shoestring
Well-known member
- Joined
- Jun 20, 2009
- Location
- Swampscott, 01907
Regardless, the numbers here are off. AFR's in the 10's is way too rich, high 11's still well on the safe side of rich at that boost level. Monkeying with the air flow meter and running random chips is not likely to get great results, neither is running cheap-o aftermarket injectors. You mention an FPR, is this a rising rate secondary fpr like a vortec?
or is this just an adjustable drop-in fpr replacing the stock one?
if so, what is the base fuel pressure (no vacuum source connected) set at?
If this were my vehicle I would do the following:
Comprehensive boost leak test, looking closely at the idle air hoses (it does not take a huge leak to greatly skew back pressure numbers and heavily impact performance)
If that passes, then I would do all of the following and then work back forward from there:
stock injectors, stock fuel pressure, boost back down to ~8psi and evaluate how the vehicle is performing (seat of the pants or something. be great to get dyno numbers, but certainly that's an expense). I might even put the oem chips back in the car, but I would for sure reset the ecu's.
Then, turn the boost up gradually, keeping an eye on the AFR's. You may be surprised at how far you can go before it's an issue. Then, before I would do anything else, I might see if raising the fuel pressure allows me to bump the boost up a little more without causing issues (even though I will freely state, I believe this is a hack and there are good arguments against doing this, many of which I've personally made)
Depending on where it's at now, you can change ONE thing at a time. For instance, bigger injectors.. reset the ecu, leave everything else alone, drop them in (but I would recommend going out and getting used legit 400+cc injectors, not running chi-com knockoffs, those are notoriously ****ty), and let the ecu learn and see how that goes. If you legitimately reach the end of the MAF, you need to make a decision on whether or not you want to keep LH or get something that doesn't suck.
I will second all this.