Thread: Injector Dynamics Users: Post up

Normal idle around 1200rpm . If I close throttle fast enough it will fall, shoot down to 10.0 AFR then die.

It sounds to me like your BOV isn't working properly.. what BOV do you have and have you checked the diaphragm internally?

You could try putting a lighter spring in if (if you have access) or cutting a coil or two off your current spring.

What MAF are you running and what's your MAF voltage at idle on a warmed up engine?



Now if the BOV was not working, wouldn't he hear a compressor surge? Or if it's low enough boost its not that loud?

Its a Greddy Type R. I am going to take it apart and inspect it.



Ford lightning MAF. Dont know the voltage off the top of my head. I only had a few hours to dial a base in the car before having to tune other cars.

I should have more time to log and graph things out tonight.

For what it is so far it squeezed out 468whp@13-14 psi with a stock head/cams. It is super responsive.

O_o.

Check out Minimum MAF Voltage. If the MAF ever dips below that point the car starts limping a bit. This is common with older Nissan MAF's. So what you need to do in that case is lower the limp voltage, so it doesn't hit it.

http://www.sr20-forum.com/tuning/17897-how-well-your-maf-performing.html

It's hard to say if this is relevant though.

It wouldn't be incredibly audible at lower load and small transitions in engine load, but it definitely is enough to cause reversion back through the maf if it was not opening up properly.

My brother had an ebay type s bov that had a diaphragm tear and it produced the exact same thing you are describing here.

Swapped a stock 1G DSM bov on there and it has worked perfectly ever since, no change to the tune, etc.

Interesting.

My flange is welded to my IC so I need to find a type S or another R if the diaphragm is bad. Or find a replacement diaphragm.

That will be something I will check tonight.

Thanks for the input guys.

Gotcha, I'm used to the compressor surges being loud, but then again most people that I've seen have compressor surges ran a lot of boost on a small turbo.



If you want to get another cheap BOV just to test it out, I would suggest the Siliconintakes.com ones. I've been running one of theirs without a problem. If it rips then I'll replace it with a better one .

i got one of each blow off valve you can try out