The ODB goes Turbo (1 Viewer)

[karlslashwarren]

35's, armor and camping gear have made my 80 (The ODB) too slow, especially at elevation. I'd go for a supercharger for simplicity's sake but it seems like turbo is my best option at this point. I’ve been reading through posts here and plotting a turbo build for my rig. Basically I’m following @scottryana’s recipe for a mild turbo to mimic the oem supercharger, with some of my own tweaks. My 96 has 209k miles and the HG was done at 150k, no known engine issues.

These threads are my main inspiration: So are there any TRD Superchargers left?

TurboClunker (a.k.a. cheap-ass slaps a turbo on his LX)

1. Use stock airbox (it’s snorked)
   
   
2. No ecu, fueling, timing mods (mimicking oem supercharger)
   
   
3. Ability to revert to stock with no welding
   
   
4. Stock exhaust from front 02 sensor rearward
   

I’m putting this plan up for dissection from you guys before I purchase parts. I’m planning on using a Treadstone manifold, borg warner s300sx twin scroll, Tial 38mm wg, Tial recirculating bov, Treadstone oil supply/drain. AEM wideband O2 gauge, turbo oil pressure gauge, egt gauge(eh why not?), and a small a/a intercooler in the ps side of the grill. Plus a whole mess of stainless tube, silicon bits and clamps to hold it all together.


I plan to use the stock airbox with the maf attached as stock, this will connect to the compressor intake of the turbo. I will use a recirculating bov to make sure air metered by the maf is not vented to the atmosphere. Then I plan to route the charge pipe under the ps headlight to a small a/a intercooler in the ps side grill, then back under the headlight again (cutting a large oval in the fender support sheet metal). I might need to relocate the radiator overflow tank. Charge pipe will have a recirculating bov on it’s way to the intake. I like the idea of leaving the maf in the stock location on the airbox so it will not be subjected to hot and possibly oily post turbo air.

Here are some more specific questions:

1. Is there any benefit to a twin scroll turbo on a single scroll manifold like the Treadstone? I figure probably not, but if there is no downside I would like to go twin scroll so I could possibly ditch the Treadstone for a twin scroll J/Y pipe configuration in the future.
   
   
2. For those who have used the Treadstone, is there enough meat to grind out the egr port?
   
   
3. Does a vacuum controlled system such as the egr even function on a turbo rig? I would like to keep the egr functional but if it won’t be doing anything, I might as well not carve out a port (if I even can).
   
   
4. I plan to limit boost to somewhere under 8 psi, would it make sense to use a boost controller to add more precision to the boost response curve? More specifically, use a low psi (4ish?) wg spring, then manipulate boost via a boost controller for more accurate pressure control. I’m new to turbos and I realize this might be fundamentally impossible due to vacuum/ spring force, just thought I’d ask. Probably overkill too but this is mud!
   

 

[inkpot]

Asuming you do all the work yourself, what do you estimate the cost of parts and any machine work to be?

 

[scottryana]

I would use a bigger wastegate.

1. Is there any benefit to a twin scroll turbo on a single scroll manifold like the Treadstone? I figure probably not, but if there is no downside I would like to go twin scroll so I could possibly ditch the Treadstone for a twin scroll J/Y pipe configuration in the future. There is no benefit to using a twin scroll on a single scroll manifold, in fact it is kind of a hindrance but since this is such a low stress system I don't think you will have any problems.
   
   
2. For those who have used the Treadstone, is there enough meat to grind out the egr port?
   
   
3. Does a vacuum controlled system such as the egr even function on a turbo rig? I would like to keep the egr functional but if it won’t be doing anything, I might as well not carve out a port (if I even can). Even with a turbo system you are not always in positive manifold pressure, the EGR will have some functionality but I would remove it (highly debated I know)
   
   
4. I plan to limit boost to somewhere under 8 psi, would it make sense to use a boost controller to add more precision to the boost response curve? More specifically, use a low psi (4ish?) wg spring, then manipulate boost via a boost controller for more accurate pressure control. I’m new to turbos and I realize this might be fundamentally impossible due to vacuum/ spring force, just thought I’d ask. Probably overkill too but this is mud! This is possible but you would be looking at an electronic boost controller of some sort since it is the only thing that would give you nonlinear boost control. There is definitely a little more boost to be had up top considering how rich the trucks run, but if you start adding too much more boost you really need to also have control of the timing so at that point you are looking at a standalone and you get timing, fueling and boost control.....

 

[nukegoat]

I am not an engine guy but do any of you turbo types have concerns about trail failures with doing stuff like this? Or is the system essentially something that can limp itself home under most failure modes? I imagine some oil leak at some critical place being a real disappointment in the middle of some long and remote trail. Sorry for the dumb questions.

