Thread: VE-T blogger, dynos, movies, and pics.

nice pic

I took the iridium plugs out today to find cyl 4 spark plug destroyed. The insulator cracked and the only thing keeping it in the motor was the ground electrode. The very tip of the electrode looks like it has been nearly melted. I guess I could have detonated on that cyl, causing the insulator to crack. I never heard any detonation though. The car just started to cut out @ 22psi. Piston looks fine from what I can see in the bore. But this plug is toast after just one week. So I guess 22psi is the limit for pump gas eh? I think I am going to tone it down to 20 to be safe. Perhaps 19. 19psi should be safe and reliable for pump gas. 24psi on 100 octane.

I put some ngk 7s in there, just coppers, side gapped, and the car runs great. I guess iridiums are a no-go then. I don't wanna spend $8 per plug to have them do this.

20-22 PSI is not safe on pump gas. You are pushing the upper limits of pump gas which will limit the life span of the motor. This proves nothing but in the long run will bleed your pocket to death.

Generally hard detonations will cause the top of the cylinder walls to oval out and also cause pitting around the edges or the top of the cyliner walls. The pistons generally dry out from detonation and the edges of the pistons tend to crank as the edges are the thinnest.

From my experience generally the larger the turbine rear housing and turbo turbine wheel the higher you can push the octane limit as the temps from less backpresure drop.

Please understand that there is a guide line to use to keep things safe on turbo motors.

0-15 PSI 93 octane pump
15-20 PSI 97 octane
20-25 PSI 103 octane

These numers above can be run a bit higher but again to keep things safe the limits above are a great measuring stick.

In my opinion once you have gotten to the point you are at damage hs been done and things will start to go down hill soon.

These are all my opinions and can be taken for a grain of salt.

I'm gunna blame your JWT ECU. Or more specifically, your inability to tune ignition timing. With proper tuning on an SR20, there's no reason Andreas' guidelines can't be stretched quite a bit. He's got a great point about larger turbos though. They are your best friend.

You are running way to much boost on that motor on pump gas. Like mentioned above 15 psi is more or less the max. Also you should consider a different method of fine tuning that motor.

that sounds good to me, i actually messed up a piston on 15psi pump here in UT 91 is the highest at the pump been running pump like that for maybe 6months

Old RRE injector help guied for boost on DSM's


1G DSM's usually ran 15-18 deg max up top for timing if u didn't get any knock or phantom knock from my experince.

+ 11ty for that, Still running around on the motor without a proper tune is quite gutsy, If you arn't going to tune it then get a knock box and headphones for when your driving.

A good tune and there no reason why you can't run 25ish psi on 98.

Any thing more than 17psi & im on C16.Just not worth blowing the motor.

Yeah but you will find out what it can and can't take on the dyno with a good knock box and tuners ears.

The motor could sound very happy and lap the boost up But yeah for a street car where each batch of fuel is different it's best to be more conservative. The biggest issue is the JWT ecu though.