More fuel or alky?

[northern87gn]

Did a test run last night with temperature around 47 deg f low humity. After the run checked my scanmaster o2 and it dipped into the high 600s at 98 mph with no KR. My question is should I bump the gain knob up from 12 oclock or add more WO fuel via TT chip? Will more meth bring the o2 back into the high 700s or do I need more fuel to do this? Controller is set at "default" for turn on and initial. TT chip is set at default also (no timing or fuel changes. (23 deg/ 21deg). Other mods in sig. Thanks Razor.

 

[matt87]

i have the same question. my o2 were dipping in the low 700s when it got cold, i was running 25-26 psi with no knock when it was warm, 70-80s, but now its knocking. i turned my initial and gain all the way up, but stiill knocking. i'm gonna back down to 20 psi and work up from there.

 

[soundguy]

remember, as the air is colder it gets denser. So 40 degree air is gonna be alot denser, meaning more air into chambers. If you're running near the limit on your injectors, you may be running on the lean side compared to warmer temps. The lean condition would explain the knocking. Adding more meth is easier than changing the programming and may not need to be changed back when temps get warmer again whereas any programming change you make will need to be redone again when it gets warmer.

 

[northern87gn]

Yes I realize the colder temps are leaning out the afr, by basic question would be can shooting more meth bring the o2 back up into the high 700s? The TT chip is very easy to increas the WO fuel. +or- 10%. So it's a horse apiece as far as adjusting goes (ok ok the gain knob is way easier )
For my current set up my injectors are overkill so giving more WO fuel should not be an issue. Guess I'll just have to do some more testing and find out for myself.

 

[Razor]

You need more fuel and leave the alky amount alone.

Better stated, while the alcohol can richen up the mixture, I rather use it for detonation control.

So if its not knocking.. leave the alky alone and get your O2's with fuel.

If it is knocking.. then add alcohol/pull fuel.

 

[Razor]

Wanted to add.... high 600's is very lean "IF" the O2 readings are accurate. I would look into fuel pump/regulator/filter/etc.. for issues.

Make sure your O2 isnt going south.. put a new AFS20 in and see if the condition changes first. As this is the easy test.

Easier test is watch your EGT's.. if you have na EGT meter. If they start climbing above normal.. lift and see why.

 

[northern87gn]

Wanted to add.... high 600's is very lean "IF" the O2 readings are accurate. I would look into fuel pump/regulator/filter/etc.. for issues.

Make sure your O2 isnt going south.. put a new AFS20 in and see if the condition changes first. As this is the easy test.

Easier test is watch your EGT's.. if you have na EGT meter. If they start climbing above normal.. lift and see why.

Will try bumping fuel up first to see what that does. No EGT or wideband..yet :biggrin:
Your answer leads me to ask another question. Hypothetically speaking if the car is running perfect at say 75 deg and the next day I take it out at 45 deg will the computer be able to compenstate and add more fuel?
I think I know the answer to this but it sounds better coming from the alkmeister.


Is WO, foot to the floor, Injector duty cycle variable via the computer and it's inputs from the air temp sensor and MAF? Or, is this duty cycle written in stone via the chip programming??

 

[Razor]

This question is really in Erics realm.. there are temp corrections done by the chip based on MAF and ATS. How Eric uses them to add fuel when it gets cold??? That one I dont know.

It was the custom to add FP when it got cold outside..

 

[Eric Stage I]

When it gets colder out, you'll need to turn the boost down due to the denser air. There are no corrections made for airtemp once the MAF hits 255.

Regards,
Eric

 

[turbov6joe]

Julio,
Reading your post kinda makes me wonder if you still shoot for a commanded A/F ratio of 11.9-12.0:1? I've been messing around with running 11.9:1 and dumping more meth....not making the power I thought it might. When I ran those good numbers in BG this year I had the A/F set at 11.4:1, the initial at factory settings, and the gain at the 2:00 or so position. I'm considering backing down to 11.4:1, turning the initial back to facorty, the gain to 12:00 and seeing what happens??? I will say this though, if my EGT is not in the high 1600º area, the car feels REAL lazy. Before I can run at the track again I need to address an electrical gremlin that reared its head last week. Seems that either the red wire from the alternator to the starter, or one of the starter wires is shorting out somehwere causing the alternator to crap out; I lost yeat another alt at the track last Friday!! Why I think it's one of these wires is that when I hooked a charger to the battery, the alt got hot...can you say GROUNDED!!

 

[Razor]

Eric thanks for posting.

Joe, I had a rear mounted battery give me fits since it shorted the power wire to the heat shield. May want to look at those wires.

I cant see how a shorted wire wouldnt cuase it to smoke/discolor. I mean from the back of the alt to starter.. maybe recheck that cable as it runs around the turbo and to the starter. Do post what you find..

Glad to hear your finally starting to run the car again.. best wishes..

 

[turbov6joe]

The wires on the starter are my first guess as they were close to the heat shield to begin with....I'll start there. Quite possibly the red wire form the alt to the starter got pinched or too close to something causing the wire cover to wear away....who knows??? I'll be under it tommorow when I get up and will post my findings...later!

What's your opinion on the A/F ratios?

