LS1Silverado05

iTrader: (41)

Just curious what psi people would consider the first baby step into getting your tune dialed in? I picked up a Tial 38mm WG and it of course has a big blue spring (1bar 14.5psi)...well, I certainly dont want to start tuning at that amount of boost and in fact wont even push that on this build for now... I would like to settle in at 8-10psi... What spring should I get that will allow me to tune safely at a lower boost to start and then dial it up with my MBC when its time?... Thanks for your opinion...

slow67

iTrader: (2)

You could probably start out with no spring, then put in the smallest available, etc.

moehorsepower

iTrader: (3)

Trying to control boost with only a wastegate is really not the best way, Using a boost controller helps, but even with controllers they can spike up boost past your desired settings. Problems with wastegats is that say you have a 9lb spring, boost will gradually be bleeding to that is can release at the specific setting or it can hold it then release the whole 9lbs at once which will end up blowing your tires away. you really need both to "try" and control boost properly.

LS1Silverado05

iTrader: (41)

I didnt realize you could run the WG with no spring.....wont it just stay open? I guess it will still build a couple psi?

I have an MBC... I just wanted to know what a good base psi is for my first tune. I am assuming its best to start dialing in a tune on a lower psi (4-5?) and then work up to your final psi (8-10)...am I wrong?

Being that I want a final psi of about 8-10 what spring should I need to meet that?... Keep in mind I will be using the MBC so I can dial it up some... Thanks..

moehorsepower

iTrader: (3)

As far as running a WG with no spring I am not sure of that, I wouldnt. But yes you can start with 4lbs and work your way up. I would take enough timing for 8lbs when you are working with your 4-5 lbs to be safe unless you know from the past that the MBC will control you settings..

Phil99vette

iTrader: (11)

Just depends, I started @ 13# with no timing, made 700 on the first pull, adjusted A/F and timing as we went, maxed out @ 1100rwhp. If you referenced your FPR the VE #s should be close as boost increases...

LS1Silverado05

iTrader: (41)

I wont be coming anywhere near those power levels right now... Maybe 500rwhp if Im lucky..

I have been told for my application that I don't need a separate FPR so I am running off the stock in tank..

MY99TAWS6

iTrader: (3)

You can look up spring on tial website. You could run no spring doubt you will build any boost at all. You can also not go w0t so you don't hit your 1bar but that isn't too great as you do want to go w0t to tune and get the afr right and check other stuff like knock retard.

I would say you should get a 8 to 10psi spring. This would still let you go to likely 20psi I think you can usually get about double out of the springs.
It would be better to dial it in a bit lower boost so you can check all that important stuff. Fuel delivery is a big one.

ls1290

iTrader: (20)

Start with low timing and RPMs monitoring A/F, knock, injector flow rate, and others. Slowly move up the RPM range if all is good, otherwise adjust and rerun. Once the max RPMs is reached, start adjusting the timing. Start off initial with the amount of boost you want to run.

LS1Silverado05

iTrader: (41)

what type of timing should I start with? and where should I bring it up to?...

Keep in mind this is a stock long block..

98Z28CobraKiller

iTrader: (17)

The process that I used was to take my 100 KPA values and double them in the 210 KPA line. Then I interpolated between the 2 which fills in the rest of the MAP. This will likely be very rich in bost. Put in the spring that you think is the correct one. Tune your no boost area of the map. Then start creeping into the boost area. Make corrections and do it again. Gradually taking the boost higher and higher with the throttle. You'll spend forever going up one spring at a time not to mention the cost of the springs. Do not just floor it and see as you will be way rich and too rich is just as bad as too lean.

98Z28CobraKiller

iTrader: (17)

I started with 12* on mine

2002RamAir

iTrader: (19)

Sorry to change subject.. Am I reading this right to get the best boost control I would want to use a wastegate with the spring and a either manual or electronic boost control? Im lookin to run about 7psi as Im a stock 02 ls1.

LS1Silverado05

iTrader: (41)

Cool, Thanks!

Yea you want to run a Wastegate and the Boost controller will let you dial it up higher than the base spring will allow.. I am going with a Hallman Pro MBC...I think it will be sufficient for me at this point..

MY99TAWS6

iTrader: (3)

Maybe get like a 5psi spring and take boost up to maybe 7.Thats all I would run on stock engine unless you go to 317 head to drop compression. Then maybe 8 to 10max. Get greedy and watch ringlands break! 12 is pretty good for safe timing. Be very careful with timing. Set afr about 10.5 to 11 and again watch knock like a hawk . You better have at least some 42s in there for 5 to 7 and 60s if you go much higher. A good intank pump also not stock pump.

And for you rookies you can't set boost pressure under the gate pressure. So if you have a 10psi gate spring that is the minimum you can run with the controller and pretty sure about double spring is about as high as you can go.

But yeh get current springs out of there and go to 5 for starters. Sure on an engine like mine all forged with tons of fuel support ,etc I can start tuning at 15psi if wanted to but even I am tuning it now at like 7.5 to make sure everything is good.

Stock engines suck for FI . Ringlands are fragile .Any tuning mistake and its new rebuild time.
But local sts guy has ran several years bone stock motor aside from 42 pounders even with stock pump ,he has racetronix but didn't even install it for that boost level.
He stays at 5psi. Car still has some ***** even at that boost level.

LS1Silverado05

iTrader: (41)

Great advice! Yea I will stay nice and low on boost..I know it will be hard to not get greedy, but I willstay 6-8psi I guess.... I will run at least 50lbers and I have a single Walbro in tank now...would I need dual or will single be fine for now?...

MY99TAWS6

iTrader: (3)

Bone stock longblock..go for under 8 for sure I would even say lock it at 7psi. Single intank like walbro is fine at 500rwhp or so. Much past 500 would start looking at twins.

You you don't need a boost referenced reg really just yet at low boost.
If are you are at stock compression 10 to 1 don't get greedy. 10psi is too much for stock compression. Run low timing too likely 12 to maybe 14. Constantly monitor and if you see any knock retard take out timing or lower boost. Alc or meth injection can let you run a bit more timing but wouldn't run much more boost. Its still not the boost but the airflow that will determine actual hp but guess close enough for basic advice.

Have money budgeted if engine goes boom.One mistake on boost control or too much timing or lean out from various reasons stock pistons will shatter.
But some guys get lucky for quite awhile.I never tried to run stock bottom on my build.I knew with my luck I would be walking or getting the flatbed sooner rather than later.

LS1Silverado05

iTrader: (41)

So we're looking at MAYBE surviving on :

6-8psi max

12-14* timing

10.5 afr

and....about 350hp? LOL... (I know I know....I need a built motor to turn it up!)

MY99TAWS6

iTrader: (3)

You should be able to get over 400rwhp on 5 to 8psi depending on turbo. 400 plus is nothing to sneeze at. Remember these cars stock put out like 300 to 320 in m6 form and
280 to maybe 300 in auto form depending on year.

400 rwhp is like 500 engine hp and thats pretty darn stout. Even 450 engine is decent power. Turbos make a lot of torque and have great area under the curves as well. So can be pretty damn impressive.

Local guys bone stock sts car running 5psi actually moves out pretty good. Figure he has 400rwhp. Course to show how boost is relative my built 408 with 7.5psi likely puts out 600 to 650rwhp. As said its airflow not just boost in pounds.My turbos flow 44 to maybe 50 pounds per minute each. So total max power is 880 to about 1000 engine hp.
But I might be getting say 65 pounds min airflow at 7.5 but your setup might give say 50 lbs minute.