can get up to 90-100hp and near 150 ft. lbs. of torque. And at that level of performance, the thing will still be solid and reliable if you take proper care and make sure your maintenance is good. You'll never reach that level of performance starting with a normally aspirated engine and adding to it.

The following things are different in the turbodiesel engine (compared to your normally aspirated engine):

- Head - different alloy for the casting
- Exhaust valves - different material
- Block - oil squirters and oil galleys to feed them with oil
- oil pump
- injection pump (LDA)
- oil cooler (not present on the n/a diesel)

I'm probably forgetting some other things.

On top of all that, your 1981 has the older, weaker head bolts. So keeping head gaskets in the thing is a problem. Those bolts can barely hold the gasket in a normally aspirated engine. VW switched to the stronger 12mm bolts for all of the diesel engines in mid 1982.
If you want more power, you'd be better off findind a 1.6 TD engine and starting there.

Basically, you can reach stock 1.6TD performance levels by adding a turbo to a normally aspirated 1.6D, but that's very near the upper end of the performance envelope for a 1.6D with a turbo added. If you want more power, you really want to start with a real 1.6TD and start modding it further from there.

[vwmike]

<snip>
I ran a JH (no squirters) for years and had no issues so I don't think this is a problem so long as you don't keep it in boost for long periods of time. If you've had experience with this though, please let me know.

There's a fundamental difference between diesels and gas engines. Diesels don't have throttle plates. They always take a full load of air. So diesels always run in boost if the engine RPM's are high enough to generate boost. They do generate more boost when the injection pump is injecting more fuel, because there's more post-combustion expansion in the exhaust manifold as the last of the fuel burns. But you'll find that turbodiesel engines run in boost a lot more than gas engines do.

I've driven a turbo diesel VW before and the thing was hardly ever in boost. It had to be in a higher gear with tons of load to see the boost gauge even move.

So far I've managed to scrounge up a few parts that I think will help this thing go faster. I was just planning to hack off a toilet bowl manifold and weld on a garret flange. With the low EGT's of the diesel I figure this should be fine.

Do a search for "EGT" on this message board before you jump to conclusions. Diesels run lean, so EGT's can get quite high, especially when operating in boost under moderate to heavy loads.

I suppose it's a consideration under boost....but I've always heard figures of around 1100 for the old spearco kits and whatnot. That seems pretty low to me.

I then have a turbine off a volvo with the diesel regulator and a good center cartridge with a .42 compressor. I also have a .60 compressor but something tells me that's just too much. I have an MX-6 intercooler that's going to be retired from the Rabbit and now I just need to come up with an injection pump for proper fuel enrichment. I've heard a peugeot injection pump is a good candidate.

So, if you guys think I'm crazy for some reason, or maybe I'm forgetting something, let me know. I'm mainly posting here hoping to hear someone elses experience with what I'm about to do. Thanks

Personally I think you're crazy.

It is possible to turbocharge a normally asthmatic VW diesel engine. With a lot of work and a lot of expense, you can get one up to 65-70hp. Going much beyond that is asking for reliability problems.

If you start with a VW 1.6L turbodiesel engine, you'll have that amount of power out of a completely stock configuration. And if you make a few mods, you can get up to 90-100hp and near 150 ft. lbs. of torque. And at that level of performance, the thing will still be solid and reliable if you take proper care and make sure your maintenance is good. You'll never reach that level of performance starting with a normally aspirated engine and adding to it.

The following things are different in the turbodiesel engine (compared to your normally aspirated engine):

- Head - different alloy for the casting
- Exhaust valves - different material
- Block - oil squirters and oil galleys to feed them with oil
- oil pump
- injection pump (LDA)
- oil cooler (not present on the n/a diesel)

I'm probably forgetting some other things.

On top of all that, your 1981 has the older, weaker head bolts. So keeping head gaskets in the thing is a problem. Those bolts can barely hold the gasket in a normally aspirated engine. VW switched to the stronger 12mm bolts for all of the diesel engines in mid 1982.
If you want more power, you'd be better off findind a 1.6 TD engine and starting there.

Basically, you can reach stock 1.6TD performance levels by adding a turbo to a normally aspirated 1.6D, but that's very near the upper end of the performance envelope for a 1.6D with a turbo added. If you want more power, you really want to start with a real 1.6TD and start modding it further from there.