 

[Razor]

Man my target at BG this year was 11.3 at 23 degree's timing.. the pickup on 11.3 was 27mph. On 10.8 was 23mph. I found why my boost dropped off.. I was missing the rear bolt on the passenger side header.

I like the sound of 11.9.. tho havent had the chance to lean it out there yet. I do know these motors like gas thrown at them. Richen it up and see where it takes you. Better always start rich then work on leaning it out.

Did you get to make any runs last Friday.. or was it a wash?

 

[turbov6joe]

Man my target at BG this year was 11.3 at 23 degree's timing.. the pickup on 11.3 was 27mph. On 10.8 was 23mph. I found why my boost dropped off.. I was missing the rear bolt on the passenger side header.

Sounds familiar.

I like the sound of 11.9.. tho havent had the chance to lean it out there yet. I do know these motors like gas thrown at them. Richen it up and see where it takes you. Better always start rich then work on leaning it out.

For whatever reason(s) my motor likes to be on the lean side and seems to lay down when the EGT's are not in the higher 1600º area. Best gain between the spilts was 30 mph @ 1710º EGT....I am going to try and lower the A/F, back down on the meth and start over.

Did you get to make any runs last Friday.. or was it a wash?

It was a BIG FAT WASH!

 

[northern87gn]

Did some more testing this afternoon after setting the WO fuel to 139 on the TT chip. (this should put the WO fuel at or near +10%.) Temps were colder than last time, 42 deg.
On a positive note my o2s are back up in the high 700s so I was pleased to see that.
On the negative side I was getting some nasty transitional knock as the boost shot up when doing launches from a stop. Knock would appear when boost needle was sweeping from around 10 to 20 pds, basically a few feet after starting to move to top of first. This was not caused by spinning or other false sources as I could here pinging from the engine. Problem did not change when I turned the gain up to the 2:00 positon. The knock was occuring well before I got the pedal to the floor.
Also, if I slowly floored it on take off I did not get any knock.
My best guess at this point is that the meth is not getting enough time to "flash" with the colder intake temps.(but does flash on longer, slower pulls due to the compressed air getting some heat into the intercooler.) Does this sound like a reasonable theory? Another clue to my theory is even in warmer temps it seems like the very first time I get into boost after a cold start I'll get one blip of knock on the knock gage, then it's done and does not happen again until the engine is cold again. (yes I do prime the crap out of it before I goose it.) Does the meth have to go from a liquid to a vapor to do it's magic? I remember seeing this transitional knock shortly after the kit was installed in the spring of 2004 when temps were also in the 40's.
Any thoughts or suggestions? Not a big deal as car is going into winter storage shortly.
I may try this to see if it helps.
1) back off timing in 1rst and 2nd gear via chip.
2) double check fuel pressure setting. (was set at 43 line off in the heat of summer)
3) Dump some "fuel stabalizer" in the tank (toluene)
Sorry for the book

 

[Razor]

I noticed you have an translator. Wonder if the settings inside of it could be skewed creating some of these issues. As the MAF does control fueling.

If the car at WOT is going through the alky.. level is coming down on the tank.. then it just could be it has too much timing.

Alky does require some heat for it to "flash". Not a whole lot.. but at least 70 degrees temp wise.

Run the motor to operating temps.. maybe a warmer T stat like a 180.. if the pipes/turbo/ motor is hot.. you typically shouldnt have an issue. Also I believe the LT1/LS1 MAF may have some temp corrections built into them.

Personally, I would try a known good stock MAF on the car and see how it responds... then work on the translator. That way some of the variables can be eliminated.

For storage.. Unhook the line to the nozzle, and run the pump.. run water through it.. then let the system run dry.. Store it dry. A little that is left in the head of the pump wont be an issue. No reason to have parts soaking in alcohol for months.

Couple of ways to speed the process up in draining, one is turn the blue knob all the way CW and hit the test button.. faster way is to unplug the MAP and jumping green to gray on the terminals.. that will simulate 30 PSI on my controller. VERY IMPORTANT>>> PLUG THE MAP BACK IN IF YOU DO THIS...

Another way is applying pressure to the nipple on the MAP.. a syringe or mity vac can be used. VERY IMPORTANT>>> PLUG THE HOSE BACK ON THE MAP

Bout 1-2 gallons of water will flush it out. May decode to do a filter inspection as well.

 

[northern87gn]

My theory about the meth not flashing turned out to be wrong. I wasn't getting the alky in quick enough at launch. Everything is running top notch now. I was running at 37 deg with no issues last night. Man these cars like cold air, my glove box popped open and everything in it ended up on the passenger seat when I got some heat in the tires.
Thanks for your excellent customer service ounce again Razor.

 

[turbov6joe]

I did some messing around with A/F ratios at the track last week. I started with a target of 11.4 and the car ran real good. I raised it to 11.6 then to 11.8 and noticed a drop of mph each time as well as considerbly higher EGT's. I then dropped it down to 11.3 and noticed the best numbers across the board. Pick up between the splits was almost 28 mph and the motor seemed to like the extra gas. My alky knob is on the 12:00 poisiton, turn on at 4 psi, and the gain slightly more than stock settings. this Friday I'm going to try even lower A/F ratios to see what happens. I'm going with the idea of introducing just enough meth to keep the detonation in check and run the motor mostly on 92 pump. HTH's