Isayimandrew's Twin Turbo Build

redondoaveb · 04-20-2022, 08:56 PM

Quote:

Originally Posted by Elmo370z

Be interesting to see your journey, as this method has everything negative going against you. Good luck, I hope this hold up.

What psi does the stock block start lifting heads?

Hotrodz · 04-20-2022, 10:46 PM

Quote:

Originally Posted by redondoaveb

What psi does the stock block start lifting heads?

Stock block 750 plus and built motor 800 plus. There is a reason Seb only tunes to 700whp regardless of stock or built. The key is torque. Now you can dial the tq down to around around 500 tq at 700whp. When I was on a stock block w/stage 1 turbos I was at 600whp and 559tq. That said the smaller turbos spool much faster and the tq comes on fast.

Sent from my SM-G965U using Tapatalk

redondoaveb · 04-21-2022, 12:04 AM

Quote:

Originally Posted by Hotrodz

Stock block 750 plus and built motor 800 plus. There is a reason Seb only tunes to 700whp regardless of stock or built. The key is torque. Now you can dial the tq down to around around 500 tq at 700whp. When I was on a stock block w/stage 1 turbos I was at 600whp and 559tq. That said the smaller turbos spool much faster and the tq comes on fast.

Sent from my SM-G965U using Tapatalk

Hey Bob, I was talking about boost and head lift. Mine's making over 700 and probably around 530ft.lbs. but as you know, we went with the larger turbos so they spool slower and the torque doesn't hit so hard. That's at 15psi. 15 psi shouldn't have headlift issues and the OP wants to stay in the 600-650 range.

My point being. My car made 745 at a little less than 16 psi before we backed it off because stock block. The OP is using the Stage 1 turbos and won't be seeing 16 psi so I don't see him having any concern with headlift as Elmo was pointing out. He needs a stronger bottom end with those smaller turbos which he has.

My car could easily hit 800whp at less than 17 psi. If 17 psi isn't in headlift territory then I'd just build the bottom end too.

That's the reason I was asking what the threshold psi number is for headlift on the stock top end

Hotrodz · 04-21-2022, 09:37 AM

Quote:

Originally Posted by redondoaveb

Hey Bob, I was talking about boost and head lift. Mine's making over 700 and probably around 530ft.lbs. but as you know, we went with the larger turbos so they spool slower and the torque doesn't hit so hard. That's at 15psi. 15 psi shouldn't have headlift issues and the OP wants to stay in the 600-650 range.

My point being. My car made 745 at a little less than 16 psi before we backed it off because stock block. The OP is using the Stage 1 turbos and won't be seeing 16 psi so I don't see him having any concern with headlift as Elmo was pointing out. He needs a stronger bottom end with those smaller turbos which he has.

My car could easily hit 800whp at less than 17 psi. If 17 psi isn't in headlift territory then I'd just build the bottom end too.

That's the reason I was asking what the threshold psi number is for headlift on the stock top end

Copy that! PSI and compression ratio work together. If you are running stock block 11:1 you well need to achieve the same results as lower ratios such as 9:1. I am at 11:1 and 20.5 psi for 700whp and 607tq. Many start see head lift at 23psi and above. For a stock block with stage 1 turbos 14psi will get you just over 600whp and 500tq. Things will start to fail at 700whp on stage 1 turbos. It may not be head lift but the rods may decide to put windows in the motor.

Sent from my SM-G965U using Tapatalk

Elmo370z · 04-21-2022, 08:02 AM

Quote:

Originally Posted by redondoaveb

What psi does the stock block start lifting heads?

You and bob are correct. It’s about torque. Cjm car never lifted head even over 50 plus passes and the drag strip. He ran 700-800+whp.

redondoaveb · 04-21-2022, 09:30 AM

Quote:

Originally Posted by Elmo370z

You and bob are correct. It’s about torque. Cjm car never lifted head even over 50 plus passes and the drag strip. He ran 700-800+whp.

At what psi does headlift become a concern?

Hotrodz · 04-21-2022, 09:41 AM

Quote:

Originally Posted by redondoaveb

At what psi does headlift become a concern?

So about 17psi **** starts to go south on stock block with stage 1 turbos. You may not get head lift but you may!

Sent from my SM-G965U using Tapatalk

redondoaveb · 04-21-2022, 09:49 AM

Quote:

Originally Posted by Hotrodz

So about 17psi **** starts to go south on stock block with stage 1 turbos. You may not get head lift but you may!

Sent from my SM-G965U using Tapatalk

So with the power level the OP is wanting to achieve (600-650), headlift shouldn't be a concern, just the bottom end which he has built?

Building the bottom end isn't a huge expense. Doing Darton sleeves with fire rings adds a lot of cost to the build. If you're not planning on a high boost build, why incure that extra cost.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
370Z G37 RHD Diy Twin Turbo Build	rovert	Member's 370Z Gallery	8	02-08-2020 04:32 PM
New Twin Turbo build in progress: Another Gamma V3 Twin turbo install	Nyght	Forced Induction	37	08-08-2017 09:27 AM
Twin Turbo Build	LafitteZ	40th Anniversary 370Z	42	10-05-2011 09:58 AM
TITAN's Twin Turbo build Done!!!!!!	kenbains12	Forced Induction	49	06-18-2010 07:32 AM