Lag

[Rosie_1008]

Only just got my GTR back from the workshop with the new addition of forged pistons and still have 500 k's before im over the safe 1000. Only been boostin it to 4000 just to run it in. It has N1's which start spooling at 2500 so it still puts you back but every now and then it feels like it doesn't want to boost. Im thinking its something to do with the turbos?? Don't know much cause the last turbo i had was in a 1 litre charade and that was only to give it enough power to get up the hills

[R31Nismoid]

Which N1's are we talking about?

[`nigno]

You on a standard tune, could be boost cutting as it hits 4000rpm if you've upped the boost from standard without remapping the ECU and removing all that business.

If they start spooling at 2500 youd be near full boost by 4000rpm i would think... or is it immediately after they start boosting?

In which case I'd check for things like leaks, wastegate, disconnected lines etc.

Can you be a bit more specific, does it surge, or just plateau out, or cut out all together in terms of boost when you say "it doesnt want to boost"

[slo-a31]

i'm not trying to be a smart a$$ but if your running it in its probabaly not underload so the turbos arnt going to spool up just in just everyday driving till much later

[mad082]

what boost are you running, and what is controlling the boost? if you have a boost controller then it may be slightly blocked and not releasing the air between it and the wastegate, so when you try to accelerate the wastegate is still open and it won't spool up properly.

[Rosie_1008]

I've talked to my mechanic about it and he reckon's its the coil pack without looking at it. He said the first time he started it up it was only running on 5 cylinders then after a couple of minutes the 6th picked up. Thinking about it, it makes sense if its a firing problem. I said it was 'every now and then' and most of the other time it's great. At 4000 it doesn't feel like it going to run out of boost!!

[Adriano]

Usually the coil wont break down until its on boost, i would try, gapping the plugs to .8 and have a good look at the coils, maybe it just has the wrong plugs.