Shift earlier for TQ.. thoughts this experiment ?

[8nutz8]

The best advice i can give is to work on your launches. Find the highest rpm you can launch at without breaking the traction limit or triggering any traction or torque control from the ECU. First time i had this car at the track i didn't know how to launch it correctly. I've since cut 3-4/10ths from my 0-60 time strictly form practicing a good brake boost launch. For reference my 0-60 time for my 91oct tune is around 4.7-4.8 and my best from my E20 tune is 4.35.
I'm also @ 5500ft elevation and have to launch at 2300rpm to build any boost though so not exactly apples to apples.

it's more by feel and watching how much boost you're building before you launch. i aim for about 3psi before i let the brake go(which is 2350rpm for me).  if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.
it's all about finding that limit where you launch and get a chirp out of the tires but don't break em loose. . . at least it was for me.


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[dubcitySHO]

it's more by feel and watching how much boost you're building before you launch. i aim for about 3psi before i let the brake go(which is 2350rpm for me).  if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.
it's all about finding that limit where you launch and get a chirp out of the tires but don't break em loose. . . at least it was for me.


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This has been the plague of getting my SHO off the line.  Mine started showing torque source 15 last November and I have been seeing much more knock sensor activity than while Brad was building my tune. 

 

[StealBlueSHO]

it's more by feel and watching how much boost you're building before you launch. i aim for about 3psi before i let the brake go(which is 2350rpm for me).  if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.
it's all about finding that limit where you launch and get a chirp out of the tires but don't break em loose. . . at least it was for me.


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This has been the plague of getting my SHO off the line.  Mine started showing torque source 15 last November and I have been seeing much more knock sensor activity than while Brad was building my tune.

Cold temps cause all kinds of havoc getting off the line... cold street, cold tires, etc... also, depending on where you live, winter blend gas can cause knock issues if you are tuned.. I know 93 is 93 but still...or it could be the more aggressive timing due to cold weather...

 

[lamrith]

The best advice i can give is to work on your launches. Find the highest rpm you can launch at without breaking the traction limit or triggering any traction or torque control from the ECU. First time i had this car at the track i didn't know how to launch it correctly. I've since cut 3-4/10ths from my 0-60 time strictly form practicing a good brake boost launch. For reference my 0-60 time for my 91oct tune is around 4.7-4.8 and my best from my E20 tune is 4.35.
I'm also @ 5500ft elevation and have to launch at 2300rpm to build any boost though so not exactly apples to apples.

it's more by feel and watching how much boost you're building before you launch. i aim for about 3psi before i let the brake go(which is 2350rpm for me).  if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.
it's all about finding that limit where you launch and get a chirp out of the tires but don't break em loose. . . at least it was for me.


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My car is PP and I plan to run with Advancetrac off, so there should not be an issue with TC kicking in?

 

[dubcitySHO]

Yeah we are waiting on summer blend to be brought back out and see if that will get us back to where we left off. 

I'm debating contacting Jason over at pimods and see if he can utilize IDS to completely remove the logic of closing the throttle blade once to much wheel spin is sensed and just let her eat, a la PP equipped full advance track shutdown.

 

[StealBlueSHO]

Yeah we are waiting on summer blend to be brought back out and see if that will get us back to where we left off. 

I'm debating contacting Jason over at pimods and see if he can utilize IDS to completely remove the logic of closing the throttle blade once to much wheel spin is sensed and just let her eat, a la PP equipped full advance track shutdown.

Let me know if you do, I was considering this, but thought he was only able to accomplish it with the 2013+ cars... see if he will do it cheaper if he has more people willing to do it.

 

[TopherSho]

You aren't high elevation right? I cant remember.

I fully expect for you to be 12's maybe even mid 12's ...your spark is on the high end for pump gas compared to some ive seen

Id launch around 2k and let it eat...it may spin and squeal but ymwith awd you should maintain good forward momentum

With sub 2.0 60' and a 110 trap you should be deep into 12's

Hopefully you have a day or night where ambiant temps are less than 70 and iat's are too bad

If your dynojet corrected numbers are high 300's and tq is mid to high 400's id say you have to run 12's

Glock coma here on the forum ran high 12's with a 2 bar tune if mine

Eugene Oregon is 430-elevation
Portland is Frikken almost seal level at 30   that will help a smidge.

