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Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 6:43 am
by Rickuk1
- IMG_4304.jpeg (347.33 KiB) Viewed 3715 times
This is the dyno graph
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 7:45 am
by Thom
The shapes of the curves aren't shocking to me, with a nice top end suggesting you use the largest A/R turbine housing for that turbo? Do you have a boost plot?
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 9:10 am
by Rickuk1
I will speak with my Mechanic and see if I can get it. The housing is 1.05 AR. This is engine power though not wheel power just for reference
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 9:12 am
by Rickuk1
Can anyone help me with posting video. It downloads and then status is denied
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 10:14 am
by Thom
I'm pretty sure you're hitting 1.0 bar no sooner than somewhere in between 3500 and 4000 rpm. We run similar turbos, though mine is single scroll. Theoretically your twin scroll should spool better, but this also depends on your ignition profile and, of course, boost settings.
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 11:11 am
by Rickuk1
When does your reach 1 bar. Do you have a dyno chart. Would you expect my turbo to perform better. I think it’s not making enough lower end of the curve is this realistic
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 12:13 pm
by blueline
Rickuk1 wrote: Thu Mar 20, 2025 9:12 am
Can anyone help me with posting video. It downloads and then status is denied
Videos need to link to a 3rd party video app such as YouTube (straightforward if you have a YouTube acct) and others such as Vimeo, Google Drive, etc.
https://www.carpokes.com/viewtopic.php?p=41609#p41609
https://www.carpokes.com/viewtopic.php? ... 910#p37696
Tom's post also shows a couple of alternatives if needed:
https://www.carpokes.com/viewtopic.php? ... 910#p37698
Re: 968 Turbo boost problems whilst mapping
Posted: Thu Mar 20, 2025 12:55 pm
by SirLapsalot
Re-boost timing on dyno…keep in mind the dyno ramp rate will effect that. So if you’re using something much faster than the car actually sees on the road then the spool behavior will look different.
Re: 968 Turbo boost problems whilst mapping
Posted: Fri Mar 21, 2025 6:07 am
by Thom
Rickuk1 wrote: Thu Mar 20, 2025 11:11 am
When does your reach 1 bar. Do you have a dyno chart. Would you expect my turbo to perform better. I think it’s not making enough lower end of the curve is this realistic
On the dyno it consistently hit 1.0 bar at ~3250 rpm, in 4th gear, but with a 0.82 A/R housing.
On the road, now with a 1.03 A/R housing and in 3rd gear it won't reach 1.0 bar before ~4200 rpm. I can't find logs starting in 4th gear. GTX3576R Gen 1, similar to your EFR7670.
Re: 968 Turbo boost problems whilst mapping
Posted: Fri Mar 21, 2025 10:21 am
by Rickuk1
Thom wrote: Fri Mar 21, 2025 6:07 am
Rickuk1 wrote: Thu Mar 20, 2025 11:11 am
When does your reach 1 bar. Do you have a dyno chart. Would you expect my turbo to perform better. I think it’s not making enough lower end of the curve is this realistic
On the dyno it consistently hit 1.0 bar at ~3250 rpm, in 4th gear, but with a 0.82 A/R housing.
On the road, now with a 1.03 A/R housing and in 3rd gear it won't reach 1.0 bar before ~4200 rpm. I can't find logs starting in 4th gear. GTX3576R Gen 1, similar to your EFR7670.
That power and torque are you making on dyno at 4000 rpm