JME cam and titanium valve spring/retainers(installed)
04-13-2006, 12:26 AM
#76
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Originally Posted by mark944turbo
"As long as I know the MAF transfer curve and the injector flow rate, I can set the AFR curves to whatever I desire from the comfort of my couch and be dead on regardless of boost level without ever going to the dyno or using a WBO2."
I dont believe you, you might get close enough for your purposes, but I doubt you can get afr within .1 at full throttle just based on airflow and injector size. You are ignoring too much!
Coming in 2 minutes is a stock full throttle fuel map, which will show it is clearly not an array of desired air fuel ratio's as fast951 claims, unless the factory was clueless. Who has a dyno printout of air fuel ratio for a stock car? Does it match?
I dont believe you, you might get close enough for your purposes, but I doubt you can get afr within .1 at full throttle just based on airflow and injector size. You are ignoring too much!
Coming in 2 minutes is a stock full throttle fuel map, which will show it is clearly not an array of desired air fuel ratio's as fast951 claims, unless the factory was clueless. Who has a dyno printout of air fuel ratio for a stock car? Does it match?
That stock WOT fuel curve looks correct. If you want to compare it to the charts from most dynos (i.e. 14:1 style ratio) just flip it upside down. Goes rich in the middle and lean on the ends.
04-13-2006, 06:32 AM
#77
Originally Posted by mark944turbo
"There is absolutely no more credible source of information on the 951 Motronic in the world than TT."
Yea, you are qualified to make this statement.
I trade emails with a few European guys who have also disassembled, understood, and rewritten various versions of motronic code. I guess you have quizzed them all?
(TT, are you a rocket scientist? I thought someone said you worked for nasa at one point..)
Yea, you are qualified to make this statement.
I trade emails with a few European guys who have also disassembled, understood, and rewritten various versions of motronic code. I guess you have quizzed them all?
(TT, are you a rocket scientist? I thought someone said you worked for nasa at one point..)
They have all recieved help from TT - directly or indirectly. They won't admit it to you, because you are a young kid, and they wish to appear heroic in your eyes.
04-13-2006, 07:42 AM
#78
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Originally Posted by jimbo1111
I don't believe this. Fuel and timing are looked up on the same map. If your statement was true than what happens when the rpm is raised to 7200 rpms. you just don't add timing. 20 20 20 20 20 21 21. What I stated earlier is the only limitation with the VR maf. If it never maxxes out. Timing can not have a proper alinement. Besides the fact that timing on a 2 valve head is not that critical. But a big mismatch can affect performance when your not running at a higher boost level. My suggestion would be to use a maf that will max out closer to the performance of the turbo that is used for the application.
First of all, they are not in the same map. What happens if you raise the rpm is that the ignition stays the same as the last point.
Timing at WOT doesn't care about the voltage from the AFM or MAF.
Eh timing is not critical? I guess I'm done here
04-13-2006, 01:57 PM
#79
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These guys are stuck in a single dimensional way of thinking. If you don't mind TT could you elaborate about how you were able to make the timing work at different boost levels. This is something I just can't grasp about your design.
04-13-2006, 01:59 PM
#80
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What makes timing less critical on 2 valve engines? I though timing is always advanced until a certain safety limit to knock is reached for max power. I can understand that the advance you need might differ between 2 and 4 valve heads in general but also depending on each individual head design. The better the head and chamber design the less advance you should need for best power.
04-13-2006, 03:30 PM
#81
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Sorry Jimbo, but the timing in the chips doesn't change with boost level when you go WOT. It would be very simple to implement (just a small map similar to the PT map), but I have not seen the need to do that. For ignition timing adjustment on the turbo setup what I have found to be a more important variable is intake manifold temperature. I have used this on turbo cars that don't have knock sensing with good results.
04-13-2006, 03:52 PM
#82
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Speeking about timing. A customer running 16psi on PUMP GAS sent me this chart for a VR Stage 2 kit.
First run was with pump gas timing, second with race gas timing (still on pump gas). (Race vs. Pump maps are selectable externally with Vitesse SW).
Notice how quickly he gets on boost, even though he started his run late at 3000rpm, he was on target in 400-500rpm. I think he would make even more power if he uses race gas with the race maps. Also, if he started his run at 2400rpm, he would have made more torque.. (larger area under the curve).
For some reason chart is not showing..
http://forums.rennlist.com/upload/s2dynopumpvsrace.jpg
First run was with pump gas timing, second with race gas timing (still on pump gas). (Race vs. Pump maps are selectable externally with Vitesse SW).
Notice how quickly he gets on boost, even though he started his run late at 3000rpm, he was on target in 400-500rpm. I think he would make even more power if he uses race gas with the race maps. Also, if he started his run at 2400rpm, he would have made more torque.. (larger area under the curve).
For some reason chart is not showing..
http://forums.rennlist.com/upload/s2dynopumpvsrace.jpg
04-13-2006, 05:45 PM
#85
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Originally Posted by 944CS
I would hope boost builds soon if he is starting the run at 3000 rpm.
Of course, it should and it does. Some turbos are sluggish and it take a long time to build boost. Slow recovery... Wish Rolex was here, he can comment on this!
04-13-2006, 06:23 PM
#86
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Very cool. I learned a couple of things. Thanks TT
Nice looking chart John.
I can't wait to get to a dyno and see how my little turbo that could compares against one of yours.
Nice looking chart John.
I can't wait to get to a dyno and see how my little turbo that could compares against one of yours.
04-13-2006, 06:30 PM
#87
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Originally Posted by jimbo1111
Very cool. I learned a couple of things. Thanks TT
Nice looking chart John.
I can't wait to get to a dyno and see how my little turbo that could compares against one of yours.
Nice looking chart John.
I can't wait to get to a dyno and see how my little turbo that could compares against one of yours.