Made our alcohol 13B PP dragrace engine on our friends Stuska dyno for a week ago.
Background: Goal was to achieve more than 313 hp that we made from our old PP motor 2 years ago ( slide injection 60 mm intake, Ron's alky set up rectangular "big" in-outlet holes)
Our new engine is more conservative with 50 mm butterflies same Ron's set up, D-shaped 45 mm venturis, big exhaust port and same ignition system Swede made ProSpark. We first dynoe'd with a new 54 mm 48 mm chokes Gene Berg carb and 22L-22T ignition on Shell V-Power fuel. Combo output 305@9300 rpm and only 231Nm@8800 rpm. Engine was wery "driveable" on the dyno made 170Nm @2500 rpm. Next we tried the Ron's methanol set up, and when spending a 5 hour leaning,richening,ignition from 22L to 38L and swapping 3 different primary systems we only came up with 302 hp@9400 rpm torque 234Nm@8800 rpm. Best power was with 32L-32T. The engine picks up 14 hp between 8000-8500 rpm, and 21 hp between 8500-9000 rpm but then it don't makes much more power. I think but of course don't know that it is the ignition system that is to weak and slows down the burn rate and therefore don't make more power. Our plan now is to test a 2 MSD 7AL-2 units with 2 trigger flying magnets systen in about 2 weeks. The engine is still left in the dyno and we will try another day tune it with the MSD set up. Goal is 350 hp but right now it seems a long way to reach the goal! I'm asking you racers familiar with these kind of problems if you please can give me some feedback.

/Lasse

 

air fuel ratios at?

 

With gasoline 0.87-0.89 On alcohol 0.92-0.94.

/Lasse

 

where are the injectors placed?
do you have any pics of the engine?

Carbs usually make more power due to the cooling effect of the fuel.

 

Injector placement with the right size TB and runner combination cannot be matched by most carbs. The hard part is figuring out the combination.
Due to the narrow tuning window you have with PP motors mechanical fuel injection is really not your best option. I would prefer to use a carb setup. EFI is the only way to gain the maximum benefits.

 

The injectos is placed just before the butterflies. 2 of the in each runner. As Chrispeed says with alcohol it's a very fine tuning window we have to work against so we might consider a electronic alky set up in the future! Damn we must have at least 350 fwhp to run with Travieso "lol"

/Lasse