? about shift-fast mod
01-30-2007, 08:38 PM
#361
iv noticed when i lock mine. I feel the car somewhat slower at first and then starts to build up speed. However, i just came across a G35c, and it was noticeable when i locked the tc i started to pull away quicker, I did this I belive at the top of 2nd. or beginning of 3rd. We have to keep practicing with this, im sure we can find a good combination as for when to lock/unlock to provide best results.
01-30-2007, 09:03 PM
#362
Originally Posted by streetzlegend
iv noticed when i lock mine. I feel the car somewhat slower at first and then starts to build up speed. However, i just came across a G35c, and it was noticeable when i locked the tc i started to pull away quicker, I did this I belive at the top of 2nd. or beginning of 3rd. We have to keep practicing with this, im sure we can find a good combination as for when to lock/unlock to provide best results.
01-30-2007, 09:30 PM
#363
Originally Posted by Nismo87SE
Nice dyno, I'm thinking that for best ET's you'd probably want to engage the TC around 5000rpm. The slippage from the unlocked TC would allow the motor to rev quicker but it puts down less power. So your going to have to find the best balance or engagement point for best performance. I'd guess based on the torque curves that 5k should be a good point to start with. The slippage would help the engine rev to 5k quicker than locked, so after that point you can benefit from the higher power with it locked.
I would suggest doing tests on how fast the engine accelerates from 4000 to 5500rpm locked and unlocked. If you look into your OUT file you will see a time stamp for each rpm sample captured. From there you can subtract the difference in speed or rpm between set points. In any event good luck! All this auto tuning seems like fun, almost sucks to drive a manual....well then again maybe not lol.
I would suggest doing tests on how fast the engine accelerates from 4000 to 5500rpm locked and unlocked. If you look into your OUT file you will see a time stamp for each rpm sample captured. From there you can subtract the difference in speed or rpm between set points. In any event good luck! All this auto tuning seems like fun, almost sucks to drive a manual....well then again maybe not lol.
I did what you recommended and ran some numbers on the OUT file.
Here is what I found as far as "time" is concerned:
With TC unlocked, it takes 3.7476 seconds for the engine to rev from 4K to 5.5K rpm.
With TC locked, it takes 3.6487 seconds for the engine to rev from 4K to 5.5K rpm.
Here is what I found as far as "speed" is concerned:
With TC unlocked, speed increases 23.225mph from 4K to 5.5K rpm.
With TC locked, speed increased 23.25mph from 4K to 5.5K rpm.
With TC unlocked, speed increases 15.35mph from 5K to 6K rpm.
With TC locked, speed increases 15.40mph from 5K to 6K rpm.
All these numbers are averages over the 4 locked and 4 unlocked runs I did.
So the bottom line, with the TC unlocked, you are able to rev MUCH faster, which we already know.
And with the TC locked, you are able to accelerate a TINY TINY bit faster reguardless of what you see in my dyno plots.
So, once again, my 1/4 mile ETs will tell everything! My car is very consistant in the 1/4 mile and I'm able to accurately tell how much the TC lockup helps within .03 of a second.
Ari, do you have any more ideas for crunching numbers?
01-31-2007, 12:50 PM
#364
I have slightly used 205/50R15 BFG Gforce Drag Radials for sale. I figured you automatic high horsepower guys might be interested. They are going to go QUICK.
http://forums.maxima.org/showthread.php?t=509126
http://forums.maxima.org/showthread.php?t=509126
01-31-2007, 08:32 PM
#365
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If you could PM me an average of your uncorrected whp/wtq locked and unlocked I'd like to run some sims in cartest. It looks like that even though the engine bogs it might actually accelerate faster with the TC locked. The only way to tell would be if you were able to "lock" 2nd gear so you can do a pull from around 1500-6500rpm. This way you can see how much torque multiplication you get and when it starts to trail off vs being locked.
01-31-2007, 09:44 PM
#366
Originally Posted by Nismo87SE
If you could PM me an average of your uncorrected whp/wtq locked and unlocked I'd like to run some sims in cartest. It looks like that even though the engine bogs it might actually accelerate faster with the TC locked. The only way to tell would be if you were able to "lock" 2nd gear so you can do a pull from around 1500-6500rpm. This way you can see how much torque multiplication you get and when it starts to trail off vs being locked.
I won't be able to make a run from 1500 to 6500 b/c if I did lock 2nd gear down that low, it wouldn't be good to go WOT at 15mph with the TC locked. I'd have to wait until I'm going a little faster revving about 2500-3000rpm. But regardless, I don't have it setup right now to prevent the gear kickdown.
