300SDL Project - PeachParts Mercedes-Benz Forum

awsrock · #1 03-20-2016, 04:20 PM

I thought I would start a thread to chronicle my adventures with upgrading my 87 300SDL.

Originally, I was planning on following the works of GSXR and Babymog, i.e. full load, 55 trim turbo, etc. I was hesitant to get a new pump for a few reasons- price, more upgrades that required custom work, breaking transmissions, etc.

I ran the 55 trim turbo from a 91 SDL for about a year, year and a half maybe. It was a decent upgrade over the KKK, even at stock fuel settings.

I then got my hands on a w140 manifold, which I found out did not work on my car, because the turbo exhaust housing would not clear the spring perch in my engine bay by about 1 inch! It was very frustrating. I later found out that my motor mount is completely collapsed, so soon I will replace that and try the manifold again.

In the meantime, I bought a new Holset HX30 and put that in my car with the trap ox manifold. I can't say it would work in a 124, but it might since most of the turbo is below the trap ox pipe. Anyway, this was an even better upgrade over the 55 trim. The turbine housing itself is not much larger than the T3, but the wheel is, and the outlet is 2.75 inch. I am a bit worried that I might need something more, but an HX35 would be overkill for what I need, I think... The HX30 should be good for at least 25 psi before it gets hot. Even right now, my intake manifold is cold to the touch when I get home, whereas it used to get pretty hot with the stock turbo.

I was then going to just stick with a full load IP adjustment and hope for a good 180 hp...figuring the HX30 would get me a few extra since it is a more efficient design.

Just recently I ended up getting myself a 6mm pump from Finland by Herlevi. I am hoping to get it put in next week. The specs are 90cc and a governor set to 6000 rpm. They also said it pulls around 50cc with no boost. The HX30 is set at 18 psi right now, I may need to up that to 22 or so, but we'll see.

Lastly, I do have an intercooler ready to go as well. It is relatively small, 27x5.5x2.5, and fits very easily in my huge US spec bumper. If I had known better, I probably could have gotten a 7" tall IC vs the 5.5, but I don't know that I'll need that much for what I am after.

Soooo, with all that, I am hoping to pull off around 210-220 hp and maybe 300 ft lbs at the crank. Much of my inspiration came from GSXR in this thread: OM603 semi-super pump testing, fitted with Bosch 6.0mm elements

He found the Bosch specs for the 603 being .46 cc per kw stock. While doing some research on STD I took note of all the 603 dyno results that people had, and it seems that everyone is continuing about a .49 cc per kw ratio, so in theory, I could pull off about 240 hp, but I doubt I will get close to that due to my low budget build (not planning on exhaust at the moment, might keep trap ox manifold if probelms with w140, etc.) Also, the 6mm are pretty close to maxxed out at 90cc, so I have long duration to deal with at high rpm. On a side note, Herlevi told me they could manage 115cc with 6mm elements if they worked on the delivery valves, but I was not really interested in going beyond 90.

Vacation begins tomorrow, and I am planning on getting the IP put in over the next few days. Since I won't have time to get the IC set up yet, I may just run the IP with the ALDA unplugged, which would limit me to 50cc, so basically stock! I am interested to see how much better a 6mm 50cc pump will run set at 6000 rpm

I'll also take lots of pictures. I did not get any T3 vs HX30 pics before I put it in, but I need to take the turbo off to reclock it, so I'll get some then.

Does anyone know what the thread on the test port in the exhaust manifold is? Need an EGT. I thought it was m10x1 but found out that isn't the case today...