 

[scottryana]

I guess it wouldn't be any more trouble some than a Toyota turbo diesel. Yes I guess you have an oil line returning to the sump but it really presents no more risk than punching a hole in the oil pan. If something did happen to the oil line it is not under pressure it is gravity drain so easily patched up with electrical tape I would guess.

I am not an engine guy but do any of you turbo types have concerns about trail failures with doing stuff like this? Or is the system essentially something that can limp itself home under most failure modes? I imagine some oil leak at some critical place being a real disappointment in the middle of some long and remote trail. Sorry for the dumb questions.

 

[inkpot]

I am not an engine guy but do any of you turbo types have concerns about trail failures with doing stuff like this? Or is the system essentially something that can limp itself home under most failure modes? I imagine some oil leak at some critical place being a real disappointment in the middle of some long and remote trail. Sorry for the dumb questions.

That is one of the nice things about the TRD S/C setup. If you loose a belt it still drives ok both on trail and highway. BTDT several times. It is kind of doggy, like a 3fe rig? , but quite functional. Now, if the rotors freeze up it would likely be hard to get enough air thru it to run above idle. That WOULD be an interesting test. Turbine would likely have the same issues if the bearings froze up.
On a side note, I rebuilt my Eaton M90 at way over 100,000 miles. It sees a fair amount of hard use with engine over 5000 RPM. ALL of the bearings were in like new condition: full of lube and smooth rolling with no visible signs of wear or abuse. I was amazed. I did have a slight bit of seal leakage on the nose cone, so I did replace that seal while I was there.
I have not heard of anyone on here that has frozen up their rotors or turbines, but I suppose it is possible?

 

[karlslashwarren]

I'm going to post my detailed shopping list soon. Very rough estimate is $2500. Gonna go bigger on the wastegate now, what would you use?

 

[karlslashwarren]

Failure in the middle of nowhere is a big concern for me as well. If i had a turbo failure on the sticks, I would probably reroute the charge pipe to make a naturally aspirated intake and bypass the turbo. Maybe try to hold the wastegate open and limit boost. Someone more knowledgeable than myself may have a procedure that's better.

 

[scottryana]

I mean if you were really really worried about a turbo failure, you could make a diverter pipe that just replaced the turbo, you unbolt the turbo bolt this in place so exhaust comes out the manifold, through the diverter to the downpipe, BUT this is way way overkill even for mud. How many turbo's have you heard of failing to the point of not allowing the engine to run?

I think creating a well put together system and the parts will last longer more miles than most of our non-rebuilt engines have left in them.

 

[karlslashwarren]

I'm about to pull the trigger on this turbo:
*Brand New* BorgWarner S300SX3- S360 T4 .91A/R Turbo *FASTEST SHIPPING* #177272 | eBay
If anything looks wrong about it or the sizing please let me know. I believe it is the same turbo from the turboclunker build. Looks like I'll need a funky Borg Warner marman flange too.

The Treadstone manifold description says it is for a 38mm wastegate. If I go to a bigger wastegate, wouldn't I be limited in flow by the 38mm orifice?

 

[Heckraiser]

I think Ryan addressed your main points and i replied to your PM. The treadstone manifold definitely has more than enough bulk to carve out an EGR port.

FWIW, I ran a Tial 38mm wastegate with a 5.8psi spring and I got exactly 5.8psi as measured on the boost gauge. No creep or fall off, and was very consistent. So if you don't want to tinker, I think you'd be fine just getting the right WG spring for the amount of boost you want.

And finally, you might want to pm @4rings5cyls . He bought my kit and might still have it on the shelf.

:edit: That BW is the same turbo I ran. Worked fine. Be sure you get the specific downpipe flange designed for the turbo (and factor that into your budget). A standard 3.5" vband does not seal well. The only one I could find online was Himni racing to the tune of about $80.

 

[Heckraiser]

I am not an engine guy but do any of you turbo types have concerns about trail failures with doing stuff like this? Or is the system essentially something that can limp itself home under most failure modes? I imagine some oil leak at some critical place being a real disappointment in the middle of some long and remote trail. Sorry for the dumb questions.

When turbos fail, they rarely fail catastrophically. Even if you blow the seals, they smoke and make heat, but you can still limp home. If the s*** really hits the fan and you break off a few blades, they will either get stuck in your cat or in your intercooler. I.e. you can still limp home.

 

[inkpot]

When turbos fail, they rarely fail catastrophically. Even if you blow the seals, they smoke and make heat, but you can still limp home. If the s*** really hits the fan and you break off a few blades, they will either get stuck in your cat or in your intercooler. I.e. you can still limp home.

