DannysZ28 Posted August 7, 2009 Report Posted August 7, 2009 I have a 4 mil lightly ported, 30mm carbs, +4 timing My question is will i have to rejet, I am changing from fmf fattys to cpi inframes? Will there be a noticable difference in power and will i see more power all the way through the powerband or just on top end. Quote
dajogejr Posted August 7, 2009 Report Posted August 7, 2009 Compared to what you have, all top end. CPI have a better overall power output compared to some of the other drag style pipes. Quote
87sheerips Posted August 7, 2009 Report Posted August 7, 2009 When I switched from T5s to CPIs I was amazed. Big carbs and CPI's woke up my ported 350 like no other. Id suggest running some 35PWK's with the CPIs. Combo has worked out great for me man.. -JD Quote
DannysZ28 Posted August 7, 2009 Author Report Posted August 7, 2009 Im running 155 main and 50 pilot. What jets sizes would you guys recommend. Its running good now and plugs look good. Quote
ToomeySheeLE Posted August 9, 2009 Report Posted August 9, 2009 Try 160mains and the same pilots... seems like your right in the ballpark. Quote
DannysZ28 Posted August 21, 2009 Author Report Posted August 21, 2009 I tried the 160 mains on the cpis but now when im in the upper rpms it has a sputter but it is much more responsive on the low end than it was with the fattys. Do you think i need to go bigger on the main jet???? Quote
spurdy Posted August 22, 2009 Report Posted August 22, 2009 I tried the 160 mains on the cpis but now when im in the upper rpms it has a sputter but it is much more responsive on the low end than it was with the fattys. Do you think i need to go bigger on the main jet???? I dynoed mine when I had the CPIs on it and we settled at 158 mains. What's your elevation? SP Quote
DannysZ28 Posted August 22, 2009 Author Report Posted August 22, 2009 Im on the east coast of nc about sea level. Quote
spurdy Posted August 22, 2009 Report Posted August 22, 2009 Im on the east coast of nc about sea level. I would think you might need to go bigger but I am no jetting expert by any stretch of the imagination. I run at about 1000 ft. Quote
DannysZ28 Posted August 22, 2009 Author Report Posted August 22, 2009 I would think you might need to go bigger but I am no jetting expert by any stretch of the imagination. I run at about 1000 ft. So you do think the sputtering is caused from it leaning out? Quote
spurdy Posted August 22, 2009 Report Posted August 22, 2009 So you do think the sputtering is caused from it leaning out? Actually I would think the sputtering would be from too much fuel. But with you being at sea level the air density is greater therefore you would need more fuel to keep from being lean. But I am also judging that based on my set up and running CPIs. Maybe my port job flows more therefore I would need more fuel, thus the bigger jet size. That is exactly why I jet mine on a dyno to get me in the ballpark. I would post in the jetting forum and see what the jetting gurus have to say. SP Quote
dragbanshee Posted August 22, 2009 Report Posted August 22, 2009 Im at about 650asl and I have the 158 main 50 pilot, I went from t5s to the cpi's and thought I would need to jet up. Went to a 160, then back down to 158, must have been richer than I thought with the t5's. Do a plug chop to be more accurate, I would think 158-160. Quote
DannysZ28 Posted August 22, 2009 Author Report Posted August 22, 2009 I tried the 158s this morning and it did the exact same thing. I am starting to think it is electrical. Is there anything else that would cause this. It starts missing and sputtering as soon as it gets on the pipe and the higher the rpm gets the worse it gets. Quote
mopar1rules Posted August 22, 2009 Report Posted August 22, 2009 my buddies shee used to break up on top end and it turned out to be the coil. do you have a buddy that could borrow you a coil for testing? Quote
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