Several years ago I got the bright idea to try installing the Bosch 6.0mm elements from the 606.962 turbo IP, into my 603.960 IP. In theory, this should have provided about the same power as a "chipped" W210 E300 turbo, or 210-220hp at the crank (170-180hp at the wheels). I picked up a used 606 pump as a donor for the elements and also a spare 603 pump to use as a core. I'll spare the long story as to what transpired between then and now (several years, lots of waiting) but I finally received a completed, working 603 pump with 6mm elements in September 2010. This was largely due to the generous assistance of an MB owner/enthusiast in WA who happened to have a friend that works at a Bosch shop. (I will update this post with the name & contact info for the shop, after confirming that they are willing to have this information posted publicly.)

Prior to the pump build & swap, I did dyno runs with a stock rebuilt injection pump, which show the stock fuel cutoff hits sharply around 4750rpm, drastically limiting power above that point. I also did a dyno run with a different maxed-out stock pump, and did testing from 0-100mph with both configurations. Unfortunately the 0-100mph testing data is slightly skewed because in the meantime, I installed LSD and larger brakes on the car, which take a bit of power to spin due to the increased rotational weight. So, the test data shows minimal performance gain between the stock pump turned up 0.5 turns vs 2.0 turns. However this isn't quite true, it did make more power since the car was slightly quicker despite the weight penalty. I'll add the dyno & performance data later, I need to compile it into an easier-to-read format.

Anyway: When maxing out the stock pump, both Casey and myself found that beyond +1.5 turns there were driveability issues, mostly that the engine would not always return to idle, and it was hard to start. So although I did test a +2.0 turns, I went back to approx +1.5 turns as the most which retained normal starting / idling. There was very little, if any, difference in power between +1.5 and +2.0 turns. Although I don't have an intercooler on the car, I do have IAT, EGT, and boost gauges. With the stock pump maxed out, EGT's would reach about 1300°F by approx 100mph (approx 30 seconds of WOT). Turbo is stock KKK, exhaust is stock but the oxidation cat fell off and resonator (middle muffler) was replaced with a straight pipe. Injectors have new #314 nozzles and are recent / balanced / etc.

I got the Bosch spec sheets for the 603.960 and 606.962 pumps, and while it's mostly in ancient Greek and Egyptian hieroglyphics, I did notice some oddities: I found it interesting that the fuel quantity wasn't linear between the two pumps. Spec sheets say ~51cc for 110kw on the 603 (0.464 cc per kw), while the 606 shows 64cc for 130kw (0.492 cc per kw). I don't get why 606 specs more fuel per kw/hp. In general the sheets are fascinating, the 603 sheet appears to indicate that 34cc of fuel is delivered at 2000rpm with no boost, increasing to ~51cc of fuel at 3200rpm with full boost, but that it drops to ~49cc at 4400rpm with full boost! The 606 pump makes more sense... 55cc @ 1000rpm, 60cc @ 2000rpm, and 64cc @ 4400rpm (no boost reference since it's all electronic). I can't figure why the 603 pump spec actually seems to reduce fuel delivery before the peak power RPM. Also of interest is that the 603 pump idle spec is ~6cc, but the 606 idle spec is nearly double that at 12cc. I suspect this could be due to camshaft profile differences, but still, twice the quantity at idle? Strange. The hybrid pump dialed in a ~79cc with 16.5mm of rack, spread was 1.6cc. The ALDA would pull about 25cc with no boost signal. Idle was 6.1cc (in spec), spread of 0.7cc. On paper, it looked great.


Installing the hybrid pump was straightforward, I set IP timing slightly advanced from spec (about 13.5° ATDC via RIV method, spec is 14°). The good news is, the pump starts and idles like stock - absolutely zero issues with returning to idle, or starting (cold or hot). Initial test drives showed much more power with much less throttle travel, which was expected. I had to turn up the transmission vac modulator 2 full turns to get good part-throttle shifts. Part throttle upshifts are way too early, but that's a separate hassle (if I adjust the Bowden cable to make the shifts correct, it causes other problems - more on that later, probably in a separate thread). Boost builds FAST, I mean it would peg the boost gauge to 15psi in a couple of seconds at ~2/3 throttle. There was little to no smoke except at WOT at higher RPM, then it would smoke noticeably. Boost peaked at 15psi, maybe a bit more.

