3.8 dyno results very disappointing...
10-04-2008, 06:31 AM
#31
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TMW157
Buy yourself the best portable dyno, a GPS based datalogger, and do a couple of runs in a secluded area or the track. Measure a 100-200kph run (62-125mph roughly) and check out the numbers and data lines.
You will then have 100% certainty whether your car is performing as it should by comparing to a database of other cars that is available. As was said before, bigger displacement will result in proportionally higher torque, so you will not feel much difference.
If you go this route, let me know and I will share with you what your performance should be.
Cheers
Jean
Buy yourself the best portable dyno, a GPS based datalogger, and do a couple of runs in a secluded area or the track. Measure a 100-200kph run (62-125mph roughly) and check out the numbers and data lines.
You will then have 100% certainty whether your car is performing as it should by comparing to a database of other cars that is available. As was said before, bigger displacement will result in proportionally higher torque, so you will not feel much difference.
If you go this route, let me know and I will share with you what your performance should be.
Cheers
Jean
10-04-2008, 10:37 AM
#32
Not really significant here but the gearing is a little off too, if the hp/calcs are based on 3.8 when 3.849 is the actual # the results will be lower than actual by ~ 1.2% or ~ 3hp on a 250 hp base
A g50/20 in 4th is 1.118 w/ a cwp ratio of 3.444 for a total gear of 3.849
A g50/20 in 4th is 1.118 w/ a cwp ratio of 3.444 for a total gear of 3.849
10-04-2008, 10:53 AM
#33
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you guys are the greatest...
you are all a truly fabulous resource for someone like me who is essentially blindly groping for answers with very limited knowledge..
If the primary oxygen sensors were not working properly would they throw a code? And if there are no air leaks, would that suggest ecu as the primary culprit for running lean? As I understand it the ecu handles all fueling and timing values, correct?
Other issue is my mechanic--a good guy, fair and knowledgeable. Unfortunately he has very limited availability these days and I may need someone else to help me out here in New Jersey. I did a search and found a bunch of names but was wondering if any of you recommended a particular shop for this particular problem? I actually checked the price of shipping to Portland and it's about $2000 at this time!
best
Todd
If the primary oxygen sensors were not working properly would they throw a code? And if there are no air leaks, would that suggest ecu as the primary culprit for running lean? As I understand it the ecu handles all fueling and timing values, correct?
Other issue is my mechanic--a good guy, fair and knowledgeable. Unfortunately he has very limited availability these days and I may need someone else to help me out here in New Jersey. I did a search and found a bunch of names but was wondering if any of you recommended a particular shop for this particular problem? I actually checked the price of shipping to Portland and it's about $2000 at this time!
best
Todd
10-04-2008, 08:55 PM
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Peak power on a varioram should be in the 6000-6500rpm range, with a 3.8/RS cams upgrade I would expect it to be even further up at 6600 or so. Be sure to check that your varioram tubes and resonance flap are operating correctly, you may just have a vacuum system leak ...
10-06-2008, 02:28 PM
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I just got word from my mechanic who thinks the lean condition is a direct result of the increase in displacement to 3.8 liters with an ecu mapped for 3.6. Meaning I probably have none of the above intake leak or varioram issues.
From my perspective this car really does feel pretty good...smooth, strong and pulls just like the healthy stock 3.6 owned by a buddy of mine. I'm just not at all optimized for my 3.8.
I think it's time to send the ecu out to Steve..anyone think otherwise?
From my perspective this car really does feel pretty good...smooth, strong and pulls just like the healthy stock 3.6 owned by a buddy of mine. I'm just not at all optimized for my 3.8.
I think it's time to send the ecu out to Steve..anyone think otherwise?
Last edited by tmw157; 10-06-2008 at 04:45 PM.
10-06-2008, 07:26 PM
#37
I just got word from my mechanic who thinks the lean condition is a direct result of the increase in displacement to 3.8 liters with an ecu mapped for 3.6. Meaning I probably have none of the above intake leak or varioram issues.
From my perspective this car really does feel pretty good...smooth, strong and pulls just like the healthy stock 3.6 owned by a buddy of mine. I'm just not at all optimized for my 3.8.
I think it's time to send the ecu out to Steve..anyone think otherwise?
From my perspective this car really does feel pretty good...smooth, strong and pulls just like the healthy stock 3.6 owned by a buddy of mine. I'm just not at all optimized for my 3.8.
I think it's time to send the ecu out to Steve..anyone think otherwise?
10-06-2008, 08:41 PM
#38
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Absolutely agree with you regarding Steve. My question was meant to address whether this car needed any further workup prior to me shipping my ecu.
If Steve was within 1,000 miles of me I'd take a trip out and leave the car with him....
If Steve was within 1,000 miles of me I'd take a trip out and leave the car with him....