Ok. So to follow this a bit further, What if you blow/freeze up a bearing on the turbine itself. Will it still pass enough air flow to run decent? Just curious, as I was told a long time ago that if I lost the belt on my TRD SC it would run so bad that I would have problems driving it up my driveway. I found out the hard way that it still wheels and drives on the hiway pretty decent, just a bit doggy.

 

[Heckraiser]

If the turbine stopped spinning, I imagine the truck would run pretty poorly, but would probably still run. I imagine the backpressure on the exhaust side would be more of a problem than intake side. That BW has a 4" intake hole and 7 blades, so still a lot of open space for the air to get through. On the exhaust side, I don't remember the blade layout, but the exhaust dump is 3.5". So air would get out, but would have a much more turbulent path. Just guessing, the overall effect would be similar to when the screws in your SC stop spinning, or a bit worse due to the exhaust turbulence.

FWIW, I've never heard of one that just froze up and stopped spinning (not that I'm an expert or anything). Usually they will smoke, develop bearing play and you'll notice the crappy performance if not the noises/smoke.

 

[4rings5cyls]

.....

And finally, you might want to pm @4rings5cyls . He bought my kit and might still have it on the shelf.

:edit: That BW is the same turbo I ran. Worked fine. Be sure you get the specific downpipe flange designed for the turbo (and factor that into your budget). A standard 3.5" vband does not seal well. The only one I could find online was Himni racing to the tune of about $80.

I do...the whole kit is currently in the classifieds. I really want to put it on, but our budget for building a house takes priority.

 

[LandCruisinMy93]

I am not an engine guy but do any of you turbo types have concerns about trail failures with doing stuff like this? Or is the system essentially something that can limp itself home under most failure modes? I imagine some oil leak at some critical place being a real disappointment in the middle of some long and remote trail. Sorry for the dumb questions.

Unless the sealing rings of the turbine shaft fail you should be able to remove the cartridge/bearing housing from the turbine housing and the oil circuit would remain uninterrupted. The turbo would no longer have drive pressure and you're essentially left with an open exhaust and in need of an intake tube or air filter you could shove on the intake. An aftermarket turbocharged motor should essentially get you back to stock power. Even a stand alone with a MAF and O2 sensors should be able to safely remap in the absence of the boost. You'd just need a method of either blocking off the turbine housing where you took the cartridge out or carry a pipe that can be placed between the exhaust manifold and exhaust in the absence of the turbine housing.

 

[inkpot]

If the turbine stopped spinning, I imagine the truck would run pretty poorly, but would probably still run. I imagine the backpressure on the exhaust side would be more of a problem than intake side. That BW has a 4" intake hole and 7 blades, so still a lot of open space for the air to get through. On the exhaust side, I don't remember the blade layout, but the exhaust dump is 3.5". So air would get out, but would have a much more turbulent path. Just guessing, the overall effect would be similar to when the screws in your SC stop spinning, or a bit worse due to the exhaust turbulence.

FWIW, I've never heard of one that just froze up and stopped spinning (not that I'm an expert or anything). Usually they will smoke, develop bearing play and you'll notice the crappy performance if not the noises/smoke.

The tolerances on the SC rotors are close enuff that the intake vacuum pulls them right up close to speed. If it froze a bearing or 2/3, I think it would be pretty rude to drive at any speed. Quality bearings are certainly the best plan on either a Turbo or SC. I recently opened mine up after way more than 100,000 miles, much of which is WOT, and the bearings were all beautiful! Only thing I really needed was the nose cone seal which was showing a little oil seepage.

 

[karlslashwarren]

I just ordered the turbo, thanks again to all of the turbo pioneers! Hopefully I can add to the data for these diy setups. I'll post more progress as the parts start rolling in.

 

[karlslashwarren]

I'm doing the prep for this turbo in a series of small projects. The first is to install the oil drain fitting in the upper oil pan. I'm due for an oil change anyway so the timing is perfect.
The plan is to drop the lower pan and install this fitting, bolted from the inside. I will probably add some split lock washers too. I like that it thru bolts so the pan doesn't need to be tapped.
Russell 697090: Oil Pan Flange Fitting -10 AN Male | JEGS

 

[NLXTACY]

Ok. So to follow this a bit further, What if you blow/freeze up a bearing on the turbine itself. Will it still pass enough air flow to run decent? Just curious, as I was told a long time ago that if I lost the belt on my TRD SC it would run so bad that I would have problems driving it up my driveway. I found out the hard way that it still wheels and drives on the hiway pretty decent, just a bit doggy.

When I had my belt problem I zip tied the bypass that I think it was you that suggested. Drove for weeks like that.