Problems tuning

[DarkStarMenace]

Ok I tried posting in Tuning Management but I guess I am not privileged enough. My mods: Big 16G, FMIC with custom 2.5" IC piping, 190 lph Walboro fuel pump, 680 cc injectors, TurboXS dual stage boost controller, Greddy Turbo timer, Apexi SAFC-II, 2.5" DP to 3" cat back exhaust, 8.3:1 Wiseco pistons, SS valves on head, K&N filter (no dye), new rod bearings and rehoned the block. I disconnected the wastegate rod to prevent boost so I could allow motor to break in for 100 miles. My problem is tuning with the SAFC-II. I do have the knock signal wire installed and read recently not to do it but my concern is I connect a scan tool and watch both short and long fuel trims, ignition timing and O2 sensor signal. I tried to set the correction factor through the fuel trims, which are at 15% negative across the board, when I actually drive the car the timing is at 30 degrees is this because of no boost or what? I feel I have a unique set up which hasn't been duplicated. Ne help would be greatly appreciated.

 

[toybreaker]

Stupid question from a newbie...

You say you disconnected the wastegate actuator rod? Did you wire the wastegate flapper open or anything? I can see all kinds of potential issues running without boost control.

Please clarify.

Thanks

 

[Terrh]

if you disconnect the actuator rod there is no need to wire the flapper open, exhaust gasses will do that for you and you will only see 2-3psi of boost at the most.. hardly any at all.

A turbo ecu will advance the timing because it isn't seeing knock because the engine isn't seeing any boost! Your engine will require much less octane at 0psi than it will at 12. I don't think that your timing numbers are off.

 

[DarkStarMenace]

The only reason I disconnected the wastegate was for break in purposes, I think you have a comprehension problem toybreaker. I am reconnecting the wastegate this weekend because I just passed the 100 mile mark. One question I had was can I tune with the car in neutral and revving in the appropriate rpm range and then take it for a spin and readjust as necessary.

 

[Talesin]

Though that'd be nice, no. It'll get you better than nothing at all, but in neutral the engine is under no load. Less likely to knock, no pulled timing and so on. You'll either need to datalog yourself (yes, there's a reason people actually buy those cables), or have a friend in the car to alter the trims on the fly, if you're willing to risk that kind of thing. You aren't going to get a good WOT tune without a log though.

Personally, I'd just get a logger and do a third gear pull, and tune off that if you don't have a WBO2. Just bear in mind that it's better to be a bit on the rich side, rather than running too lean and killing the shiny new engine. (Running pig rich will do similar due to washing the cylinders and raised EGTs, but it'll be a lot less prone to detonation. And yes, too rich WILL raise the EGTs, just as too lean will. :b)

 

[DarkStarMenace]

Well im using an aftermarket OBD2 scantool, and actually one of the best scantools i have used for imports. I can select which information to look at. For my car I look at Ignition Timing, Long Term and Short Term fuel trims, and #1 O2

 

[DarkStarMenace]

But thanks for the advice, I also have access to Scan tools that can record data as you drive, so I'll take the car for a whirl and c what happens.