01-31-2007, 10:13 PM
#367
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Join Date: Aug 2000
Posts: 2,807
Originally Posted by Aaron92SE
You'll have to tell me what you mean by uncorrected.
I won't be able to make a run from 1500 to 6500 b/c if I did lock 2nd gear down that low, it wouldn't be good to go WOT at 15mph with the TC locked. I'd have to wait until I'm going a little faster revving about 2500-3000rpm. But regardless, I don't have it setup right now to prevent the gear kickdown.
I won't be able to make a run from 1500 to 6500 b/c if I did lock 2nd gear down that low, it wouldn't be good to go WOT at 15mph with the TC locked. I'd have to wait until I'm going a little faster revving about 2500-3000rpm. But regardless, I don't have it setup right now to prevent the gear kickdown.
01-31-2007, 10:28 PM
#368
Originally Posted by Nismo87SE
I meant the pulls without drivetrain loss, actually then again I guess I don't need that since cartest allows the user to input drivetrain loss.
Do you need each HP and TQ number for each rpm? Or do you just need an average of the peak HP unlocked and locked?
It would be easiest to get the average numbers by ballparking it according to my chart. Or I could average the numbers for each rpm! That would take forever.
02-02-2007, 09:41 AM
#369
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Join Date: Aug 2000
Posts: 2,807
Originally Posted by Aaron92SE
What actual numbers do you want?
Do you need each HP and TQ number for each rpm? Or do you just need an average of the peak HP unlocked and locked?
It would be easiest to get the average numbers by ballparking it according to my chart. Or I could average the numbers for each rpm! That would take forever.
Do you need each HP and TQ number for each rpm? Or do you just need an average of the peak HP unlocked and locked?
It would be easiest to get the average numbers by ballparking it according to my chart. Or I could average the numbers for each rpm! That would take forever.
02-05-2007, 09:57 AM
#370
I dynoed without locking tc and with locking tc. The entire HP curve when locked was lower than without tc being locked. without it being locked i got 230WHP, with it locked i got 226WHP. I locked it as soon as I steped on the gas at about 3200 in 3rd gear. The bad part is that I did not get TQ reading because the ignition signal did not work on the dyno. All I got was WHP based on the drums speed. I did not like the whole dyno experience and I will be doing it again at another location.
02-05-2007, 10:15 AM
#371
Originally Posted by streetzlegend
I dynoed without locking tc and with locking tc. The entire HP curve when locked was lower than without tc being locked. without it being locked i got 230WHP, with it locked i got 226WHP. I locked it as soon as I steped on the gas at about 3200 in 3rd gear. The bad part is that I did not get TQ reading because the ignition signal did not work on the dyno. All I got was WHP based on the drums speed. I did not like the whole dyno experience and I will be doing it again at another location.
But your HP numbers seem to be in sync with my HP numbers. They are roughly the same. The motor's inconsistancy can do that 4hp loss. The only way to know for real with dealing with such a small increase in power is to do like 5 runs before and 5 runs after and take an average.
But I bet you would have seen a torque curve that looked similar to mine if you were able to look at that.
02-05-2007, 11:21 AM
#372
Originally Posted by streetzlegend
I dynoed without locking tc and with locking tc. The entire HP curve when locked was lower than without tc being locked. without it being locked i got 230WHP, with it locked i got 226WHP. I locked it as soon as I steped on the gas at about 3200 in 3rd gear. The bad part is that I did not get TQ reading because the ignition signal did not work on the dyno. All I got was WHP based on the drums speed. I did not like the whole dyno experience and I will be doing it again at another location.
In my case, with the 2800 stall converter, there was a considerable RPM drop. I had crazy better power to the wheels with the clutch engaged, but with nitrous, the extra power is available immediately - no spooling required. The same deal with NA, I suspect.
It's gonna be a long time until spring - single-digit temps in the morning here.
03-13-2007, 06:47 PM
#373
It's time to bump this thread.
I'm revising the Shift_Fast_2 to incorporate fuel-cut and ignition-cut along with nitrous-cut, with the goal of shifting during momentary cuts (much faster).
I think that controlled shifts that launch with the TC clutch off, momentary cut at 5000, lock the clutch, momentary cut at 6500, shift into 2nd gear w/clutch on, momentary cut at 6500, shift into 3rd gear - that's the goal......
This will take two MSDs, a stack of relays and other fun stuff, but do-able. I think I'll mix the third nitrous stage into shifting into third gear.
