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No..its all too hard. There is nothing wrong with the bearing - just the rubber - I have packed it with urethane (pic to follow..). It will last for years. Then - or if it does fail - I will take the whole shaft to a driveshaft engineer and have it ported professionally. The whole thing is going back in tomorrow.
Steve (webb) - I am using the nozzle from the autospeed kit.. the rest is my own.
jim ~
I have 'repaired' the center bearing with with urethane. I think it will be just as good as a new one (that I can't get anyway...). A complete refit - cutting off the uni ends, re-splining the shaft, welding, balancing etc would have cost several hundred $.
Anyway - I will soon be finding out its its as good as new - as next weekend I am taking the car to Winton for its first real race weekend! Also, I have drained the fuel from the tank and tomorrow I am going to see if it will start and run on E85. It had better - as I am buying 140 litres of it... :).
I am going to increment the part of the fuel table that is (about) above 1 bar and 4000 rpm by 50 % (in green in the pic...) and the rest by 40 %. Should be a good place to start. My WB Lambda will still convert the AFR reading to a gasoline AFR so that a WOT AFR will still look like 11 - 12.5:1. I have 'private practice' at Winton on the Friday to sort this all out :)
On straight methanol or E85, what real AFR do you actually need to run?
Steve - obviously there would be some debate about the most suitable AFR's for E85 - but here is one view....
Mode ........... Gas .... E85 ...... extra % (mass) ... extra % (flow)
Stoich .......... 14.7 .... 9.765 ........ +50.5% ................ +42%
Lean power ... 13.2 .... 8.47 .......... +55.8% ................ +47%
Rich power .... 12.5 .... 6.975 ........ +79.2% ................ +69%
So far I have drained the car of gasoline - and added 20L or E85. The car started and ran fine on it - Idling at about 13.1:1 (GAS AFR (so about 8.4:1 E85 AFR)). I have decided to 'sort out the fuel' on a dyno instead, actually - so I am taking it to Beninca's dyno on Wednesday.
So we get to see what sort of power it will make! Awesome :)
yes we will! anyway.. (hope its more than the stock 190 at the flywheel - that must be about 150 at the wheels..) I have a question that you (or someone may be able to help with...)..
.. I have noticed that the car is running rich at WOT at about 3-4000 RPM. It seems that it is being caused by the values in the 'WOT Enrichment table' - that pump in up to 23% more fuel if you keep the pedal flat.. I need to dial this out - has any body tried removing the values in the WOT enrichment table and just using the needed fuel level in the main fuel table instead? The table works as a multiplication factor..so the 1.23 at 3199 and 3803 RPM tells the ECU to add 1.23 times the amount of fuel called for in the main fuel table - AT ANY BOOST LEVEL..
jim~
the main fuel table is for constant throttle position {gas pedal at a constant angle}.
'WOT enrichment table' is % corrective map and it is something like the old 'acceleration pump' in the weber {and other} carburetors. Try to accelerate your Giulietta without this pump and you can see what happens.
yes, i get it - but its making the AFR's too rich :) - and my Giulietta actually had eight fuel injectors for its four cylinders.. & no carbs :).. So as you come through 4000 (ish) RPM @ WOT (planning to keep the thing at WOT till 7500) - the AFR's momentarily go rich as the 23% is implemented (down to 9:1)- but then it sorts its self out as more sensible values are in the tables later. but the car bogs down (a tiny bit..) because of that.
jim ~
8 f. injectors? wow!
try to adjust the % WOT map, not to remove them - I think at least.
I think the WOT map is a bit of extra safety for the standard engine. There is no real harm running it extra rich on WOT for a road car as you don't hit that very often. note the maximum values are around 3500 rpm, right where the OE turbo will be most efficient and able to pump in max boost and where the engine will achieve max torque.
Accelerator pump needs to work on part throttle too, not just WOT, Its usually taken from the "acceleration" of the load sensor. At a guess, in this case probably the TPS.
I would set the values in that table to 1
Dyno Results..
I took the car to a dyno in Melbourne, today. Its at Beninca motors who have dealt with Alfa's for many years. My purpose was simply to make sure that the AFR maps for the car , now running on E85 were where they needed to be... I could have done this at private practice - but its reassuring to have another opinion (and a different AFR meter...). As it turned out the maps were pretty good - just needing a bit of tweaking really..