Smoke = lack of air. I tried turning up the wastegate, which is adjustable on the KKK. At first I did 3 turns on the setscrew. But the car made less power, and less part-throttle boost. I mean a LOT less. At 2/3 part throttle, instead of shooting to 15psi like previously, it would slowly climb to 15-18psi. The change was obvious. Peak boost did increase (I saw spikes to 23psi at upshift time) but the part throttle loss was awful. The KKK wastegate operates much differently than the usual Garrett, it's hard to explain, but I think this is what caused the odd behavior. At any rate, I ended up with a final setting of +2.0 turns on the wastegate, this provided more boost than stock, without the loss of part-throttle power. Unfortunately, it's still not enough air. Although peak boost is ~20psi or so, as RPM's climb under load you can clearly see the boost drop off. It drops from 15-18psi back down to about 12-13psi near redline in lower gears, and from 20psi down to 15psi near redline in 3rd gear. Again, I think it's the funky KKK wastegate design, it's not happy operating outside the design specs.


Here are videos of the gauges during WOT runs. The first video (9MB) was taken prior to the final wastegate adjustment and shows slightly lower boost levels. The largest video (38MB) is the best, if you have the time to download it, and shows the current boost level:
http://www.w124performance.com/movies/Mercedes/1987_300D/


I can't test past 80mph at the moment due to high EGT's... as you can see in the video, they hit a bit over 1400F by 80-85mph. I'm not comfortable with those temps. I need to get more air in there. My options are:

1) Swap in a 3.5L 0.55-trim Garrett turbo, which I have on the shelf. Hopefully the Garrett wastegate won't cause the weird loss of boost like the KKK. This should (in theory) be a straight swap with minimal mods.

2) Add a small side-mount intercooler. I have a 300ZX IC that should work perfectly, although it's rather small. But it should help at least a little. I can't add a large front-mount unit like Casey did without cutting the bumper (or swapping on an AMG bumper). That is in the long-term plans, but I'm not going to do that anytime soon.


Comments? Any ideas on how to get EGT's down without headers, big IC's, water injection (already tried that - waste of time), or giant aftermarket turbos?

UPDATE: Before & after dyno graphs are on page 3, post #32 (click here).

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

I'd like to see the 55-trim unit and its effect.

I'm planning (hoping) to do a lot of the same, but as finances have been pinched in the past year or so, it has fallen from will to hope to. Have the 55-trim, have a 3.5L IP, have the #22 head, and had been given "dibs" on a set of 6mm elements coming out of a member's 606 IP (haven't heard though, they might have gone elsewhere). Also have a local Bosch shop interested in the project.

I don't understand the wastegate, why tightening the wastegate would decrease high-rpm boost unless the wheel is simply going supersonic and no longer compressing efficiently? Sounds like possible catastrophic failure was on its way anyhow, I'd be a little scared of over-revving a turbo if that was the case.

The 55-trim unit will then have a higher max. flow from the compressor?

Also, do you have a source that can tell me if the cam in my two IPs are the same? I'm looking for a higher injection rate, which I expect that the 3.5L IP will have (is the IP you've tweaked your 3.5L unit?).

Did you (or are you planning to) run it on the dyno since the changes?

__________________

Gone to the dark side

- Jeff

I have a spare 606 pump with elements that I might consider selling, so if your deal falls through, drop me a line. I also have the current 606 electronic pump (sans elements) which I'd sell cheap if anyone wants it.



I don't fully understand it myself, but again due to the funky KKK wastegate design, I think it was somehow restricting flow. It wasn't the wheel going supersonic or anything as that would not have prevented low-RPM boost from building. I did one full-throttle timed run (it was slower than the others, of course) and promptly changed the setting.


In theory, yes. I'm hoping it will also keep boost level to a steady pressure rather than dropping as RPM's increase.


