So Cal Dyno Day
#196
07-27-2005, 11:35 PM
Originally Posted by eldy
I already communicated to Shawn about it. And he offered to have me do my runs over for free.
The dyno stopped capturing at 6300 rpms, 95% of that is closer to 6000 rpm. My thoughts on it were the same as Shawn's. The engine was using less mechanical advantage (4.935:1 < 5.204:1) to turn the hubs than the dyno was told so the torque values were depressed rather than elevated.
If the raw torque numbers can simply be shifted to the left since the dyno thought 6000 rpm is actually 6300 rpm (since engine speed is derived from hub speed with a Dynapack), then I could use Excel to divide the raw torque numbers by the correct ratio (4.935) then multiply by "corrected RPM" and divide by 5250 to determine HP. In fact when I do that, peak hp (for up to 6000 rpm) stays the same, just shifted down to 6000 rpm. It is interesting to note that by using the approximated slope of the torque curve, there would be 215 ft-lbs. @ 6500 rpm. Using those numbers we would have 266 hp @ 6500 rpm.
Let's start a poll about who's theory is right and the ones that are wrong buy the ones that are right dinner!
The dyno stopped capturing at 6300 rpms, 95% of that is closer to 6000 rpm. My thoughts on it were the same as Shawn's. The engine was using less mechanical advantage (4.935:1 < 5.204:1) to turn the hubs than the dyno was told so the torque values were depressed rather than elevated.
If the raw torque numbers can simply be shifted to the left since the dyno thought 6000 rpm is actually 6300 rpm (since engine speed is derived from hub speed with a Dynapack), then I could use Excel to divide the raw torque numbers by the correct ratio (4.935) then multiply by "corrected RPM" and divide by 5250 to determine HP. In fact when I do that, peak hp (for up to 6000 rpm) stays the same, just shifted down to 6000 rpm. It is interesting to note that by using the approximated slope of the torque curve, there would be 215 ft-lbs. @ 6500 rpm. Using those numbers we would have 266 hp @ 6500 rpm.
Let's start a poll about who's theory is right and the ones that are wrong buy the ones that are right dinner!
#198
07-28-2005, 05:03 PM
Eldy,
I've worked out the complex maths for ya and here's the bottom line ...
Your torque is underminded by 5.39% while the rpm is over rated by 5.39% (referencing to 4.935 vs 5.201 FD ratio).
Your HP figures are actually not effected because the two error factors (TQ and RPM) cancel themselves out in the formula for calculation. Visually, you'd simply shift your HP curve to the left by 5.39% (e.g. 6300 rpm -> 5979 rpm). Having said that ... it is entirely possible you could actually have an even better result by reving it another 500 rpm, since since the VQ usually reaches it's peak HP figure at ~6400rpm (assuming the ECU observes no knock-like activities).
On the other hand, your Torque curve (which is the prefered chart for analyzing gains and losses) will need to be shifted up by 5.39% and the the left by 5.39%.
Of course, this is all in theory and I'm very confident in it, but I still say take up on the FREE re-dyno and see it first hand to settle it all. The question is, Do you feel lucky?
I've worked out the complex maths for ya and here's the bottom line ...
Your torque is underminded by 5.39% while the rpm is over rated by 5.39% (referencing to 4.935 vs 5.201 FD ratio).
Your HP figures are actually not effected because the two error factors (TQ and RPM) cancel themselves out in the formula for calculation. Visually, you'd simply shift your HP curve to the left by 5.39% (e.g. 6300 rpm -> 5979 rpm). Having said that ... it is entirely possible you could actually have an even better result by reving it another 500 rpm, since since the VQ usually reaches it's peak HP figure at ~6400rpm (assuming the ECU observes no knock-like activities).
On the other hand, your Torque curve (which is the prefered chart for analyzing gains and losses) will need to be shifted up by 5.39% and the the left by 5.39%.
Of course, this is all in theory and I'm very confident in it, but I still say take up on the FREE re-dyno and see it first hand to settle it all. The question is, Do you feel lucky?
#199
07-28-2005, 05:25 PM
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Originally Posted by THX723
. . .
On the other hand, your Torque curve (which is the prefered chart for analyzing gains and losses) will need to be shifted up by 5.39% and the the left by 5.39%.
. . .
On the other hand, your Torque curve (which is the prefered chart for analyzing gains and losses) will need to be shifted up by 5.39% and the the left by 5.39%.
. . .
Luckily the Dynapack software stores the "raw" recorded torque values measured at the hub for each run.Just got tired last night so I didn't plot the "corrected" run vs. the baseline run in Excel. I expect area under the curve to increase an additional 0.25% from 4000 to 6000 rpm!
When are you going to be down at Church's yourself Clint? I still owe you a drink/dinner whatever for "you know what."
#200
07-28-2005, 10:37 PM
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<img src=https://g35driver.com/forum/attachment.php?attachmentid=18223&stc=1 />
!
Seven percent gain over baseline in area under the curve between 4000 and 5960 rpm!
We have to note, however, that the baseline pull was done in 4th gear. On the second dyno day, using the proper ratio, we did one pull in 4th and it showed the same trend after approximately 5700 rpm where the hp curve would flatten out quickly. Shawn said that the ECU might be doing something to lessen power output as we near the 156 mph speed limiter. So the overall gains over baseline might not be as drastic as shown on this graph.
I will set up a time with Shawn and get all this all sorted out.
!Seven percent gain over baseline in area under the curve between 4000 and 5960 rpm!
