190E 3.0-12v Turbo - Page 27 - PeachParts Mercedes-Benz Forum

eurotuning · #**391** 01-16-2012, 10:37 PM

Maybe your intake or exhaust manifolds are affecting the air flow and its causing the gases to slow down, just my thoughts.

Adolfo

Quote:

Originally Posted by Joreto

Yep, I also think that it definitely is a flow issue, which got me wondering if the air filter could cause such a restriction (I using an Apexi filter). Seems like I have to do a run without the filter and see

.

Joreto · #**392** 01-17-2012, 05:24 AM

Could be, I'm suspecting it's probably an exhaust flow problem since I'm using the stock intake, but I'll do some test as soon as the weather gets better.

P.S. would be nice to get the TQ curve to have the shape of the current HP curve.

Joreto · #**393** 02-11-2012, 03:07 AM

Recently I've been thinking of running more boost, I'd like to run ~15psi but the problem is that the ignition timing even at the moment is quite retarded at torque peak ~10 degs. . This got me thinking about what effect the intake camshaft (advanced vs retarded) has on the ignition timing. Question is, if I keep the intake cam off (retarded), will this allow me to run more ignition advance i.e. keep the cam retarded in order to lower cylinder pressures which may allow me to run more timing at higher boost ?

whipplem104 · #**394** 02-11-2012, 08:56 AM

It should allow you to run more boost without detonation. The advance promotes cylinder filling. Since you are looking for more top end then more boost and no advance should work for you. It might have an effect on turbo spool though. You might run the advance on until boost builds and then shut it off. Also running less timing is not a problem. I scale my timing just for a more linear power output. I start out at 6-7 degrees on the low end and then slowly add more timing until 13 on the top. With e85 I can run 15 degrees all the way through. But on race gas, e85, regular gas the motor stops making more power at 15 degrees. There might one more horsepower with a degree or more. N/A I ran up to 22 degrees from my but dyno. But much more than that and it would detonate. I think stock they run 18 degrees max timing.

oldsinner111 · #**395** 02-11-2012, 09:43 AM

they have calculators on the net to figure horsepower from your 1/4 time and speed

Joreto · #**396** 02-12-2012, 03:31 AM

whipplem104, thats exactly what I was thinking, just wanted to confirm that I was on the right track

. Once the weather gets better I'll retune the fuel and ignition tables for the retarded intake cam and do some tests.

Joreto · #**397** 05-25-2012, 09:45 AM

Some testing from today. Looks like I'm starting to improve the launch of the car, boost is still ~0.6 bars (8.7 psi).

Joreto · #**398** 06-04-2012, 02:03 AM

Upped the boost a bit and the car started to pull a lot better. I was aiming for 0.8 bar (~12psi) but it turned out that the MBC I used for the test could not keep the boost stable across the rpms (borrowed it form a friend). Anyhow I'm pleased with how the car performed with the raised boost,so I'll be getting a proper MBC.

Here is a log in 4-th gear from 2000 - 6700 rpm, you can see how the boost peaks at 188kpa and than slowly goes down to ~ 172 kpa ...

duxthe1 · #**399** 06-04-2012, 01:55 PM

What version of MS are you running? I have an MS2Extra and now that I've got the tables roughed in I've contemplated using the boost control feature. Dialed in, I'm confident it would be more consistent than a MBC.

Joreto · #**400** 06-05-2012, 02:10 AM

I'm using MS2Extra 3.1.0. . Megasquirt's boost control is pretty good, I used it on the previous engine, even had it wired through a switch which gave me 2 boost setting. However I think I may have found out why the boost tappers down with the MBC, this weekend I'll make some modifications and see what happens .

Joreto · #**401** 06-14-2012, 02:08 PM

Did a test to see if the air filter is restricting the flow to the engine and the result is that it's not the problem. Here is the graph, black line is without the filter, blue line is with the filter.

Having eliminated the air filter as a probable cause next I'll measure the backpressure and see what it turns up ......

whipplem104 · #**402** 06-14-2012, 03:13 PM

i was looking. what is your timing at this point? it looks really low.

Joreto · #**403** 06-14-2012, 04:43 PM

Just looked at the log and it looks like I'm runing on a test table I made Saturday (for testing purposes). Here is the timing according to the log :

timing rpm boost
9.0 4000 175kpa
7.5 4400 185kpa
8.0 5000 180kpa
8.0 5500 180kpa
8.5 6000 178kpa
9.2 6500 174kpa

This is what the plugs look like :

Joreto · #**404** 06-17-2012, 09:30 AM

This weekend I played around with different cam settings and it turns out my car likes the cams to be retarded. Since I don't have adjustable sprockets, advance/retard was done by moving one tooth on the sprocket. Here are the results :

*Black line is with both intake and exhaust cam retarded (left the car like this), red line is stock settings and blue line is the stock exhaust setting but intake advanced (VVT was left off as not to cause valve clearance issues ).

I also tested different turn off point with the cams retarded and best result was at 4500rpm. Here is the graph :

* switch of point - Black line is at 4500 rpm, red line is at 3000 rpm and blue line is at 5000 rpm

Downside is that I had to re-tune the mixture and I still have to tune the idle to be solid as before .

whipplem104 · #**405** 06-17-2012, 07:06 PM

That is really solid data. I do know that tuning through the switch point of turning the cams off is hard to do. The dip is normal but can be minimalized. I think that you should try with the intake in the stock position and exhaust retarded. With the cam advanced on up to 4500 or so. Also I think if you can add timing without knock you should. My engine wakes up a bunch at 13-15 degrees of timing. You are not running that much boost so if you have decent fuel I would think you could get there. I only pulled that much timing out of mine on pump gas when it was 85-90 degrees and up. Anything above 35c intake temps.
But be safe. That is were the dyno tells you what is happening better on the tune.
Nice work though. Changine the timing is a pita.