What level of octane do I need? - Performance Forum

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What level of octane do I need?
Sunday, January 13, 2008 7:34 PM
I'm really in need of help right now to figure out what I can do.

I have between 240 and 285psi of compression depending on the timing I'm using.

  • At 240psi, I can get away with 91. The car will run smoth and I get good gas mileage. I have not much power. IE : 16.3 at 87mph
  • At 275 psi, 94octane doesn't cut it. The car from idle to any rpm is runing rough. Kinda like runing on 2. Black dirty plugs and blue smoke. (Most likely detonation)
  • At 285 psi, it's scary. It sound like a diesel school bus with no muffler. Once it hits OT, the engine runs better but I've blown a platinium electrode at that pressure. Again, I fear detonation.


The spark timing as NOT been changed yet since I don't have my burner yet. I sure need water injection to help reduce detonation but can I run it ALL the time? It will be after the Tb and mostly 4 nozzles.

Other than that, I don't feel like running 110 octane on the street. Kinda pricey at 250$ a tank.



Gilles
2.3 Ho


Re: What level of octane do I need?
Monday, January 14, 2008 1:00 PM
!!!!!!

i found out why the RP prom was giving use Knock!, it was set up for the older crank, got it fixed, and pulled like a raped ape!..

email me, i will send you the .bin

(you wont need higher octane than 93.)

Chris


'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: What level of octane do I need?
Tuesday, January 15, 2008 9:14 PM
You can send it to me but I don't think it il get rid of the knock I have now.



Gilles
2.3 Ho

Re: What level of octane do I need?
Wednesday, January 16, 2008 9:27 AM
Mfk-223 wrote:I'm really in need of help right now to figure out what I can do.

I have between 240 and 285psi of compression depending on the timing I'm using.

  • At 240psi, I can get away with 91. The car will run smoth and I get good gas mileage. I have not much power. IE : 16.3 at 87mph
  • At 275 psi, 94octane doesn't cut it. The car from idle to any rpm is runing rough. Kinda like runing on 2. Black dirty plugs and blue smoke. (Most likely detonation)
  • At 285 psi, it's scary. It sound like a diesel school bus with no muffler. Once it hits OT, the engine runs better but I've blown a platinium electrode at that pressure. Again, I fear detonation.


The spark timing as NOT been changed yet since I don't have my burner yet. I sure need water injection to help reduce detonation but can I run it ALL the time? It will be after the Tb and mostly 4 nozzles.

Other than that, I don't feel like running 110 octane on the street. Kinda pricey at 250$ a tank.

Why. If it is idling like crap then I think you have some serious issues Gilles. I doubt water injection is the answer (at least not for it to simply run). What are your AFR's and EGTs with 275+ compression? Or are you still adamant about tuning just on a narrowband?


-

"Youth in Asia"...I don't see anything wrong with that.
Re: What level of octane do I need?
Wednesday, January 16, 2008 2:25 PM
It is idling like crap it has too much compression. Retarding the timing alone won't do it IMO. Runing water injection would help reduce detonation and with some timing retard, I should be able to get it to run right.

I'm getting a wideband now. I'm going to start tuning it so it's important to do it right.



Gilles
2.3 Ho

Re: What level of octane do I need?
Wednesday, January 16, 2008 3:08 PM
...I HAVE a LG0 .020 head gaskit shim around... want it?

Chris


'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: What level of octane do I need?
Wednesday, January 16, 2008 4:15 PM
i'll ta ke that .bin since you guys (team green) are supposed to send me the 95 w41 bin a couple months ago and never received anything... lol you guys are lazy haha



Re: What level of octane do I need?
Wednesday, January 16, 2008 6:13 PM
i dont have it..... email me some time, i can send you my moded Jbody burn. my GTZ is gone, but the drive train is in my 95 Z.


Chris



'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: What level of octane do I need?
Wednesday, January 16, 2008 9:20 PM
The shim would bring me around 11.3:1. It would most likely run fine on 94. I PM'ed you.



Gilles
2.3 Ho

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