FI tuning question

[arghx7]

Originally Posted by Fear

Its not an "issue" thread... Its a "can the tune bend rods"

I was told by the tunner they pull timing to cut power to prevent rods from bending...

As I've pointed out in other threads, this is an appropriate approach to mitigate risk of damage. Even if the engine doesn't really knock (due to E85 or race fuel), the more you advance the timing the higher the peak combustion pressure. That stresses the hell out of everything including the rods.

You don't have to knock the engine to stress the crap out of it. You don't even have to advanced spark past MBT to exceed the peak firing pressures it was designed for. Lots of airflow from the turbo combined with retarded spark is a less efficient way to make power but it keeps combustion pressure down.

[woode]

Originally Posted by jamesm

Also it's important to note that how you use the car is a very important factor. The guys driving around at 400+whp (myself included) aren't tracking their cars on that boost, at least most of them aren't . It's one thing to have a few maps, drive around daily at 10psi and kick it up to 18 for the occasional highway pull. Actually tracking the car for 20-30 minute sessions at any boost level is a lot more dangerous. My good friend blew a basically stock, untuned engine at the Dragon just driving hard. It happens, and it has as much to do with how it's used as with how it's tuned, though those are the two big factors. The best you can do is just make sure the tune is safe, and not turn up the boost unless you have the cash on hand to fix what may (or may not) come of it.

Most important part.

I am going on 8000 miles / 6 months of over 400hp / 20psi on completely stock internals and I am problem free. The car sees at least 16psi every single day multiple times. There's no knock, but the heat generated from the timing and boost to keep knock away would eat my engine up if I tracked it I am sure.

But, like jamesm said - I don't track my car (yet.. working on building an engine to handle that)

[Fear]

Those of you that have been above 400 for a while, do you have dyno graphs of your current tunes?

I'd be interested to see if your power comes on slow or if it hits hard and fast..

[sw20kosh]

Originally Posted by vgi

Because of posts like (promoting tuners) that I was sent home as completely tuned and said to make 299whp while the next day log showed knocking everywhere. And I won't take the usual BS "it's the car problem" because I dropped in a well woking NA and expected to get a well working FI car, so whether it's a mechanical or software it should have been addressed. To this day I still have a shitty tune now though it seems overly concervative as my car feels slower than NA until over 5k rpm.
I strongly suggest anyone who gets a tune do their own logging.

People can only speak from experience. I have had experience with 3 different tuners and from these 3 I know which one worked out the best for me. That is the tuner I will recommend.

[xwd]

Of course I would only recommend someone I have personal experience with and even then it doesn't work out for everyone. Everyone should also learn how to datalog and know what to look out for, it's really not difficult at all with the tools we have available for the car.

I've seen people get turbos put on and tuned and they don't even have a boost gauge...

[Ross]

Get a wide band, hook it up to the ecu, verify its output and make a custom map for logging it at minimu. Force induction should require a wide band.