Mr. Lamar,

whatever happened to the slide throttle fuel injection you
have on your website? Seems like a good answer to both efi
and carb in terms of cost, reliability, and simplicity.
Vlad


Thanks for reminding me. I just took it off the web site.
Too expensive to make. Technically risky. If the pressure is less
than about 5 psi vapor lock on auto gas is a real problem. I just took
it off the web site. I recently discovered the  Holley 500 CFM
two barrel carb with leaning capabilities that is far cheaper
with way less technical risk.

The slide throttle is still viable for fuel injection
both 555 type and computer type. Some people may prefer
one over the other. The computer type is probably mandatory
for turbo charged engines.

As I see it today you have five good choices in order of cost
and HP for 250 HP p-port engines taking into considerations idle quality.

Holley 2B or other carb. RX8 eng only. ~ $400
555 EFI ... butterfly up stream from the plenum. RX8 eng only. ~$500
555 EFI ... slide throttle. ~ $500
computer EFI ... butterfly up stream from the plenum. RX8 eng only. $1000
computer EFI ... slide throttle. $1000.

My guess is the difference in HP from top to bottom would be less
than 15 HP all with the same 2.8:1 gear ratio.

The cost can vary some what particularly if you are willing to find
cheap throttle bodies and fuel injectors in junk yards.

The 555 systems use a mass airflow sensor and the computer types
use a manifold pressure sensor which is fundamentally a cheaper device.
Also the computer systems can take up to an extra year to tune and install.
If you have a lot of electronic expertise this process can be shortened
but then you can also build a 555 system. The carb of course is the
easiest, quickest to install and requires zero electronic capabilties.

It is amazing how fast things can change.

Paul Lamar