erratic boost SR20

Canada Nissan Automotive
1

Hey, I’ve got an SR20DET conversion done on my 240 that’s been trouble free for over a year now. Anyways, I’m having this weird problem where the car is making great power UNTIL 6000rpm where it falls on it’s face, Festiva style. I’m running both an analog and digital peak hold boost gauges and will see .95bar dead on to where it’s currently set and is not slow to get there either. But even just running off of the wastegate it’ll bog hard at 6.

I’ve tried tightening the spring on my blow off valve, re-gapping my plugs to .6 and done a complete boost leak test to 40psi with no leaks so I know I’m not losing it to a cracked intercooler or boost pipe. The clutch isn’t slipping as the rpm stays solid and I’m starting to run out of options. Idles great and pulls hard up to 6 so if you guys have any ideas to contribute I’d love to hear them. One other thing, I’m a bad donkey and am still running last years gas as I haven’t even burnt a tank yet (weak, I know) but can’t see this power loss at a specific rpm as a fuel related problem unless I’m way lean. I’m running a Walbro 255lph pump which are supposed to be good to 350hp and I’m nowhere near that so I’m guessing that’ll be ok.

Thanks in advance,
Kurt

2

Stock Turbo

It’s not big enough

3

you’re saying a stock turbo can’t be turned past 6000rpm? even just running direct off the wastegate it’ll hit the wall at 6000… I’ve been rolling stockers to 7500 for a while now. I may agree with you at 14-17psi but at 8 I would hope it’d be ok. Thanks for the reply, please keep the ideas coming.

Kurt

4

The last year’s gas thing concerns me. Did you put any stabilizer in it over the winter? Id run it real easy till you get that burnt out. Also check your base timing, make sure that its where it needs to be.

5

hmmm thats weird. have you logged any pulls to see whats going on? ( i know you have a 240 with no diagnostic port… but just checking )