How much boost should I start with?
#1
How much boost should I start with?
How much boost should I start with on pump fuel? This is really not a DD any more, it mainly sits in the garage or is trailered from one event to the other. It is street legal and will see some street use. So I really plan on running a 50/50 mix with race fuel when on the street and 100% race fuel at the track. I am also going to run a meth kit. Here is the build...
408 iron block
Ross pistons 10.25:1 with the L92 ported heads.
GMPP intake and Edelbrock Low Elbow
Eagle rods, eagle shaft
230/240 600 lift 114 center
Stock manifolds 2.5" SLP Y pipe to 3" to rear mounted GT88, exhaust wrapped all the way back, 50mm waistgate
Front mount intercooler, 2.5" cold air up to intercooler and 3" to TB
All piping mandrel bent
3600 stalled 4L60E Built
Moser 9" with 3.70 and spool.
Aftermarket radiator.. expecting to keep coolant temp down under 170.
Self tune with HP Tuners, keeping AFR between 11.5 to 12 max
I am thinking of starting my tuning with the 5lbs spring in the waistgate, then swapping to the 7lbs spring, then stepping up to the 10lbs spring. It is a Turbosmart waistgate so I can put in up to three springs at once, 12, 15, 17, and 22 lbs combos are possible, pretty flexible.
My goal is 800rwhp so I really do not know what boost level it will take but I am hoping it should not take more then 15lbs. I am thinking I should be good with up to 7lbs on pump fuel, 10lbs on a 50/50 mix, and 15 on 100% race fuel.
Any advice here will be greatly appreciated.
Thanks
408 iron block
Ross pistons 10.25:1 with the L92 ported heads.
GMPP intake and Edelbrock Low Elbow
Eagle rods, eagle shaft
230/240 600 lift 114 center
Stock manifolds 2.5" SLP Y pipe to 3" to rear mounted GT88, exhaust wrapped all the way back, 50mm waistgate
Front mount intercooler, 2.5" cold air up to intercooler and 3" to TB
All piping mandrel bent
3600 stalled 4L60E Built
Moser 9" with 3.70 and spool.
Aftermarket radiator.. expecting to keep coolant temp down under 170.
Self tune with HP Tuners, keeping AFR between 11.5 to 12 max
I am thinking of starting my tuning with the 5lbs spring in the waistgate, then swapping to the 7lbs spring, then stepping up to the 10lbs spring. It is a Turbosmart waistgate so I can put in up to three springs at once, 12, 15, 17, and 22 lbs combos are possible, pretty flexible.
My goal is 800rwhp so I really do not know what boost level it will take but I am hoping it should not take more then 15lbs. I am thinking I should be good with up to 7lbs on pump fuel, 10lbs on a 50/50 mix, and 15 on 100% race fuel.
Any advice here will be greatly appreciated.
Thanks
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#8
Yes I did forget to mention that. I do plan on going to a dual intake set up with larger injectors but I want to run it for now. Thats also why I am thinking of starting with 5 or 7 lbs. Thanks for reminding me, I have CRS (cant remember ****).
My main conserne is the compression ratio. I am starting to regret going with 10.25:1.
My main conserne is the compression ratio. I am starting to regret going with 10.25:1.
#11
Massmotorsports sold them to me. They speced them for 600crankshaft. They are the Fast 39# LS3 style flowed at GM psi. If they will not then I need to have a serious talk with them. They told me they put them on their 600 to 620chp stuff. That should be good to 550rwhp I ould think.
#17
You are all right, my injectors and single 255 fuel pump is lacking. I know this is true, I was hoping it would be enough for 5 LBS for the time being until I am able to spend the money on the daul intake pump kit. I will be puting these injectors up for sale real soon. They only have 200 miles on them so maybe I can get a good price on them to go against the purchase of larger ones. How much do you want for your 60lbs ones? Are they the shorter LS3 style? I have to stick with that do to my fuel rail kit.
So what I am hearing is "do not run any boost with my current fuel injectors/pump set up."
How about max boost psi after I upgrade the fuel system,, 15, 20 psi limit with my set up and 10.25:1 compression?
So what I am hearing is "do not run any boost with my current fuel injectors/pump set up."
How about max boost psi after I upgrade the fuel system,, 15, 20 psi limit with my set up and 10.25:1 compression?
#18
TECH Veteran
iTrader: (3)
I would think you might not need to go past 15psi to hit 800rwhp with your setup.
And as everyone said twin pumps and boost referenced reg, bigger lines and rails at that power level would be a good thing,80s would likely be better upgrade than 60s which would get pushed at 800rwhp. For now keep low boost likely 5 is a good thing.
Get used to tuning it , and start conservative on timing .You can run more boost with higher compression but you have to go down on timing. Alc injection can help get timing up again though or of course race fuel.
You also may find that 800rwhp is not really needed all the time. I am pretty content to run around at about 650rwhp most of the time thats still 750 engine hp and up it for track or maybe the occasional duel.
And as everyone said twin pumps and boost referenced reg, bigger lines and rails at that power level would be a good thing,80s would likely be better upgrade than 60s which would get pushed at 800rwhp. For now keep low boost likely 5 is a good thing.
Get used to tuning it , and start conservative on timing .You can run more boost with higher compression but you have to go down on timing. Alc injection can help get timing up again though or of course race fuel.
You also may find that 800rwhp is not really needed all the time. I am pretty content to run around at about 650rwhp most of the time thats still 750 engine hp and up it for track or maybe the occasional duel.
#19
TECH Veteran
iTrader: (1)
You are all right, my injectors and single 255 fuel pump is lacking. I know this is true, I was hoping it would be enough for 5 LBS for the time being until I am able to spend the money on the daul intake pump kit. I will be puting these injectors up for sale real soon. They only have 200 miles on them so maybe I can get a good price on them to go against the purchase of larger ones. How much do you want for your 60lbs ones? Are they the shorter LS3 style? I have to stick with that do to my fuel rail kit.
So what I am hearing is "do not run any boost with my current fuel injectors/pump set up."
How about max boost psi after I upgrade the fuel system,, 15, 20 psi limit with my set up and 10.25:1 compression?
So what I am hearing is "do not run any boost with my current fuel injectors/pump set up."
How about max boost psi after I upgrade the fuel system,, 15, 20 psi limit with my set up and 10.25:1 compression?
#20
I like the way you think. I did not think about lowering rpm limit for the time being, that idea sounds good to me. I will order the 5 lbs spring and use it first until I get use to tuning boosted and I have the fuel system up to par, thanks guys for the input.