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Locking Out Timing and Pulling O2's

orange395w

OG MEMBER
Staff member
Well gents, today I'm going to try an old method of EFI tuning that many hardcore racers still use today. If this works I think the 5.0 guys will be trying this the next time out at the track.

For those that don't know or who are simply unfamiliar with the 5.0 setups, there is a spout (plastic plug) in the distributor wiring. (passenger side fender on SN95's). When that spout is plugged in your ECM has full control of timing advance. The problem with letting your computer control this is the fact that the computer pulls out timing.... for emissions and fuel economy and bs like that. Not optimal for racing.

Think about how powerful the car would be if you had full timing from idle. It would probably be hard to control the car and it may not want to go straight, lol.

The next step is to pull the o2's. Why? Because, pulling the O2's puts the computer into open loop fuel mode, the processor does not try to maintain 14.6. It goes to preset values for rpm and load.

After doing these two things the operator has some control over tuning. It is a carburated approach to fuel injection. Now you can adjust timing and fuel pressure manually to get the car where you want it.

The method of madness will be to set a base timing with the SPOUT PULLED OUT. I will set mine to 32* to start out. I'll make a pass and see how the car performs. If it is lean I will bump fuel pressure 2lbs and make another pass. Once it looks good I'll bump timing another 2*. I will repeat this method until the car slows down. At that point I'll retard the timing back 2* and lock it down.

I predict some big changes ahead for the Notch. If by chance I blow a head gasket. New cylinder heads will be in order. :)
 

wickedstangs

Chula Vista, CA
Staff member
Administrator
Sweet, I used to do this with my 94. Good luck wish you would have told me I might just meet up with you tonight... Good Luck.

[ame="http://www.youtube.com/watch?v=5g-l-vnC3XA"]YouTube - Wicked Stangs Blue Streak[/ame]
 

orange395w

OG MEMBER
Staff member
That thing sounds like it's coming apart. Anyway, now back to your original broadcast........:)

Well guys this didn't go as well as I had hoped for, but it didn't go bad either. I'm confident that I will get a new Personal Best with this method, but it didn't happen on this night. I didn't stick to my original game plan which was to make small changes wether being fuel or timing, but not both at the same time. I learned alot from this experience, but most of all I learned not to rely on the wideband so much.

Not that it mattered much on this night, but I was supposed to increase timing until the car slowed down. I thought that meant E.T., but I was supposed to be tuning for mph. Too many variables when tuning for et, such as track prep, tire pressure, driver error etc.

It should also be noted that even though the times don't show it I could feel the car accelerating faster than usual. It even caught me off guard on at least 3 occasions and bounced off the rev limiter ruining the possibility for a new best time. Anyway here are the results from the other night.

1st pass: Timing 32* FP @ 44lbs = 7.02 @ 97.1mph w/1.56 60'

2nd pass: Timing 34* FP @ 44lbs = 6.99 @ 98.1mph w/1.53 60'

3rd pass: Timing 34* FP @ 46lbs = 6.95 @ 98.3mph w/1.53 60'

4th pass: Timing 34* FP @ 48lbs = 6.94 @ 98.3mph w/1.52 60'

5th pass: Timing 36* FP @ 50lbs = 6.96 @ 98mph w/1.50 60'

6th pass: Timing 36* FP @ 52lbs = 7.00 @ 97.3mph w/1.54 60'

7th pass: Timing 36* FP @ 51lbs = 6.94 @ 98.2mph w/1.51 60'

8th pass: Timing 38* FP @ 52.5lbs = 6.98 @ 97.7mph w/1.52 60'

9th pass: Timing 38* FP @ 50lbs = 7.05 @ 97.3mph w/1.57 60'


Notice how the 1st four passes got faster everytime I made a change. Pass 5 is where I started to screw things up by not sticking to the plan. On pass 5 I added fuel and timing. I should have increased timing by itself. If the mph would have slowed down I could have added fuel afterwards. I was able to duplicate the 6.94 pass @ 36* which tells me it may have went faster without soo much fuel pressure. Either way I have a good starting point for next time out. (36* FP@48lbs)

It should also be noted that the air was crap that night. Humidity was at 57-60%. The day I ran the 6.89 the humidity was at 35%. Everyone was running anywhere from .03-.10 slower than normal. I am reading up on how to read spark plugs and buying tools as we speak, so I don't have to rely on that stinking wideband. :)

5.0 guys I think this method is worth a try.
 

spdpilot

Well-Known Member
You were like a mad scientist with your car. My son who is use to all the latest electronics was like what is that? He had never seen a timing light before.

Reminds me of the good old days. A twist on the carb here, a bump on the timing there. Back when I use to build the carb'd race motors. Skills lost on most people today. Good Stuff!

You were working hard at it, thats for sure.

The humidity was about 65% according to my meter. The air was really bad and even after letting my supercharger cool for an hour, you could still fry an egg on it.

