Dont want to high jack the thread, (but it is close to topic). Just got back from the dyno, ( i am somewhat of a newby) and saw some nice numbers from my rebuild. What should the EGTs be on a 9 LB boost deal (efi) at WOT?? any comments would be helpfull


Thanks, Dave

Probably 1300 - 1350*

Ultimately your AFR will control your EGT. What did you have for AFR numbers?

won't know unless you actually measure them.too many variables to high egt's,fuel trim,and timing for the quick 2.

Thanks For the replys. Should have looked closer at afrs. I think 12.5 ?? Egts where 1600 on big pull. Dnyo guy is changing some stuff this morning. Might fatten it up?? To get egts lower?

i'd be adding some timing.

12.5 AFR is a good number to look for peak HP, however too lean for everyday use on a blown marine motor IMO.
Unless you are using a newer EFI set up that can compensate for changing conditions.

What rpms do you like to cruise at, real world? Funny how a 1 min WOT pull on a dyno seems so voilent, but after the engine is tucked away in the bilge, that 1 min run turns into 10+ mins runs, the sound baffling of the boat makes it not sound so hard on the engine. Don't be afraid to run it like you would on the lake Do some 10-20 min runs at 3800-4000 as well.

If those ETG numbers are real and a number that shows up on a second pull STOP!! Way to high and you will not keep a supercharged engine together in a boat with EGT's like that. They should be brought down into the 1300-1400 range or lower. Air fuel ratios that are to lean can raise the EGT's as well as retarded spark timing. Check with the dyno operator and make sure is EGT sensors were good and the system calibrated properly to give accurate EGT numbers. I think under 9 lbs of boost on the engine I would try and keep the air fuels closer to 12.0 especially at WOT.

Best Regards,
Ray @ Raylar

YIKES !!!!!!!!!!!!!!!!!
back em down BIG Daddy











ROCK ON !!!!!!!!!!!!!!!!!!!!!
ITS A SKATER NATION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !

Wow,

I didn't even see the 1600, I was fixed on the AFR. Hope he has inconel valves