Single Turbo & 91 Octane - How much boost?

ShadyOrb

Lurker
Sep 4, 2021
22
3
0
I just finished my single turbo conversion a few weeks ago, and I want to turn up the boost.
Currently with 14psi springs I get ~11psi w/ JB4.
Map2 is 17psi and I'm not sure if that is safe as I only have 91oct available.

- What is a safe level of boost on 91 octane?
- Also, for JB4 Map6 can I just set the boost I want under User Adjustment Settings and rip it?


Here is a log from the other night
https://datazap.me/u/shadyorb/n54-6266bb-2nd-gear-map-1?log=0&data=1-4
 
  • Like
Reactions: Siimaa

Kaane

Private
Jan 7, 2019
31
15
0
Ride
2008 535i
You could run 20 psi or 10 psi, it all depends. How much timing, how efficient the turbo is, how good the intercooler setup, what is the DA, ambient temperature. Way too many variables.

Work with a good tuner and they will extract safe power.
 
  • Agree
  • Like
Reactions: ShadyOrb and wheela

DaddyBoost

Specialist
Jul 8, 2017
55
-5
0
Ride
135
17 psi no more than 7* of timing.
20psi, no more than 5-5.5* of timing
22 psi no more than 4* of timing.

All in all, do not exceed 11.6 afr as you would rather cool the block and run a bit richer
 
  • Informative
Reactions: ShadyOrb

Torgus

Colonel
Nov 6, 2016
2,415
1,929
0
Boston
Ride
ACF 6466 E92 + METH
please see this page


and see the reply,

also ,this means good condition and setup

1st: there is no log

2nd: you are quoting Shiv who is known to lie to sell his products. Shiv got ran out of this community before he started fleecing other car communities with his open flash product.

3rd: I have never seen it repeated

4th: The claim is they only used an inline walbro and the stock fuel pump. Stock injectors, stock HPFP, stock HP rail, no PI. 100% stock block.

5th: Shiv states, "There is plenty more power to be hand on 91oct" and then says " this 600+whp result is something that I'm not entirely comfortable with. Sure it can do this on a steady state 4th gear WOT pull on a cool evening. But environment conditions (and fuel quality) can vary day to day, month to month, etc,. This is the reason I would still recommend running 19psi on 91oct."



Maybe I am wrong and you can make it. Is it safe? Would you want to daily it that way? Let me just say I am VERY skeptical of 600whp on 91. Even on 93 with 10% Ethanol.
 
Last edited:
  • Like
Reactions: The Banshee

Siimaa

New Member
Aug 31, 2022
1
0
0
I just finished my single turbo conversion a few weeks ago, and I want to turn up the boost.
Currently with 14psi springs I get ~11psi w/ JB4.
Map2 is 17psi and I'm not sure if that is safe as I only have 91oct available.

- What is a safe level of boost on 91 octane?
- Also, for JB4 Map6 can I just set the boost I want under User Adjustment Settings and rip it?


Here is a log from the other night
https://datazap.me/u/shadyorb/n54-6266bb-2nd-gear-map-1?log=0&data=1-4

Thank you for the link!
 
Last edited:

yuli8466

Specialist
Sep 6, 2018
99
22
0
1st: there is no log

2nd: you are quoting Shiv who is known to lie to sell his products. Shiv got ran out of this community before he started fleecing other car communities with his open flash product.

3rd: I have never seen it repeated

4th: The claim is they only used an inline walbro and the stock fuel pump. Stock injectors, stock HPFP, stock HP rail, no PI. 100% stock block.

5th: Shiv states, "There is plenty more power to be hand on 91oct" and then says " this 600+whp result is something that I'm not entirely comfortable with. Sure it can do this on a steady state 4th gear WOT pull on a cool evening. But environment conditions (and fuel quality) can vary day to day, month to month, etc,. This is the reason I would still recommend running 19psi on 91oct."



Maybe I am wrong and you can make it. Is it safe? Would you want to daily it that way? Let me just say I am VERY skeptical of 600whp on 91. Even on 93 with 10% Ethanol.
thank you for your detailed reply

yes , you are right ,that may be some "marketing skill" or " promotion information" , but I think with it can run 91oct . because when I was 19T twins ,I run 21psi 5degree with stock DI and very little Port injection with PUMP GAS, the block is stock, and piston is 9.5. If he run 6466 which is a lot bigger than my twins. I think even his piston is stock ,it is possible to run 21psi \6466\ pumpgas. and the power , maybe above 550whp and a little lower than 600whp. but it should be near.

now I run E30 and 25psi everyday ,So I can't test single turbo pump gas 21psi.
 

DaddyBoost

Specialist
Jul 8, 2017
55
-5
0
Ride
135
thank you for your detailed reply

yes , you are right ,that may be some "marketing skill" or " promotion information" , but I think with it can run 91oct . because when I was 19T twins ,I run 21psi 5degree with stock DI and very little Port injection with PUMP GAS, the block is stock, and piston is 9.5. If he run 6466 which is a lot bigger than my twins. I think even his piston is stock ,it is possible to run 21psi \6466\ pumpgas. and the power , maybe above 550whp and a little lower than 600whp. but it should be near.

now I run E30 and 25psi everyday ,So I can't test single turbo pump gas 21psi.
He will be close to hpfp limit at around 570whp, so unless there is helix, that will be the limitation.
 
  • Like
Reactions: The Banshee