With the "Alaskan pipeline" installed, and 23.5/12/15 Hoosier slicks, this could be fun....... with the modified OBX headers, a lot of fun.....
I'm revising the Shift_Fast_2 to incorporate fuel-cut and ignition-cut along with nitrous-cut, with the goal of shifting during momentary cuts (much faster).
I think that controlled shifts that launch with the TC clutch off, momentary cut at 5000, lock the clutch, momentary cut at 6500, shift into 2nd gear w/clutch on, momentary cut at 6500, shift into 3rd gear - that's the goal......
This will take two MSDs, a stack of relays and other fun stuff, but do-able. I think I'll mix the third nitrous stage into shifting into third gear.
With the "Alaskan pipeline" installed, and 23.5/12/15 Hoosier slicks, this could be fun....... with the modified OBX headers, a lot of fun.....
03-13-2007, 07:05 PM
#374
Originally Posted by grey99max
Did you experience any drop in RPMs when you locked the clutch ?? If you did it again, would you engage the clutch at a higher RPM??
In my case, with the 2800 stall converter, there was a considerable RPM drop. I had crazy better power to the wheels with the clutch engaged, but with nitrous, the extra power is available immediately - no spooling required. The same deal with NA, I suspect.
It's gonna be a long time until spring - single-digit temps in the morning here.
In my case, with the 2800 stall converter, there was a considerable RPM drop. I had crazy better power to the wheels with the clutch engaged, but with nitrous, the extra power is available immediately - no spooling required. The same deal with NA, I suspect.
It's gonna be a long time until spring - single-digit temps in the morning here.
Right now I am very happy as to how quick my shifts are, I even had a friend of mine that has some overall tune car experience go for a ride in my car and he was extremely impressed as to how my car shifted so quick. I guess while the clutch is engaged the shifts are more firm.
03-13-2007, 07:14 PM
#375
Originally Posted by grey99max
This will take two MSDs, a stack of relays and other fun stuff, but do-able. I think I'll mix the third nitrous stage into shifting into third gear.
With the "Alaskan pipeline" installed, and 23.5/12/15 Hoosier slicks, this could be fun....... with the modified OBX headers, a lot of fun.....
With the "Alaskan pipeline" installed, and 23.5/12/15 Hoosier slicks, this could be fun....... with the modified OBX headers, a lot of fun.....
It is most definitely going to be an interesting track season. I think we'll see a lot of progress with the 4th gen community this year
Between grey, streetz, aaron, and myself, we should see lots of testing and effort in NA, FI, and nitrous.
03-13-2007, 07:18 PM
#376
Originally Posted by Tatanko
Sounds like you've got solid 12's ahead of you, my friend.
It is most definitely going to be an interesting track season. I think we'll see a lot of progress with the 4th gen community this year Between grey, streetz, aaron, and myself, we should see lots of testing and effort in NA, FI, and nitrous.
It is most definitely going to be an interesting track season. I think we'll see a lot of progress with the 4th gen community this year
Between grey, streetz, aaron, and myself, we should see lots of testing and effort in NA, FI, and nitrous.
03-13-2007, 07:32 PM
#377
Originally Posted by streetzlegend
Yea rpm's always drop when I engage the clutch, because it causes more load on the engine. I am learning that the best time for me to lock it is when my turbo is already at full boost, once i lock it while in full boost you can really feel the car just move alot faster although the rpms are going up slower you can see the MPH go up very quick. specially in 4th gear, it pulls just as hard as 3rd gear when locked.
Right now I am very happy as to how quick my shifts are, I even had a friend of mine that has some overall tune car experience go for a ride in my car and he was extremely impressed as to how my car shifted so quick. I guess while the clutch is engaged the shifts are more firm.
Right now I am very happy as to how quick my shifts are, I even had a friend of mine that has some overall tune car experience go for a ride in my car and he was extremely impressed as to how my car shifted so quick. I guess while the clutch is engaged the shifts are more firm.
Well - I see you're interested... I found the engine dropped RPMs with the TC locked because the loss in the torque converter was eliminated. It felt like shifting into a manual transmission, so the RPMs dropped - a bunch, in my case, because of the 2800 stall speed.
I mentioned this before, but spraying with the TC clutch locked and rolling in first gear was scary - the 10-inch DRs broke loose immediately and bounced off the limiter several times. This was lots different than the usual launch results - I tried them both. Locking the TC while in 2nd gear about 4000RPMs and spraying the first stage around 60 MPH spun both DRs and drifted me across the highway. Doing that again and hitting the second stage took me to 105 MPH almost immediately.