We have to note, however, that the baseline pull was done in 4th gear. On the second dyno day, using the proper ratio, we did one pull in 4th and it showed the same trend after approximately 5700 rpm where the hp curve would flatten out quickly. Shawn said that the ECU might be doing something to lessen power output as we near the 156 mph speed limiter. So the overall gains over baseline might not be as drastic as shown on this graph.
I will set up a time with Shawn and get all this all sorted out.
#201
08-01-2005, 02:13 AM
Hey all, sorry about the gear ratio mistake. We were really belting out the cars and I just missed it. Hopefully Eldy can get down here soon for a retest just to be sure on the numbers.
Regarding the fellow with the wheel scratches, bring it on by and we'll take a look at it and see what we can do to make things right.
Oh, and I like hanging with all you guys so much my new Laser Red 6MT Coupe is being shipped from Phoenix tomorrow. Didn't know the 19's were standard equipment this year till we went to the dealer. Just have to fight the fiance for drive time now (she's been monopolizing the S2000 lately.
SC
Regarding the fellow with the wheel scratches, bring it on by and we'll take a look at it and see what we can do to make things right.
Oh, and I like hanging with all you guys so much my new Laser Red 6MT Coupe is being shipped from Phoenix tomorrow. Didn't know the 19's were standard equipment this year till we went to the dealer. Just have to fight the fiance for drive time now (she's been monopolizing the S2000 lately
.SC
#205
08-01-2005, 11:13 PM
Originally Posted by Churchautotest
Hey all, sorry about the gear ratio mistake. We were really belting out the cars and I just missed it. Hopefully Eldy can get down here soon for a retest just to be sure on the numbers.
Regarding the fellow with the wheel scratches, bring it on by and we'll take a look at it and see what we can do to make things right.
Oh, and I like hanging with all you guys so much my new Laser Red 6MT Coupe is being shipped from Phoenix tomorrow. Didn't know the 19's were standard equipment this year till we went to the dealer. Just have to fight the fiance for drive time now (she's been monopolizing the S2000 lately.
SC
Regarding the fellow with the wheel scratches, bring it on by and we'll take a look at it and see what we can do to make things right.
Oh, and I like hanging with all you guys so much my new Laser Red 6MT Coupe is being shipped from Phoenix tomorrow. Didn't know the 19's were standard equipment this year till we went to the dealer. Just have to fight the fiance for drive time now (she's been monopolizing the S2000 lately
.SC
Now does this mean well see you at one of the G35 track days?
#206
08-01-2005, 11:30 PM
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Originally Posted by Hydrazine
Hehehe! You we drawn into the seductiveness of the G35. Congratulations!
Now does this mean well see you at one of the G35 track days?
Now does this mean well see you at one of the G35 track days?
BTW, Tony.. I actually DID move the intakes into the wheel wells like we talked about. Please check out the thread in the FI forum, I am soliciting opinions on a potential issue with it. thanks.
#207
08-01-2005, 11:51 PM
Originally Posted by GurgenPB
Was gonna say the same thing. COngrats Shawn, welcome to the club.
BTW, Tony.. I actually DID move the intakes into the wheel wells like we talked about. Please check out the thread in the FI forum, I am soliciting opinions on a potential issue with it. thanks.
BTW, Tony.. I actually DID move the intakes into the wheel wells like we talked about. Please check out the thread in the FI forum, I am soliciting opinions on a potential issue with it. thanks.
Did you install new exhaust yet?
#208
08-02-2005, 01:02 AM
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Originally Posted by OCG35
Aw man.... I was hoping you were going to do the holes in the hood route "Shrek" look - LOL
Did you install new exhaust yet?
Did you install new exhaust yet?
Exhaust is next, waiting on some tips.
Gurgen
#209
08-02-2005, 04:00 AM
Probably not going to see much, if any track time (may take it out once just to see) - its a little heavy compared to the S2000 and I've already got lots of race tires for that car (and the price of tires for the G35's 19s is ridiculous). What it does is give me a much more relaxed daily driver with acceleration that won't leave me longing for my S2000, and now I can park the S2000 while I put together a bigger engine for it.
While I'd like to keep the G relatively stock (I leased it), I can't resist the idea of at least throwing an intake on it, and it sure could use a lighter flywheel - the mod bug is hard to ditch.
BTW Tony, I think I have some of your thermocouples and multimeter at my shop.
SC
(and the price of tires for the G35's 19s is ridiculous). What it does is give me a much more relaxed daily driver with acceleration that won't leave me longing for my S2000, and now I can park the S2000 while I put together a bigger engine for it. While I'd like to keep the G relatively stock (I leased it), I can't resist the idea of at least throwing an intake on it, and it sure could use a lighter flywheel - the mod bug is hard to ditch.
BTW Tony, I think I have some of your thermocouples and multimeter at my shop.
SC
#210
08-02-2005, 04:06 AM
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Originally Posted by Churchautotest
Hey all, sorry about the gear ratio mistake. We were really belting out the cars and I just missed it. Hopefully Eldy can get down here soon for a retest just to be sure on the numbers.
Regarding the fellow with the wheel scratches, bring it on by and we'll take a look at it and see what we can do to make things right.
Oh, and I like hanging with all you guys so much my new Laser Red 6MT Coupe is being shipped from Phoenix tomorrow. Didn't know the 19's were standard equipment this year till we went to the dealer. Just have to fight the fiance for drive time now (she's been monopolizing the S2000 lately.
SC
Regarding the fellow with the wheel scratches, bring it on by and we'll take a look at it and see what we can do to make things right.
Oh, and I like hanging with all you guys so much my new Laser Red 6MT Coupe is being shipped from Phoenix tomorrow. Didn't know the 19's were standard equipment this year till we went to the dealer. Just have to fight the fiance for drive time now (she's been monopolizing the S2000 lately
.SC