Engine swap, 617 to ??? - Page 3 - PeachParts Mercedes-Benz Forum

derherr65 · #31 10-11-2006, 02:38 PM

I'm hashing out some ideas with a programmer friend of mine. My initial model uses a pressure sensor, a servo, and speed controller. They are relatively inexpensive black boxes from radio control vehicles. The turbo blades would default open by spring tension, but with the ignition key on close until XXPSI is reached, then open as wide as possible while maintaining XXPSI. One advantage is if anything electrical fails the spring should overpower the servo.

I still trying to think of a mechanical system that does the same.
Oh, and high boost with low throttle position shouldn't be a problem. You ever lifted out of the throttle going up a hill? There you go.

derherr65 · #32 10-11-2006, 07:38 PM

Though... if you're going to buy a VVT then the have to re-arrange the exhaust system anyway.... perhaps it would be easier and cheaper to try sequential turbos? Basically add a little turbo and pipe it's exhaust and wastegate into the stock turbo or a slightly larger second turbo. Any thoughts, other than "Cool! A twin turbo Mercedes"?

#33 10-11-2006, 09:35 PM

Quote:

Originally Posted by Rashakor

Well, now you caught my attention! Where can we find that 3.9L? the only ones i have ever seen for sale are the monsters 5.9 and 7+ Liters. Of course i have no intention to do such a conversion but it always interesting as a case study.

Delivery vans are the most common sources. Frito Lay, FedEx, UPS, and USPS used them the most.

#34 10-11-2006, 09:44 PM

Quote:

Originally Posted by gsxr

You can get 180-200hp without a VVT, and it will be far easier... I don't know of anyone who's gotten an aftermarket VVT setup installed & working well on a MB diesel (yet).

There is a thread on here where a member installed a GT23V VNT turbo on his SDL.

There is nothing magical needed to control a VNT turbo. All you need is a pressure actuator instead of a vacuum one and plumb it like a traditional wastegate. I've got one all set to install, I just need to make an adaptor plate and oil lines.

VVT= Variable valve timing
VNT= Variable nozzle technology (turbo)

derherr65 · #35 10-11-2006, 10:09 PM

After mapping out the lines and valves and stuff required for a sequential setup I quickly retreated back into VGT territory.

VVT = variable vane turbo/technology
VGT = variable geometry turbo
I don't think they've quite settled on a term yet.

Quote:

Originally Posted by ForcedInduction

There is nothing magical needed to control a VNT turbo. All you need is a pressure actuator instead of a vacuum one and plumb it like a traditional wastegate.

That's my current plan, but what's the best turbo?
Holset he300 - Variable, water cooled, 100-300HP, wastegated.
Garret GT2359V - variable, 200HP, from MB 320CDI.
Garrett gt1749V - variable, 150HP, volkswagen.
dodge? TBO352 - variable, 175HP, 1987 dodge
Garrett GT2062V - variable, 160HP, volvo
Other???
Jeep liberty? Is this a variable? For $100?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=200035361367&fromMakeTrack=true

Rashakor · #36 10-12-2006, 09:50 AM

could somebody rename this thread?
something like
OM617 Turbo Upgrade: VVT vs VGT

derherr65 · #37 10-12-2006, 10:06 AM

Ah, but then the first 1/2 of the discussion would be mislabeled... so you'd have to rename it "1/2 engine swap and 1/2 turbo swap", but then there's also several posts about injection pumps, and a few about swapping to a different car altogether... so it's really "2/5 engine swap, 1/10 injection pump, 1/10 car swap, 2/5 turbo swap"... which gets to be ungainly very quickly. Plus can you imagine the time required and confusion cause by renaming every post that drifted a little? Said succintly, accept drift, continents do it, and so do we. But a new thread for the best variable sounds perfectly reasonable.
Variable turbos, which is the best?

gsxr · #38 10-12-2006, 02:30 PM

Quote:

Originally Posted by ForcedInduction

There is nothing magical needed to control a VNT turbo. All you need is a pressure actuator instead of a vacuum one and plumb it like a traditional wastegate. I've got one all set to install, I just need to make an adaptor plate and oil lines.

Not all VVT's have mechanical (pressure/vacuum) actuation... some are electronic... be careful before you buy a unit to play with. To get the true benefit from this you'll have to do more than just plumb it like a tradtional wastegate.

derherr65 · #39 10-12-2006, 03:11 PM

True, but will it be an improvement over my stock T3 with the mentioned simple control?

gsxr · #40 10-12-2006, 03:17 PM

Good question. I'd be more tempted to just go the Finnish SuperTurbo route if I was going to deal with all the hassle of custom exhaust plumbing though. What it might lack in low-RPM ooomph is more than compensated for once the boost builds.

derherr65 · #41 10-12-2006, 03:26 PM

Lol, yes, but I'd hate to try to drive a car daily with that kind of boost threshold. It should be great on the highway, but in town? Oh my!

I imagine the Holset he300 is too much, but wouldn't water cooling be nice! No coking, lower intake air temps, lower EGTs, and ability to dial in more fuel accordingly.

Garrett gt1749V - variable, 150HP, volkswagen.
Garrett GT2062V - variable, 160HP, volvo
Garret GT2359V - variable, 200HP, from MB 320CDI.

So the question is which best matches? I'm guessing the smaller garrett spools up quicker, and since it can support 150HP will easily handle a stock 617. I suppose it depends on where drivability begins to deteriorate, or where the stock IP runs out of fuel. Which happens first, and when?

gsxr · #42 10-12-2006, 03:28 PM

From what they report, the in-town power is fine, better than stock... but when the boost hits, you better have the car pointed towards an empty space. I don't think the power delivery is particularly linear or flat, though, which is what the VVT would provide if implemented correctly.

derherr65 · #43 10-12-2006, 03:38 PM

Quote:

Originally Posted by gsxr

but when the boost hits, you better have the car pointed towards an empty space.

I have a '65 mustang for that. No boost needed... yet.
I plan on keeping to maximum boost at stock or a couple PSI above. Nothing too drastic.

GREASY_BEAST · #44 10-12-2006, 04:33 PM

first off, this thread is great. Secondly, I would be seriously worried about twisting a MB like a pretzel with a 4BT... from what I've read they put out something like 265ft-lb stock... and as far as height goes, they are exactly the same as the 6BT... it would be cool as hell though... after you figure out how to put a tranny, driveshaft, rear end, suspension, etc etc etc that can handle the torque...

derherr65 · #45 10-12-2006, 04:43 PM

You missed the solution RASHAKOR and I agreed on... stock tires. You can have as much torque as you like without hurting anything as long as you keep stock tires on it. As evidenced by our driving experience, and I'm sure yours, stock tires will spin before anything breaks. It does not matter whether your engine has 200ftlbs or 700ftlbs, the tires only allow 150ftlbs(let's assume) to be transferred. That means the suspension and drivetrain are only under the force from those 150ftlbs.

It may seem counter intuitive at first, but check with a few drag racers. You can double engine power and race without breaking anything, until you upgrade the tires or suspension for more traction.