MPS adjustments for a 2056cc w/Raby cam Options

[Bleyseng]

I finally have gotten the MPS for 2056 with the Raby 9550 cam adjusted right. Blair and I got a LM1 meter and tuned it using my laptop and driving around for load testing, then jumping out to minutely adjust the MPS to set the A/F. Took awhile but it is amazing to drive the car and change the A/F setting a tiny hair of a turn to go from 12.5 to 13.5 to 1. Wow, the MPS diapharam setting are that delicate but I was able to set the cruise, idle and WOT and the car runs super sweet now. Tons of power all thru the rpm range until 6200 where I stop. I haven't noticed the high rpm lean out others have reported as the WOT and cruise A/F stay stable until 6200 rpms right where I set them up.

Basically, a short cut would be to use a 037 MPS thats factory calibrated as that is very close to where I ended up, maybe a hair lean.

Using a Wavetek my baseline reading are for my tuned MPS:
15hg- .78
4hg-1.32
0hg- 1.58

Compared to my readings of a 037 OEM MPS:
.15hg-.75
4hg-1.27
0hg-1.53

I set my A/F ratios to 12.5 to 1 at WOT, 13.6 to 1 at cruise and idle.

Using the 9550 cam, HD valve springs, and the bigger exhaust valves (38mm) demand more fuel over a stock MPS. I have installed a NOS 043 MPS and it runs ok but the A/F reading are closer to 14 to 1 and hesitates instead of taking off smoothly. Dropping down to 13.6 to 1 on cruise really smooths the engine out and you have to set the WOT at 12.5 to 1 to get the power and smooth run up the rpms scale.

Blair and I will be playing with this more just to see what all more we can figure out or damage... I can see where the programmable EFI would really be fun. This is old school but it again proved that the Djet is fairly tuneable and adjustable to modified engines.

(IMG:http://www.914world.com/bbs2/html/emoticons/burnout.gif)

[BigDBass]

I wonder if I will ever understand what any of that means! (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)

[brant]

Geoff,


my LC-1/ XD-16 tuning session starts in roughly 3 weeks....

what tips can you give me.
anything you can describe or observed would be helpful.

my MPS is already drilled out..

so sounds like you did you constant and full throttle acceleration?
is clockwise Rich or lean?
how long, and how sensitive?
any tips?

thanks sir!
brant

[Bleyseng]

You must take out the machined plug to adjust the WOT, so figure out how to do that. Mostly its using a heat gun and cooking the epoxy until its very soft (the MPS gets freakin hot!) and use a pick to remove the epoxy out of the threads. Then tighten the plug until more threads are exposed and clean some more, then unscrew it carefully. I clean the threads with a tap then.
Counter clockwise is richer/ clockwise is leaner

We did multiple runs at cruising, say 30 mph in 3rd or 4th gear. WOT runs were in 3rd or 4th so we did end up going pretty damn fast at times...

The meter screen is ok to look at but on a laptop you can have several dials of data. We got the rpms thingy so we data logged that too plus the A/F ratio on the laptop which is much easier to see when riding shotgun.

To get the proper WOT ratio I had to adjust the plug way out so its not flush like the OEM units but so is the inner/outer screws backed off pretty good so I don't think I'll have too much flex.

Like I said, the inner/outer screw adjustments are pretty minute. Turning the screws very slightly affects the A/F mix alot so go slow!!!! Don't start cranking down on it or backing it off, just use very small 1/32th's of a turn and see what the results are.

[JeffBowlsby]

Geoff, Brads website lists different OEM settings for the 037 MPS:

0 1.44
4 1.26
15 0.72

(IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

Your 'stock' 037 looks considerably richer than his data, could that have any effect on your results? Additional NOS OEM 037 MPSs I have tested lock in right on Brads numbers too.

[Joe Ricard]

Wow Geoff, I am seriously impressed. Just goes to prove if you got a real understanding of how something REALLY works and the right tools to do the job. FI is easy. (IMG:http://www.914world.com/bbs2/html/emoticons/clap56.gif)

[JoeSharp]

Geoff: While I was tuning mine I was woried about where my outer cap wound up, it seemed out a little far. I think it is still a little rich. As I leaned the motor out it really came to life above 4500rpm. 12.3 at WOT. I'm hoping to put this motor in my driver.
:PERMAGRIN: Joe

[Bleyseng]

QUOTE (Jeff Bowlsby @ Apr 5 2006, 11:34 PM)

Geoff, Brads website lists different OEM settings for the 037 MPS: 0 1.44 4 1.26 15 0.72 (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) Your 'stock' 037 looks considerably richer than his data, could that have any effect on your results? Additional NOS OEM 037 MPSs I have tested lock in right on Brads numbers too.

Yes, I have noticed that and blame it on the differences in location-Phoenix VS Seattle

[TeamAxisRacing]

QUOTE (Bleyseng @ Apr 5 2006, 09:17 PM)

WOT runs were in 3rd or 4th so we did end up going pretty damn fast at times.

(IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/mueba.gif) all i can say is djet is fun but i cant wait to throw a haltech or autoronic setup on there.. technonlogy and honda delsol 3rd brake lights are cool (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

[TeamAxisRacing]

QUOTE (Bleyseng @ Apr 6 2006, 05:33 AM)

Yes, I have noticed that and blame it on the differences in location-Phoenix VS Seattle

if i remember its like 14.7-1 in seattle vs 14.2-1 in phoenix due to the altitude (IMG:http://www.914world.com/bbs2/html/emoticons/stromberg.gif)

[Bleyseng]

QUOTE (TeamAxisRacing @ Apr 6 2006, 09:40 AM)

QUOTE (Bleyseng @ Apr 5 2006, 09:17 PM) WOT runs were in 3rd or 4th so we did end up going pretty damn fast at times. (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/mueba.gif) all i can say is djet is fun but i cant wait to throw a haltech or autoronic setup on there.. technonlogy and honda delsol 3rd brake lights are cool (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

Me too but I am outta $$$$ (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)


Too many trips to Suriname will do that.

[Frank S]

Hi guys,

I'm new here and have received my 2.0 1973 D-Jet 914 from California in January. At present the body is for paint removal and repainting in the body shop and I'm just about to take care for the engine.

I want to use a 9590 cam with 2056cc and stay original with the rest.

Since you have some expirience with that setup (9550 cam which is not so different).
I would like to ask at which CR you are running?
I don't want to overheat the engine and planning for CR 8.0 or max 8.2.
How does your engine idle and at what RPM.
What other work than the MPS tuning was required to make it run smooth?

Thanks,
Frank

[stugray]

Brant,

You should have a look at my system these days.
I took the car out for a run yesterday. And went right by your house (assuming you still live in the neighborhood NW from the intersection of hwy66 & hover)
With the datalogger, I can see where I was WOT with the data from the throttle position sensor.
Then I can look at the AFR only in those areas for my WOT "dyno pulls".
I am currently running a little rich in the 11-12 range.
I can also see CHT & EGT during those periods, but I havent calibrated my temps yet.
AND even with the front oil coolers taped over I cant get my oil temp even UP TO 180.

[brant]

Brant,

You should have a look at my system these days.
I took the car out for a run yesterday. And went right by your house (assuming you still live in the neighborhood NW from the intersection of hwy66 & hover)
With the datalogger, I can see where I was WOT with the data from the throttle position sensor.
Then I can look at the AFR only in those areas for my WOT "dyno pulls".
I am currently running a little rich in the 11-12 range.
I can also see CHT & EGT during those periods, but I havent calibrated my temps yet.
AND even with the front oil coolers taped over I cant get my oil temp even UP TO 180.

sounds cool...
and looking forward to seeing you in a couple of days
for the track... the 12 range is ideal
extra cooling under high demands from the rich mixture, and better than lean

[Phoenix914]

Hi guys,

I'm new here and have received my 2.0 1973 D-Jet 914 from California in January. At present the body is for paint removal and repainting in the body shop and I'm just about to take care for the engine.

I want to use a 9590 cam with 2056cc and stay original with the rest.

Since you have some expirience with that setup (9550 cam which is not so different).
I would like to ask at which CR you are running?
I don't want to overheat the engine and planning for CR 8.0 or max 8.2.
How does your engine idle and at what RPM.
What other work than the MPS tuning was required to make it run smooth?

Thanks,
Frank

Frank S, I don't have an answer about CR for your engine, but

(IMG:style_emoticons/default/welcome.png)

You should start an intro thread with pictures! (IMG:style_emoticons/default/beer.gif)

[MichaelB]

Geoff,
Thank you for posting your numbers! Now we have a more accurate starting place for 2056 MPS adjustment. I have recently rebuilt mine with a diaphragm from Tangerine Racing and found pbanders number's lean.

I'm adjusting from a motivate MTX-L meter. Oh the joy.

[Bleyseng]

Hi guys,

I'm new here and have received my 2.0 1973 D-Jet 914 from California in January. At present the body is for paint removal and repainting in the body shop and I'm just about to take care for the engine.

I want to use a 9590 cam with 2056cc and stay original with the rest.

Since you have some expirience with that setup (9550 cam which is not so different).
I would like to ask at which CR you are running?
I don't want to overheat the engine and planning for CR 8.0 or max 8.2.
How does your engine idle and at what RPM.
What other work than the MPS tuning was required to make it run smooth?

Thanks,
Frank

I am running 9 to 1 CR and it never overheats but I also run Premium gas.
I set the idle at 1050-1100 rpm set when the engine is hot.
tuning the MPS made it run smooth along with having the injectors cleaned.
On a 1973 using the stock 039 ECU you have to run the 017 CHT to get a good idle.

[worn]

I am running 9 to 1 CR and it never overheats but I also run Premium gas.
I set the idle at 1050-1100 rpm set when the engine is hot.
tuning the MPS made it run smooth along with having the injectors cleaned.
On a 1973 using the stock 039 ECU you have to run the 017 CHT to get a good idle.

That is the CR I am running. I find I have to run a bit richer than I want to keep the heads cool. The engine runs better lean but it overheats if I try to run at 60 mph. What is your A/F most of the time, or at different loads? I have trouble looking down at the gauge and the road at the same time.

edit. Sorry, I should have read the post you made at the beginning of the thread, but it has been awhile since I first checked it out. I will have to do some more logging. I did a lot of inductance measurements early on, but then began to tune on the road.

[r_towle]

At 60 mph you may to still be in fourth gear and not be lugging the motor in fifth with the fan speed lower.

[Mblizzard]

Will be sending mine to Geoff for the same set up?