1995 E320 Horsepower Gains
 

Is it feasible to increase the horsepower on a 1995 E320?

If so, do I need to do anything with the transmission?
I am beginning a transmission overhaul, so if I can strengthen the the transmission now now I might as well do it.

I have the M104 engine, and I believe the 722.3 transmission.

The real answer is "It depends"

How much power do you intend to make and through what means?

Thank you for your response!

Somewhere between 300 & 400 HP would be awesome. I suppose that wide range indicates my level of knowledge here. I don’t need more horsepower than I know how to steer (or do I?).

I would enjoy modifying the car & learning, more than driving it after I’m done. It will also provide a good opportunity for me to teach my growing boys about cars.

Can I change the displacement?

Can I fit high flow parts for intake & exhaust?

Any turbo or super charger options?

Does the computer severely limit what’s possible?

Also, I have a very high risk tolerance and I am willing to fail completely here :cool:

I’d say the easiest way to get more hp would be to get a e420

Boost will be your no 1 option but you will dig deep in your pockets.

Yes there is a 3.6L version of the 104 engine, but they get rarer by the day.

Intake wise its hard to beat the OE engineering. You may be able to free up the exhaust a little with a custom system, but I'd be surprised if you could tell from the driver's seat.

Yes, custom or custom.:rolleyes:

Pretty much. Although standalone options abound;)


I think the best advice is to pick a direction and go for it. 6-8 PSI of boost will get you over 300HP pretty easy and not be a ticking timebomb. Transmission wise a competent basic rebuild should be adequate for the power you're targeting.

Thank you again.

I am thinking the displacement change would be the most fun & educational, but I am only thinking about physically changing my block (i.e. boring out the cylinders, changing the pistons & crank shaft).

I believe I have the 3.2L engine. I found engine specs here: http://www.peachparts.com/shopforum/tech-help/51532-m104-2-8l-3-2l-3-6l-bore-stroke.html

I did a quick search for the 3.6L engine and saw prices around $3k, which is not only high but also doesn’t provide so much learning.

So I have these questions:
1) Are there any meaningful differences in the engine blocks used with the 3.2L and 3.6L M104 engines?
2) Can my block accommodate a bore & stroke change to convert it to the 3.6L specs?
3) Would my computer changes be limited to over-writing the software with what ever is used in a 1995 Mercedes with the 3.6L?
4) Can I convert to 3.6L with a 3.6L short block, while using my intake & exhaust parts?

Yes


Several mm overbore. The 3.6 has little meat left between cyls and is considered a poor candidate to boost because of it.


Yes assuming no core shift.

Find an appropriate module and swap it.

You can but the 3.6 has a rare crankshaft, different rods, pistons, camshafts and engine breathing inlet tube. Its unlikely you'd be able to source these without just buying a 3.6.

Conclusion, building a 3.6 is a losing proposition. Not impossible, but the long way around without any benefit, more cost, and plenty of opportunity to screw it up.

What are your thought on using the OM603 3.5L Crank Shaft & keeping the same bore?

http://www.peachparts.com/shopforum/mercedes-benz-performance-paddock/284473-useful-3-2l-m104-specs-using-honda-connecting-rods-10.html

With om 603 crank u will need shorter rods, low compression height pistons with really short skirt. Just short rods stock piston will hit the crank and is still over deck way too much. M111 piston and rod combo might work but i havent tested yet. Problably u will need to bore block too, i dont remember if m111 had same bore version. Short rod was i think in 2.0 and 2.3 versions.
Boost is the way to go.

This, outside of having a donor 3.6 car to swap everything from.

It is cool to have a 3.6 swap but boost can make far more power.

The AMG motor uses factory 145mm rods. It is a R/S ratio of 1.56. How short do you wanna go?

How much boost can the 3.2L block withstand before bad things happen?

The block is not the weak link. In order of failure basically stock pistons 1st. At around 500hp. They will last here but if you breath some knock on them at this point they will collapse the ring lands. I think you could get 100-200 more out of them at least for a little while. I have run 11-12lbs of boost with a supercharger for many years on these. Probably add a bit more from a turbo since parasitic loss is lower. Given a proper sized turbo a well put together motor with good exhaust system that can breath and head studs. I think you could get to around 800hp before the headgasket started failing. This is an assumption but I think a reasonable one. Cometic gaskets or something of that nature and some minor tweeks to the block and 1000+ is with in target. I made over 900 ft/lbs of torque with an om606 which is basically the same platform. You could make a lot less tq and make some good hp up top with the m104.
Stick with the smaller bore 3.2l and spend your money on a good tubular turbo manifold and a proper turbo that does not cost 50.00 and you can make a lot of power on these. Dump the stock ecu completely and go aftermarket. Way easier and more reliable. OE stuff is really old and you should basically replace the entire fuel supply system.

143mm rod and 30mm compression height piston, i know r/s issue, but thats best combo what i have found and might work, easy way would be full custom but i have no budget or intrest.
Right now everybody wants to sell me full m111, if i sourse pistons and rods and they will rotate, then there will be new thread.