M103 and 7psi of boost.... - PeachParts Mercedes-Benz Forum

iwrock · #1 09-03-2010, 06:43 PM

Getting the stuff together to mildly boost the M103 in my 300TE....

I know CIS is good to about 7-8psi of boost, so I am looking at approx 7psi of boost.

What sort of HP do you think I will be putting down to the wheels after I dial CIS in? My target is to be in the 225-250 wheel horsepower range.... Think its possible?

TheDon · #2 09-03-2010, 06:54 PM

Quote:

Originally Posted by iwrock

Getting the stuff together to mildly boost the M103 in my 300TE....

I know CIS is good to about 7-8psi of boost, so I am looking at approx 7psi of boost.

What sort of HP do you think I will be putting down to the wheels after I dial CIS in? My target is to be in the 225-250 wheel horsepower range.... Think its possible?

drop in an M104.. done

RBYCC · #3 09-03-2010, 10:33 PM

Quote:

Originally Posted by iwrock

Getting the stuff together to mildly boost the M103 in my 300TE....

I know CIS is good to about 7-8psi of boost, so I am looking at approx 7psi of boost.

What sort of HP do you think I will be putting down to the wheels after I dial CIS in? My target is to be in the 225-250 wheel horsepower range.... Think its possible?

7lb boost on my M103-12V TT made 263RWP and 302 torque on a Mustang load dyno.
Add about 15% if your using an inertia type like a DynoJet.
Double the power compared to the stock base line pulls (135RWP/145 torque)

Shoomakan · #4 09-04-2010, 02:59 AM

Quote:

Originally Posted by RBYCC

7lb boost on my M103-12V TT made 263RWP and 302 torque on a Mustang load dyno.
Add about 15% if your using an inertia type like a DynoJet.
Double the power compared to the stock base line pulls (135RWP/145 torque)

Weak

Shoomakan · #5 09-04-2010, 03:01 AM

For the record, I have a newfound respect for these engines. I always knew the cars were solid, but the engine is a masterpiece as well. Starting to like it more than an M30... But don't tell anyone!

Good luck iwrock! I LOVE Tourings, my old E30 was a Touring. Best sleepers ever, and good luck!

BAD300 · #6 09-04-2010, 05:14 AM

Is it just me or does it seem to be the flavour of the month

iwrock. You will get good sound advice here on this forum for boosting your M103. You don't need an M104 lol. M103's are proven strong boost luving engines but to end up with a HP rating you need to let us know the turbo you are going to use? Tuning, tuning, tuning! Are you after reliable HP? Then you need to look @ all the variables. A few of us are embarked on turbocharging their M103's as I write. A few others have gone before us & have invaluable advice.

Make note that the stock 3.07:1 W124 diff can only 'reliably' handle 200 odd HP. The 722.3 trans (in good condition) can handle the HP yo are chasing no worries. The engine. Respected....easily.

Have a look @ the members threads that have &/are doing builds now to get an idea of the potential of these engines. You have to respect them

RBYCC · #7 09-04-2010, 12:16 PM

Quote:

Originally Posted by Shoomakan

For the record, I have a newfound respect for these engines. I always knew the cars were solid, but the engine is a masterpiece as well. Starting to like it more than an M30... But don't tell anyone!

Good luck iwrock! I LOVE Tourings, my old E30 was a Touring. Best sleepers ever, and good luck!

I look at the M103 as a comparison to the early 265/283/327 Chevrolet small block engines.

Simplistic in design and bulletproof which is the foundation needed to build a reliable performance motor.

Start layering on the evolution of the M104...additional cam, VVT, more electronics and emissions...

Out of the box more power.. but IMHO the M103 is a more responsive engine.

The more components and sophistication, the more variables that present problems when you're building a performance engine.

Keep it simple...

Look at American drag cars...antiquated push rod engines with only the needed number of valves per cylinder with a cam sitting down low in the valley...
Making 750-1000HP without the help of electronic fuel injection and ignition control.
Running big old 1100CFM gulpers and magnetos...
Simplicity at it's best....

kynsi · #8 09-04-2010, 02:43 PM

Quote:

Originally Posted by RBYCC

M104...additional cam

Simplicity at it's best....

I agree.

