[Mic5rbns]

I often get a strong smell of fuel in my exhaust when I floor it in second gear. Not to much carbon soot in tail pipes. SC with GT500 fuel pumps plus other engine mods. Would CNC ported heads help? What I would like to do is keep my boost at 10psi, 39# injectors. I think I'm in denial, I want a more efficient engine without building the bottom end right now.

[First5.0]

a tune to adjust air fuel ratio is your best bet

[stang93mustang]

A stronger spark to burn the fuel also.

[sqidd]

Originally Posted by Mic5rbns

I often get a strong smell of fuel in my exhaust when I floor it in second gear. Not to much carbon soot in tail pipes. SC with GT500 fuel pumps plus other engine mods. Would CNC ported heads help? What I would like to do is keep my boost at 10psi, 39# injectors. I think I'm in denial, I want a more efficient engine without building the bottom end right now.

The efficiency of the burn is 75% down to the combustion chambers design. And 25% fuel atomization.

The optimal combustion chamber within reason would be to mill the heads for a smaller chamber and use a set of dished pistons (only dished under the chamber) with the smallest valve relief’s possible and set the squish between the non dished parts of the piston as tight as possible. With a steel H beam rod .8mm would be as far as you want to go on a non race motor. This setup will burn more of the air/fuel charge because it will not have the tapered edges of the OEM combustion chamber. For lack of a better term you would be making it more “Hemi”. Of course we are talking about a ton of work and custom pistons.

Better atomization will come down to injector quality. I don’t know how many holes the stock or common aftermarket injectors have but on the Ducati motors I build most of them come with a 6 hole tip. On my last big HP motor build I reached 98% duty cycle with the 6 hole injectors. I swapped in some 12 hole injectors ($$$) and the duty cycle went down to 76% while maintaining the exact same A/F ratio. The spray pattern or atomization can have a massive effect on the efficiency of the combustion chamber. In my case I used almost 25% less fuel at WOT.

A long shot is if someone makes a surface discharge plug for the 3v. If so a set of those and some high power coils make a huge difference.

[Back@itagain]

If you wanted to maintain 10 lbs, you would have to increase the speed of your s/c. Opening any of the intake/exhaust paths allows for greater flow thus reducing boost. It would be more efficient just less boost.

My car has a noticeable fuel smell also but I get a considerable amount of carbon built up in my exhaust tips. Best way to get better spark into the combustion chamber that I have seen successfully used is to convert to an LS style coil on plug.