The Sr20 Finally Blew!

[oh what a nissan feeling!]

Well, i took the ke30 to the drags last week, and things didnt go so well.. :D

 

I spent the morning setting the boost to the precise 11 psi, and making sure everything was sweet, and loaded her on the trailer and off to the willowbank raceway. On the way i dropped into the servo to pick up some octane boost i normally use the nos brand but all i could get was some dodgy "octane boost and clean". So thinking this would be better than nothing, i put it in :D .

 

On my first run i forgot to let the tyres down to 18, and smoked the tyres pretty bad, but once i got to third it was breaking down like crazy, it was running that bad that i was changing gears at 6000. It ran a 13.7 at 106mph :y: I couldnt hear what was happening because of the noisy ride i was racing.

 

Soi took it out on the street and it was pre detonating like crazy, from 3000 onward. So naturally i wound the boost off till it stopped pinging at about 6 psi. :P It has run on 11psi for the past year with no dramas, The only thing i had changed was putting that crappy octane boost in the fuel.

 

I did 3 more runs on 6 psi, but without boost the thing is damn slow, running high 13s the whole time.

 

So i got annoyed and did what any stupid prick would do, put the boost back in it :) So it pinged its way all the way down the track, and developed a lovely bottom end tick/knock, and that was about it. :P

 

Moral of the story, don't buy crappy'octane boost and clean'. :D

and if it don't work take it home!

[Trev]

Was it Nulon octane boost and clean? I have never had a problem with running it in my boosted cars, When was the last time you got fuel for it and what do you run?

Edited January 4, 2007 by Trev

[oh what a nissan feeling!]

yeh it was nulon, as stated the car ran excellent that morning, and every day up till then. The fuel was two weeks old i worked out. The only variable between the morning and the drags was the octane boost. :D

[Des]

So I'm guessing rebuild time ?

[oh what a nissan feeling!]

yeh, kind of. I have a standard s14 turbo bottom end there that is in overrated condition so i am just going to reassemble that and put it under the existing head. I also have some gtir cams there i am not using in my good motor so i think i will put those in too with the adjustable cam gears.

 

I would finish my good motor but i can't really afford it at present, i have most of the bits, its just need machining which is going to add up, and i have not yet decided on cams either.

[Trev]

It probably cleaned up the fuel system a bit and fouled the spark plugs.

[oh what a nissan feeling!]

um no. because that would mean the engine would miss, not pre detonate.

[Trev]

um no. because that would mean the engine would miss, not pre detonate.

 

The octane boost and clean has a lower octane rating than the octane booster so it would of had a slightly lower octane.

 

put the boost back in it So it pinged its way all the way down the track, and developed a lovely bottom end tick/knock, and that was about it.

 

With that you havnt tuned it to run the lower octane thats why it was pinging (that is why i said fouled plugs but it also had detonation), Unfortunatly Nulon can't do anything about it as it was an "operator error".

 

What do you normally run in it as a 13.7 is pretty good with a back off.

Edited January 5, 2007 by Trev

[oh what a nissan feeling!]

The car is not tuned to run octane boost at all. It is tuned to run 98. I only use octane boost at events where i know it will cop a raping.

[Trev]

The car is not tuned to run octane boost at all. It is tuned to run 98. I only use octane boost at events where i know it will cop a raping.

 

I would be on the phone to NULON.

[cuzzo]

The fuel was two weeks old i worked out.

Would this be another reason that it could have been pinging?

[NickZ]

The reason more likely is you got some dirty fuel into one of the injectors or one injector has a meltdown and the injector isnt firing correctly so its a lean cylinder, that will make it ping and pre detonate, my last 20v did this same thing, as the cylinder is lean the plug gets very hot and starts pre detonating the fuel going into the cylinder, i found mine by pulling all the plugs and finding one was white and the rest where black.

 

I don't belive its the octaine boost or the age of the fuel. Fuel lasts longer than 2 weeks.

[pozman]

optimax has a two week useby, its one of the highest octane but it looses it really quick, but it shouldn't have caused that much of a problem (not 10psi diference)

[oh what a nissan feeling!]

The reason more likely is you got some dirty fuel into one of the injectors or one injector has a meltdown and the injector isnt firing correctly so its a lean cylinder, that will make it ping and pre detonate, my last 20v did this same thing, as the cylinder is lean the plug gets very hot and starts pre detonating the fuel going into the cylinder, i found mine by pulling all the plugs and finding one was white and the rest where black.

 

I don't belive its the octaine boost or the age of the fuel. Fuel lasts longer than 2 weeks.

 

Yeh, a definate possibility, but not in this case, the pinging was to a far greater extent than just one cylinder, the breaking down was very severe, and if only one cylinder were effected it would have still performed much better. The other option of course is the fuel system, but i certainly hope that is not the case as i replaced the pressure pump (044), and the lift pump (130gph) only two months ago. :)

[irokin]

The other option of course is the fuel system, but i certainly hope that is not the case as i replaced the pressure pump (044), and the lift pump (130gph) only two months ago. :)

 

What about the regulator? Could have blown the arse out of the diaphragm.