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Z7 Turbo Kit and proper boost

ARFF22

ARFF22

New member
Finally bit the bullet and ordered the Z7 Turbo kit and since I am totally new to the turbo game have a couple of questions. Ordered the Z7 kit with the inter-cooler and front and rear power logs, since I have SLP Headers and I know they are not compatible with the kit. I have a stock L36 engine with an SLP Cat Back exhaust. My first question is, what is the best/safest setting I should set my boost at? I've seen that these cars with the Z7 kit can pretty much be safely set-up to run anywhere between 6lbs to 15lbs of boost? So what should I set the car up at, it is a daily driver and I do not plan on racing it, just want a quicker car. Secondly, I ordered the Boost Controller with the kit and the controller looks pretty straight forward. But I do not know how I will know how much boost I'm running or adjusting? Am I missing something? The manual boost controller is pretty simple in that you turn it one way to add boost and turn it the opposite way to decrease boost. So if I want to run 9lbs of boost, for example, how do I know how much to turn the controller and/or which way to hit that boost amount? Thanks in advance for the help
 


You dont really know what the boost controller will do.. You basically have a base boost set by the wastegate, then you use the boost controller to increase the spring pressure in the wastegate.

Setting a boost controller is trial and error for the most part. Just put it on fully closed, then start to open it until you see boost you like.
 
I safely run 15psi on my intercooled Z3/rockered car without knock. I originally started off at 10psi and moved up from there. As darkhorizon stated, start with the boost controller all the way close and make short runs until you dial it in where you want it.
 
You got me going in the right direction, but I guess my basic question is, how will I know how much boost I am running, still a little confused? Got the premise down of starting off with the boost controller closed and slowly open until happy, but when I get to that "happy place", how will I know what the boost amount is? Do I need some type of boost gauge? VictorSmalls, you state you are running 15psi, so my basic question is how do you know you are running 15psi, what tells you this? Do I need a scanner? Because the boost controller is a mechanical device I'm assuming the PCM really has no control over boost amount? Appreciate the help, just new to the forced induction game, don't want to over boost and blow up the car. I hope I'm asking this correctly?
 
Correct, I run an autometer boost gauge that is tapped into a vacuum line.

IMHO you should run a wideband gauge and a boost gauge if your turbo. These are two need to keep an eye on items.
 


Thanks for the input, what model autometer gauge do you guys recommend that would match the red oem stock GP gauges? What mounting location options do we have, I really don't like the A-Pillar location. Is there a specific vacuum hose it should be spliced into?

Can you give me brief description of the wideband gauge, not really sure what it does and what is involved for hooking it up. Seen a lot references regarding that piece, just not sure what it does and how it will benefit.
 
ARFF22 said:
Thanks for the input, what model autometer gauge do you guys recommend that would match the red oem stock GP gauges? What mounting location options do we have, I really don't like the A-Pillar location. Is there a specific vacuum hose it should be spliced into?

Can you give me brief description of the wideband gauge, not really sure what it does and what is involved for hooking it up. Seen a lot references regarding that piece, just not sure what it does and how it will benefit.
Click to expand...

You can check out all of the boost gauge options Autometer has to offer on this page.

Auto Meter - Gauges

As for the wideband, I use a AEM UEGO and have been very happy with it over the last year. The just of it is to have the rear O2 sensor turned off in your tune and the Wideband sensor will take its place. Other than that it is plug and play.

AEM Wideband O2 UEGO Gauge - Monitor Air/Fuel Ratio with the Digital 30-4100 - Wideband O2 UEGO, X-WiFi, EMS Series 2, Engine Management, F/IC, Tru Boost, Gauges, and more Automotive Performance Electronics
 


uego is the way to go for the wideband, i normally like to have it as close to the turbo as possible, I mount my right where the wastegate merges with the turbine exhaust. it definitely needs to be pre cat though. the Boost gauge needs to be tapped into the intake manifold. and you just need to get creative with mounting it. a lot of people use the air vents.

