Dyno'd my 1987 300D
 

I took my 1987 300D to the dyno last week, after turning up the full-load on the injection pump, and doing some road testing. The dyno video is at this link (18MB), you can see the dyno graphs at the end:

http://www.w124performance.com/movies/Mercedes/dyno/87_300D/

It put out approx 140hp at the wheels, with 190lb-ft of torque. Assuming a conservative 18% powertrain loss, that would be 170hp and 230lb-ft at the crank. Using a more generous 20% loss estimate translates into roughly 175hp and 235lb-ft at the crank.

I also had the car weighed on a digital scale. After correcting for a few items in the car, it was 3600lbs with a full tank of fuel - well above the MB claimed curb weight of 3375. Even adjusting for the heavier brakes, tires, sway bars, etc that are on the car, that's still a big difference. My E500 numbers off by a similar amount. I'm seriously starting to think MB published "dry" weights, without fuel in the tank. That would almost exactly account for the discrepancy, on both cars.

Anyway, this does answer a number of questions I've had. First, the Finns were right, 170-175hp may be all we can get with the stock pump (excluding propane or methanol injection). Second, my car was maxed out at 170hp (crank hp) when I turned up the full load screw out +0.5 turns a couple of years ago. The next +1.5 turns (done last month) did nothing except cause starting & idle problems. And finally, the excess weight is probably hampering the performance, compared to a bone-stock (or stripped down) model. My 0-60 is consistently in the low 9's, at ~2600' elevation. I'm guessing it might drop to high 8's near sea level.

Photos of the dyno session are here:
http://www.w124performance.com/images/dyno/87_300D/


I'll go back to the dyno after I get the hybrid pump built with 6mm elements. I'm hoping for 180hp (or more) at the rear wheels. I also plan to look into some different options for the turbo, and try to plumb an intercooler to help reduce EGT's.

For a step-by-step tutorial on how to adjust the full-load screw on the OM602/603 pump, check out this thread... just be warned that you need an EGT gauge if you increase the power output, or you risk grenading the motor due to excessive temps.


:stuart:

How hot is hot?
 

Interesting. What are your EGTs now?

I haven't adjusted the full-load screw on mine yet, I'm still recovering from the discovery that I have only 5-1/2 working cylinders.

Jeremy

Peak EGT's are higher of course, and they build faster. It's fine as long as I don't stay at WOT for more than 20-30 seconds. It's more of a problem in hot ambient temps, and when climbing long grades, but otherwise they're not excessive under normal driving conditions.

:mickey:

You building it yourself or sending the pump off to finland? Also i know you have done a LSD upgrade to your diff but can it handle the extra power you plan on gaining with the new pump?

I'm not surprised on the weight Dave. Probably without options, including those which are standard in the US, such as SRS, ABS, A/C & ACC, Electric Windows and Locks, Power Sunroof, ... those power seats must weigh 100# each.

The door sticker on my late '87 says 930# CC, not sure whether that is with or without fuel but hopefully it is as equipped on options, a US market sticker.

The tuning project sounds successful, sticking with the 2.65:1 gears or something a little hotter?

Wow Dave, very cool stuff. After I get the new head on mine, this gives me something to shoot for ;)

Gutted cat?

Still have that AFM?

What's your boost level?



I turned my SDL up around half a turn around 18 months ago, been running great @ 13.5psi. Looks like we're up around 30hp/30tq over stock, not bad at all considering it was free to do. :)

I prefer to keep my stuff simple, not really interested in going for an IC at this point, since it seems this power level is pretty safe long term. If it was low cost, fairly easy, and did not induce excess lag I would consider for sure.

I found a Bosch guy in the USA who's willing to try the pump modifications. This would only be larger elements, not all the Myna wizardry (external full-load adjust, modified governor linkage, etc etc). On paper, this should be good for at least 210hp at the crank, but I'm hoping for more.

The 185mm LSD should be fine. The Finns often don't even bother upgrading the diffs. I'm planning to leave it in there until it grenades, and if that ever happens, then I'll build a 210mm diff. I expect the 185mm unit should handle at *least* 250hp. The 210mm is good through at least 500hp, which is way overkill for my needs.

:o

That's the weird thing, the 3375-lb. curb weight is for the USA-spec model! The stripped Euro model has a lower curb weight (per the TDM). The power seats are approx 70 lbs each, btw... I weighed them. ;) Anyway if you add the weight of a full tank of fuel to the published curb weights, the result is awfully close to what the digital scales indicate (for an unmodified car), assuming 7 lbs per gallon * 18 gallons = 125lbs, plus 3375 curb wt = 3500 lbs fueled. (My modifications, stereo, etc add up to about an additional 100 lbs.)

I'm sticking with the 2.65 diff... anything lower (2.87, 3.07) would compromise MPG, freeway cruising, and top speed. As power increases, the car can tolerate taller gearing. If I got the power WAY up, I'd actually like a 2.47 ratio, but the speedo would need to be custom modified, since there was never a 2.47 installed in any 124, anywhere in the world (AFAIK). I also don't know if a 185mm gearset exists in that ratio.

:o

Cat fell off a while ago - no power gain, but EGT's dropped a bit. AFM? Not sure what you mean, but EGR and ARV are also mysteriously missing. Boost level is stock, peaks around 14psi. There's zero smoke at WOT so more boost would just add heat, not power. I need more fuel, not more air. I want the IC mostly to reduce temps, on both intake & exhaust. The dyno guy's eyes were as big as saucers, watching how fast the intake temps shot up during the run... he commented that IAT's rose faster than RPM, lol! :D An intercooler would dramatically help with that. I'm going to try a side-mount unit from a 300ZX as a short-term solution until I can get a large FMIC like Casey's.

:stuart:

Air Flow Meter. It's the big black box under the air filter housing.

Hrm, what turbocharger do you have on there (is this the KKK car)? My KKK is going on the shelf as I gave up looking for a reseal kit and it leaks BIG time. I am going to rebuild that 603 T3 from my parts car. I know it's a .50 trim if it can be compared to the KKK. :confused: (I'm modifying an extra T3 for my SD for the .50 trim wheel and housing from a Volvo, slightly more efficient)

Interesting on the the side mount Z32 IC. I'll have to follow that install, seems like it'd have short piping to limit lag. Just don't want to deviate too far from stock for ease of upkeep.

Yup, AFM is that box deal under the air cleaner.

In any event, cool stuff!

Ah, I thought that might be what AFM referred to. :o Yes it's still there, but the flapper door inside is jammed full open, so there's no restriction. It's been like that for a while now. There wasn't much difference with that mod, I doubt the AFM was hurting power levels at all.

Yes, the car has the stock KKK turbo, which according to the factory docs is a KKK-K24. I'm not sure what the trim is but I think it's 0.50? I was thinking about using a T3 with 0.55 trim, which might offer a tad more airflow as power levels move upward. (?) Are you working on a 617 or a 603, btw?

Nice! Did you notice a difference killing the ARV? Mine is still working because I was under the impression it didn't do much. Of course it can fall off at anytime.


I need to check the boost on the SDL and crank up the full load a bit, I'd be happy with slightly faster than stock.;)