Simplicity you mention remains me my experience of m104 inlet cam. I was very exited to do megasguirt controlled cam. I played whith that 104 electric cam sprocket. Then I threw it away. Okay, there war huge power gain when cam was swiched in right position (from wrong position). But... Really the adjustable sprocket is only a economy thing. We can get even better torgue and power whith a normal longer duration cam. Or i think so.

Just for example to simplicity.

iwrock · #9 09-05-2010, 04:07 AM

Quote:

Originally Posted by Shoomakan

For the record, I have a newfound respect for these engines. I always knew the cars were solid, but the engine is a masterpiece as well. Starting to like it more than an M30... But don't tell anyone!

Good luck iwrock! I LOVE Tourings, my old E30 was a Touring. Best sleepers ever, and good luck!

Hehehe, I will not!

For those that are curious, I am going to do it to this car:

iwrock · #10 09-05-2010, 04:16 AM

Quote:

Originally Posted by BAD300

Is it just me or does it seem to be the flavour of the month

iwrock. You will get good sound advice here on this forum for boosting your M103. You don't need an M104 lol. M103's are proven strong boost luving engines but to end up with a HP rating you need to let us know the turbo you are going to use? Tuning, tuning, tuning! Are you after reliable HP? Then you need to look @ all the variables. A few of us are embarked on turbocharging their M103's as I write. A few others Have gone before us & have invaluable advice.

Make note that the stock 3.07:1 W124 diff can only 'reliably' handle 200 odd HP. The 722.3 trans (in good condition) can handle the HP yo are chasing no worries. The engine. Respected....easily.

Have a look @ the members threads that have &/are doing builds now to get an idea of the potential of these engines. You have to respect them

As of now, I am planning on running a single T3.

And regarding the diff.... The wagons got a spicier 3.27 gearset. Already blew one up doing some sliding, so we will see how this one does. My transmission was replaced with an MB rebuilt unit approx 50k miles ago, so I think I should be good there as well. My engine came out of a car with approx 100k miles, and have since put approx 30k miles on it.

I am reading the threads, and making notes on what to do, and what not to do! But, with this being said, I cannot wait to get started!

BAD300 · #11 09-05-2010, 04:21 AM

All the best with the wagon

tbomachines · #12 09-05-2010, 09:40 AM

I'm (sort of) with you in embarking on a low-boost streetable M103 project. Biggest hurtle for me is money since my school bills have hit so its a long road ahead.

What were you thinking of for an additional injector? User Nick.ged had a turbo technics add'l injector and mount for sale not too long ago which would be the easiest route but probably not cheap. I was considering buying a used TBI unit from a chevy 454, welding the venturis/injectors inside of the intake piping and flow testing it. What were you planning on with that?

ps2cho · #13 03-14-2011, 12:42 PM

I ran some basic #'s....

6PSI BOOST 3L M103 REQUIRES 31.3lbs/min CFM @ 6300RPM.
roughly 85% efficiency = 26.6lbs/min CFM

Hp = airflow lb/min x 10
26.6 x 10 = 266hp <- 6PSI BOOST

So my calculations compared to RBYCC seem pretty close.

I'm tickling with this idea too right now Justin. A low boost aiming for ~260HP.

RBYCC · #14 03-14-2011, 03:59 PM

266rwp with a 3.07 gear will move you to 60 in a low five second range...

tbomachines · #15 03-14-2011, 04:06 PM

Quote:

Originally Posted by ps2cho

I ran some basic #'s....

6PSI BOOST 3L M103 REQUIRES 31.3lbs/min CFM @ 6300RPM.
roughly 85% efficiency = 26.6lbs/min CFM

Hp = airflow lb/min x 10
26.6 x 10 = 266hp <- 6PSI BOOST

So my calculations compared to RBYCC seem pretty close.

I'm tickling with this idea too right now Justin. A low boost aiming for ~260HP.

Thanks for this info, I have been looking (kinda half assed) for CFM predictions. Converting your calcs to CFM that is roughly 410cfm depending on the density of the air coming in. To make an add-on injector setup from a TBI unit the 454 unit should be more than enough for fuel but the airflow would be a bit tight at WOT and 7lbs or more of boost. Is anyone else interested in going down that path? The turbo technics injector is nice but personally I'm strapped for cash with a hankerin' for power...

Actually just thinking - the stock MAP plate-type sensor is really not going to flow much air, I cannot see it adequately flowing this much air...thoughts? Going to hot wire is an option but there's another expense.