Race gas and stock timing with Portfueler

[powellds2]

Hey, I'm about to go to the track and run my car for the first time being boosted. I am currently spiking 15 and settling around 12 to 13ish with afr's ranging from 11.2 to 11.6 My question is, can I raise the boost with 100 octane race gas to 18 psi and be alright with stock timing? I know I can boost up to 15psi with stock timing, but after that, I need to retard it. So, will it work? Thnx

 

[rizzzo29]

normally the stock fuel system is able to handle 18 lbs with about a 90-100 percent injector duty cycle, the stock timing should be fine, but what you want to do is not most recommended.

so otherwise technically yes, you can, but its pushing the stock 4g63 to the limit. up to you if you trust it or not.

 

[powellds2]

normally the stock fuel system is able to handle 18 lbs with about a 90-100 percent injector duty cycle, the stock timing should be fine, but what you want to do is not most recommended.

so otherwise technically yes, you can, but its pushing the stock 4g63 to the limit. up to you if you trust it or not.

I'm sorry, I forgot to include that I am 420a with the portfueler, I have the stock injectors as primary and 490cc injectors as the secondaries. Built motor as well. 8.8:1 JE pistons and Eagle rods.

 

[powellds2]

I was planning to use 100 octane, I should be safe running up to 20 psi with afr's in the 11.2 to 11.6 range correct?

 

[slickers111]

Oh god. That is highly Not recommended to run that much boost with the 420A.
Your car will handle it for a little bit, but Then you need to turn it back down to about 4-6 PSI.
Keep funning high boost on the Stock 420A, it WILL blow.

 

[dalesmitsu]

First, props having the motor fully built.

Yes, a fully built 420a can handle 18psi. Not sure about your injectors could be too small.

Whats your mod list and fuel sytem.

 

[slickers111]

Oh, I missed the post saying it is built. That is my bad.
As long as it is Tuned good, and your fuel system can deliver, you will be safe.

 

[VTEC_lol]

I was planning to use 100 octane, I should be safe running up to 20 psi with afr's in the 11.2 to 11.6 range correct?

I would say that mid 11's is rich enough to be safe to run more boost. you could probably knock the timing up a bit as well. do you have a datalogger? if so just hook it up and check for any knock retard.

 

[powellds2]

I'm sorry, I forgot to include that I am 420a with the portfueler, I have the stock injectors as primary and 490cc injectors as the secondaries. Built motor as well. 8.8:1 JE pistons and Eagle rods.

Fuel mods^^ Yes, the motor is built, it's pushing 15psi right now without issue. I do have a datalogger, but I have heard that if the motor picks up knock, it will only retard the timing a couple degrees, (like 2 or 3). So, if timing fluctuates anywhere from 15 to 20 at WOT normally without knock, how will I know if I'm getting knock? As of right now, I don't have the ability to control timing, but I am getting a MSD with boost retard soon, so that will be taken care of. But, I'm going to the track on the 4th, so I wanted to put 100 octane in so I could boost more. Think I'll be okay?

 

[powellds2]

Went out and did some data logging. Looks like I'm leaning out at 6k rpm up with afr's in around 12:1. Gotta add some fuel for now, but my question still stands, do you think I can run 20psi at the track with 100 octane on 11.2 to 11.6 afrs with stock timing/ignition?

 

[luckynumber5]

Its hard to say, I doubt anyone wants to risk your engine on a guess

Only thing I can tell you is watch the knock response and get the air fuel right. I had a 3800 Grand Prix GTP that really loved the 110 Octane BMS offers, it would run almost knock free with few mods and thats very hard to pull off otherwise.

 

[bmxunderground]

Just curious, what are you EGT's looking like at 15psi WOT.