Ramius83

Ok, the car has been running successfully now for the past 2 weeks now on the Blitz boost controller. However, some new problems have come up now.

1) There is some massive "serging" of the car under full boost past 4000k RPMs. What I mean by this is the car feels like it is backfiring, or misfiring, or something. It gets to be so bad that I have to let off the gas pedal. It does this somewhat in 1st, somewhat in 2nd, but all the time in 3rd, 4th, and 5th. I cannot explain it. I am running 1-step colder NGK coppers, fuel pressure at about 9 psi of boost is around 82 psi. Anyone know?

2) This brings me to my other problem. With the 8:1 disk in the Vortech FMU and at 9 pounds of boost, I was seeing 82 psi of fuel pressure. I JUST put in a 10:1 to see how much more rich I would be and guess what, it stays exactly at 82 psi. What is going on here?

Tomorrow, I am going to order some two-step colder NGK copper plugs to bring down the cylinder temps, and at the same time, I am gonna run another compression test. Thanks for the help guys.....

AllGo

iTrader: (1)

Erik have you dropped the gap down on your plugs? You should be around .035" This will get rid of most of the high rpm missing.
Even if you are running the Walbro 255lph HP then it will not support more than around 90 psi at that comsuption level but you should have enough room with the 8:1 and an s-afc

Y2KevSE

iTrader: (13)

How quick is your gain rate and the limter rate (not called limiter rate, but I don't remember what it is right now)?

Ramius83

The gain on the boost controller is at 5-15, depending on my mood. But it is no where near the 50 range that most people do warn me about on the other forums. I am gonna re-gap the plugs tomorrow and see what happens before I spend more mula on other plugs.

Also, on these plugs, the top portion (the metal strip) is slightly white colored. Any concern here?

Lastly, what do you mean at this fuel consumption I will barely see 90 psi? I don't quite understand how the fuel pump can be "maxing" out at this boost level on the Vortech FMU.....

AllGo

iTrader: (1)

The pump cannot flow the 255 lph of consuption at those high fuel pressures. Look at mardis site i think is list the values for specific psi levels and corresponding flow. I am just sure that the walbro cannot flow over 90 psi at that consumption i/e injectors pretty much open.

Y2KevSE

iTrader: (13)

I'm running 80 for the gain on the boost controller and I never hit higher than .8 over my 10 psi limit. The only times a spike happens is if I'm rolling at 4k-4.5k.

Turn down your limiter rate thingy.... not the actual limiter, but the rate at which it goes down if boost hits the limit.

Ramius83

But Kev, would this be absolutely causing the problems I am having here? On the boost screen, there is a gain screen. But, the only limiter I see on the boost controller is on the boost warning screen.

Y2KevSE

iTrader: (13)

I experienced the same surging until I played around with the limiter rate thingy (or whatever you call it). Yes, the limiter is on the warning screen. It's not the PSI limit, but the other limit. Sorry, I don't remember what it's called.

I fixed the surge by bringing the rate down. IIRC, the closer the 0 the less exhaust the WG will vent. I have mine at either 6 or 7.

MAXIN

iTrader: (5)

The blitz manual says, "if the solonoid is more then 3 feet from the turbo, boost spiking or surging can occur." Or something like that. Also if the gain is set too high surging or spiking can occur so you might want to check those while ur at it, like kev suggested. Gain should be set the below the point when you start surging or spiking..... The limiter is just the percentage it decreases the boost when it reaches the warning level.

Ramius83

I did some messing around with the numbers, and my wastegate is about 2 feet from the wastegate. But, I am still having that surging problem. Mainly, from a start it does NOT occur. But, when I am driving down the road and I accelerate and hit 4000+ RPMs, then it starts to shutter and "misfire/surge".

turbo97SE

iTrader: (3)

If you turn off the boost controller, does it still surge? Not sure if you want to try the vacuum T or manual boost controller to narrow it down. The white on the plugs doesn't sound very healthy. Have you put the thing on a dyno with A/F yet? You could be super rich in some areas and super lean in others. Sorry I can't be of more help than that.

thebigsadler

iTrader: (4)

i know you don't want to spend anymore money, but I would seriously consider investing in a cartech fmu if I was you and getting the car tuned on the dyno with a wideband o2.. it could seriously work wonders on your car.