GTX3076R vs GTX3582R for single turbo n54

[boost135]

hi

I'm currently single turbo on a 135i n54 6AT with a gt3582 journal bearing AR 82.
full boost is around 4400 rpm @ 24psi. on pump gas with meth.
Can anyone share logs and insights of running a GTX3076R with a 1.01 AR or smaller, to reduce lag slightly as I use the car for dig racing and spirited street driving because its an Auto it becomes very hard to launch the car as the lag is terrible, 1st gear is a waste of time only starts boosting properly in 2nd gear onwards. 60 ft is around 2.3 on street tyres 0 to 60mph is around 5.3 with MHD antilag.
would it make a difference to swap out the CHRA for a gtx3582R in terms of spool or go with a smaller frame turbo, i would like boost to come in around 3800 or below if possible

 

[Twisted Tuning]

what exactly are you using for boost control, just curious as that may be the issue. what rpm do you start the pull for boost to take until 4400rpm to make only 24psi? because my turbo is double that size and i make 52psi by 4500rpm.

is this a stock internal N54? stock compression? you have a log?

 

[jzx_andy]

There's some decent info/logs in here for comparison: https://www.spoolstreet.com/threads/q-bottom-mount-single-turbo-responsive-setup.7370/

gen2 3071r with an unknown rear housing made 19psi at 3100
gen2 3576r 0.83 made 19psi at 3700

Both manual cars in 3rd gear.

Id say the 2 above setups seem pretty healthy and optimised given the choice of turbo. 3576r with a .83 should go hard and feel responsive enough for most people in a twin scroll configuration. 3076r shouldn't be too far off the 3071r in terms of boost threshold, but if you're limited to single scroll I'd suggest a g30-770 0.83, as it's basically a 3071r sized turbo that can flow more than a 3076r.

 

[boost135]

@Twisted Tuning
im using a GFB boost controller with custom tune, yes stock internal n54 with 7.5 inch cooler and meth.
the 2nd log on 14 feb was done on wastegate pressure from 1st gear, you will see how long it takes to spool in first.
thanks for the insight @jzx_andy not sure whats causing my issue, adjusted the GFB gain settings as well to try improve spool, checked for boost leaks car feels laggy especially 1st gear

 

[Twisted Tuning]

the gain on the GFB was never really good to me. you have to crank it up really hiigh for an effect.

 

[r0nd3L]

There's some decent info/logs in here for comparison: https://www.spoolstreet.com/threads/q-bottom-mount-single-turbo-responsive-setup.7370/

gen2 3071r with an unknown rear housing made 19psi at 3100
gen2 3576r 0.83 made 19psi at 3700

Both manual cars in 3rd gear.

Id say the 2 above setups seem pretty healthy and optimised given the choice of turbo. 3576r with a .83 should go hard and feel responsive enough for most people in a twin scroll configuration. 3076r shouldn't be too far off the 3071r in terms of boost threshold, but if you're limited to single scroll I'd suggest a g30-770 0.83, as it's basically a 3071r sized turbo that can flow more than a 3076r.

GTX3071R Gen 2 is my log, it is .83 T3 Divided housing on Speedtech manifold. Car is extremely fun and responsive, but I think the turbo is a tad too small. It's probably making a bit over 500WHP on E85. I think something like G30-770 or G30/35-900 would be a better choice and still spool well