Piglet's Rebuild Of His Busted Tomei 2.8

[Mick_o]

BAAAHAHA! GET EM!

[33GTRV]

My oh my. You really are endeavoring to excell on this build. Good find sir, good find.

[Piggaz]

. 18 X 10.5+15. it'll fit like a glove hahaa!

[Marko R1]

Appropriate design too. Fat fags are known as teddy bears. You are into something here

[Piggaz]

Lol. Piss off you jerks!!!

[Mick_o]

Dunno if your Alcons will fit underneath a set of tiny teddies?

Since when did Arnotts start making rims anyways?!

[Ants]

Ba ha ha ha ha!!!!! That's gold or should I say pink for Paul.

[Pezhead]

I was thinking these! Thoughts?

so a very small modification and voila! Piggy!

[Ants]

You could have given tiny piggy some pierced nipples too

Edited March 10, 2013 by Ants

[Piggaz]

You could have given tiny piggy some pierced nipples too

LOL!!

Here we go!!!

[Piggaz]

Rang the guys at UE today. A new set of injectors are in the car. It hasn't been ran up under load yet so we don't know if thats the issue. Tomorrow we will know. I have a funny feeling its a valve spring. Stupid car!

[ezy_09s]

Rang the guys at UE today. A new set of injectors are in the car. It hasn't been ran up under load yet so we don't know if thats the issue. Tomorrow we will know. I have a funny feeling its a valve spring. Stupid car!

I wouldn't think it's a valve spring because you say it only does it when loaded up .. A dud valve spring & it would be rooted everywhere .

[Marko R1]

What exactly triggers the miss? Is it just load on its own or a combination of load with high revs?

[Piggaz]

I wouldn't think it's a valve spring because you say it only does it when loaded up .. A dud valve spring & it would be rooted everywhere .

At 19 psi it happens at 7000 RPM

at 26 is happens at 5000 RPM off

at half throttle we can turn it to 8500.

More pressure behind the valve forcing it open? I'm sure the ramp rates of these cams are not helping the situation haha.

[Marko R1]

I had a miss with my other gtr and the cause was a faulty coil pack (what do u expect after 20yrs of abuse). Splitfires fixed that.

However, your above post throws my theory out as it definitely sounds more mechanical. I agree with u paul but its not an educated guess.

[Piggaz]

I had a miss with my other gtr and the cause was a faulty coil pack (what do u expect after 20yrs of abuse). Splitfires fixed that.

However, your above post throws my theory out as it definitely sounds more mechanical. I agree with u paul but its not an educated guess.

Definately not coils. Borrowed Joey's set which did 430 ish 2 hours before hand.

[ezy_09s]

At 19 psi it happens at 7000 RPM

at 26 is happens at 5000 RPM off

at half throttle we can turn it to 8500.

More pressure behind the valve forcing it open? I'm sure the ramp rates of these cams are not helping the situation haha.

Wasn't this a freshly built head with new springs etc ..

Hmm it's strange alright but I would still think if a spring was off you would still encounter problems at 8500 rpm .. But it doesn't do it at partial throttle.

[Piggaz]

Wasn't this a freshly built head with new springs etc ..

Hmm it's strange alright but I would still think if a spring was off you would still encounter problems at 8500 rpm .. But it doesn't do it at partial throttle.

Everything in the head was brand new. The springs are HKS step 2's. Maybe due to the fast closing of the valve it's just enough to cause issue with higher boost at higher RPM?

[GTRsean]

Shim the valve springs. They need more seat pressure!

[ezy_09s]

Shim the valve springs. They need more seat pressure!

What Sean said . I tried looking for the spring pressures on HKS step 2's , but can't find figures .

It would seem you may have a much too aggressive profile for the springs .