New turbo for old wagon - PeachParts Mercedes-Benz Forum

duxthe1 · #1 11-12-2018, 09:33 PM

It's a day I knew would come eventually, the turbo I installed on the wagon about 40k miles ago is starting to crap out. It's way too small and I spin the ever loving dog piss out of it, so this isn't a surprise. It is, however, an opportunity to put a more appropriately sized turbo on the old girl.

I've spent the past week shopping around and ordered the replacement this evening. It is spec'd as follows: T3 .63 AR turbine housing, stage 3 turbine wheel, T04E 50 trim compressor wheel in a T04B compressor housing, journal bearing center section.

The .63 turbine housing may still be a bit on the small side for a 3 liter motor but huge peak numbers are still the lowest priority for my AWD auto wagon. It's certainly more appropriate than the old .48 housing, though I may miss the ability to power bake and launch with 6PSI in the manifold. The "stage 3" wheel, wasn't selected for any real reason other than that's what almost all of the turbos I considered were spec'd with.

The T04E 50 trim wheel was chosen over the 54, 57, and 60 trim options. It's map's highest efficiency island appeared to be where I'd be using it. The 57 and 60 both could make more peak power, but area under the curve is what I'm shooting for. The T04B housing may loose a few CFM compared to the T04E housing at peak, but having the simpler packaging of the smaller "B" housing will make this more of a drop in replacement.

This turbo should be capable of 450hp without pushing it very far out of its efficiency range. I doubt I'll shoot for that, will have to see how much my injectors can support, and whether my cold side plumbing doesn't hit the wall before the injectors do.

All I can do now is wait for shipping, but will update along the way.

whipplem104 · #2 11-12-2018, 09:43 PM

You should buy this old 722.3 stalled converter I have. Then you wont even know you put a bigger turbo on it on the launch.

sm. pelle · #3 11-13-2018, 05:28 PM

Going with "ebay" turbo? Kinda thinking to take same route. Have one sedan m103 what needs turbo, planing kind a same specs, max 400 hp cruiser.
Hows your 722.3 is lasting? My main consern is that i cant get any signal to cut spark/retard ignition for gear changes. Or some newer ones have some? I have 86.

duxthe1 · #4 11-13-2018, 07:41 PM

No, not an ebay turbo. This is a real Garrett. Ebay turbos are the epitome of you get what you pay for. Actually that isn't even true, there are several claims on the interwebs that the trim ordered and paid for on an ebay turbo doesn't add up with the calipers on the wheels.

My high mile 722.3 gave up third gear a couple years back. We have an old timer in the shop that knows them inside and out and he built me one up a little beefier than stock. Honestly don't know what all he did, I just trusted that he knows his stuff. I did go in the valvebody and raise the working pressure and defeat the 3 and 4 gear pressure reduction. If anything I'm worried about the converter ballooning. Even with the small turbo I've noticed 3-4 upshifts where the RPM doesn't change despite significant acceleration. Once I get it setup with the new turbo I'm not gonna beat on it too hard right away.

Whipple, this car is a touring car, not really built for drag. That didn't keep me from launching hard if the situation called for it, but a stall converter would probably be out of character for it. If anything I'd be looking for a stock converter that can hold what it will put down, but feel free to shoot me a number.

sm. pelle · #5 11-14-2018, 02:53 PM

Ok i think before a real issue im not gonna think about. If u have driven so long then by looks 722.3 will not gonna be an big issue. Gearbox/month ratio would be bad.

atypicalguy · #6 11-14-2018, 08:51 PM

Quote:

Originally Posted by whipplem104

You should buy this old 722.3 stalled converter I have. Then you wont even know you put a bigger turbo on it on the launch.

What is the stall rpm on that? Probably too low for a diesel...

Sent from my SM-G955U using Tapatalk

whipplem104 · #7 11-14-2018, 10:59 PM

Honestly I do not remember exactly. I think it was around 2500 rpm. But that was with supercharger. But that is also what the brakes would hold. It might have been a bit higher or lower. But it was not to aggressive so it had street manors.

atypicalguy · #8 11-15-2018, 09:02 AM

I should be in boost by 1500 so maybe not the best choice.

whipplem104 · #9 11-15-2018, 11:23 AM

So why would you want a stall converter?

atypicalguy · #10 11-15-2018, 03:19 PM

I agree. Just thinking in case it doesnt come up as quickly as expected. I do need one of those harmonic balancers and some valve springs though.

whipplem104 · #11 11-16-2018, 09:46 AM

If you think it will spool by 1500 or so the 2500 is a brake stall. So it takes load to get there. It would be tighter with no boost. Let me know on the balancer and springs. The balancer is a must as far as I am concerned.
We are getting ready to do rods and pistons but I do not want to take away from this thread any longer.

duxthe1 · #12 11-17-2018, 01:22 AM

The wait is over, the turbo has arrived. I also ordered a new wastegate actuator, separately, and it came in today too. Since the new turbo is going to make more power for the same boost pressure, I'm lowering the base pressure from 11 to 7 psi with the new actuator.