I can't launch with the TC engaged, but if I cut spray for a fraction of a second, I can engage the clutch or shift a gear very quickly. That is what I'm building now - plus a 4-button shifter for dyno tests. I'm still chewing on details, but it's starting to make sense.
03-13-2007, 07:38 PM
#378
Originally Posted by grey99max
Well - I see you're interested... I found the engine dropped RPMs with the TC locked because the loss in the torque converter was eliminated. It felt like shifting into a manual transmission, so the RPMs dropped - a bunch, in my case, because of the 2800 stall speed.
I mentioned this before, but spraying with the TC clutch locked and rolling in first gear was scary - the 10-inch DRs broke loose immediately and bounced off the limiter several times. This was lots different than the usual launch results - I tried them both. Locking the TC while in 2nd gear about 4000RPMs and spraying the first stage around 60 MPH spun both DRs and drifted me across the highway. Doing that again and hitting the second stage took me to 105 MPH almost immediately.
I can't launch with the TC engaged, but if I cut spray for a fraction of a second, I can engage the clutch or shift a gear very quickly. That is what I'm building now - plus a 4-button shifter for dyno tests. I'm still chewing on details, but it's starting to make sense.
I mentioned this before, but spraying with the TC clutch locked and rolling in first gear was scary - the 10-inch DRs broke loose immediately and bounced off the limiter several times. This was lots different than the usual launch results - I tried them both. Locking the TC while in 2nd gear about 4000RPMs and spraying the first stage around 60 MPH spun both DRs and drifted me across the highway. Doing that again and hitting the second stage took me to 105 MPH almost immediately.
I can't launch with the TC engaged, but if I cut spray for a fraction of a second, I can engage the clutch or shift a gear very quickly. That is what I'm building now - plus a 4-button shifter for dyno tests. I'm still chewing on details, but it's starting to make sense.
03-13-2007, 07:50 PM
#379
I'm going to the track on the 25th of this month and will at the very least be using my current ghetto configuration of the push-button shift_fast. I won't have time to wire up the TC lockup or experiment with 4th gear engagement before then (not like I need 4th gear), but I'll at least get some NA shift_fast testing done. We'll see if maybe that + the DR will shave a tenth 
03-13-2007, 07:53 PM
#380
Originally Posted by streetzlegend
Would you agree that it is unsafe to engage the clutch in 1st gear low rpms? Iv been told by a couple of poeple including an old orger that owns a GN, he told me he locks his tc after the 1-2 shift, because in 1st gear it would be to harsh on the tranny.
Imagine a 1/2 second cut in ignition while shifting a gear, or engaging the TC clutch. The load is off the tranny, and it shifts FAST with the shift_fast mods.
I've done this last year, cutting nitrous while shifting with the Shift_Fast_2, and I was impressed.
There is one wire for all coil power, one wire for injector power, and you can open the ground to a nitrous relay. Cut any of these and power drops for an instant, and shifting is quick and easy on parts.
Even with headers....
03-13-2007, 07:58 PM
#381
Originally Posted by Tatanko
I'm going to the track on the 25th of this month and will at the very least be using my current ghetto configuration of the push-button shift_fast. I won't have time to wire up the TC lockup or experiment with 4th gear engagement before then (not like I need 4th gear), but I'll at least get some NA shift_fast testing done. We'll see if maybe that + the DR will shave a tenth
03-13-2007, 08:03 PM
#382
Originally Posted by grey99max
Well - this should be interesting. Push them buttons hard, and watch the tach.
03-13-2007, 08:08 PM
#383
Originally Posted by Tatanko
I think you've already heard about my previous street testing. It actually shifts hard enough and fast enough that even the 2 to 3 shift was darn near jerking the wheel out of my hand.
Yup, you need two traction bars...... I used to have that problem, but no more!
03-13-2007, 08:31 PM
#385
Originally Posted by Tatanko
Aren't they out of production, though?
Here's the driver's side. Note the attachment point on the LCA.
03-13-2007, 08:58 PM
#386
Originally Posted by Tatanko
Between grey, streetz, aaron, and myself, we should see lots of testing and effort in NA, FI, and nitrous.
Just kidding.I really want to hit the track and do 13.5s all motor. But I am running out of time! The weather is warming up and I still have more work to do on my car. I've just been so insanely busy with making phenolic intake spacers that I haven't had time to work on my car for myself!
