MB 124 M104 + Big turbo - Page 3 - PeachParts Mercedes-Benz Forum

kynsi · #31 03-03-2010, 10:25 AM

Quote:

Originally Posted by Pagz

Hey!,
Im just curious as to how the torque looked on each setup!
Hmmm,so why do manufacturers use twin over a single?(surely single is cheaper?)

What sort of rpm are we hoping to see from the 104?

Cheers,
Paul

There was not big torgue at all, maybe good to the 300e tranny which went guite loud lately...
600nm at 6000rpm whith big turbo (not enough revs to get to the torgue peak

).

Twin turbo went 1/4 mile 14.01 last summer. Easy to drive always 14 sec time...
That video in youtube is only 1/4 mile whith big turbo and it was way too slippery to have good time. Time was 13.xx... (hahaa 300e manual 5 speed gearbox ym.1985

)

PUMPISH · #32 03-03-2010, 05:37 PM

never that saab pistons is better quality then mercedes.
Mercedes pistons is very high quality pistons, much stronger then the most of other car models. Much higher aluminum quality

Use m103 pistons and machine then only in the midle and not the whole surface like you did, its totaly wrong.

I have h-beam rods what you can use with m103 or m104 pistons

kynsi · #33 03-04-2010, 01:03 AM

Quote:

Originally Posted by PUMPISH

never that saab pistons is better quality then mercedes.

Use m103 pistons and machine then only in the midle and not the whole surface like you did, its totaly wrong.

Even thou aluminium were strong, but reson is that it is so thin. I think saab used highest guality piston material and clearances are what i expect from turbo piston. Also the pin is bigger, what is good to turbo use. But we will see what happen...

I didnt machine hole surface, only 1mm from centre. 5mm was left alone in sides.

You have good results from mercedes 103 piston, but my engine didnt like pressure that much. Ofcourse e85 what you have in Sweden is better fuel for high power.

Joreto · #34 03-04-2010, 03:51 AM

Kynsi, how much boost were you running when the piston gave up ? Also from Pumpish and your experience with stock internals, can we deduce that the m103/m104 can safely handle 500hp @ the crank on stock internals ?

kynsi · #35 03-04-2010, 10:23 AM

Quote:

Originally Posted by Joreto

Kynsi, how much boost were you running when the piston gave up ? Also from Pumpish and your experience with stock internals, can we deduce that the m103/m104 can safely handle 500hp @ the crank on stock internals ?

Piston? You mean pistons 5 of them

.

Those tiny turbos 1bar, one big 1.3 bar.

One piston were broken long time ago because crack was polished. I suppose that piston went whith small turboes. Most of pistons had fresh cracks. Or maybe cracks just didnt move and they look like new.

I think power depends fuel you use. Pumpish and his mercedes, audi and other cars, makes me think that ethanol burns "softer".

Turbo E320 · #36 03-04-2010, 11:36 AM

E85 is 105 octane and a lot more has to be dumped into the cylinders than gas so you could theorize that it kind of 'cushions' the blow.

JayRash · #37 03-04-2010, 01:16 PM

With E 85 u need to flow alot more to reach the same AFR target, ethanole cools the charge better so coupled with the extra flow needed the charge is better cooled than with just using petrol.
Then the main advantage comes from the extra octane. now this allows 2 things to happen:
1- u can run more advance safely with no knock.
2- from my experience with evo tuning i have learnt that on sudden lift off at high loads when timing is set close to the limit u get knock. this knock is the reason many pistons break.
one way to counter this on normal petrol is to make sure the timing map has no sudden diff in number in the cells.

kynsi · #38 03-04-2010, 03:12 PM

Compression rato sets around 8:1 whith new pistons.

I also noticed that i wrote wrong in my earlier post, my old engine actually had something near 10 compression instead of 9.2.

PUMPISH · #39 03-04-2010, 08:28 PM

Quote:

Originally Posted by kynsi

Even thou aluminium were strong, but reson is that it is so thin. I think saab used highest guality piston material and clearances are what i expect from turbo piston. Also the pin is bigger, what is good to turbo use. But we will see what happen...

I didnt machine hole surface, only 1mm from centre. 5mm was left alone in sides.

You have good results from mercedes 103 piston, but my engine didnt like pressure that much. Ofcourse e85 what you have in Sweden is better fuel for high power.

We have several m103 cars running 98 oktan gas over 1.8 bar without any problem, stock gasket and 9.2 comp

I was running my first kit for 1.7 bar and 98 oktan the whole summer without blowing anything.

Maybe your tuning map is not perfect and your engine spikes

PUMPISH · #40 03-04-2010, 08:30 PM

Quote:

Originally Posted by Joreto

Also from Pumpish and your experience with stock internals, can we deduce that the m103/m104 can safely handle 500hp @ the crank on stock internals ?

500hp its just a baby power for m103/104 if the engine in good condition

BUT stil most impotent to TUNE RIGHT!

We had a lot of clients blowing the engines only becaurse of bad tuning and even racing pistons and rods could not safe it...

Get a perfect tune of your EFI and run a lot of safe HP!

Joreto · #41 03-05-2010, 02:21 AM

I agree that tuning is one of the most important things and tuning the ignition is very crucial, thats why I like to tune my car a bit conservative i.e. lose say 5 hp but be safe

. So I guess that with the right tune 500hp @ crank will be no problem.... something to aim for later this year, first I'll see what number I get @ 1 bar on this turbo.

kynsi · #42 03-05-2010, 05:08 AM

Quote:

Originally Posted by PUMPISH

Maybe your tuning map is not perfect and your engine spikes

maybe i did so. People blow up their engines less boosted. You are guite of tuners. Numbers are impressive.

My case: I just needed to build an engine, and i wanted to test this combination...

kynsi · #43 03-05-2010, 05:15 AM

Quote:

Originally Posted by PUMPISH

impotent to TUNE

:-)

kynsi · #44 03-05-2010, 01:30 PM

Yess...

Tomorrow im going to get another broken getrak from another diesel fellow. Maybe I can fix that gearbox whith my broken box. My box broke cluth shaft and other box is broken in fourth gear. Dont need 722.3 yet...

kynsi · #45 03-06-2010, 09:25 AM

It seem to be bossible to fix that...