[Charlie Stylianos]

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http://forums.pelicanparts.com/showt...postid=1070574

[87turbolook911]

Hey Charlie,

I know you were hoping for more, but look on the bright side.....now you have data/reason to support your need to increase power. It'll also serve as a good baseline as you tweak and dial in the motor in the future.

But like many of the others on Pelican said, "I don't think 184 is a number to sneeze at". Also driving ability has much to do with how fast a car is. Remember my encounter with the Z06 Vette I told you about?

Wish I was there see you and Marc get strapped onto the dyno...

[estrellajon]

Where can I get my 930 dynoed as well as a Porsche tech who know to adjust CO, A/F, timing and such?

[Charlie Stylianos]

Jon,

I went to Autothority for the baseline run. I did not have them do any tuning while I was there. I'm sure they can adjust the timing and play with the idle CO relatively easily and you can see what their affect is throughout the RPM range, but I get the feeling they are mostly familiar with DME/Motronic setups as the tech was asking me how I would adjust the fuel mixture on my CIS. Pretty much any shop with a CO meter can set the idle CO, but tuning a/f mixtures throughout the RPM range requires playing with the fuel pressures. I personally don't know of a local shop that does this.

[estrellajon]

Charlie, is Autothority reasonably priced? For them to ask you how to adjust a CIS system is kinda deceiving though. Especially if I'm still getting acquianted with my 930.

[William Miller]

Charlie, I finally found and ordered my Euro Fuel Distributer from Vertex.
They were the only place I could find it.

I noticed that you were thinking of tweeking your CIS system.
It's ironic that you were thinking you needed more fuel flow, but it looks like your closed loop CIS is actually keeping it a little rich.
How long was the test run?
Are you still thinking of backdating your's?
If you want, I will have 3 different fuel distributers at my house sometime next week. Earlier than later I hope.

I have two of them apart. The 79 that I have been running on my car and the US 81-83 like yours that was on my car when I bought it.
I had to pay a core charge and might return one or decide to keep it.

I thought you might like an oppertunity to see what's inside.
The US 79 has the crack. The 81-83 looks like new. I think it was actually a new unit when the PO had it installed a few years ago.
It needs to be sealed up and maybe flow tested.

I'm trying to find the correct sealer. Someone suggested the loctight 574 like we used on the engine case. I have a tube on it's way with the order.

I actually have this installed on the engine at the moment. The other night when I found the leak on the other one I installed this one. I haven't run the engine yet. there was a tiny bit of fuel seeping from the joint.
I think it's ok for me to see what effect it has on my A/F ratios as a test.

I really can't wait to see what the ROW one looks like and if it will finally solve my lean midrange running condition.

I also got all the parts for my "in-dash" control pressure meter.
The gauge on the dash is an ohm meter. I found instructions on the VDO site to figure out the the resistance range that the sender would have to produce. I bought a $2 variable resistor "pot" at radio shack.
It goes 0-1000 ohms in 15 turns. You take the wire to the sender and hook it to one of the leads from the pot then you ground the other lead from the pot. as you turn the screw on the pot you can watch the needle on the gauge go up and down like the pressure sender would do.
You adjuat the screw so that it makes the needle go to 5 bar. Unhook the pot and read the resisitance. (It was 208 ohms at 5 and 232 with the needle pegged at the top.) It was 10.7 ohms at ) bar and 0.6 ohms pegged at the bottom. So I need a 0-5 bar (0-80psi) pressure sender with an ohm range of 0-240.
VDO makes a universal sender with these specifications.
It wasn't easy to find one locally because most part stores only list them by application.
I found mine at Boat US. They listed them by psi range and the ohms.
It's made by Teleflex a well known manufacturer.

I believe the tempature gauge, fuel and oil level gauge work the same way.

I'm still working to find the higher pressure gauge for oil pressure.
I saw a picture of an earlier 911 gauge that had the tempature on deg. F and the oil pressure 0-100 psi.

Remeber mine is a Euro. Does the US SC have this gauge?

[Charlie Stylianos]

Jon,

Autothority makes performance chips for Motronic EFI, so they probably know those systems the best. I'm guessing they use that dyno mostly for motronic performance tuning and for folks like you and me who just want to see what our cars 'can do'. The tech who was helping me did not really know too much about CIS and how to adjust the fuel pressures, etc.
Check out: Bosch Fuel Injection and Engine Management
by Charles O. Probst. Great book for understanding CIS.
http://www.amazon.com/gp/reader/0837...657029-3840756

BTW: $75 for 3 torque and horsepower pulls. $115 if you want air/fuel as well.


William,

Pretty ironic huh? I thought I would be running lean also, at least somewhere in the RPM range, but the leanest it got was 13.2 @ 3.5K and the richest was 12.0 @ 5.6K. Pretty linear and yes a little rich, not a bad thing if I want to prevent preignition. The plugs do look a little sooty, but don't know if I'm going to do much about leaning out the mix. It runs well, pulls strong, round cool and doesn’t ping. Some say max power for NA engines is attained at an a/f of 12.6, others say 13.2. Maybe I'll play around just for the sake of science

I had 3 pulls, all three were in 4th gear at wide open throttle from 2200 to 6700 rpm. If felt like forever hearing the engine building up to a LOUD whine/scream at 6700RPM.....

After seeing these results, I don't think I'm going to backdate to a Euro Lambda or a k-basic. Its getting plenty fuel and think I can get the curve a little more linear by richening the idle CO and increasing the system pressure to lean out the curve a little at the 4k+ range. Yes, all this just for kicks. I may call upon your CIS pressure tuning expertise here.

BTW: I have heard that a gasket shellac works well for sealing split fuel distributors. Seen them in most every auto parts store.
http://www.sariainternational.com/au...on-shellac.htm

[William Miller]

Jon, I have the probst book if you want to barrow it.
I have another one as well. I didn't see much discussion about turbo's. But it's really the same but very application dependant.

Charlie, with the K-lambda system, i recall that you can tune the mix with a dwell meter somehow hooked up to read the frequency or cycles of the frequency valve. I didn't get too involved in that chapter since it has no use for me. I would love to see it happen.
I wonder if the age of oxigen sensors effects the control system.
There are a lot of variables that can effect it. (Air filter is another guess.)
You are far closer to the optimum than I think I will ever see out of my k-basic. A little on the rich side too.

Let me know if you try and hook up the dwell meter.
I have one if you need it. I would imagine dwell meters will be relics soon.
Don't need them for points except for those that are keeping the early cars going.

[Charlie Stylianos]

William,

I bought a dwell meter specifically for checking the frequency valve duty cycle, but don't need it now that the O2 sensor is unplugged. The O2 sensor is disconnected and CIS is currently running open loop which is a constant 65% duty cycle unless at WOT, where CIS will then ignore all O2 input and run full rich. I just need to tweak a little to get this 'full rich' setting a little leaner and maybe get the A/F mapping a little more flat. I'm not too concerned about tuning the part throttle a/f as I'm not concerned about max perfomance when I'm tooling around town. This will take some experimenting with the idle co%, system and control pressures, but its really not a huge priority right now as I'm pretty safe running a little rich as it is.

[William Miller]

My rebuilt fuel distributer should be here today or tomarrow.
Dis you want to look at the one that is like yours while it is apart?