I'm not really looking for big power. I was figuring I'd just hook up the wastegate and leave boost pressure wherever it lands. 10psi would be my guess. I'll be running an intercooler so charge temps won't even be all that high. If I could get the power of the stock TD, then great....that's better than it is now. I don't really consider this to be a costly upgrade because I already have the turbo (free). I'll weld up the manifold for it ($20 for a flange at most), use the intercooler I already have (free), get the TD LDA off a peugeot ($3.50 I think at my local yard for the whole pump - they call it a mechanical fuel pump), I'd probably need 3-4 mandrel u-bends and a braided flex coupling ($80 or so)....so I think I'm running over my previous budget of $100....but oh well. TD's just aren't easy to find around here and competition is fierce. Not to mention finding one that doesn't need to be rebuilt is very difficult.

[vwmike]

I just went and checked, and my truck has 12mm head bolts. So I guess that isn't as much of a concern now. I can add an oil cooler, no problem. Are there any other specific areas that you think I might run into a problem? Thanks!

[Wingaman]

Why using mandrel bent piping for your IC on a 70 hp diesel engine ?

Use PVC, muffler pipe or prestone hose like i will use on my 1,9TD in my jetta when i will have my volvo 850 ic(she will be near 110 hp at 15-17 psi at WOT). It's cheap and make the same job  

[vwmike]

Mandrels are only about $10 each in 2" diameters. I need to use them to make the downpipe so why not just buy a couple to make the charge pipes? Besides, I like not being ghetto when i work on my cars.

[therabbittree]

Mike do it!... it is 1000 times easier to turbo charge a diesel then a gasser...My friend blake had one he built for years raced for years also 16sec 1/4mile times...i also did up a 1.5 na once it was a slug but i think it was becuase i lowered the compression too much....any how get a set of head studs , get egt and boost and oil pressure guages , mount the egt pre turbo..try to keep it under 1400 ...and if you do run 1400 don't keep your foot in it for long..ie more then a min or so...put a oil cooler on it too i'm sure you got em laying around..they can take 35 plus psi of boost mine and my buddy blakes did...put in a air regulator in the waste gate line and adjust in the truck....with stock injectors your only mods basically will be adjust max fuel screw on pump...turn in screw until rpms don't return quickly to idle when the engine is revved quick / blirped, (take the collar of the screw)...and if you get a LDA pump or the top off of one turn the pin so the notch is facing the pump gear..also you can grind the notch in the pin deeper, adjust the spring seat all the way down and soften the spring it self, also grind the height of the nylon washer down...all this gets max fuel asap...the timing can be advanced, and you will need the high boost to burn the extra fuel....these head gaskets have a wide fire ring if you want to o-ring the head / block ... thats the down fall of the IDI's easier to blow head gaskets stock... with my 12mm 1.6Td td pump on a 1.6L td stock injectors i did 134hp at the wheels..at waterfest 2years ago.
    sorry for the delay i was going  to reply at vw sport...it took me 1/2 to type this ..my computer is on the fritz, keeps bugging out ha...email me i you have and questions thanks
Deo
\x/ hillfolk!
[email protected]

[vwmike]

Thanks Deo! That's more of the information I was looking for! I feel like this is a black art. No one wants to tell me anything other than "don't do it, that's bad". I want to know what breaks but it's sounding more like it just gets too hot and melts pistons or blows head gaskets. Is there any place with pictures of the mods to the pump? I was just going to swap an LDA on from a Volvo or Peugeot pump (I've heard it would work with my stock pump). What turbo were you using?

