Quote:
Originally Posted by Hecklebone
This is the best i have ever had it running. I can accelerate up hills now, but not like my STI of course.
I have new VDO boost and EGT gauges. The peek boost now is right around 10psi, which suprises me for such a tiny turbo.
Where i am at now, this seems to be the most power i can extract with little smoke. Remember, i am in Denver and go up from here. Also the Pinz is about 7000 pounds.
This all sound abut right? If so, i suspect my two options for more power are a bigger turbo(i have the fuel capacity) and/or a custom grind cam shaft.
Thanks for all the info so far gents, i wouldnt be this far along without your assistance!
We need a dancing bannana emoticon..the Ford Raptor forum has them and my buddies are giving me grief. (Dancing bananna goes here)
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Sounds like you have got it dialed in pretty good now.
Stock boost w/o intercooler is right about 10, actually a tick less on most of them I have measured, so you're right on there. The intercooled motors run more, 12.5 pounds stock I think on the exact same turbo just with the compressor housing clocked the other way -- but the only way they can get away with that and get as much of a power bump as they do from it is because of the intercooler. One thing, though, is that when tuning for high altitude, from the perspective of the motor's survival (i.e. absolute manifold pressure) you can really raise the boost considerably, since w/o electronic engine management your wastegate is only working against relative pressure vs the atmosphere so the actual amount of oxygen entering the motor for a given static boost setting is less at higher altitude than it is at sea level or 5280'. In other words, you need a higher pressure differential vs atmospheric at altitude to cram the same amt of O2 into the motor that you do at the stock boost setting at sea level, thus correspondingly running an appropriately elevated boost setting at higher altitude could give you enough air to make the motor perform like it should with a stock boost level at low altitude, except...
The catch to keep in mind with this is that while you can turn up the boost to achieve that oxygen mass compensation at altitude, it will come with a lot more heat than the same absolute pressure (i.e. O2 quantity) would at sea level with a lower pressure differential, due to having to spin the turbo much faster to achieve it -- so an intercooler becomes necessary in order to reap much benefit from it, or water/methanol injection, as 745TG suggested. With a stock turbo at high altitude, making one of these really fly is very tough due to the issue of charge air heat generation, and with a larger turbo at altitude boost lag could become unbearable - an unfortunate catch-22 that probably only a well-managed VNT arrangement could fully resolve... However, with a stock turbo adding an intercooler, combined with slightly elevated boost levels, should make it able to perform roughly as well as it does, stock, at sea level most of the time. My theoretical assessment anyway -- hoping to have a chance to put the theory to the test with mine at some point here, it does fine driving around in Denver traffic, but I am still having trouble getting used to the difference in power with it when climbing hills...
Were you maxing out at 60 on the flat in top gear in the trans, or in 3rd? I've had both my MT and AT TD Volvos up here at Denver altitude and above on multiple occasions and generally find the automatic to be an advantage in getting the vehicle rolling since the converter helps build boost faster, but the one disadvantage is that when climbing hills or fighting a headwind, the ZF's torque converter lockup in top gear oftentimes comes right at the point in the rev band where it drops the engine speed down to where it can't quite pull anymore and hobbles the thing. Your rig is probably geared much lower overall than a Volvo car but depending on where your shift and lockup points are, there could still be more to be gained by playing with the trans kickdown cable some...
We'll work on getting the banana loaded in.
