968 Turbo boost problems whilst mapping

[Rickuk1]

IMG_4304.jpeg (347.33 KiB) Viewed 3714 times

This is the dyno graph

[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?

[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

[Rickuk1]

Can anyone help me with posting video. It downloads and then status is denied

[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.

[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

[blueline]

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

[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.

[Thom]

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.

[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

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