versiitality of set up

[wideopen231]

Spud,

After rereading artical on nitro on site.Seems my setup should be pretty versatile  for straight alky to 30 or 35%. No plans for running nitro mix every weekend,but for some show stuff.setup is.
 482 TFX-92 hemi
BAE fuel  heads
12.7:1 compression
296 at .050 cam with .800 lift
DSR pump at 6.8 gpm
Enderle hat with k barrle
.037 nozzles and around 130 main.
Mag 12 34* to 38*
4.10 gear 32 tall tire

questions: tuneup calculator calls for .012 richer which is also lot more pressure with .039 nozzles its same main.Better to change nozzles and keep pressure same?Figure no changes to leanouts this way.
             Have hi/lo valve body any benifit to high gear leave.Since hi only run cost about .5 thinking it would offset gains from nitro.Plus added heat to trans and converter not  great ,but if its fast so what.
          Anything that would make setup more versatile for changing from alky to aky/nitro and K.I.S.S. still apply?
             Just thinking or maybe wondering ahead.

             

[Spud Miller]

 If the pressure increases to over ~130 PSI on a pass, then I'd put larger nozzles in it, otherwise I'd leave them alone. The only change I'd make to any lean outs is to disable them especially at first. Your metering valve percentage will change. Your timing looks ok.

 Leaving in high gear will cancel all the benefits of nitro and will indeed roast things. At low percentages, I'd use that transmission!

 Have fun,
 Spud

[dreracecar]

is this engine blown or hat injected???

[wideopen231]

injected.

[msundstrom]

What you are running is very close to my combo only mine is BBC and 1 point less compression. I have run 2 different BBC combos and a 30% load tuneup has been the same as my straight methanol tuneups, 40% changes big time. It is fun!
Mark

[wideopen231]

Base combo performance numbers and what did you pickup with 30% load,other than big grin?

[msundstrom]

.3 seconds approximately and 40% an additional .2

[Spud Miller]

 The crew and I have discussed a few times what my car would do now on straight methanol instead of straight nitro. Lower compression ratio, low gear, rear gears, tight converter...it's heavier now too. It would be a quite a bit slower than back when I started with a typical methanol setup. I started in the 8.60 range. The consensus is we'd be doing 9.30's or worse vs. our typical 6.80's on 100%.

 Hopefully, we will find out when my daughter starts driving it in 5 or 6 years. That's exactly how we plan to start out...0% and work our way up again.

 Spud

[wideopen231]

What would be the highest percentage with setup above.Maybe changing converter to makeup for eixtra torque.Figure bottom end is about as strong as going to get.Already running grp aluminum rods,KB billet crank,Heck same stuff TF ran for long time.Bjgget limit would be pump flow and shallow pockets.LOL

[dreracecar]

Back in the beginning of Nost A/F the rule was only the 80a (6.5) could be used for both types of engines either injected nitro or blown alc.  It was felt by the rules makers that this would even out the cars for close racing around the 6.90/7.00 range.  JC Constance could not get below 7.20 without back-sideing all 8 pistons running injected nitro with the small pump--- AND Gene Adams was doing the tuning

[Spud Miller]

What would be the highest percentage with setup above.Maybe changing converter to makeup for eixtra torque.Figure bottom end is about as strong as going to get.Already running grp aluminum rods,KB billet crank,Heck same stuff TF ran for long time.Bjgget limit would be pump flow and shallow pockets.LOL

You could run up to 75% by just changing the pump and nozzles. Generally, around 40-50% will have you driving through a standard methanol-duty converter though and you'll need a bigger/tighter unit. At 75% you'll need it tighter again. If you have a compression ratio optimal for methanol (high) then 75% would not be wise. So, to do 75% you'd probably need different pistons too.

 Spud