Debating on raising boost back to 18PSI.

[1986SVOTURBO]

Ever since I had to replace the head gasket, I have kept my boost at 16PSI. I ran it at 18PSI for years and I am not 100% sold that the difference was the reason the head gasket went. I would like to run 18, but cannot afford anything breaking right now.

Any thoughts would be appreciated.

[fiveohmike]

Bump the fuel pressure up with an adjustable reg to be on the safe side?

[Horsewidower]

"I would like to run 18, but cannot afford anything breaking right now."

So caution would be best? I think you've answered your own question.

[Alex L]

Bump the fuel pressure up with an adjustable reg to be on the safe side?

i dont get why everyone says to do this; it'll cause the LTFT to pull pulsewidth and negate any changes after a few minutes in closed loop...

[GAboySVO]

i dont get why everyone says to do this; it'll cause the LTFT to pull pulsewidth and negate any changes after a few minutes in closed loop...

Because it helps when you are WOT in open loop mode and running 18psi.

[fiveohmike]

Assuming SVO's are the same EEC-IV system, they go into open loop mode when WOT above a certain RPM and use dedicated Fuel Maps. Increasing fuel pressure beyond stock will force more fuel at WOT, helping with leaning out in the upper RPM's and saving head gaskets.

Unless I am way off base about the SVO EEC

Mike

[Alex L]

Nope, single fuel table. Diff ign tables, and IME LTFT does affect WOT open loop.

[GAboySVO]

Well my last dyno runs show that increasing fuel pressure move the A/F ration down the scale, so it is proven to have the desired effect of moving the A/F ratio out of the danger zone at WOT.

[Alex L]

Hrm, interesting. On my last runs with a stock computer, the lower AFR would be trimmed out after 3~4 trips down the quarter mile.

If it works, it works, I just never got it to work had much better luck trimming WOT multi

[KevinH]

Worked for a over a year on my setup untill i stepped it up to larger injectors

[1986SVOTURBO]

Thanks guys. I probably did answer my question.

[NOTACARLO]

Running 18 psi (sometimes 20) on an alky kit. Almost pointless with the brick wall mounted above the turbo.