I may end up finding another dyno :\  Only getting 298hp out of 383ftlbs just seems weird to me...  that just doesn't math right.

What year is your SHO?

If you have DMR functionality the car will tell you how much torque its making.

2010 ..

 

[TopherSho]

if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.

Ahhh i think i got it.. the TQ source will show a spike and a value of 15 ?

 

[ajpturbo]

if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.

Ahhh i think i got it.. the TQ source will show a spike and a value of 15 ?

Topher your car does not have this problem

 

[TopherSho]

if you launch too hard you'll get too much wheel spin and the ecu will close your throttle and limit boost. it will show up as torque source 15 in the logs when that happens but you'll feel it either way.

Ahhh i think i got it.. the TQ source will show a spike and a value of 15 ?

Topher your car does not have this problem

I did not think so since I have never seen the TQ source move   .. but a good bit to know for launching harder.

 

[TopherSho]

closing the loop.

returned to AJP's rev-11 without rpm edits and times improved slightly over shifting 500 rpm early.  It baffles me but it must be a boost thing which I am VERY new too.

that begs the question of delaying the shift.  I think I will try it with manual shifting and shoot for 6300-6400 rpm as a test.

 

[StealBlueSHO]

LMS tunes shift pretty up there around 6400 or 6500 RPMs. But there is a major drop off in boost that high in the RPM range. LMS and other people swear by it...

 

[TopherSho]

FOR SCIENCE!

 

[16MagSport]

I asked AJP to have my tune pull in the shift to 4th a little sooner.  I have not had a chance to run that tune yet.  I am afraid to log on the street after a $450 ticket last time, so I am waiting for the track.  I was shifting to 4th too close to the finish line.  It needs to get into 4th sooner so it can take advantage of the pull I feel after the shift.  It just felt like it tapered off too much in 3rd and then pulled harder after the shift.  I sure hope to get a log at the track in the next few weeks and see how Brad's big changes he made for me worked.  I asked him to try and get the boost to ramp a little with rpm so the top of 3rd would feel better.  After I log at the track and if things look good, I want a little more aggressive tune for 96 octane which I can get at the track.  I definitely want 13.5 @ 100mph, but I was hoping the street tune would do that and the race tune would do even better.  This new tune may do it on a cold night if his changes worked as expected and a slightly earlier shift point helps.  I think I just asked to shift 100rpm sooner.


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[TopherSho]

I asked AJP to have my tune pull in the shift to 4th a little sooner.  I have not had a chance to run that tune yet.  I am afraid to log on the street after a $450 ticket last time, so I am waiting for the track.  I was shifting to 4th too close to the finish line.  It needs to get into 4th sooner so it can take advantage of the pull I feel after the shift.  It just felt like it tapered off too much in 3rd and then pulled harder after the shift.  I sure hope to get a log at the track in the next few weeks and see how Brad's big changes he made for me worked.  I asked him to try and get the boost to ramp a little with rpm so the top of 3rd would feel better.  After I log at the track and if things look good, I want a little more aggressive tune for 96 octane which I can get at the track.  I definitely want 13.5 @ 100mph, but I was hoping the street tune would do that and the race tune would do even better.  This new tune may do it on a cold night if his changes worked as expected and a slightly earlier shift point helps.  I think I just asked to shift 100rpm sooner.


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Interesting,  so you were pushing for more boost in the higher rev range of third?  was it dropping off?  i have not really seen the boost drop in mine but it is a different setup.

my next experiment is to shift at 6300 in all gears.. about 150-300 rpm later than normal as a test.  i don't think it will make a difference as i still shift into 4th before the finish line regardless.

