Fish Jetski wrote:Whoa, this topic sure has gone off course a little. My tune has FFC and LC, and they are pretty awesome although I try not to put too much pressure on the driveline too often.
Yes, I was trying to avoid that. It seems though that some people can't help themselves.
Guys - I need some feedback with others with either TBE or Dump ONLY + tune + dyno to back it up on where my tune falls short compared to others'. I think my baseline of 156kw is about right, but my overall gain is not enough, and the turbo (VF54) comes on too far up the rev range for a smallish turbo, especially with the long gearing in the Liberty.
For what it's worth - the EJ255 in the 4Gen makes ~130kW ATW stock, and the 5Gen GT makes ~150kW ATW stock. Although there are some differences between the engine itself in the 4Gen GT and 5Gen GT, I'm sure the difference in turbo contributes somewhat to the ~20kW difference, and all other things being equal, if the VF54 can give a better top end, it probably suffers at the bottom end in a direct comparison with the VF46. It would seem to me that the VF52 and VF54 are probably closest in terms of comparison - and a mid 2,000s full boost figure sounds about right in that case.
As I understand it, a dump pipe should have the turbo spooling a little earlier (as it should flow more freely than the stock pipe, and that should let the turbo spin up ~200rpm earlier). Unfortunately your dyno graphs show power and torque curves (for what it's worth, completely ignore those flywheel torque figures, they're WAY out, though you can rely on the shape of the torque curves), but you've not shown any before and after boost curves. They'd tell you if the turbo is boosting "better" than it did before.
My tune is based around 16.6PSI max - what boost are you guys running to achieve 200kw ATW, or what do you run with E85?
I can't comment on the specifics of the 5Gen and VF54, but I know that on 4Gen with either the VF46 (stock) or VF52, 18psi is often used as a safe target. I suspect you'd pick up a decent amount of extra top-end power with another PSI or so of boost if that's safe on the 5Gen and VF54 - again, assuming the VF52 and VF54 are similar, that should be possible. Your graphs not showing boost also means it's hard to tell if the turbo is managing to hold boost all the way to redline, or if it's falling away (and there are ways, in a tune, to influence that). You mentioned 16.6psi max boost - if it only 14.7psi or even less once you get beyond 5,500rpm? The advantage of a VF52 swap over a VF46 on the 4Gen cars is that the VF52 will hold boost longer, but it will come onto boost later (all other things being equal) - in general, stock turbos are selected by manufacturers to ensure good driveability on public roads, and they're not terribly concerned with peak power (note that for several versions now as an example, WRX STIs have basically had the same peak power output - but they drive quite differently across versions).
All that said - check this:
http://sjautomotive.com.au/images/Dynog ... XA-KIT.jpgWith just the XA kit (just a tune, no hardware changes), they're topping 180kW ATW (according to their dyno). MRT say that their "XB kit" (tune, dump, 3" exhaust, CAI) gives another 10kW over the tune alone. So, all things being equal, I'd expect your car to fall somewhere between 180kW and 190kW based on MRT's own documentation (though I personally find it hard to believe that a CAI, dump and full exhaust "only' gets you 10kW).
With the same dump pipe + tune mods the VF54 on the 2.5T seems to land slap bang between the TD04 (standard in MY08 WRX, MY09 Forester) and the VF52 (MY09+ WRX) in terms of outright power, and starts to lose boost around 1000RPM higher than the TD04, but it does not come on until about 2500RPM. The big advantage of the TD04, is because it is small it comes on at around 1800RPM, almost like a twin scroll Golf GTI (had a tuned Skoda Octavia RS for a while

) so it has awesome flexibility for a single scroll. So each time, I end up waiting for the VF46 to come on about as long as the VF52, but with only about 50% of the power gain. WTF? I also cruise in 1 gear lower than my MY09 Forester XT that weighs the same, cuts the air like a brick and only has 155kw ATW (with same mods) at 50, 60 and 70km/h.
Peak power isn't a reasonable way to determine anything about cruising rpm/gear. Torque is more important here, area under the torque curve (and it's shape, not ultimate height), the ratios in the box, the final drive, they all impact at what rpm and gear you cruise at.
One thing to ask Mercury is what were their goals when tuning your car. Were they chasing peak power, or were they chasing a car that was really responsive in the mid-range, etc. You stated at the start that you were happy with the tune, though it seems now that you're less happy when comparing it with other cars (remember though that comparing tunes between different cars isn't necessarily going to work well). Really, don't get hung up on a headline figure produced on a dyno by someone with a vested interest in telling you how good they are - if you're happy with the car, then be happy with it, and don't worry what others may think.
Please give me some further information so that I can go back to my tuner in the next few days to get some more info on E85, as well as a retune based on the feedback from this thread.
E85 may require more mods like fuel pump, injectors, etc.
Go back to the tuner with feedback based on how happy YOU are with how the car drives. Don't worry about what anyone on an Internet forum thinks.