The cams are totally different between 3.0 and 3.5L, and early/late cams are also different (changed around 90/91, I think). Myna requires an early cam (RS157, vs RS178/R181) for their uber-pump mods. My hybrid was built on a 1987 300D core pump. I had a 3.5L pump briefly but sold that a while ago, never used it for anything.

Someone is running a 3.5L in a 3.0, it seems it was either you or Sixto.

'90/'91 is about as "early" as you can get for the .97x IP cam, mine is from a '91 car so I guess I'll have to find someone to run the numbers from the tag to discern which cam it is.

I'm still not convinced that the effect was from the wastegate, low RPMs from the engine would be lower turbo RPMs also, but I'm pretty sure that you understand how supersonic airflow affects things like turbos so I'll move on.

Are you using the stock intake system (including the AFM)? Is the intake hose going to present a problem with the shorter-intake (sans-ARV) 55-trim turbo?

__________________

Gone to the dark side

- Jeff

When you compare power potential between 603 and 606, how do you account for the difference in valve count? Would a 603.96 and 606.96 have comparable dyno results with identical pumps?

Does the simpler exhaust manifold of the 606 and 603.971 mean higher or lower EGTs? I imagine the more direct shot into the turbine means quicker response, but moving the restriction upstream will raise EGT.

You're running a wrapped manifold, right? Or is it Jet-Hot coated? Any plans to wrap or coat the .971 manifold before installation?

Can you measure EGTs simultaneously at the #1 runner and EGR supply port? I'm curious to know the energy drop across the trap replacement pipe.

Sixto
87 300D

Watched the videos, wow you're pulling some pretty hefty EGTs and IATs (especially considering you're driving in the cold and snow!).

More air will certainly help but it seems like the boost is maintaining pretty well as the EGTs rise, makes me think that a bigger turbo isn't going to have a dramatic enough effect to be able to stay below that 1400C number above 100MPH or so (at least not to the original 130+ mph redline).

I'm thinking that you'll need an aftercooler to keep it under control with that fueling.

Next question/comment: What made you choose the .96x IP over the .970 IP you had (for modifications)?

__________________

Gone to the dark side

- Jeff

Not me, but a couple people over on the STD forum (?) put a 3.5 pump in a 3.0 and said it made more low-end power. The 3.5 pump is calibrated for less fuel up top though (especially the .970) so I never had much interest in playing with one.


It was really weird, hard to explain. But when cruising at say 30mph and rolling on the throttle (say half to 2/3 throttle), it just wouldn't spool up. I can't possibly see how that could be the result of supersonics. It's not like it shot up and then died (although, I suppose it could be that my current high-RPM problem could be related to this somehow).



Yes, for now, the idea is to keep things as stock as possible, due to lack of time for custom fabrication. And, I'm curious to see how far we can take the stock setup power-wise, i.e. what the limit is for factory manifolds & turbos.

Good point Sixto, the 606 should flow a bit more air, which would explain why it gets a bit more fuel... but doesn't quite explain why that doesn't translate directly into more power (i.e., the fuel-per-hp amount should still be similar, no?)



I'd think that less restriction would be good and in theory should reduce EGT's slightly, no?



Current mmanifold is Jet-Hot coated (click for pic). When the .971 manifold gets installed (later on, as this will need custom exhaust fab) it will likely get coated as well.



I'm not set up to measure that, but it would be interesting to compare, eh?

Yeah, tell me about it. Ambient temps were ~35F, btw.



If you watch carefully, the EGT's seem to be fairly stable when boost is near 20psi, but then climb rapidly as boost drops to 15psi. Could be coincidence though. (?)



Normally I'd agree, but the guy on the STD forum with 7.5mm elements in his M-pump on a 617 has managed 250hp at the wheels with no intercooler, just a larger T3/T4 hybrid turbo!!! Click here, see post #14 and #17. That 30psi of boost probably helps. Note that he went from ~200rwhp to ~250rwhp by increasing boost and the pump rev limit. Still no IC.



I was never convinced that the .97x pumps were the way to more power, and the fact that Myna would charge extra to replace the .97x cam with a .96x cam seemed to at least somewhat corroborate that.

If a semi modified pump would just appear at my door step I would be happy. I will let you guys figure it out and I will either try to duplicate or buy what you did. I am only interested in maybe 250hp at the crank.