I think you are on to something. Like I said, its a learned skill that if you get good at it, makes the difference between winning and losing. If every thing else is good, this will make it better.

You got that car really well put together. And you sure made me remember there is a lot more to racing then just making power.

I was pretty flustrated with my car. I got to stop racing different cars and focus on one. I kept babying it out of the hole as if it were my truck.

It was fun for me. I can learn alot from you.
 

Lordgufi

Well-Known Member
while you may not want to rely on your wide band. its a great tuning tool. I still personally prefer to tune by knock counts ( i'm set in my DSM ways ). ... Yes... I tuned my old talon to purposely knock.
 

orange395w

OG MEMBER
Staff member
while you may not want to rely on your wide band. its a great tuning tool. I still personally prefer to tune by knock counts ( i'm set in my DSM ways ). ... Yes... I tuned my old talon to purposely knock.


There is no better way than to read a spark plug for tuning. The wideband is in the collector. Alot can change from the cylinder to the collector. I do think it's a good tuning tool, just not the best for what I'm trying to accomplish. The plugs can tell you things that the wideband cannot. As for DMS I have no idea WTF you're talking about, so I'll stick to this stuff, lol.
 

Lordgufi

Well-Known Member
DSM is a Diamond Star Motor... aka Eclipse Talon Laser... its my referance to my old car...

its what i learned most of what i know now from and I definatly learned a ton from that heap.

Best lesson yet... DO NOT GET FRUSTRATED!
 

orange395w

OG MEMBER
Staff member
I was pretty flustrated with my car.

I feel for you on that part of things. When you drop $800 on tuning you expect to go faster. I would be concerned with that MPH. For what you have it should be alot higher. You're car could have been pulling alot of timing being that the air was so bad up there and the car was so hot.

The one wheel peel doesn't help, but I'd give it another go with some better outside air temps and conditions and see what happens.
 

orange395w

OG MEMBER
Staff member
hope all works out better for you bobby.

This is the way I see it so far.......There is more tuning to be done as the car hasn't seen it's max potential yet using this method of tuning.

The best time ever was a 6.89 @ 98.7mph on a cool night with only 35% humidity

I've already run a 6.94 @ 98.3 on a hot night with 65% humidity.

That's .05 off. We are talking hundreths of a second here. One more trip out to the track should do it for me. I'm hoping to run consistant 6.80's before the transbrake.
 
M

Mustangcwo

Guest
Next test and tune at Barona should be much cooler and hopefully the California humidity level will return. I wont be doing much tuning next time out, but it will be fun running the new setup. I think you are taking the right approach with your tune, although I am far from the expert. I do recommend fewer changes and more passes to figure it out....but that's tough with the way Barona is staging the cars. :nonono:
 

spdpilot

Well-Known Member
I feel for you on that part of things. When you drop $800 on tuning you expect to go faster. I would be concerned with that MPH. For what you have it should be alot higher. You're car could have been pulling alot of timing being that the air was so bad up there and the car was so hot.

The one wheel peel doesn't help, but I'd give it another go with some better outside air temps and conditions and see what happens.

I kept focusing on the ET, but when I got home and really looked at the MPH closer on the slips. The MPH really was low. That bugs me. Even if I did pull a 1.60 60ft vs the 1.97, with that MPH of 79-81, there is no way I could do much better then maybe an 8.60-8.70.

Bad air...maybe. But Dante did some tuning after the M vs W event, where on street tires i was trapping 86-87 mph. So, I got to wonder if something changed. Thats alot of HP missing somewhere. But that supercharger never did cool at all. When the track took a break, I went up and it was scorching hot still.

The car is going on a diet. I am deleting the rear seat and replacing the fronts with some light weight ones. Moving the battery to the trunk. Getting rid of the spare tire. Also, I didn't set the shocks. They were still at 3 all around. Then also going to remove the front sway next time.

The last run, I video taped the run and both tires were spinning. I don't know alot about rear ends, so is that something that could come and go?
 

orange395w

OG MEMBER
Staff member
The downside is you will have to play with the timing to see what your car likes. It's not ideal for street driving, fuel economy etc. You're car adds and pulls timing all the time depending on conditions. With the spout out you will be @ x* of timing all the time. With the spout out you should pull O2's as well.

If you don't want to tune it like that I recommend going to find a spout at the JY. If you are only racing it then I will be glad to help you tune it at the track. If you plan to drive it cross country go get a spout!
 

beejay31000

BULLWINKLE
its not being driven across country, its gettin traileres.....but i do need to drive it to work and back a few days a week. fuel economy and stuff doesnt matter to me. its already uncomfortable as hell, so that cant get any worse. i added a little bit of timing (by listening) and the car feels good. more power at the high end. i also took out some fuel. i cant tell you what its actually sitting at right now, but its not detonating. i would like to tune it tho, if anything to make sure its safe.

if in unplug the o2's i'll throw a code right. and the little devil light will come on.
 
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