190E 3.0-12v Turbo - PeachParts Mercedes-Benz Forum

RBYCC · #1 05-22-2009, 08:31 AM

Quote:

Originally Posted by Joreto

If that's the case, I'll leave the pistons alone . Turbo E320, I seen that pic of the modified head but come to think of it, since I'll be running less then 1 bar ( 14.5 psi) of boost (0.5 daily and maybe 0.8 - 0.9 at the strip ) I wondering if there is a need to modify anything at all. Maybe just smooth out the inward edge since sharp edges help detonation .

If you are still stock at 9.2:1 then you need not reduce your compression....just maintain a rich enough AFR under boost to prevent detonation.

Keep in mind you are not constantly under boost...
I can drive all day and as long as I don't rapidly increase my throttle opening I stay in vacuum to atmosphere on the gauge.

I've raised my boost to about .68 bar with no problem.
The install is about two years old with initial boost at .42 bar and slowly working up via the MBC.
About 6000 miles on the turbos and running stronger and stronger.

Ed A.

JayRash · #2 05-22-2009, 08:45 AM

Quote:

Originally Posted by RBYCC

If you are still stock at 9.2:1 then you need not reduce your compression....just maintain a rich enough AFR under boost to prevent detonation.

Keep in mind you are not constantly under boost...
I can drive all day and as long as I don't rapidly increase my throttle opening I stay in vacuum to atmosphere on the gauge.

I've raised my boost to about .68 bar with no problem.
The install is about two years old with initial boost at .42 bar and slowly working up via the MBC.
About 6000 miles on the turbos and running stronger and stronger.

Ed A.

Ed at 0.68 your car should do the 1/4 in the high 13's and trap of almost 107mph

Flooring it from 50mph to 100 mph thats the sweet spot.

but in 2 yrs 6000miles!!!!!! boy did i abuse my poor w124, i did almost 15k miles in less than a year.

Joreto · #3 05-22-2009, 11:42 AM

Today I got good news, the problem is a bent valve on the sixth cylinder, pistons are fine. Must have bent the valve when assembling the head ...

. Since the engine is apart I've decided to do a full rebuild i.e. new piston rings, conrods and main bearings, valve oil seals, and so on

. I've ordered the parts and hope to have the car ready by the end of next week .

Ed, I can maintain a rich mixture with no problem with the current injectors (6x630cc) and Megasquirt. I can even get it into the 10-s with no problem (currently it's tuned rich ~ 11.0:1 at boost, as a rule I start rich when tuning and then go back), I can also pull back timing . The engine compression is stock 9.2:1

RBYCC · #4 05-22-2009, 11:52 AM

Quote:

Originally Posted by Joreto

Today I got good news, the problem is a bent valve on the sixth cylinder, pistons are fine. Must have bent the valve when assembling the head ...

. Since the engine is apart I've decided to do a full rebuild i.e. new piston rings, conrods and main bearings, valve oil seals, and so on

. I've ordered the parts and hope to have the car ready by the end of next week .

Ed, I can maintain a rich mixture with no problem with the current injectors (6x630cc) and Megasquirt. I can even get it into the 10-s with no problem (currently it's tuned rich ~ 11.0:1 at boost, as a rule I start rich when tuning and then go back), I can also pull back timing . The engine compression is stock 9.2:1

Go for it then....boost is a very sweet thing !!!!!

c280nz · #5 05-22-2009, 06:17 PM

those are massive injectors considering what boost level you are aiming for,
have you upgraded you fuel pump also?
and what fuel pressure are you running?

Joreto · #6 05-23-2009, 01:40 AM

Quote:

Originally Posted by c280nz

those are massive injectors considering what boost level you are aiming for,
have you upgraded you fuel pump also?
and what fuel pressure are you running?

I'm running the stock 2.5-16v twin pump setup, stock pumps for now, fuel pressure is set at 3 bar at idle with vacuum/boost signal disconnected from the fuel pressure regulator .

Oh btw I've decided to go with three-material Sputter bearings.