I guess I could hand deliver a pump to myna and fly back home with it. It might be worth an email to them to figure out prices.

Good luck, I will be watching.

__________________
08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

You will need 7.0mm or larger elements to get 250hp at the crank... the 6.0mm can only support about 210-220hp at the crank.



Myna's price is about 900 EUR (approx $1200 USD) plus freight both ways, you supply the core pump with "RS157" cam (1986-87 vintage). They will install their custom made 7.0mm elements and an external full-load adjustment. Doug had them do a pump, they'll dial it in how you want, he asked for approx 300hp as-delivered (IIRC) and the external adjustment allows you to turn it up or down ±30% for a range of about 210-390hp at the crank from min to max.

The one complaint I've heard is that the Myna elements are not as precise as Bosch, and they have a louder idle, and louder operation at speed too. This is partly why i wanted to use the Bosch 6.0mm elements, which are as quiet and smooth as stock. Rough cost for the 6.0mm treatment is ~$600 for new Bosch elements and ~$600 labor, but the pump stays in the USA and the techs here speak fluent English. And the result is no louder than with stock settings.



Thanks!

I understand the same, someone here was running one in an '87 300D and said the same thing about improved low-end power, but had noticed nothing about the high-end. However, since the .970 had a reduced high-idle setting (by 250rpm IIRC) it would make sense that the pump high-idle would have to be increased to match that of a .96x pump for a true comparison (an easy adjustment). Other than that, it makes sense (to me anyway) that the .970 pump would need a higher injection rate (faster rise of the cam) for better emissions (accomplished without the trap-cat on the .97x) I would assume, ... I'd like to know how it differs though. Did the Bosch book give fuel numbers for this pump also?

I didn't notice this, odd.

Although it is possible that there is a down-side to the later pump's cam, it is also IMO very likely that the development of the Myna elements was done with the early cam profile, and is thus matched to it, ... not to the other cam(s) so that's what is required. The 603.96x IP is probably the most common mechanical 6-hole Mercedes pump also, so I can understand why it was used for the development of the Myna pump/elements.

If I'm correct in this assumption, then there is no correlation between the 606t 6mm elements and the .96x IP cam, it is a only a guess whether they would perform as well (or better) in a .970 IP. BTW, I'll be happy to send you a good .970 IP to play with provided it comes back in its original condition.

Do you know if a 606na manifold will fit a 603 head? It seems that if it would, it would make a great starting point for intercooling a 603 so that you don't have to deal with all of the fabrication on the (dismal) 603t intake manifold/plenum.

__________________

Gone to the dark side

- Jeff

I have a suspicion that the crossover-tube on the 603t will result in a serious restriction to high flow rates, would like to see that go away first. Still, hard to argue with that kind of boost=power w/o high EGTs, is it just a function if higher RPM? I had a CAT engine in a motorhome years ago, turned up the high-idle to allow full-fueling at max. RPM, gained a lot of climbing power (but never dynoed it). That plus the simple fact that HP is a function of torque and RPM, if you can gain 20% more RPM without losing any torque, you've gained 20% more HP.

__________________

Gone to the dark side

- Jeff

This is a little over my head since I am not well versed in IP's. I have a known good '87 IP from a US om603 in the basement... is that the preferred RS157?

I plan on "turning up" that pump with stock elements whenever I get around to getting an EGT/boost gauge installed. The pump on the car now leaks pretty good.

For the money I think 225 hp is fine, I think

__________________
08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

I'd love to see more than 225hp, the problem is the costs escalate so quickly. As Dave is showing, higher fueling will require a new turbo and gauges, going significantly higher will then require a custom aftercooler and custom manifolds, higher will require new transmission and diff, new engine mounts, more and more and more.

You can quickly turn a car worth under $4000 on average, into a $20,000 "investment" that is no longer practical as a daily, and hard use will mean frequent repairs.

This is one of the things that has me following Dave's journey here, his modifications are tame enough that the extra kick in the pants won't break the bank and require everything else to be upgraded and wear out quickly.

__________________

Gone to the dark side

- Jeff