Fine Tuning Help

Just finished reassembling a 72 nova 3100lb backhalf, originally a 516 bbc, 15:1 cr, Dart out of the box 345's, Dart T-Ram with a Birdcatcher. 36 Nozzles and 115 pill, it went 9.00s.

Now the car has a 555, 15:1cr, Dart cnc'd 325's, same upper end. I stepped the nozzles up to 37 w/ 115 pill assuming the bigger cid would like it. -1 pump, 33 degrees timing, glide , 4.56 gear. 10.5x33 tire, 33 degrees timing

Tested on wed, 52 degrees out, 29.89bp, 48h, found it didn't like the 37s way fat, dropped it back to 36's, same 115 pill.

Car woke up and went 8.904@152, 1.30 60ft [nitrous convertor], all moving in a positive direction.

egt reading w 36s 1250 degrees

At this pt whats the steps to fine tune this combo,

Start by leaning it out and how many numbers at a time, increment's of 5?
Do I play with timing?
Suspension works, no huge wheelstands.

Car is set up for 8.50 index and has a 200 shot on it which I wont use til I feel comfortable I have a safe tune up it.
My chassis guy used to run TAD and said to try 35's and step the pill down to try to create more pressure to atomize the fuel.

Thanks in advance for your input.

 

I would suggest putting in 4 32 nozzles in the front cylinders, 80 pill cw 50hs @ 40lbs
if it runs rich bring up the main to 088. and lower hs to 30 lbs. watch the 1/2 track numbers, launch and everything else same. the idea is to get a good methodical way of thinking, look at the first half performance as with a heavy car this is tha hardest part. looks like your area nozzle versus returns are screwy. does the engine have enough comp ? probably not with asperated deal you can never get enough. If you can install a divider in the tunnel it would probably help. plus the scoop does it have one? or inj tubes. trying to get aheavy car to run up to half track is the key, work on the top end later. if it is way too rich from start to 1/2 track then a nozzle change may be in order, you are dealing with nozzle area versus pump flow capacity at a low rpm range most injection people do not work with, most blown stuff will hit 6000 rpm right at the launch, your car you are trying to launch at around 4 - 5000 and the pump flow at this rpm is a lot lower than you may think so to get fuel into the engine you need press, by smaller nozzles. this will make the returns much more active as the pressure is there to work with you may find going down to 24 nozzles may be the ticket, remember its not the max hp number you are dealing with but the poweer @ 4000 rpm wich may be half of what you may think.suspension is also very important and should be scrutinized as well have a good chassis guy look at it running, survey all chassis components and write all adjustments and changes down this is very important a later look at notes could enlighten some further discussion.

 

even with the suggested nozzles if the fuel sytem reaches 90 psi it is good for 1150 hp
28 nozzles at the same press 960 hp, remember if the engine does not have a good comp ratio it will have lower hp numbers. do a comp test you should have over 250 psi comp. an aspirated alcohol injection system is very tricky as you will get a lot of advice from people that run blown stuff as this is more common, EGTs will look like it is getting richer if it is too lean as ther will not be any heat reaching them from lack of burnt fuel. carefull fuel system service is also the key keep it clean and service it every time out. Do not leave fuel in the sytem or tank ever.lube pump after ea use cap it and seal.As soon as there is a huge performance change ( poorer ) it is usually debris in the fuel system do not overthink this, make sure the battery is always fully charged, the car should start right off, warm up is very important do not let it just idle you need to get some heat into the engine right away, one way is to warm up and set idle with 3 way closed off far enough to idle up to warmup speed 2000rpm. this will help get rsidual fuel out of the cylinders and heat up the heads.