A/F number drop with alky?

[scot w.]

My target A/F is set at 11.4 and spraying alky with dual nozzle's. On my recorded run lastnight my ACTUAL A/F was bouncing around at 11.13 / 11.25. but when you review the log and overlay it onto the Target A/F the bubble is right on the 11.4 box's only (no other box's) so i know it's not pulling from another box. The o2 corr was 0.0 most of the run and -3.0 at the end.

I was just wondering when using 93 pump gas and dual nozzle alky if it will show alittle less on the log than it really is.

Scot w.

 

[scot w.]

Anybody? Surely with all the people here with Alky & a F.A.S.T system has got to know this...

 

[scot w.]

Is This A Stumper!!

It's hard to belive everyone on here running alky with a fast system can't answer this!!

 

[Reggie West]

I am seeing the AF ratio drop from the target of 11.4 to 9.

Keep in mind this is on a Stage 2 motor with a dual bb 80 turbo on C-16 race gas.

We will be turning off the alky set up because of this and the injector duty cycle is going nuts with the alky under WOT.

I dont know if there is just too much being thrown at the motor of if the race gas and alky are screwing up the wide band O2.

I will keep you posted.

 

[tbirdv6]

I am seeing the AF ratio drop from the target of 11.4 to 9.

Keep in mind this is on a Stage 2 motor with a dual bb 80 turbo on C-16 race gas.

We will be turning off the alky set up because of this and the injector duty cycle is going nuts with the alky under WOT.

I dont know if there is just too much being thrown at the motor of if the race gas and alky are screwing up the wide band O2.

I will keep you posted.

Are you running a volt booster by chance?
FRED

 

[Reggie West]

No I am not.

I am not seeing a voltage drop on the data log. But I will check it again.

That might explain the duty cycle going nuts.

 

[Razor]

Scott.. you still screwing around with air fuel in the 11's.. told ya.. put it down to mid 10's.. and work on it from there.

Alcohol has a lower stoich as a fuel. Meaning it will drop your target.. meaning YOU need to change the target down to 10.5-10.8 to start. Your car may end up liking 11.3 in the end, but playing with a leaner air fuel .. leads to broken parts.

Stoich on methanol is ~7:1 Stoich on Gas is 14.7:1. Meaning if you tune for 11.5 on gas.. you need to come down when meth is added.

I feel like a broken record on this.. and everybody keeps tuning for 11.5:1 with a **** load of methanol getting pumped in.. guess the head gasket change will make you fatten the tuneup.

Reggie.. if the alcohol pressure is constant.. and the injector duty cycle is constant.. the air fuel has to be constant. And get the air fuel down into the 10's. Be amazed how much power you'll make and the engine will live a lot longer.. Then when you get the car on a track.. move the target up.. little at a time and see if the MPH goes up.

http://videos.streetfire.net/video/4bae3760-bfe8-47c0-bf74-989201817f00.htm

This was a 109 motor at 10.3:1 air fuel.. 9.59 at 140+ .. guess its making plenty of power :redface:

 

[Reggie West]

Scott.. you still screwing around with air fuel in the 11's.. told ya.. put it down to mid 10's.. and work on it from there.

Alcohol has a lower stoich as a fuel. Meaning it will drop your target.. meaning YOU need to change the target down to 10.5-10.8 to start. Your car may end up liking 11.3 in the end, but playing with a leaner air fuel .. leads to broken parts.

Stoich on methanol is ~7:1 Stoich on Gas is 14.7:1. Meaning if you tune for 11.5 on gas.. you need to come down when meth is added.

I feel like a broken record on this.. and everybody keeps tuning for 11.5:1 with a **** load of methanol getting pumped in.. guess the head gasket change will make you fatten the tuneup.

Reggie.. if the alcohol pressure is constant.. and the injector duty cycle is constant.. the air fuel has to be constant. And get the air fuel down into the 10's. Be amazed how much power you'll make and the engine will live a lot longer.. Then when you get the car on a track.. move the target up.. little at a time and see if the MPH goes up.

Video - Richie HIPSI 9.59 @ 140 at Need2Speed's Dead Hookers event at Bradenton Motorsports Park. TSM Buick

This was a 109 motor at 10.3:1 air fuel.. 9.59 at 140+ .. guess its making plenty of power :redface:

Razor I am not knocking the kit, rather the opposite I can tell the thing works well and to your credit my Dads T type is running a stock block street car and it works very well with pump gas.

I know the GN is in need of tuning and that is all.

 

[scot w.]

Scott.. you still screwing around with air fuel in the 11's.. told ya.. put it down to mid 10's.. and work on it from there.

Alcohol has a lower stoich as a fuel. Meaning it will drop your target.. meaning YOU need to change the target down to 10.5-10.8 to start. Your car may end up liking 11.3 in the end, but playing with a leaner air fuel .. leads to broken parts.

Stoich on methanol is ~7:1 Stoich on Gas is 14.7:1. Meaning if you tune for 11.5 on gas.. you need to come down when meth is added.

I feel like a broken record on this.. and everybody keeps tuning for 11.5:1 with a **** load of methanol getting pumped in.. guess the head gasket change will make you fatten the tuneup.

Reggie.. if the alcohol pressure is constant.. and the injector duty cycle is constant.. the air fuel has to be constant. And get the air fuel down into the 10's. Be amazed how much power you'll make and the engine will live a lot longer.. Then when you get the car on a track.. move the target up.. little at a time and see if the MPH goes up.

Video - Richie HIPSI 9.59 @ 140 at Need2Speed's Dead Hookers event at Bradenton Motorsports Park. TSM Buick

Julio, No i'm not still at 11.4! this was before i talked to ya a couple days ago. i'm out of town right now for another certification class and when i return i'm going to put it to 10.8 like you said and then i'll give ya a call. and i'll be re-tourqing the heads when i get home and then a leak down test after that to establish the need of a head gasket change.

DON'T GET SNIPPY!!!:biggrin:

 

[Razor]

Razor I am not knocking the kit, rather the opposite I can tell the thing works well and to your credit my Dads T type is running a stock block street car and it works very well with pump gas.

I know the GN is in need of tuning and that is all.

Call me and i'll see if I can help. Keyboards are tough places