 

[Vortech347]

This thread is a good read.  I've often wondered about an earlier shift point as these engines aren't really like typical SHO and DOHC cars that love to sing after 4k.  Mine always feels like it's running out of pull after 5700ish.  Most turbo car's I've worked on or ridden in pull like an SOB until you shift.  (mostly single turbo mustangs)

But it's hard to have your cake and eat it too with the availability of so much low end torque.  Driving the SHO around it feels like my terminator.

 

[TopherSho]

This thread is a good read.  I've often wondered about an earlier shift point as these engines aren't really like typical SHO and DOHC cars that love to sing after 4k.  Mine always feels like it's running out of pull after 5700ish.  Most turbo car's I've worked on or ridden in pull like an SOB until you shift.  (mostly single turbo mustangs)

But it's hard to have your cake and eat it too with the availability of so much low end torque.  Driving the SHO around it feels like my terminator.

  /arnold/ Get in the SHO!  /arnold off/

But in all seriousness in the OEM pipes you ARE running out of steam FAST at the end of the RPM band, mine drops off by a estimated 160ish-WTQ on a mustang dyno, or a loss of 220ftlbs of WTQ estimated by DYNOJET.  That's a serious loss of TQ. 

So I experimented with the help of AJP, and we dialed in WoT to shift perfectly and drop me down to 3900-rpm for 1-2 and 2-3.  Sadly as he wisely predicted we did not gain anything.  Actually I lost about 50ms on the deal.

As it turns out, despite rpm dilation, boost loss due to oem intake and oem exhaust the gain of rational force via RPM and mass offset the gain of 30ftlbs of Average wheel torque. 

So now looking in the Livernois forums they swear by shifting much higher for drag racing at least so that will be my next experiment.  I think I will aim for 6300rpm as after 6400 my specific car farts (braps and pops out the exhaust) and fuel cuts.

I do not expect much though..  I think oem shift points with the oem exhaust is pretty dead on.

But .. FOR SCIENCE!  I will update the thread.  First i must go into the shop today to get my free fule pump or wire harness for my p0627 code.

 

[16MagSport]

The boost wasn't really dropping off, but it did slope downward.  On the 2-3 shift the boost would spike and it would take a while to get all the way down to the desired boost.  I wanted it to have as much boost at the top of 3rd as it does a few hundred rpm after the shift.  If we just turned it up, it might have too much as it spikes on the shift and enters the next gear and still feel like it is falling off.  Fyi, this is my wife's daily so not going crazy with it.  Just having fun while the Stang is laid up.  I do miss the steadily increasing pull until you shift with the centrifugal supercharger but I love how much low end torque the turbos give this little 6 cylinder in a 5000lb SUV.  It would smoke my Mustang when stock.  Hell, it would even outhandle the Mustang on the stock suspension.  Lol


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[Vortech347]

The boost wasn't really dropping off, but it did slope downward.  On the 2-3 shift the boost would spike and it would take a while to get all the way down to the desired boost.  I wanted it to have as much boost at the top of 3rd as it does a few hundred rpm after the shift.  If we just turned it up, it might have too much as it spikes on the shift and enters the next gear and still feel like it is falling off.  Fyi, this is my wife's daily so not going crazy with it.  Just having fun while the Stang is laid up.  I do miss the steadily increasing pull until you shift with the centrifugal supercharger but I love how much low end torque the turbos give this little 6 cylinder in a 5000lb SUV.  It would smoke my Mustang when stock.  Hell, it would even outhandle the Mustang on the stock suspension.  Lol


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As a fellow centri owner I totally agree.  Nothing like having your ass pressed between the seat and seat base at 6000rpm.

 

[16MagSport]

I really need to fix my Stang.  Damper broke and wallowed the keyway on the crank.  Need a new crank so I might do the entire rotating assembly and step it up to 363 cubes with more compression and run NA to last longer and not generate so much heat on the road course.  I don't want to go too high though so the s-trim can go back on for the strip occasionally.  I can add the Snow boost cooler I never installed.  I also have AFR 195's and a Systemax intake to go on when I put it back together.  I think those heads with the big bore will run really well NA.  My Eddy's are too small to take advantage of the 4.125" bore.


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