90s Cummings turbo installed onto a 617 - PeachParts Mercedes-Benz Forum

chasinthesun · #1 08-03-2018, 09:30 AM

Recently came across this cl add for a rather nice 300d but the modification with the turbo looks like it ruined the hood , any real gains in power with this larger turbo ?

tjts1 · #2 08-03-2018, 09:36 AM

Cummings?

LOL

Diseasel300 · #3 08-03-2018, 10:10 AM

Unless they turned up the fuel on the stock IP or installed a SuperPump, no. All you'll get is ridiculous amounts of turbo lag. I'd be curious what other "mods" this guy did, could be the tip of the iceberg...

97 SL320 · #4 08-03-2018, 06:59 PM

There isn't one " universal Cummins " engine turbo, they made many sizes of engines. The 3.3 is common in medium sized skid steers, 3.9 for backhoes.

MCallahan · #5 08-07-2018, 09:38 AM

No telling what they have put on there. Unless they really know what they are doing, this is a redneck hotrod job. As said, unless they selected a proper sized turbo with a compressor that had a proper map to work with the requirements of the Mercedes engine, and correctly modified the injection to provide more power, this is useless. A huge turbo suitable for a big Cummins engine is oversized and will lag, probably never coming up to speed enough to provide full normal boots. As compared to the factory unit. The equivalent of putting a huge Holley four barrel carb on a Honda 4cyl, thinking it will give more power.

tdoublenastywitit · #6 08-08-2018, 01:31 PM

A new bigger turbo does nothing without a super pump.

tyl604 · #7 08-08-2018, 02:05 PM

Was there supposed to be a picture here someplace?

Dan Stokes · #8 08-09-2018, 11:53 AM

I concur - after my Dieselmeken pump I was in a position to NEED more turbo and Tim at Tim's Turbos made one for me and it works. I'm still in the process of turning up the boost (I'm being cautious and doing 6 PSI per meet) and it has brought me up to 136.2 MPH so far. However, as noted, the lag is MUCH more pronounced than with the stock turbo w/clipped vanes. In Land Speed Racing lag isn't much of an issue but it would drive you nuts on a daily driver.

Dan

DeliveryValve · #9 08-09-2018, 02:18 PM

Quote:

Originally Posted by Dan Stokes

... However, as noted, the lag is MUCH more pronounced than with the stock turbo w/clipped vanes. In Land Speed Racing lag isn't much of an issue but it would drive you nuts on a daily driver.

Dan

This is probably when you'll need to compound that new turbo with an HX25 or something small like that to keep you sane.

97 SL320 · #10 08-09-2018, 02:20 PM

Quote:

Originally Posted by Dan Stokes

However, as noted, the lag is MUCH more pronounced than with the stock turbo w/clipped vanes. In Land Speed Racing lag isn't much of an issue but it would drive you nuts on a daily driver.
Dan

While I haven't done it, but someone likely has tried it, spraying diesel fuel or propane in the exhaust manifold for a short time might get the turbo spinning. ( If the exhaust is hot enough to light the fuel )

97 SL320 · #11 08-09-2018, 02:37 PM

I first heard of the compressed air system a while back on Rally / Pikes Peak cars. ( Subaru ? ) A fuel system would be simpler than a self charging compressed air system given you are not on the off the throttle.

Though, if you charged the air tank pre run, a solenoid could be used to dump the tank.

https://www.sae.org/publications/technical-papers/content/2013-01-1310/

https://www.roadandtrack.com/new-cars/car-technology/news/a27515/volvos-diesel-turbo-lag-solution-is-compressed-air/