AFR with procharged setup
04-26-2015, 10:50 PM
#11
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I recently learned of a M3 procharged intercooled setup that runs 7psi, and has the same air intake temps at wot, as a roots blown 10-71 WITHOUT an intercooler running similar boost . (130-140*)
I think we've all been led to believe roots blowers make tremendous heat and centrifugals simply blow icy cold air out of them.
If its a blow thru carb setup, I'd be very careful with leaning the afrs too much. The fuel distribution sucks on those setups. While you maybe will see 11.8 Afr average from the bank of the 4 cylinders, you very well can have a cylinder in the 12's ....port injection with a good intercooler, high 11's no problem at wot. .
I think we've all been led to believe roots blowers make tremendous heat and centrifugals simply blow icy cold air out of them.
If its a blow thru carb setup, I'd be very careful with leaning the afrs too much. The fuel distribution sucks on those setups. While you maybe will see 11.8 Afr average from the bank of the 4 cylinders, you very well can have a cylinder in the 12's ....port injection with a good intercooler, high 11's no problem at wot. .
04-27-2015, 12:00 AM
#12
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I recently learned of a M3 procharged intercooled setup that runs 7psi, and has the same air intake temps at wot, as a roots blown 10-71 WITHOUT an intercooler running similar boost . (130-140*)
I think we've all been led to believe roots blowers make tremendous heat and centrifugals simply blow icy cold air out of them.
If its a blow thru carb setup, I'd be very careful with leaning the afrs too much. The fuel distribution sucks on those setups. While you maybe will see 11.8 Afr average from the bank of the 4 cylinders, you very well can have a cylinder in the 12's ....port injection with a good intercooler, high 11's no problem at wot. .
I think we've all been led to believe roots blowers make tremendous heat and centrifugals simply blow icy cold air out of them.
If its a blow thru carb setup, I'd be very careful with leaning the afrs too much. The fuel distribution sucks on those setups. While you maybe will see 11.8 Afr average from the bank of the 4 cylinders, you very well can have a cylinder in the 12's ....port injection with a good intercooler, high 11's no problem at wot. .
04-27-2015, 01:18 AM
#13
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joe,while i understand what you are saying,a m3 on a 502 really does not get spun very fast to make 6 lbs boost.this is why in my opinion it can be run a little leaner.and we now know it is in a light small boat so i think 11.5-11.7 he will be fine.i am soon going to be doing a 565 with an m3 making 6 lbs boost and i am a little concerned about intake air temp because that m3 is being spun at the max rpm to produce 6 lbs.i am going to install a air temp gauge in the manifold to assist tuning on dyno day.this engine will find it,s home in a 26 ft cat that will only see wot for 45 seconds max.you can be sure this one will not see lean afr,s.low 10s at wot.
04-27-2015, 06:07 AM
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joe,while i understand what you are saying,a m3 on a 502 really does not get spun very fast to make 6 lbs boost.this is why in my opinion it can be run a little leaner.and we now know it is in a light small boat so i think 11.5-11.7 he will be fine.i am soon going to be doing a 565 with an m3 making 6 lbs boost and i am a little concerned about intake air temp because that m3 is being spun at the max rpm to produce 6 lbs.i am going to install a air temp gauge in the manifold to assist tuning on dyno day.this engine will find it,s home in a 26 ft cat that will only see wot for 45 seconds max.you can be sure this one will not see lean afr,s.low 10s at wot.
http://www.offshoreonly.com/forums/g...percooler.html
Last edited by MILD THUNDER; 04-27-2015 at 06:12 AM.
04-27-2015, 12:24 PM
#17
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we are using a blow thru demon with the boost referenced throttle shafts with a hat, while back ran a prosystems blow thru in the box..worked ok, just a pain to deal with, then did EFI but could not stop the RFI interfence from messing with tha ECM. We are not running the procharger intercooler, have a larger one mounted on the floor. Back when we had the EFI on we were seeing inlet temps less 100.
04-27-2015, 04:49 PM
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Cool beans. I remember years back here there was a company making some intercoolers for procharged setups, that seemed to really help with bringing the air intake temps down. Not sure if they are still around. From what I been hearing lately talking to some procharger guys, ATI's intercoolers arent all that great.
http://www.offshoreonly.com/forums/g...percooler.html
http://www.offshoreonly.com/forums/g...percooler.html
04-27-2015, 04:55 PM
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