Controlling boost question
Thread Starter
On The Tree
iTrader: (1)
Joined: Jul 2002
Posts: 192
Likes: 0
From: Austin, TEXAS > *
Controlling boost question ** NOTE: The example I use here is extreme. I'm using it to clearly demonstrate the concept of my question, not asking whether the specific numbers listed are good ideas. **
Say someone was running a built 408 with an S88 turbo in front of it pushing 20+psi. For normal driving however, they want to be able to turn the boost down to 5psi. The wastegate on the car is fine for the 20+ psi adjustment, but even held all the way open the motor is producing 10psi.
Now say this driver had perfect vision and perfect coordination and was able to back off the throttle quickly and accurately to hold the MAP readings at 5psi (at his "adjusted" WOT).
Would he be causing some sort of damage by doing that? I mean, clearly he's not putting out as much power as he could be. Clearly the turbo's doing some good since he's seeing 5psi. What kind of reliability problems might he be looking at by doing that?
PS: Assume the motor can take 20psi, so don't say the problem would be "he might mess up and spike boost" because the spike wouldn't be damaging.
Say someone was running a built 408 with an S88 turbo in front of it pushing 20+psi. For normal driving however, they want to be able to turn the boost down to 5psi. The wastegate on the car is fine for the 20+ psi adjustment, but even held all the way open the motor is producing 10psi.
Now say this driver had perfect vision and perfect coordination and was able to back off the throttle quickly and accurately to hold the MAP readings at 5psi (at his "adjusted" WOT).
Would he be causing some sort of damage by doing that? I mean, clearly he's not putting out as much power as he could be. Clearly the turbo's doing some good since he's seeing 5psi. What kind of reliability problems might he be looking at by doing that?
PS: Assume the motor can take 20psi, so don't say the problem would be "he might mess up and spike boost" because the spike wouldn't be damaging.
Staging Lane
Joined: Jun 2006
Posts: 91
Likes: 0
From: alabama
There shouldn't be anyproblems at all. I did something like this in my GSX, i would keep the boost low <5 psi going around town, or id try my best. My High boost was 18.5 psi.
im assuming the car is proprly tuned
Also a larger wastegate could be used to lower the boost, if its making 10psi and the WG is wideopen. Larger wastegate and a boost controler that has 2 different boost settings.
im assuming the car is proprly tuned
Also a larger wastegate could be used to lower the boost, if its making 10psi and the WG is wideopen. Larger wastegate and a boost controler that has 2 different boost settings.
Thread Starter
On The Tree
iTrader: (1)
Joined: Jul 2002
Posts: 192
Likes: 0
From: Austin, TEXAS > *
Originally Posted by TurboSSLS1
There shouldn't be anyproblems at all. I did something like this in my GSX, i would keep the boost low <5 psi going around town, or id try my best. My High boost was 18.5 psi.
im assuming the car is proprly tuned
Also a larger wastegate could be used to lower the boost, if its making 10psi and the WG is wideopen. Larger wastegate and a boost controler that has 2 different boost settings.
im assuming the car is proprly tuned
Also a larger wastegate could be used to lower the boost, if its making 10psi and the WG is wideopen. Larger wastegate and a boost controler that has 2 different boost settings.
Thread Starter
On The Tree
iTrader: (1)
Joined: Jul 2002
Posts: 192
Likes: 0
From: Austin, TEXAS > *
Originally Posted by Stupid Boost
Go with an S88 and a 50mm powergate from Turbosmart. Then you can run low or high boost without any concerns of spiking.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
the only problem i could see is if you wernt running a speed density tune. it would have your MAF maxed out and then i would imagine would lean out since its not seeing as much of a load as it would WOT. Thats just a guess tho
TECH Enthusiast
Joined: May 2004
Posts: 567
Likes: 0
From: Colorado
Originally Posted by coop5885
the only problem i could see is if you wernt running a speed density tune. it would have your MAF maxed out and then i would imagine would lean out since its not seeing as much of a load as it would WOT. Thats just a guess tho
Originally Posted by 280Z28
I think you misread him. 
Man the BOV would be SCREAMING if you tried this :haha:
Man the BOV would be SCREAMING if you tried this :haha:
Thread Starter
On The Tree
iTrader: (1)
Joined: Jul 2002
Posts: 192
Likes: 0
From: Austin, TEXAS > *
Originally Posted by coop5885
that raises the question of would the BOV be open, because it needs to see vaccum to open, so if it was in boost then the WG would be the only thing open
They will also open under [lots of] pressure, but now that I think about it I don't think you'd have that much build up.
Thread Starter
On The Tree
iTrader: (1)
Joined: Jul 2002
Posts: 192
Likes: 0
From: Austin, TEXAS > *
Well I got my throttle body working with a program I wrote. I plan to use this concept for gear and rpm-based boost control (among other things). The wastegate is a Progate so it's big enough to adjust where I need it as well.