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Author Topic:   How do you tune with Methanol?
rnoswal53
Dirt Maniac

Total posts: 120
posted March 21, 2005 08:38 AM  
I have heard that you almost can't get it too rich with methanol, then I have heard the opposite! How do you know how much is too much as far as jetting goes? The plugs look very clean after a run. With race gas in my other car it was easy to tell if it was too rich because it would start missing, so you just backed off a few numbers.

How do you go about just getting it close or right on. I have a 750 cfm by Bolaws that I borrowed from a friend. It seems good I guess no one wants it too lean and I want to avoid that if at all possible.

Thanks
Russ

A&M Motorsports
Dirt Maniac

Total posts: 117
posted March 21, 2005 11:50 AM  
Assuming your fuel pressure and everything else is correct, you can install a thermocouple and a pyrometer in the number 5 or 7 header tube. This will allow you to tell if you are lean or rich. Too lean you burnem up and too rich you can wash the rings and bearings right out of the engine.
If you want to read the plugs you'll need some type of magnification and a light. One sure sign of a lean condition or detonation is when you see aluminum on the insulator.
When all else fails do it the coon *** way, spit on the header tubes. LOL

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Artie Perilloux
A & M Motorsports

Racer111
Dirt Freak

Total posts: 259
posted March 21, 2005 03:31 PM  
Call Bolaws.They will probably give you a good starting jets #s.

donslink1
Dirt Freak

Total posts: 318
posted March 21, 2005 04:23 PM  
Read your water temp if it is running hot fatten the jet if you cant heat it up drop jet.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted March 21, 2005 04:33 PM  
Id ask the carb maker for starting point. Then run it and look at the plugs. You will need a magnifying glass and a light but you can still read them on alky.

rnoswal53
Dirt Maniac

Total posts: 120
posted March 22, 2005 07:24 AM  
Ok. I'll see if I can't contact Bolaws and I may even try the spitting thing.....lol. Anyone seen a magnifier and light setup?

Russ

NJantz
Dirt Forum Champ
Total posts: 755
posted March 22, 2005 09:22 AM  
I damaged two engines last summer that showed signs of a lean condition after teardown. After that expensive lesson we now take them to the chassis dyno so the jetting can be corrected based on air/fuel measurements.

Keep a close eye on the intake coolness/condensation also. However that nor water tempertaure are not always great indicators to go buy, neither are looking at spark plugs with an unaided eye. IN my opinion the dyno is the best method to use to arrive at the correct jetting.

mekomod51
Dirt Full Roller

Total posts: 42
posted March 22, 2005 10:11 AM  
You start with the carb buidlers suggestions and you can move up from there after you have checked plugs and water temp.
When you have gone too big you will be able to tell becasue the motor will stumble and loose responsiveness.

fastdad12
Dirt Full Roller

Total posts: 33
posted March 22, 2005 05:41 PM  
Speedways still sells the magnifying glass flashlight. another thing that they have that would be quite helpful is the champion spark plug tuning guide.



Racer X
Dirt Freak

Total posts: 256
posted March 22, 2005 06:23 PM  
We like to see them with a light tan color to them.No specks or flakes. Always better to start off a little fat and work down.

fastdad12
Dirt Full Roller

Total posts: 33
posted March 22, 2005 06:25 PM  
Same with Chicks?

rnoswal53
Dirt Maniac

Total posts: 120
posted March 22, 2005 06:35 PM  
Pretty good fastdad12................lol

Russ

Racer X
Dirt Freak

Total posts: 256
posted March 22, 2005 07:13 PM  
What??? You thought I was talking about spark plugs lol

52mod
Dirt Roller

Total posts: 11
posted March 23, 2005 07:53 AM  
Pyrometer set approx. 4" off the header flange. Shoot for 1380 but do not exceed 1400 degrees.

If you realy want to tune to exact AF ratio I hear great results about the new wide band O2 sensors. Alot of drag racers are using these for consistent ET's.

dan murray
Dirt Full Roller

Total posts: 34
posted March 26, 2005 12:36 AM  
If you don't have a digital egt device put some new plugs in it, go out and run some hard laps shut it down at the end of the straight coast in and you pretty much want the 1st thread-2nd thread of the plug blue from heat discoloration. Then look with a magnifying glass on the insulator all the way down into the plug to make sure there are no traces/spots of alum. Make jet changes accordingly. And rich is the worst for alcohol- runs like **** if it does run and washes lubricants, bad for guides also, Alcohol is forgiving on the lean side. I personally have had an alcohol engine too lean -1585 degrees egt for the duration of a 20 lapper with no damage found at teardown. Wouldn't want to do it again, rejetted to achieve the 1380 ballpark.

FASTLAP
Dirt Maniac

Total posts: 171
posted April 02, 2005 04:32 AM  
Is that 1380 number a ballpark for wide open throttle? I have a dyno sheet with egt's on it that aren't even close to 1380 at wot. Was thinking it was running rich. Also what avg # should I look for at lower (3k) rpms's to know if I'm too fat?

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