The car made 250hp (rear wheel). It could make more in its current trim (between 50 - 100hp more) but for some reason we were not able to get boost over 1.2 bar sustained over 5000rpm. I am not sure yet whether this is because of:
a). a problem of configuration in the pierburg boot control valve table. in the ECU.
b). lack of flow capacity in the turbo its self.
c). the wastegate being pushed off its seat.
d). too weak a spring in the wastegate actuator
e). timing issue (too retarded).
hmm. something to work on. I actually suspect (a).
Overall, i was happy, as the car is now running smoothly on E85 - as does not seem to have any trouble starting. But, I am keen to be able to make 1.5bar boost out to 6500 rpm.
jim ~
what about APS?
Oem one has 1,5bar max reading.
That's an interesting thought Nick, I will bear it in mind. The highest reading I saw for boost was actually 1.45bar (at low rpm...). But as I don't want to go over 1.5 bar - the current sensor may do..
Ok this is a problem with the maps for the pierburg ! :) Why dont you ask well the tables are written for a different turbo that you have since you are driveing only on track and the MAP will cut off at 1.5 bar i reccomend this solution.
http://www.geocities.com/chmwatson/FAQs/mbc.html
Greets
This is what wrinx and I have except ours only have two connections, one from the turbo and the other to the wastegate. The other pipe is just blocked.
Monster boost control thread
This one:
http://cgi.ebay.co.uk/POWERTEK-BOOST...s_CarParts_SM?
wrinx
Certainly looks to be strong from that read out. Good result Jim.
Do you have a before and after inlet / exhaust temp reading when changing to E85? Difficult to compare over different days and locations but maybe it's an obvious difference?
Nick, Alfa Jack the rear anti roll bar thread is here..
http://forum.berlinasportivo.org/sho...+anti+roll+bar
in my opinion - having used it quite a bit now, it will be fine for a street car. It both reduces understeer and controls body roll.
Nik. I wasn't driving the car on the dyno so i could not see the exhaust temp gauge from where I was...and its not logged to the datalogger. I will have a close look this weekend at Winton and report back..
If i do have to get a new boost controller, i will probably go for the Turbosmart EBoost 2.
http://www.xspeed.com.au/shop/produc...2a3a5dd31d2905
As it turns out the problem with "low" boost was simply the values we were using in the 'over boost limit' table that controls pierburg valve... problem solved..
well at least that problem....
Another small issue that I am having is 'compressor stall' (or surge) at low RPM in 2nd gear when full boost is demanded by a request for WOT...Anybody had similar issues?
Nik. The exhaust temp was running a consistent 600 degrees C. Thats measured 6" after the turbo. The turbo body was 450 degrees C after a 'cool-down' lap
Yes, it can happen in some applications.Quote:
Originally Posted by jimnielsen
Fixes;
Dont drive it like that
Reduce the boost at that RPM point(s).
Get an anti surge compressor cover or modify the one you have
Respec the turbo for a higher RPM boost threshold. i.e. modify the turbine
Respec the compressor wheel (usually a smaller one)
Make the engine consume more air at that RPM point, head porting, cams etc.
Bleed/purge extra volume needed with some sort of fancy blow valve.
Dont worry about it, replace the tubo when it dies (can be the cheapest solution)
One interesting thing that I have noticed in the mountain of data that we collected from Winton is that the car makes its peak power right after the warm up lap...I am going to fit a waterspray unit to the car before I run it again - so it will be interesting to compare if that can stop that happening.. or at least reduce it..
How do you measure the power output? Can you log the engine temp and inlet temp on the same graph?
Steve, the power output is derived mathematically using the cars Cda, rolling resistance, mass and gear ratios. Its really a good method of seeing if the power of your car is increasing or decreasing over different days or runs on the same day, but I wouldn't rely on it as a means of determining what the exact power output it is (though many people do :) - )..
but yes, you can log any of the parameters that you can collect data for and display them on the same graph..Here is one that shows inlet manifold temp v's power..As you can see as inlet temp rises power falls..
jim ~
so, according to this graph you need to keep inlet temp lower than 45 degrees, am I wrong?
no, you're not wrong at all. More generally, it would seem that keeping the inlet manifold temp low is important. Perhaps with the water spray I can keep it closer to the 45 degree figure. The ambient temp at the time was approx 15 degrees C.