i wouldn't try that under full load

 

You have to understand that it only leaned about 2%. It was too rich by 2% on the top end, and then leaned into my actual target a/f ratio when I got off the throttle. To be on the safe side for the next time out with the car, I only leaned that section of the fuel table 1%. We'll see how she does with that. I'll be keeping an eagle eye on the exhaust temp gauge.

We're still only at 31 psi boost with a static CR of 9.25:1 on methanol. Still pretty safe. Things will start getting more critical closer to 40 psi boost with this static CR.

 

no worries
i was just using my personal experience of static comp ranges of 7.2 to 12 :1 with up to 38 psi and methanol fuel
would hate to see some one hurt damage there engines from only 1/2 the story told in a forum..
yes 2% is the key link to your comment

 

Hey Alky, which lambda do you recommend or use for Methanol ?

 

My tuneup is presently at 31 psi boost. I expect I'll need to go richer as I push the boost level higher. Understanding that, at 31 psi boost, I'm presently getting best safe power using a lambda range of .744-.765. The plugs plating is burning 1/2 to 1 1/2 threads.

 

alky, are you still using the tec3R, I was asking which brand and model of sensor do you use for getting the reading with the tec3r ?

 

Yes, I'm still using the TEC3r with the latest WinTEC4 hardware, firmware and software upgrades.
I'm using a wide band sensor from Performance Trends. It's calibrated to readout gasoline numbers, which I've just gotten used to tuning with.
Translating the above lambda range, the readout range is 10.9-11.2:1. This translates to an air/alcohol ratio of 4.8-4.93:1.
I should also add that I use the O2 reading as a tuning reference only. I do not use O2 correction. It is turned off.

 

Thanks, I gotta say your threads are amazing.

 

Thanks. I really appreciate that. When I first started wanting to tune with methanol, a little over 15 years ago, there wasn't very much written, or shared about tuning with methanol. Even far, far less when it came to using nitrous oxide with methanol. I thought that was odd. Why was that? What was the big secret? I learned to tune with this fuel with very little help from very few others.
Methanol is an absolutely amazing high performance fuel. I'd really like to see more people using it, and I just feel I have to share what I've learned about it with others.

 

Donnie, refresh my memory so I don't have to reread all of this: At first you used the N2O assist, found that retarding the timing helped burn more of the unused N2O/fuel out the exhaust gaining a larger benfit. Next you added a small N2O/alcohol shot to the turbine inlet and found more gains. Correct?

Now I've thought for years about the turbine inlet deal but never got around to trying it. With the smallish shot you're using how much does it affect EGT? I'm thinking why not change my current .047" jet I'm using in the intake to maybe a .020" to help with converter flash and just bypass the motor and feed the rest (or more) with some fuel directly to the turbine? As far as driving the turbo does it care if it is seeing exhaust energy or energy direct from the nitrous/fuel?

This is a 4 cylinder Ford, alcohol with a 475 BW. I use a single dry nitrous nozzle in the charge pipe to spool up, it shuts off at 20 psi. I would like to try this to eliminate the issues I've had with tuning around the nitrous assist. It's mechanical injection so it is not very easy to make small tuning adjustments. Plus on pro tree racing maybe start the spray a little before I set the TB to get things moving sooner. I would think it would be hard to get the EGT's out of hand over 2 seconds of on time?

 

On the first question. Correct. I would add that the primary nitrous system is jetted at a rich burn limit mixture. Your mechanical injection system should be tuned to a good standard power level without the nitrous injection first. After you have that dialed in, all you should have to do is jet your primary nitrous system to a point where just one jet richer on the fuel side will cause rich missing. If you're using a dry system, I can see where you might have a problem finding the correct amount of fuel to add. But still, all you need to do is be on the edge of the rich burn limit. When the nitrous system hits and the engine dies because it's too rich, just lean it out bit by bit until you have a clean hit. That should give you the correct mixture, along with the right ignition timing, to allow a good ALS reaction. But then, I can see the problem with mechanical injection if you don't have a way to turn the extra fueling for the nitrous system on and off.
Second question. For the 2 seconds of 'on' time that I've tested the system, the EGT gauge was still climbing when I shut it down, but never got over 1000 degrees F in that 2 seconds. What the max EGT might be if I were to stay in the system longer, I imagine I'll never know. I don't have any reason to stay on the system any longer than 2 seconds. And no, the turbo doesn't care where the extra energy came from.

