Well, I guess if its not broke don't fix it! If you are getting good drivability from Alpha-N mode, leave it alone. If you decide to try speed-density mode again you might try lowering your VE values at idle until you get a reasonably close match between target and actual AFR. I've got mine idling at a target AFR of 14.5 and I'm using a maximum of two degrees of timing trim. With these settings, I am getting a pretty smooth idle at around 800 RPM. It is a good idea to balance your stacks with a gauge (your orignal purpose for this thread). I did this and my idle quality improved quite a bit. Be sure to follow the proceedure that TWM recommends when you do this. It involves unhooking parts of the linkage and adjusting other areas of the linkage to get things right. I think that their website has a .pdf that you can download that explains how to do this. Good luck with the rest of your tune and let me know if you would like any help with that.

- Fred

THanks Fred!

len

Fuel pressure
 

Rick,
why is your idle pressure lower than WOT pressure? My regulator holds pressure at the same level throughout the load range. Do you have lower alternator voltage at idle?
I am running 65# injectors at 45 psi with a Bosch inline pump fed by a Carter electric and the pressure stays at 45 psi no matter what I do with load. I have a Denzo 65 amp 3 wire feeding a 6AL, electric water pump, FAST Sequential EFI, both pumps, PI data logger and a 16" electric fan so fairly large electrical load. I also use Alpha N because cam overlap does not allow
use of the MAP sensor.

Check your close loop setup
...I know our setups are different

FAST?

That shouldn't be happening.

Have to ever logged a session to see what is going on?

After I re-read about it (on page 102 of the manual), I realize it was it dropping below the min RPM (it was right on the edge). Two cut offs that will put you into open loop mode: coolant temp and RPM. There are some other items in there also worth reading.
I agree it is not due to heat at the O2 sensor.

Ye, I don't think you want to be in closed loop at idle. There are too many things that are going on until the engine heats up. I have the idle really solid, although a bit high right now as I keep leaning out the lower left cell to get a better A/F ratio.

What mode do you run in? speed density or Alpha N?

Sorry, I didn't know you e-mailed me
 

Cobra #3170 I have a vacuum controlled regulator in my fuel system. My system was setup for a blower setup with a Paxton. you need 1-3 pounds of fuel for every pound of boost you make. IMO it's the supply at a steady pressure more than the pressure of the Fuel. I was only going to 10 psi for the system. I have too many little issues with the setup and belt I was running. Lack of hood clearance at this time didn't help either. I now have a paxton hood and may down the road retry this setup. I have an 70 amp orginial Alt setup with external regulator. It is not enough because of the added things on the car I have run. I have the ECU, 3 cooling fans, 2 (255liters pumps) MSD 6AL, 2 (4") cooling fans under the hood, and trans and readend cooler in the near future. Like Freds car I am going to a 130A alt setup. This is needed to all the power I am now running. Amp gauge needs to be changed to a Volt Gauge. Some rewiring also will be needed. I do know from racing that my Alt can't keep up my battery at full charge (12.6-12.8 volts) and run all the other power components. My alt only puts out about 35-38 amps under 1000 rpms. Just the 3 fans, MSD, ECU and fuel pump Draw more power than this and drain the battery. At 10.2 volts my MSD will not fire the spark plugs. I did get a little side tracked but have found that dropping the fuel pressures only at idle rpms with large injectors, IMO helps at idle to fine tune the motor. I have no smoke of any kind when I hit the throttle and no delay of responce from the motor. The fuel pressure goes from 43-44 psi to 52-54psi under a drop of a vacuum signal to the regulator. IMO a believe in having way too much supply and volume to a fuel system. 2 1/2" seperate fuel supply lines with a fuel pump on each one and 1 return line of 3/8". My gas gets warm after a 20 minute race run, but has not cause any problems yet. I do run between 1/2 and 3/4 of a tank of gas going out for each run and come in with just under 1/2. This is straight pumped gas. Hope this help with your question.

Hi Rick,

Does the alternator fit an FE without using different mounts? I searched, but could never find anything that wasn't too deep.

len

TO you guys running Alpha-N on an FE.

How have you got your A/F ratios set up? I'm mostly at a 13.5. I have stage 3 heads. I understand that these motors like to run rich.

len

Alt on the L/S on my motor
 

kobrabytes Len I have my Alt on the L/S on my engine up at the top just below my outlet and upper radiator hose on my car. The reason was because of room being tight from the blower and my P/S pump is on the lower R/S mounted to the timing cover bottom 2 bolt holes. My timing cover is one that works with a solid motor plate and mounts to the frame rails. The correct ERA way is that it mounts on the R/S of the motor in a higher location. Except for my Alt being a little short in max output (70a) it has worked fine for 11 years. I am going to a bigger 120-130a because of charging issues when racing. Too much draw with the added pumps and fans. Rick L. Ps the Amp gauge and wiring through it must be changed to a Volt gauge. The old gauges where only set to handle 60 amps with spikes in the 90's for a short time.%/

Hi Len,

I am using a 100A alternator onto my ERA/FE. This did take some modification to get it to work but they were not difficult. To begin with, I am using a set of March 2-V (groove) pulleys which puskes the belt about a 1/2" further from the motor than a 1-V pulley set would. I then used a single groove pulley on my alternator and used a combination of ERA's FE alternator mount kit with a custom set of spacers and water pump bracket (I have a shelby pump which did not fit the original ERA support bracket) to get everything to line up using the outer of the two grooves on the crank and water pump pulleys. I machined the back (unused) groove off the water pump pulley for appearance reasons. LAst step was to go the the local auto parts store, buy 2-3 belts that were close to the right side, and find a belt that would fit the best. The whole setup fits and works great. Here's a picture of the end result:

http://www.clubcobra.com/photopost/d.../Engine_21.JPG

Here's a picture of the setup with the engine out of the car. I switched from the bracket shown in this picture to the ERA version because the alternator need to be further from the engine to fit ERA's chassis.

http://www.clubcobra.com/photopost/d...l_Engine_9.JPG

I hope this helps.

- Fred

THanks Fred, nice setup!