20B N/A dyno
 

A friend of mine Magnus is now on a Dynapack hub dyno. The engine has a very large streetport with 3 Weber 48IDAs!, very cool set up with short carbon fibre intakes. They have problems with the midrange being to lean 14-14-5 afr and on top 11 to 11-5 afr. E-tube is F11 with 210 main and 190 air jets. They will try F7 to get a more even fuel curve. Ignition L20 T10 on MSD 6s. Power is now 306 hp@9200 rpm! At wheels:) Approx 348 hp at cranc. I will come back with an update when the dyno session is over.

/Lasse

313 hp@9200 rpm final result. That's 355 cranc hp:) F7 tube with 190 main 180 air gave afr 13.0,unknown chokes. Timing was best at L 20 deg lost hp with L 22 deg split 5 deg gave a little bit more hp compared to 10 split. Lotus super seven wheigs only 1565 lb:icon_tup: A real rocket on the road:nod:

/Lasse

A carbed 20b? Wow that is very interesting. Good numbers!

Got the torque numbers. 258 Nm@5800 rpm at wheels or approx 293 Nm at cranc. Pretty low numberas as i see it.

/Lasse

You got any pictures of this little beast?...

Side draft or down draft?

nice numbers, its interesting it didn't want much timing

IDA is a downdraft

F11 and f7/8 emulsion tubes suck! Try using f2 and f3 emulsion tubes with larger chokes- 45-46mm. Your going to need larger main jets and smaller air jets. Somewhere around 245-260 main and 100 to 130 air. Try that and let me know what kind of power you make. I'm pretty sure you will be surprised :)

Hope to have some pics this week.

/Lasse

Thanks for the tips! Hope to have the Lotus 7 for another dyno session later this year. The air horns are only 50 mm long:scratch:Maybe he should try the 100 mm instead?

/Lasse

We recently rebuilt a stock 13b 6-port, that is in a Lotus/kit chassis. At a mere 160hp and 1200lbs it is VERY quick. 313rwhp 20b....... drool. Also insane.

Just heard from Magnus,the engine builder that the Webers only has 37 mm chokes! I would have tried more like 40-42 mm for even more hp:)

/Lasse