If I don't have my car ready by the end of March, then I don't know if 13.5s will be possible. The weather is warming up WAY too fast this year! It will be 85 degrees tomorrow in NC!!! That's crazy!
I will need 50-55 degree temps in order to beat my record. It's possible since my local track should start running on nights for TnT soon.
03-14-2007, 06:24 AM
#387
I think I am going to get a pushdown switch for the TC. That way I can let go when I shift faster.
I am going to have to expierment with this because I do not want to do it at 5000rpm and have the rpms drop. If that happens then the vi is cut off again and I am sure that will slow me down so I am gonna have to do it before 4900 or a lil after so I don't turn off and on the VI.
I am going to have to expierment with this because I do not want to do it at 5000rpm and have the rpms drop. If that happens then the vi is cut off again and I am sure that will slow me down so I am gonna have to do it before 4900 or a lil after so I don't turn off and on the VI.
03-14-2007, 08:29 AM
#388
Originally Posted by Kevlo911
I think I am going to get a pushdown switch for the TC. That way I can let go when I shift faster.
I am going to have to expierment with this because I do not want to do it at 5000rpm and have the rpms drop. If that happens then the vi is cut off again and I am sure that will slow me down so I am gonna have to do it before 4900 or a lil after so I don't turn off and on the VI.
I am going to have to expierment with this because I do not want to do it at 5000rpm and have the rpms drop. If that happens then the vi is cut off again and I am sure that will slow me down so I am gonna have to do it before 4900 or a lil after so I don't turn off and on the VI.
What will it hurt if the VI switches back and forth, if the engine RPM changes at the same time? Wouldn't that help keep the engine up power for the actual RPM ??
And that's just a question - I'm not sure of the dynamics of the TC clutch thing yet.
03-14-2007, 08:33 AM
#390
Originally Posted by grey99max
Well, you're an adopted 4th Gen now...... 
Yeah, the 4th genners are the only guys I can relate to in the 1/4 mile. It's nice to have a family.BTW, I still have testing to do with the TC lockup. With my Home Dyno software, I am able to measure exact time between speeds. So I will be able to easily measure my 35-80mph time (which is my entire 2nd gear). I want to play around with the switch and see which yields the best times before I hit the track.
03-14-2007, 08:42 AM
#391
Originally Posted by grey99max
That's part of the fun - my MEVI is switching at 4800 right now, and when I engaged the TC clutch, it dropped below that number. Back and forth - my MEVI is electric, so it's fast.
What will it hurt if the VI switches back and forth, if the engine RPM changes at the same time? Wouldn't that help keep the engine up power for the actual RPM ??
And that's just a question - I'm not sure of the dynamics of the TC clutch thing yet.
What will it hurt if the VI switches back and forth, if the engine RPM changes at the same time? Wouldn't that help keep the engine up power for the actual RPM ??
And that's just a question - I'm not sure of the dynamics of the TC clutch thing yet.
I figure if it stays on the "shorter runner" side the entire time it will be better. No need to wear out the plastic peices
03-14-2007, 09:12 AM
#392
Originally Posted by Kevlo911
I figure if it stays on the "shorter runner" side the entire time it will be better. No need to wear out the plastic peices
Or at least so the RPMs don't drop below the point where the MEVI / VI switches, right? Once the clutch is locked, then it should stay locked, I think.
Our weather just got better, so when the sand gets washed off the highways, I can go out and experiment again !
03-09-2010, 11:58 AM
#393
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You could pretty easily set up a microcontroller to simulate those outputs on up/down shifts from buttons on the steering wheel. It would take some time and know-how but certainly doable for pretty cheap.
03-09-2010, 12:22 PM
#394
I seriously contemplating doing exactly that before I decided to do a five speed swap. It would be a great beginner's project for micro controllers. It would also compliment valve body modifications very well. You could get fancy and put a little seven segment display in the cluster to show you what gear you were in.
03-09-2010, 01:07 PM
#395
That sounds pretty interesting, sadly I doubt anyone would try doing that, I personally think there is a bit of lack of auto support here and only a few of us are willing to get our hands dirty to keep trying stuff with our autos, also once we found out about the Suprastick we basically stopped messing around with these shifting ideas, Jime, Aaron, myself all have the suprastick and I dont remember if grey99 got one as well, he might still have his rig working.
It would be cool if someone tried it, a cheap alternative to the suprastick (~$300)
It would be cool if someone tried it, a cheap alternative to the suprastick (~$300)
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