 

The procedure that I'm using with great results for a Pro light has been;
Pre-stage the car at an idle.
Set the transbrake and TB creep enable button.
Go WOT.
As the throttle hits WOT, the nitrous is activated by a WOT switch.
As the rpm rises and reaches 2800 rpm the transbrake creep is enabled for a programmed amount of time which stages the car.
On the amber, I release the transbrake button.

This procedure gives me a little more time with the engine on the nitrous before staging the car so that by the time the amber light comes down, I've been on the nitrous system very close to 2 seconds. My system shuts down at 175 kPa, a little less than 2 seconds on the system.
Since the tb creep is a programmed procedure, there's nothing that I really have to do except go WOT. The nitrous activates automatically and the car stages automatically. All I have to do is look out for the amber and release the TB button.
I'm presently working on my tb creep feature to get the car to more gingerly creep into stage, instead of lurching into stage. This will buy me a little more time on the system, too, if needed.

 

Thanks, that confirms what I've been thinking on the EGT part. I'm going to give it a try this year. My biggest problem is going to be the varying fuel problem. My fuel system idles at 30 - 45psi and runs 200 at full boost/rpm. Hopefully it won't change too much while in the spool up portion of the boost and launch rpm areas.

When considering just the turbine inlet side of the N2O do you see better results with a rich mixture or closer to stoich? I'll probably have to start the shot near stoich just so it winds up near too rich by the time it shuts off at 20psi or so boost pressure.

I've seen several of your launch videos and it sure does look like it takes a big old lurch into the beams. Ever thought about 4 wheel line lock? I've been doing it that way for years because without the nitrous on a pro tree I would have to really stand on the footbrake to build enough boost to bump in with. That left the rear suspension fully loaded and it would bounce all over if I released the footbrake after hitting the trans brake. I'm not thrilled about trying to launch with so much preload but it sure makes it easier to get in the beams.

Thanks for the info, I've been playing with my alcohol setup for 20+ yrs now and sure could have used some of this kind of help back then. Glad someone else wants to be the guinea pig! lol

 

The afterburner uses a mixture that is typically a good power ratio for methanol. Equivalent to an air to methanol ratio of 5:1.

 

dave,
i run mechanical injection
the new systems are way better for controling
email me if you want new hardware / ideas..

 

if you changed some tuning methods, the heads will flow more.. 8)
im not going to post here... i will take it to PM

 

Interesting. How can you possibly say that without knowing the exact specs on the heads, or all the tuning methods I'm using? As an example, I've had others claim publicly that they could spool this turbo without nitrous, only to find out in PM that they really didn't have a clue how difficult it really is with this combination. Please. If you think you have a solution, present it for our evaluation. Otherwise, save the grandstanding for your friends.

 

Donnie,

I know you havent tried the nitrous just at the turbine alone. Have you thought on weather or not the mixture would light off from just heat without the flame in the exhaust from the ALS.

I am also considering doing this on a 4.3 v6 , blowthru carb setup. I would just rather not run it through the motor if it doesnt need to. Similiar issue with getting up on boost. Its my buddies ride and I originally put an 8 in. converter I had in it and it spooled very nicely but road the stall point in third cuz the convertor was for a different application. The converter thats in it now was a used deal because he is on a tight budget. Being its built for a v8 this v6 cant get enough RPM to spool unti about 1 second out at the track.
At this point it would be cheaper to piece a kit together and do this than by the right converter.

 

It's possible that if there was enough heat in the turbine housing the mixture would autoignite. Frankly, I'll let someone else experiment with that angle. If it delayed lighting off, you could end up with one heck of an exhaust side explosion. If I were to try it out, I would install a very short downpipe after the turbo and point it in a safe direction and do some testing. The short downpipe would greatly lessen the chance of damage if there did end up being any appreciable delay in the mixture lighting off.

 

I was thinking of doing the same thing but using a smaller shot of nitrous in the motor just for lighting off the "after burner" . Cylinder pressure is cylinder pressure. As long as you turn the nitrous off after the launch I don't see it being much harder on the engine than boost alone at higher levels? You could even use a pressure switch to turn the nitrous shot going in the motor off after initial light off of the "after burner". Thats my take anyay.