500 efi Upgrades???
 

Just curious what my options are. I would like to build H.P. without supercharging the motor. What would result in the most cost effective way to accomlish this task?
Thanks for any help.

Re: 500 efi Upgrades???
 

hp comes the easiest from displacement and compression. if the motor is 8 to 1 make it 9.5 to one.

if it can be made bigger easily... do it.

beyond that becomes a complex and endless discussion of combinations.

you have to make the first decision by defing your goals specifically. power desired, reliabilty required, fuel available, nominal expected operating conditions etc etc. and , of course, how many convenience stores there are in your neighborhood between your engine builder and you to fund it all.

Re: 500 efi Upgrades???
 

I feel the biggest concern is who to send your ECU to for re-mapping. Its a scary thought that all the money and work you put into the motor means nothing if the fuel curve is wrong.

Re: 500 efi Upgrades???
 

You can update cam and some porting to gain some hp without sendind ECU out for reprograming, it will clean up soot on transom just call teaque this is small hp gains, it all depends how much hp you want.

Re: 500 efi Upgrades???
 

What are the realistic increases by doing port work, possibly a re-map, etc. etc. . What octane would I have to run?
I'm asking because I have to do a little freshening to my motor and figured I would kill to birds with one stone. It's very important that the motor still maintain reliabilty.
Thanks

Re: 500 efi Upgrades???
 

Your biggest gains in horsepower are going to be upgraded induction system. Remapping the ecu is also a very good recomendation. You can pick up an easy 25-30 horsepower there. The engines are very rich out of the factory. The next biggest gains would be aftermarket cylinder heads. A Brodix or Dart head upgrade wil result in on average 65-70 HP improvement or more especially in conjuction with a camshaft change. The cylinder heads will also have a smaller combustion chamber which will help bump up the compression and make more power also. Feel free to contact me for package information. (216) 398-8500

Best Regards,

Dean Gellner
Gellner Engineering Marine Power

Re: 500 efi Upgrades???
 

We have done several of these upgrades with cnc ported aluminum heads, a bigger camshaft and a bigger throttle body that is what will hold you back from making over 625 HP. We have a Ecu Program for different stages of upgrades.

Re: 500 efi Upgrades???
 

TYLER

Would a 600 hp level be possible with reworked stock heads, a custom cam, optomized quench area, and a ecu reprogram, without the throttle body switch? Thanks Larry.

Re: 500 efi Upgrades???
 

For all the work you would put into the heads you would be better off with some cnc ported aluminum heads.

Re: 500 efi Upgrades???
 

For remapping call arazona speed have sent a few to them with very good results