What are your mods?

 

ET: 12,377
SP: 180,00km/h ( 111.9mph )
RT: 2,234
60ft: 1,959
330ft: 5,289
660ft: 8,023
990ft: 10,310

This first run was good. Removed some weight for the second run + added mixture of race fuel. Something was wrong since engine did not rev well, just 13.1. I was not sure if the race fuel mixture or hotter weather was the reason. Changed fuel back to normal street mixture and lowered tire pressure even lower: 1.0bar/15PSI. Noticed immediately that engine do not work well but pushed pedal down up to final line: 13.29. Engine sound was really bad and got restricted performance notice. I did not have OBD scanner with me so the only way was to drive slowly 40miles back to home. During the drive I saw unstable rich side mixture for the left bank. At home scanner says P0305 Cylinder 5 misfire and P1316 Misfire rate excess emissions. Well, need to check and change coil/plug for that cylinder sometime tomorrow. Unfortunately I deleted two first runs incar camera recordings, but here the last "misfire" run.

https://www.youtube.com/watch?v=o77D...ature=youtu.be

 

Cylinder #5 plug. Ground electrode hits the center one. NGK Iridium BKR7EIX-11 . One grade colder than orginal ones.

 

The fun is over....again. This time fatal engine damage. Today's endoscopy shows that top of cyl 5# piston is toatally melted and rings can be seen there. Interesting that I drove 50miles to the shop and then back and no signs that something is wrong even at 80mph. Checked fuel trims, AFR and engine temperature. Everything was fine and no additional noise from the engine can be heard - but everything may happen at any time. Total engine rebuild is coming....after two head gasket failures in two years. This is motorsport. I am just angry that no way to go for standing mile competition after ten days....to see and feel high speed numbers.

 

oh my! Well, when you run a car hard sometimes the weak points rear their head!

Id love to see what your xjr could do in the standing mile, but next time after the rebuild!

 

were you running standard gaskets or 4.2 ones?

 

4.2 ones.

 

Stock goes 140mph. I got 149.2mph two years ago. Now the result should be 160-165mph if the 155mph speed limiter is deactivated.

 

New video of the piston damages. Not fully melted as said by a shop guy but very visible damages. I still drive the car slowly at low rpms. Next time forged pistons of course.
https://www.youtube.com/watch?v=YXCU...ature=youtu.be

 

I needed to change vechile but wanted to keep same speed.

 

"Cabin crew, please be seated for take off"

Operation Rocking Piggy

 

Tested Sony external microphone:

 

video private? ... can't watch it

 

I can see it fine?

 

I can see the last one, but previous videos don't load (shows private), at least on my end.

 

Twin Screwwwwwwww!

 

I wonder what injectors are fitted as I've seen burnt piston damage from high boost and a momentary fueling problem leading to melted pistons.
Uprated fuel pumps, a 'boost-a-pump' and high flow injectors are standard when going TS on this engine, the stock stuff doesn't really cut it for drag strip racing, although I suspect the OP has carried these mods out?

 

Stock injectors give easily very rich mixture by adding fuel pressure. I have widebands and gauges for both banks and in this run it was set for quite "lean" 12.0 because of high octaine race fuel. Normally it has been 11.0 or under at WOT. Actually before the widebands my AFR was well under 10 and that explains why the 1/4mile results were not good at that time.

The main reason for my engine as well as some others here with same kind of damage has been weaker knocking control of AJ26 ECU.

Enough rich mixture + wath/meth injection and you can safely get 550++ hps with stock 360cc injectors. Of course bigger injectors give you more safe margin since they do not reach 100% duty cycle.

Fuels pumps: 2*Walbro 255. Enough for 1000bhp

 

Two years ago: