Is there something I'm missing, can't get under 1.7 sec 60 foot

[iminhell1]

This has happened to me a few times now. It's not predictable that I've been able to nail down, but I'm not logging either.
But it seems every time I try to load the engine more on the line and really cut a light, it will but then I get stuck in 2nd and won't shift. It's always when I'm really close to that 1.6x, like 1.721, 1.733 ...
Is there maybe something relating to G force in the ABS computer that I've missed?

I know the tire will hold and I have room to load more and build more boost on the line. It's just the trans thing that always ruins the pass.

 

[Rcboosted2007]

Have you done the xhp flash?

 

[typedRew]

Shifting yourself or letting it shift in sport?

 

[MoreBoost]

Maybe there's a torque limit you are hitting with the flash you are using?

 

[iminhell1]

Shifting manually. Starting in 2nd.
XHP stage 3
I have not done the 2048 delete. Haven't seen a need to as I'm scaled and keep reported TQ under 700.

 

[typedRew]

What rpm are you commanding the shift at?

 

[Silent11]

im having similar issues with 6At and XHP3... when it hooks with MT et streets it goes into 3rd right away at 3500-4000rpm.. manual mode.. if it spins it stays in 2nd with no issues... xhp said i have too much torque... around 550wtq right now...cant get anything lower than 1.85 60 foot

 

[Coupes66]

im having similar issues with 6At and XHP3... when it hooks with MT et streets it goes into 3rd right away at 3500-4000rpm.. manual mode.. if it spins it stays in 2nd with no issues... xhp said i have too much torque... around 550wtq right now...cant get anything lower than 1.85 60 foot

I have only tried launching in 2nd gear twice but have experienced the same with the transmission automatically changing into 3rd half way through 2nd. When I launch in 1st gear, there are no issues. Is that the same with yours?

 

[Silent11]

I have only tried launching in 2nd gear twice but have experienced the same with the transmission automatically changing into 3rd half way through 2nd. When I launch in 1st gear, there are no issues. Is that the same with yours?

i havent tried to launch in first yet, kinda scared of what will the 1-2 shift do to the axles

do you lower boost in first when you launch ?? how much boost are you running ?

 

[Coupes66]

i havent tried to launch in first yet, kinda scared of what will the 1-2 shift do to the axles

do you lower boost in first when you launch ?? how much boost are you running ?

I have done about 80 runs on the standard axles without any issues. I have just recently changed to a M3 diff and axles mainly for a stronger diff. Best 0-60' time has been 1.659s but consistently in the 1.7-1.8s range. Only getting to around 5-6psi boost at launch. Need higher stall to get more boost. I run 28psi boost during the run. Run 275/40R17 MT ET Street SS radials.

 

[noorj]

I have done about 80 runs on the standard axles without any issues. I have just recently changed to a M3 diff and axles mainly for a stronger diff. Best 0-60' time has been 1.659s but consistently in the 1.7-1.8s range. Only getting to around 5-6psi boost at launch. Need higher stall to get more boost. I run 28psi boost during the run. Run 275/40R17 MT ET Street SS radials.

1.6x is a great 60' time for this platform though! What's your 1/4 time/trap? Turbo setup?

 

[Silent11]

I have done about 80 runs on the standard axles without any issues. I have just recently changed to a M3 diff and axles mainly for a stronger diff. Best 0-60' time has been 1.659s but consistently in the 1.7-1.8s range. Only getting to around 5-6psi boost at launch. Need higher stall to get more boost. I run 28psi boost during the run. Run 275/40R17 MT ET Street SS radials.

28 psi in first ?? and it hooks ?? im spinning when i launch in 2nd at 21.5psi ...same tires as yours..around 17-20psi in the tires, whats your tire psi ?

 

[Coupes66]

1.6x is a great 60' time for this platform though! What's your 1/4 time/trap? Turbo setup?

Best ET is [email protected]. Best speed is 133mph. I am running twin Super RB Evo turbos.

 

[Coupes66]

28 psi in first ?? and it hooks ?? im spinning when i launch in 2nd at 21.5psi ...same tires as yours..around 17-20psi in the tires, whats your tire psi ?

I run 16-17psi in my tyres but I am only launching at 5-6psi boost. No way could I get 21.5psi boost at launch. You must have a 4,500-5,000rpm stall converter to get that sort of boost at launch.

 

[iminhell1]

Silent11,
You just need more seat time.

I'm doing your 60's (and lower) on street tires and E-diff.


I've made 400 ish passes on stock axles and street tires. Zero problems. No diff brace, stock bushings (inserts only). I've only had a hint of wheel hop a few times, get out of it right away and alls well.



I just think it's a timer issue. Something with the brake/throttle correlation error, but it's not being thrown as a code. I don't know how to test my theory though.

 

[Silent11]

Silent11,
You just need more seat time.

I'm doing your 60's (and lower) on street tires and E-diff.


I've made 400 ish passes on stock axles and street tires. Zero problems. No diff brace, stock bushings (inserts only). I've only had a hint of wheel hop a few times, get out of it right away and alls well.



I just think it's a timer issue. Something with the brake/throttle correlation error, but it's not being thrown as a code. I don't know how to test my theory though.

ive had plenty of seat time and ive cut 1.8 on street ps4s as well but since ive put the mt et havent had very much luck with them

I wasnt thinking of building 21 psi at launch i was just wondering if your boost in 1st is lowered to 10-15 psi perhaps

 

[iminhell1]

I think I make about 4-? at launch. I honestly never look. Attention is on the tree ... majority of my fun now is grudge and cutting a good light wins.

But my 2nd is neutered at 18psi but 3rd+ is 26psi. I'm severely fuel limited. But I'm also on stock turbos.
The only traction issues I have on track are when I don't do a good burnout and still have water in the tread. ... I really need to start backing in when I can.

 

[Rob09msport]

26psi on stock turbos