I think that I may be detonating on the high end. However, before I pull the plugs, what does it sound or feel like. I get a little surging feeling under full boot past 4500 RPMs, but goes away right around 5500 RPMs. Thanks all.....

 

to me it sounds like slapping thin metal plates together...like a metallic slapping/ticking, I dunno how to describe it

 

Yeah, to me it sounds like a fast, metallic rattling sound.

 

Marbles rattling in a big can.

 

So if I am getting a surging sound under full boost in those specified RPM ranges, then I am probably not detonating. Also, my plugs aren't really showing it either. Man, I cannot figure this ***** out....

 

What do you mean by a surging sound?

 

Not a surging sound, the car is actually surging, like misfiring, backfiring, something. Ask Dixit what it feels like.....

 

Are any of your plugs bend (closed gap)?
If so then you are detonating. And it sounds like yo have a nut or bolt rattling around in the cylinders and does about the same amount of damage.

 

Plug gap too large?

 

Did you try turning down the warning limit? I think I asked you to try this before but I don't remember if you did.

 

Try adjusting your 'gain' on the BC. Blitz says if its set too high it can cause surging or spiking.

 

Yes, that too. But I think he's using 20 or so.... I'm using 80 for gain and 6, 7, or 8 as the limit.



Are you done yet? Haven't heard from you.

 

yep, ygm

Only 20? wow... What is the boost ratio set at?

 

Yeap I was in his car last night and when he goes WOT like around I think it was 4k-5krpm the whole car surges. Like as if the engine is running up the rpm range and cut out/blip and continues on. Makes you think there is something seriously wrong. Cause it jerks the car so you can feel it. And yes you can hear the surging on the engine as it climbs through the band.

I honestly dont have the slightest clue.

Dixit

 

bad tank of gas ? maybe octane booster.

 

could be running ridiculously rich?

 

Woah, that's a long email. I'll check it out.

My boost ratio or Erik's?

 

That's exactly what happens to me when I over/under do a setting.

 

Sounds like a very underdamped feedback loop system. You engineers will know what I mean. I know jack about boost controllers, but isn't there a way to turn down how fast the controller responds to changes in boost pressure? Maybe that's the "gain" Maxin was talking about.

 

Yea I know I was drunk and rambling.....


I meant Erik's boost ratio... whats yours anyway?


Stephen, yes thats exactly what the gain is, blitz calls it 'boost response'

 

Gain is at 80, and the warning ratio is like 6 or 7. The plugs are gapped to .035, which is about normal for my HP numbers. I am going to order a 10-11ish spring for the Tial and pop it in there and see if the car does this ALONE on the wastegate and not on the boost controller. Now, I just have to freakin loosen those allen heads on the Tial which I could not do before....

 

I read through the email, but I'll respond a little later.

My boost ratio is set at 19 or 20 (manual setting)... forgot which one.


Have you tried turning off the BC? Does it still surge?

 

Have you thrown your car on the dyno? My guess is you are running super rich in some part of your rpm range. I have had this exact same problem. It is kind of FMU related. you will probably find that you are super rich and then it leans out as your boost goes up. Are you on stock injectors? I had this really bad before I installed my AFC. Even after instaling the AFC, I could not take out enough fuel in that region and still get bogging and backfires a little. A change in FMU disc and injectors would help. Finding that right combo will probably take time.

The kit you have was designed to be very conservative on fuel supply. A rich condition is easier to fix than a lean condition.

 

I am right now in the process of buying a Vortech Super FMU to help with this. If that deal falls through, then I will just get a Cartech.

The fuel pressure builds fast as heck and at 4-5 pounds, I am already at 83 psi, which is where it maxes out at. And to top that off, I ONLY see at most 83 psi with an 8:1 disk, 10:1 disk, and 12:1 disk. What the f.u.c.k. is going on lol. I just cannot figure it out. I have the Walbro 255HP lph pump, SARD FPR, and regular Vortech FMU, with a so far untuned S-AFC. Something funky is going on and I can't figure it out. I do not have a vacuum leak at idle becuase I am seeing 17-20 Hgs at idle. I do not surge when I unplug the wastegate because it is only hitting a max of 5.8 psi without the boost controller. And, this problem is really only occurring at higher boost levels, say around 8-10. Anyone care to justify this crap?

 

I am about to sell the damm kit and get a Hayabusa lol. But this problem has been hitting me since day one and many people have looked at it and can't offer me any help.