nitro tuning

We started out last night with 12% since changing to the 4:86 gears. The car just acted rich mph was 133-132 egts on some cylinder in the high 900's. I had adjusted the high speed to open around 85 lbs , opened it up a round and got a little egt heat, then decided to up the nitro to 16%.

We started getting a few fireworks out the headers on the 2 step picked up 1 number of 60' and 7 mph , busted 140 mph in the 1/8 .. I had been told if you are not running at least 15% its not worth messing with, that must be true because that was a big change imo.

Kerry Clark came up to jackson to help and hang out ,very nice meeting you Kerry and I appreciate your help.

big mph for sure!

Looks good Randy although don't let that door fly open and fall out!

Dave.

Randy, let us adore you

Sounds great!

Nice. You know what they say: If a little is good, then more must be better. How about bumping the specific gravity up to 20% now?

Paul

I am beginning to discover why fuel cars have zoomies gonna have to hire some door fanners or something .
Lem and I were discussing why the higher % seemed to lean out , kinda had me confused no bigger jump than that was and of course he knew , he said its all that oxygen in the nitro the more you put in it the leaner it will be .

Its kinda cool Lem still offering tuning advice, he knows if I wanted to burn gas I would have a bass boat instead of a race car .

Here is some top end video shot by Stanley Stickler its got a few of our members kinda ashamed getting my tail spanked but its good video .

Any idea on what nitro percentage would be needed to get you close to the 4.89 cut-off?

Spud told me from the get go 20-22% from what et's I had ran in the past . I really did not think it would take that much , but the smaller % do not seem to change a lot.

It seems rich on the big end , but the 60' does not pick up like alcohol does when its rich so some tuning on a smaller load might pick up some et have not tried yet. Supposidley getting too lean will torch something quicker than anything so I am being careful.

I was really concerned my ignition would not be up to par but no misses on the big end so far and mph is increasing with the %.

The nitro stuff can be a little confusing, it damn sure is to me anyway.

Since it does carry a bunch of it's own oxygen the first thought is a fat mix should be a good thing because more fuel is more extra oxygen making more power. And with the fat mix there is more wet fuel volume that should help keep the chamber temps under control. But if all that is 100% true why do you see both injected & blown nitro guys with high speed leanouts for the top end charge if being "leaner" would mean less oxygen making less power. Maybe total timing plays a really big part on a fat vs lean nitro mix since nitro is said to burn slower/harder to light.

I guess it might in some way be kinda similar to the old nitrous vs new nitrous tuning thinking when adding multiple stages. In the old days when the nitrous guys fried an engine on 2-3 stages the internals looked burned up & lean. So they added more fuel & were surprised when they burned them up even faster. Now days they run 2-3 systems scary lean with a bunch of timing taken out by the time the 3 system is on (hence the big blue header flames).

DILLIGASDAVE wrote:The nitro stuff can be a little confusing, it damn sure is to me anyway.

Since it does carry a bunch of it's own oxygen the first thought is a fat mix should be a good thing because more fuel is more extra oxygen making more power. And with the fat mix there is more wet fuel volume that should help keep the chamber temps under control. But if all that is 100% true why do you see both injected & blown nitro guys with high speed leanouts for the top end charge if being "leaner" would mean less oxygen making less power. Maybe total timing plays a really big part on a fat vs lean nitro mix since nitro is said to burn slower/harder to light.

I guess it might in some way be kinda similar to the old nitrous vs new nitrous tuning thinking when adding multiple stages. In the old days when the nitrous guys fried an engine on 2-3 stages the internals looked burned up & lean. So they added more fuel & were surprised when they burned them up even faster. Now days they run 2-3 systems scary lean with a bunch of timing taken out by the time the 3 system is on (hence the big blue header flames).

Dave,as i understand it,the reason for a high speed leanout is the pump is pumping more fuel than the engine needs as it gets up to speed into high gear.i'm pritty new to injection so i could be wrong,KY and Fabio have been a big help to me on tuning alky.i can also tell you Spud Miller is a sharp alky tuner too!

The way I understand it there is a certain amount of fuel left in a cylinder from cycle to cycle as the engine reaches its choking point coupled with the way a mechanical pump works. Its a less amount with alcohol and more with nitro because of the burn rates of the fuel. The problem is the temperature nitro burns at with excess atmosphere oxygen and that is shock sensitive you have got to keep enough fuel in it to not detonate during compression stroke.

There was a fuel altered pitted next to us last weekend. I thought I might learn something from him. He was making exhibition passes behind us and when he came back he would pull all the spark plugs out and spin his engine over to blow all the nitro out. I asked him why he was doing that and he said he was running 60 % with a steel rod engine and just shutting the ignition switch off at the end of the track and not shutting the fuel off.
Then he came back and pumped the fuel out like that , he said the only time he had blown an engine was starting it so he figured out it was because he was not pumping the fuel out. I told him I thought just killing the ignition like that would explode the thing he said no I did not ask for any advice

We went back to music city yesterday for the dds race. I had changed the front springs from 200lb to 275 The car was wheeling a little more than I liked and I had a little slack in the anti roll bar so adjusted it out. The first launch was good the 60 time was within .001 of last time there a month ago , but the car drove left just a tad and I lifted.

After the sun got off the track I mixed in some 18% nitro on the 16% in the cell when it got hold the car picked up 6 numbers that was launching at 4600 rpm . I was pretty happy considering the weather conditions Anyway got by the mcamis blown 57 of Mr Boles and mr Frame took me out with his 700+ inch bbc .

Lem Evans wrote:Randy, let us adore you

Lem Evans wrote:

Lem Evans wrote:Randy, let us adore you

Pat said he is gonna line your gas burning azz out next time he sees you

I thought he lined you out about running nitro the 1st time you met him.

I can't be lined out

Thanks for the nitro reports Randy. I really like them. Wonder how it will work with efi??

i'd been back to hang out but i went to a truck pull.the weather sucked where i was,on the TN/AL line.

I think that's the lowest barometer I have ever ran on Lee not to mention the heat.

I am sure it would David . I am not noticing any tuning issue differences over methanol really. What I was not expecting is most of the et gains are on the big end of the track and the converter seems to be holding its own so far. I might have jumped the gun on putting the 4:86 gears back in might try the 4:30's out again.

The only difference than methanol I am noticing is when you shut the fuel off after a run its makes a squeaking noise out the headers if you don't hit the kill switch pretty quick. It does not do that after you idle up to the line and kill it with the normal fuel shut off procedure so it must be engine heat related. The highest egt I had last weekend was 1120 and the coolest was 970 so its still a little rich and on the safe side I think.

I don't think I will try it....16:1 cr and nitro sounds like a recipe for disaster. I'm going to test M-1, M-5, and C-16 at the end of the week hopefully. I'm not buying any of the Q-16 stuff. I have a friend that will give me some C-16.

Oh forgot about that 16:1 you are probably a perfect gas candidate. I would watch that m-5 , I personally think its a lot more detonation prone than a small percentage of nitro.

KY JELLY wrote:Oh forgot about that 16:1 you are probably a perfect gas candidate. I would watch that m-5 , I personally think its a lot more detonation prone than a small percentage of nitro.

You are correct JW Kelly, that's the reason I went back to plain alky with the spray...........more power to get anyhow lol.

"you are probably a perfect gas candidate"
kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk

With a filled block ?

Lem Evans wrote:"you are probably a perfect gas candidate"
kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk

With a filled block ?

forgot about that , plain old methanol I guess