Drag/Acceleration Mods to improve ¼ mile times and unofficial track thread

Flash tuners typically enrich the low end AFR target and disable lean spool mode, providing a fixed AFR target across the power band. I've always been convinced they do it to make their logs prettier and not for any tuning reasons, as both provide drawbacks (more fuel demand causing fuel pressure crashes, potentially slower spool up, etc), but as many know trying to reason with some of these flash tuners is like pissing in the wind.

With a JB4 flash fuel wires are only needed if you want to change the air/fuel ratios set in the flash. On other applications where this is more popular people tend to lean out the flash air/fuel ratio in the midrange to allow more boost without crashing fuel pressure.
 
He doesn't have any 1/4 mile times yet. Lives in a big city and not close to any tracks. 117 on 91 ain't bad.

1/4 mile trap is really the only relevant measure of performance IMHO, short of 60-130 times, which is the gold standard these days.
 
Will Hatzer does a mild 14 PSI (JB4) / 16 PSI Tork tune for 91 octane and uses the Jb4 to up the boost when he runs better fuel. He ran a 3.99 0-60 no brake snip on just the tork tune. This seem like the best solution for 91 octane if you don't want to do WMI. His base Tork tune is as fast as most E30 and WMI guys.
I personally like my setup, I run some boostane and map6 from time to time when i wanna go faster :), Sadly near my house the DA is Shit and I can't find a nice long flat area to do 1/4 mile and I'm not near a strip. That being said since im keeping my stinger I'm gonna add meth and possibly a diffrent catback around the first of the year and goto the track.. Right now launching my car is super pickey..... If I use LC as intended I hit the Tq limiters @ 1000nm :( but if I catch it just right I skirt under neeth them and the car goes like a rocket.... This has been fixed in Tims tune, Sadly I've been hella busy with work and not had time to get my ecu updated to the fixed version.
 
______________________________
Flash tuners typically enrich the low end AFR target and disable lean spool mode, providing a fixed AFR target across the power band. I've always been convinced they do it to make their logs prettier and not for any tuning reasons, as both provide drawbacks (more fuel demand causing fuel pressure crashes, potentially slower spool up, etc), but as many know trying to reason with some of these flash tuners is like pissing in the wind.

With a JB4 flash fuel wires are only needed if you want to change the air/fuel ratios set in the flash. On other applications where this is more popular people tend to lean out the flash air/fuel ratio in the midrange to allow more boost without crashing fuel pressure.


This is something I may need to explore once I find a AWD dyno and get some METH.
 
trap speed is typically a indcator of HP where ET = ability to launch + hp. So if a car trapped lets say 13.5@120 they were slow as hell then bigended the track......
 
From interior to exterior to high performance - everything you need for your Stinger awaits you...
1/4 mile trap is really the only relevant measure of performance IMHO, short of 60-130 times, which is the gold standard these days.
Those are good for comparing RWDs which have traction issues, are lighter and have less power train loss. But also ignores launch tuning and shift times which are critical for 1/4 mile ETs where most people still race.
I was impressed my fat old girl gt2 awd hit 9s 60-130 as that race is a huge disadvantage for us big boned gt2s.
 
Those are good for comparing RWDs which have traction issues, are lighter and have less power train loss. But also ignores launch tuning and shift times which are critical for 1/4 mile ETs where most people still race.
I was impressed my fat old girl gt2 awd hit 9s 60-130 as that race is a huge disadvantage for us big boned gt2s.
I need to get test a 60-130 pull I'll see If i can this weekend. I'll be doing it non stacked as I've been to lazy to toss the jb4 back in
 
Speed limiter?

On the boost decay at the shift it's factory logic to keep turbine speed down. When they flash map they can remove/alter that logic.

No, I have the speed limit and torque limit removed by ECU mapping (didn't touch anything else). Since RPM do not increase and stay at a low number the car keep using super high boost during that gear. I really don't understand this and I am not the only one, a friend of mine with a G70 and JB4 has exactly the same thing (not saying that its piggyback related, we just compare logs often).

Your boost holds nicely into the high RPMs (custom map?) but do lose lots of boost on the shift when the throttle closes.
I don't go that fast to test acceleration in 7th gear. I think 5th is all I ever get into. :)
No, I use JB4 map 8. :)
I do 40~170mph pulls quite often.
7th gear is so slow I try to stay in 6th as long as possible.. :(
 
Last edited:
What speed is it at there? Other than a factory speed limiter don't see what the issue could be. Unless it's not making enough power to further accelerate. Maybe you removed the ECU limiter but there is a TCU limiter in effect.
 
What speed is it at there? Other than a factory speed limiter don't see what the issue could be. Unless it's not making enough power to further accelerate. Maybe you removed the ECU limiter but there is a TCU limiter in effect.
Around 167 mph. Doesn't the TCU only limit the high RPM range?
 
______________________________
From interior to exterior to high performance - everything you need for your Stinger awaits you...
Around 167 mph. Doesn't the TCU only limit the high RPM range?

It also reads road speed, could be limiting based on driveshaft speed too.
 
How are you complete disabling tq limiters ? Can I mail you my ECU file and you do it ?
 
167 is stock limiter do you have a flash or a cut wire to exesd that?
 
167 is stock limiter do you have a flash or a cut wire to exeed that?
Stock limiter is 169 and I have got the speed limit removed (increased to 210+) by ECU flash.
 
By the time you shift into 7th your now into your second over drive gear, is it possible the car just doesn't have enough power to keep pulling? What do the XT26 cars logs look like? I'm very interested in your flash, What shop did it? I'd like to have my tq limiters removed so I can stop banging into it.....

7th gear 0.565:1
 
From interior to exterior to high performance - everything you need for your Stinger awaits you...
Stock limiter is 169 and I have got the speed limit removed (increased to 210+) by ECU flash.
What tune are you running?
 
______________________________
No, I have the speed limit and torque limit removed by ECU mapping (didn't touch anything else). Since RPM do not increase and stay at a low number the car keep using super high boost during that gear. I really don't understand this and I am not the only one, a friend of mine with a G70 and JB4 has exactly the same thing (not saying that its piggyback related, we just compare logs often).


No, I use JB4 map 8. :)
I do 40~170mph pulls quite often.
7th gear is so slow I try to stay in 6th as long as possible.. :(
If you have tq limit raised why the big throttle close on shifts?
 
Thats my question as well, Super weird or maybe its a side affect of the car freaking out ? my logs don't look like that
 
By the time you shift into 7th your now into your second over drive gear, is it possible the car just doesn't have enough power to keep pulling? What do the XT26 cars logs look like? I'm very interested in your flash, What shop did it? I'd like to have my tq limiters removed so I can stop banging into it.....

7th gear 0.565:1
The XT26 don't use JB4 (custom tune) so no log to look at. I should not be lacking power. A friend of mine with less horsepower pushed it to 185mph a few times.

What tune are you running?
Custom

If you have tq limit raised why the big throttle close on shifts?
Will ask. There must be another reason.
I know that the limit is only removed under certain circumstances including oil temperature. I have seen the throttle close between shifts only since lately when the weather got colder. May be related, may be not. I will update you guys when I get more info.

Thats my question as well, Super weird or maybe its a side affect of the car freaking out ? my logs don't look like that
Not sure. It doesn't occur if I shift earlier, but if I shift earlier I sometimes get thrown back into the previous gear so its a tricky timing to find.
 
Do they have a tcu tune ? I know a few of the videos should higher shifting. How much boost are you running in your base tune and do you have xt26?
 
From interior to exterior to high performance - everything you need for your Stinger awaits you...
Back
Top