I'm building a direct port system for my 418. I plan on using a dedicated fuel cell for the spray and starting out with a 250 shot. My concern is the fuel orginally before I started I was told that C16 or 110/120 would be fine in the fuel cell and then 93 in the tank. After some more reading I've heard some horror stories related to detonation as a result of pump in the tank even though it's being supplemented by the fuel cell.

Is this something that can be worked around reasonably with timing and cooler plugs or for a 250+ shot and I'm going to need race fuel in the tank too? I have no desire to cook my engine!

Some details on the engine which was designed for N02...

Katech 418 CID 4.070 Bore
Diamond Custom Forged Pistons
Dragon Slayer 4.00" Crank
All forged internals
11:1 Compression

 

For safety, Colder plugs and timing for one would help, but dont risk a motor because you were too cheap to put 5 gallons of pure 110 or better in the tank. Do not mix the 93 with the 110.

 

Im doing 116 in the tank and 116 in the fuel cell. I would start with a 200 shot then work your way up to the 250 shot that way if something goes wrong you can detect it maybe quicker then with the 250 shot or a 300 shot go slow dont jump the gun.. I would talk to JLws6 or ATV racer or one of the sponsors. Did you uprade your pump in your fuel tank. if not do that for sure.

 

Thanks I got the FJO Digital Progressive Controller as well as the Lingenfelter launch controller to retard the timing. I will definately start with a 200 shot and all the other items you guys mentioned. Slightly concerned that it sounds like my tuner would have alllowed the car to spray 250 or more with 93 in the tank.

 

I run 93 in the tank and C16 in my cell. Just make sure you do a few dyno passes and pull some plugs to check. I know Allan had to pull a little more timing out of my car due to the 93 in the main tank, but it still laid down good numbers.

 

Appetite for destruction.

 

mixing gas is bad. anyone who runs 93 in the back and 112 in the front is just lazy and asking for trouble. and i don't give 2 ***** how many nuckle heads have done it on a 150 shot. you get to 250 or so and its a different game iwht less margin for error. if your car makes 600 fwhp na and you add 250 to it 2/3 of you fuel is 93 from chevron. good luck with that....

 

For an average street car that does not need race fuel I see nothing wrong with running 93 in the main tank and C-16 in the dedicated.

Running C-16 in the dedicated is a bennifit for not having to worry about ethonal cut fuel through the fuel solenoid. The C-16 is going to increase the over all actain a hair. Just like running an octain booster.

Now on a car that has high compression and throwing a good size of juice at it yes I aggree that running a 109 up fuel in the main tank is needed.

Dave

 

I'm on the line with this one mainly because of not knowing some fine details about my engine. The previous owner did all the internals and by all calculations my compression is somewhere between 11:1 and 12.5:1. The pistons are custom by Diamond but that's all I know the heads are custom by GTP. Assuming a 64CC combustion chamber, flat pistons, 4.070 bore, 4" stroke that's somewhere around 12:1 cr (with a lot of assumptions). Given that previous owners keep saying 11:1 pistons must have quite a dish in them or I got 72 cc heads hard to figure out (again a lot of assumptions).

Either way I agree with all the previous statements I'm not going to do anything lazy or half *** with this engine nitrous is a all new to me and I probably would go down the route of FI if it wasn't for all the backpedaling I would have to do... I'm still trying to get more info out of this car before I move forward with nitrous and diagnose a few other issues the plugs showed some signs of detonation even though I'm not really picking up on it at the track or on the dyno.

 

Not trying to be a dick, but he is running 11:1 compression.