My honest recommendation though, if you arent trying to be FAST, which is the right way to look at it, then you should just run a vacuum hose from the turbo directly to the wastegate. this will give you the lowest setting of boost. which means you dont really need a boost guage or wideband. and also gives you more than enough power for a daily.

another thing you will be able to look into now is exhaust. if you have tuning then no need for a cat, and a turbo can really muffle a car, along with providing all the back pressure needed. on a v6 personally I would run 4" straight, maybe running to 2 three or 3.5" duals to keep the flow of the stock bumper. but I would also personally run WAY more boost. if I were in your situation, I would get a local shop to make me a 3" system.
 
fwiw, i bought a marshall scx(?) boost gauge that has a recall function letting me know what was the highest psi it hit as well as a low and high warning light(which i dont use much). reason i haev that is because im not going to stare or glance at my boost gauge when im going full throttle, plus since i am still running the stock 2bar map, it only registers up to ~14.5psi, which as of now im at 18psi ;-) im using the ngk afx wb and its not bad.
 
My honest recommendation though, if you arent trying to be FAST, which is the right way to look at it, then you should just run a vacuum hose from the turbo directly to the wastegate. this will give you the lowest setting of boost. which means you dont really need a boost guage or wideband. and also gives you more than enough power for a daily.
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This totally defeats the purpose of a turbo! because you would no sooner start to build boost and your wastegate would be opening...

A way to test and see what boost pressure your controller is set for is once you have everything fully assembled i would take an air compressor and set it to about 7 psi and put it on the manifold side of the boost controller, with the controller turned all the way down your boost gauge should read near 0, then slowly turn up the boost controller until you get the same amount of pressure you have the air compressor set to. Has worked well for setting the boost level for me in the past. This way you can also confirm that you have your vacuum lines connected correctly and should hear the wastegate actuate. And depending on the downpipe your kit comes with your slp exhaust should work just fine. No reason to go any larger than 3". If you ever want to make more power later just get a cutout.
 
TurboKent said:
This totally defeats the purpose of a turbo! because you would no sooner start to build boost and your wastegate would be opening...
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so either, dont know how a wastegate works, or you never seen a good setup.

the waste gate will have a set pressure where it will open. and it wont open until you hit that pressure. so your wastegate wont open until you hit full boost. not just starting to boost. my current DD runs a 15 psi wastegate. so if I run the line from the intake straight to the wastegate, my boost gauge will read 15 psi til redline, or I up the boost with the controller.


Oh and im totally gonna get flamed for this I know, but you DO NOT TURBO A GRAND PRIX TO BE FAST. you turbo one for more power, or better gas mileage, to be unique, or because you have nothing better to do. but it will NEVER BE FAST.
 


mountaineerjeff said:
so either, dont know how a wastegate works, or you never seen a good setup.

the waste gate will have a set pressure where it will open. and it wont open until you hit that pressure. so your wastegate wont open until you hit full boost. not just starting to boost. my current DD runs a 15 psi wastegate. so if I run the line from the intake straight to the wastegate, my boost gauge will read 15 psi til redline, or I up the boost with the controller.


Oh and im totally gonna get flamed for this I know, but you DO NOT TURBO A GRAND PRIX TO BE FAST. you turbo one for more power, or better gas mileage, to be unique, or because you have nothing better to do. but it will NEVER BE FAST.
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How do you figure that? A basic turbo setup on a grand prix and that grand prix will run high 12's. If you.aren't trapping 110+ in a 1/4 on a turbo setup your doing something wrong.

A wastegate also doesn't tell when your turbo is the most efficient. Usually run a smaller spring to start tuning and then raise the boost via boost controller.
 
matt5112 said:
12's is slow.

ls1 f body with minor mods like gears and exhaust is well in the 12's.
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Lol what a comparison there. Maybe if you had a 12 second f body or gp, you would understand, but it all looks easy on the internet, right?
 
^^^+++10000
prixs arent fast and 12s arent fast either. and i still see an average stock grand prix with nothing but a turbo still running mid 13s at best.



the OP is talking about running 9psi, any turbo that is efficient in that range, is too small for the 3.8. to be efficient you would need to go twin turbo like the 3000gts. and just run twin 11b's

he also asked for the best/safest setup, not the one with the most power.
POWER
INEXPENSIVE
RELIABLE

now pick 2, since you arent going to be fast, then you might as well be cheap and reliable. easiest way to do that, is use the system he bought, run wastegate pressure and be done with it.
 
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