If the math is right, my injectors can comfortably make 400hp, which should be around 18 psi. The megasquirt previously had trouble with the boost control spiking the pressure and then trailing off. An artifact of the undersized turbo, I suspect, as no amount of tuning the control could remedy the problem. I'm hopeful that I can dial in the boost control better, with the more appropriately sized turbo.

Lastly I ordered in a new battery for the old tuning laptop. It's already came in, taken a crap, and awaiting a return or replacement. Going to need significant re-tuning once I get the turbo installed so that's a problem. I'm planning to swap it Monday and try my best to get the new VE table sorted in the small window of working laptop I have available.

turbonetics · #13 11-19-2018, 04:27 PM

Great project!
I will do the same thing with my 300E manual which is allready converted to EFI,just need to buy T04E

.Hope that my gearbox will hold.

duxthe1 · #14 11-21-2018, 01:07 AM

I pulled an all nighter Monday, after work and finally in the wee hours, it was alive. Every. Damned. Thing. ... was a fight.

Here's a tip. The Mercedes 5 bolt turbine housing DOES NOT MATCH the common Ford 5 bolt housing. (Which BTW is the only version commonly sold) First hurdle, bolt my wastegate housing to a turbo that has 3 out of 5 bolt holes in the wrong position and 30% of the flange not even matching up.

Undaunted, I pressed forward. About 1/4lb of mig wire later, I've added enough meat to the wastegate housing to move the bolt holes and seal the perimeter. My 12" disc grinder was invaluable in that endeavor. Smoothed with a burr, the flow through the modded housing looks pretty good. Tiny sharp shards of steel now everywhere, but mainly in my hands and fingers.

Alright I can bolt the turbo together. Yay! In my 4matic engine bay the .48 turbine housing was a really tight fit. Trial fit the .63 housing, damn. Needs a lot more room. Numerous pie cuts, hammering, and welding (swearing, bleeding, and moments of self doubt) and I can finally lower the engine onto the mount with minimal clearance between the body and turbine housing.

The 4matic hydraulic lines run through the rear corner and one had previously rubbed through on the downpipe. Now its even tighter so I decided to re-bend the 3 lines to run straight down to the motor mount and then straight back. This actually ends up giving more room than I had with the downpipe on the .48 housing. Too easy? Yes. The compression coupling used to fix the previous damage decided to leak. Tightening it revealed that one of the nuts was split and wouldn't tighten. At 2AM no parts to be had, bodge a fix until a new coupler can be acquired.

Time to actually start assembling the turbo onto the car. Lets bolt up the drain flange/adaptor. Hmmmm, the bolts aren't tightening. Oh, they're one thread larger than the feed, or any other Garrett turbo I've ever futzed with. Timeserts were the only fix I could manage and even then I wish the larger threads had left more meat to thread the insert into. At least its the drain. The oil feed threads were correct and match my oil feed line. Can't explain why I still had to tap them when the original bolts started to seize before tight.

Downpipe to exhaust system has a 3" band clamp. It's moved far enough that it won't quite seal despite a nearby flex joint. It is easily the biggest exhaust leak. F*** it! Its far enough under the body that it'll be ok for now. I'll probably get another flange and just drop it off at the exhaust shop.... eventually.

Wastegate. New actuator was expected to be customized to the install. Only by this point I've emptied the spool of mig wire and its after midnight. Make do I guess and get creative. Cut, thread, grind. Eventually it mounts. It does need a boost source to operate the wastegate, only the T04B housing has no bung to thread the nipple into. Not wanting to drill a hole into the thin part of the casting to try and thread the nipple into, I looked to the steel intermediate pipe. Could weld a nut and drill and pipe thread it. No wait, out of mig wire. I have a flange welded to mount an EGR valve, (only for show for emissions) and that weld is the only meat to drill into on this half of the engine's cold side plumbing. Get to drilling, threading, it ain't pretty but the wastegate boost source is done.

The rest of the heat shield and air filter and plumbing went back without too much fuss. My K&N needs cleaned and re-oiled pretty bad. Wasn't happening at 2:30 in the morning. They say specifically not to clean them with compressed air. F*** that too, just blow it out.

With everything all together and running without anything worse than a hyd fluid drip, I loaded the new tune I prepped for it. Pretty close, at least at idle. Start autotuning the VE table on the drive home. Noticed that it only boosts 5-6 PSI. Gonna have to go in and put more pretension on the wastegate. Damn it. It was a fight just to get it where its at. When I go back in and shorten the rod it won't be under the weight of the rest of the project.

So that's where its at. Needs more wastegate spring tension to get to my 7PSI baseline. Needs some tuning, and exhaust pipe work. Need some sleep. Bad.

sm. pelle · #15 11-22-2018, 05:44 AM

Good work, what manifold and injectors u were using?