[therabbittree]

for pump mods here or the old gtd board is good ro vw specific info if general ve pump look at theturbodieselregister.com ..lookin first gen forums and stickys they use the same ve pumpon dodge cummins engines from '89=93m in the pickup but case and other construction/ gensets/ and marine resources use the ve also...i have never swapeda pump top myself ..so i can't help you there ..might be easier to buy a good used 1.6L td pump probably could get one cheap $100 or less if you look good... Black art...man tuning gas turbo is a black art diesel is just add fuel and add boost to cool egt ..its all about egt..control that and make the power.. with a gasser it's detonation and staying stoich or richer..pain in the ass..i'm doing a g60 management ,jh shortblock, with crossflow head for my buddies rabbit and its soomuch easier to do a diesel..ha.... i used a stock kkk turbo from a early jetta turbo diesel with mine and a eco diesel intake (one with out the blow off valve).. sure at 35 psi that turbo was way out of its range but it kept my egt down .. cleared my 12mm pumps smoke up .... my new project will have twin staged turbos ...working on a mechanical tdi setup and hopfully soon a 5cyl idi setup for a quantum syncro wagon i'm doing..either way for  both I plan on using  the stock td turbo for the smaller one and a hy35 holset turbo for the larger one... twin staged then i can get quick spool up and good cool high boost within a map for the top end. Just need to make sure i don't blow a head gasket..so im looking at firerings ..1 pieces metal orings the tractor pullers use in place of file fit stainless o rings..firerings hold higher psi because o the 1 piece and it loses the builder error in file fitting the o ring gap etc... i hope to hold 40 -50 psi reliably..the dodge guys push 80-100 easy and the puller push 200 plus psi.......i just want to clear upmy hopefully overfueled smoke really quick and keep egts down under 100 pre turbo under large load etc..twins helped my dodge ..I haven't been able to break 1100 degrees pre trubo loaded towing any thing since...so i guess i need more fuel ha...hehe so don't get me wrong a vw td is better suited for building a turbo project as it has the oil squirters , better oil pump, bigger prechambers, selite faced valve, supposedly heat treated head, grafol coating on piston skirts etc... so a turbo na diesel probably is pushing the stock design ..but if you watch your gauges there no reason it won't work.. plus i take it you can work on engines and rebuild them if you break it..and if your driving a old na rabbit you definately know maintence is what keeps a vehicle going.... you never get something for nothing ..like wise you gt out of it what you put into it etc.. hopoe that help ya out
later
Deo
\x/ hillFolk!

[hillfolk'r]

hey deo remember my old truck,,was a na with turbo setup,,ran for like 80k,turned up,and boosted,,if ya kept it mild,itll last 4 ever,,the piston coolers are the key to he cooling,but itll work,,looks like they can be put in a na block too

[scopefrfd]

I personally owned a callaway turbo diesel.  It was in a caddy and  the engine was a converted NA 1.6D.  The only real mod that had to be done was the block had to be drilled and tapped at a slight angle for the oil drainback for the turbo on the back of the block.   Callaway ran a huge rotomaster T04, same unit as on the gas engines at the time.  It was setup to run 12lbs of boost @ 1400egt on a radically ported NA cylinder head.   The engine didn't really make boost until 2500-2600 rpms.  After that it pulled like a train all the way to the 5500 redline I used.   The pump enrichment screw was turned in about 1 full turn to make the 12lbs of boost @  and a max of 1400EGT.  I ran a therm sandwich adapter and a earl's oil cooler.   The engine was completely overhauled for the turbo installation.   I also ran a 2" TT exhaust because at the time that was the biggest they had.


The boost may sound low but the ports were enlarged so much that the boost levels might have been down but it really flowed the cfm's into the engine.  Remember boost levels only show the restriction in the intake tract.  Remove the restriction and with everything being equal your boost readings will go down.   The p/u was used for both work(I did residential energy conservation I used it to drive from home to home) and play the majority was highway miles.  It was a great highway vehicle, it could do 100mph.  Going down the highway at 65 the turbo always made 1-2psi of boost.   I didn't mind not having boost down low because on the highwaiy I made boost all the time.  


I took it skiing almost every week for 2 yrs (I miss not having the college season ski pass.) :-(  Believe me there are some big hills on NH,VT,ME highways with long periods of being on high boost.  Point being, I ran that engine for 6 yrs, never had any trouble, never blew a headgasket, cooked a valve, etc. and I eventually gave it to my nephew and it still runs great and makes 10lbs+ of boost.  I easily put 100k on that engine.  I speak from experience, those NA diesel can take alot of abuse, and I wouldn't hesitate to turbo one again.

[VWRacer]

Good info, scopefrfd, and I'd love to hear more about porting the diesel head. You have any old pics or can you tell us more about it? Thanks! Stan