w126 Body 300SD Water/Air Intercooler Project - Page 14 - PeachParts Mercedes-Benz Forum

#**196** 03-08-2006, 06:49 AM

eBay Link

Due to my cr@ptastic welding skills, I can't really "build" my own intercooler setup. It's really the only A-W intercooler I can find on eBay that will fit my needs the best. The only reason I chose this specific one was the price ($215 after shipping vs. $299 BIN in most other auctions.) What really concerns me is they all basically use the same picture, measurments and specs.

Anyway. Since the w123 has less room to work with than the W126, I'll have to route the tubing differently but still use an intake similar to Brandon's. The turbo outlet will take a more exotic route under the alternator, up around the lower radiator hoses, and into the lower port of the intercooler. Because of this layout an electric driven radiator fan will be my only option.

Of course this is all just speculation until I get the intercooler in my hands.

#**197** 03-08-2006, 09:33 AM

You will want to check and make sure that the turbo will clock down far enough to let you do this....the clearance between the exhaust manifold and the compressor housing gets VERY close at points...I know with my modified turbo it will touch if the output faces down...luckily I still have a good 1/4inch gap

ConnClark · #**198** 03-08-2006, 11:13 AM

ForcedInduction,

You got the same intercooler I got. I also got it from this guy. Unfortunatly he tends to take forever to ship. I bought mine on Feb 15th and haven't got it yet. Read the comments on his feedback. I suspect he does not have the item on hand, and accumulates several orders to get a bulk discount from his source. I'll bet he ships both of ours at the same time.

I'm fortunate that he lives in my state. That way if he rips me off , when I open up a can of Whoop@ss, they can't bust me for crossing state lines to commit a crime.

I did some plots on the turbo map. I'm convinced that a change in compressor wheel and housing is needed after adding the intercooler. With the cooler intake charge the turbo gets into the choke region quickly. I think one off a 85 dodge daytona will work great.

#**199** 03-08-2006, 03:26 PM

Quote:

Originally Posted by ConnClark

ForcedInduction,

You got the same intercooler I got. I also got it from this guy. Unfortunatly he tends to take forever to ship. I bought mine on Feb 15th and haven't got it yet. Read the comments on his feedback.

I did some plots on the turbo map. I'm convinced that a change in compressor wheel and housing is needed after adding the intercooler. With the cooler intake charge the turbo gets into the choke region quickly. I think one off a 85 dodge daytona will work great.

That's good to know, I'll watch him closely.

HERE is a Garrett Hybrid T04B compressor upgrade for any T3 based turbo. I'm reluctant to return back to the T3 turbo. Most of you know the "woosh" the MB T3 lets out when you let off the accelerator quickly after it builds boost? From the research I've done, thats the compressor going into surge. That's not too much of a problem on an automatic, but for people (me) with manual trannys it's a major concern. The last thing I want is to snap the turbo's shaft during a shift (And there is NO FREAKING WAY I'm installing a blow-off valve!). That's also one of the main reasons I favor the K26 installed now.

I also pulled my fan shroud out of the webs to study the clearances around it. It almost looks like I can still run the tubes as planned and use the updated plastic fan.

bgkast · #**200** 03-08-2006, 03:35 PM

Doesn't anybody make a non rice-whistle blow off valve?

#**201** 03-08-2006, 03:45 PM

Quote:

Originally Posted by bgkast

Doesn't anybody make a non rice-whistle blow off valve?

First

Second

Diverter Valves won't make the wimpy little squeak the rice buckets puke out. Still, it's one more thing to install and they look d@mn stupid on a diesel. I'll take an EGR over a BOV.

boneheaddoctor · #**202** 03-08-2006, 03:45 PM

blowoff valves are needed on THROTTLED engines due to the surge you will get when you slam shut the path the compressor air exits....

Not an issue with a diesel.

ConnClark · #**203** 03-08-2006, 04:14 PM

That hybrid T04B compressor upgrade may be(probably is) to much air flow. You might end up operating in surge all the time with it.

The intercoolers allows us to pack 10-15% more air into the cylinder. So we only want a compressor wheel that pumps about 10-15% more air. A drastic change will not get us much if anything because it won't operate in an efficient area of the compressor map.

Operation in surge for short periods, such as taking your foot out of it, is okay. Its when your turbo goes into surge under load or stays there for a while that its a big problem. When the compressor enters the surge zone it effectivly stalls. When under load and this happens, your turbo's shaft RPMs go through the roof. Under prolonged surge your compressor wheel gets very hot and can actually melt, but from what I understand it usually frags before then.

Blowoff valves serve two purposes. Overboost protection and surge supression. On my 85 they have a blowoff valve right on the compressor housing.

bgkast · #**204** 03-08-2006, 08:42 PM

Good thing I don't have a turbo...I don't really know anything about them

#**205** 03-09-2006, 01:39 AM

HERE is a video (not any of that PutFile junk) that shows exactly what I'm talking about when I mean "surge".

If that's not surge speak up, I'd love to know what it is.

ConnClark · #**206** 03-09-2006, 10:26 AM

Its surge but its not prolonged surge.

deerefanatic · #**207** 03-09-2006, 06:29 PM

ya, Mine does that sometimes when I'm running around 38 in town in 3rd gear. I first thought it was the turbo, but then I thought " Na, to long of a delay after letting off the throttle."

What's weird is when I left off in these conditions, there's like only 4 lbs of boost.

Oh, well, it sounds cool!

Bajaman · #**208** 03-09-2006, 09:32 PM

Surge is not a problem with diesels. I think that that vehicle in the video had a straight pipe or something so that what your hearing is not surge really, but an absence of combustion. I recently installed a 3" straight pipe on my Scout. It sounds very similar to that. I watched my boost gauge and pressure NEVER goes up when I let off the go pedal, only down...
bb

ConnClark · #**209** 03-10-2006, 11:14 AM

Its surge alright. Boost drops under surge because the compressor is stalling and not compressing the air. Much like a wing stalling and not generating lift. Surge can and does occur on all turbo charged piston engines when the RPMs drop fast enough.

boneheaddoctor · #**210** 03-10-2006, 11:40 AM

Funny....my W116 has boost turned up a bit and has the IP turned up. I run a Boost and EGT guage and never see surge on it ....ever. Not saying surge doesn't happen...becasue it does....mostly on gassers however. Throttle plates play a large part in it. Or those being run on the ragged edge.