Texas_WS6

iTrader: (9)

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

otherwhitemeat

iTrader: (3)

I would start with the 12psi spring....I was told that anytime over 15psi, I should be running race gas or a mix of it.

Texas_WS6

iTrader: (9)

Whats your combo? Are you running higher compression too?

speedcrazy2

iTrader: (1)

i think he forgot to mention that all he has for fuel is the 255 in tank pump and 39lb injectors right now,do you think it would be wise to run 12lbs. with that setup

01ramair500hp

you will prolly max out those injectors, and also you may wanna think about adding another walbro in tank pump. better to be safe then sorry!

Pro Stock John

iTrader: (34)

Inadequate for 800rwhp.

I'd start out at 7-9, start timing out real conservative.

'Trust'

iTrader: (24)

That won't support much. He needs at least another 255 in the tank and 60 lb/hr at a minimum. Also, using the stock feed is pushing it at that level.

Texas_WS6

iTrader: (9)

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.

Texas_WS6

iTrader: (9)

Shouldn't the fuel system support 550 to 600rwhp?

'Trust'

iTrader: (24)

I don't even know if 39's would support 550RWHP. As far as compression, as long as the tune is good and you're conservative on boost you'll be ok. More boost and you'll need meth or some kind of water injection.

Texas_WS6

iTrader: (9)

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.

moehorsepower

iTrader: (3)

You will run out of injector faster than you think with that combo. As of now you may only be able to hit 5lbs due to lack of fuel..

Pro Stock John

iTrader: (34)

I made 550rwhp with a single intank, but it was not enough pump for 600rwhp.

I think you should run 60 lb injectors now, why tune the injectors twice.

hellbents10

iTrader: (10)

Those injectors would be good for 600hp at the crank n/a, with a BSFC of .45 or so. With FI and running BSFC rates in the area of .55-.6 you will run out of fuel a lot sooner. More then likely you will have a hard time making 450+ to the tires with them.

BigRich954RR

iTrader: (1)

YUP same here.

Ill sell you my old 60lb injectors but you still need 2 pumps and a rail mounted FPR

crf538

iTrader: (3)

yeah i would think about 5 pounds it all those injectors want, get some fuel injectors

Texas_WS6

iTrader: (9)

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?

MY99TAWS6

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.

gametech

iTrader: (1)

Until you can upgrade the injectors and pump, what about running your 5 or 7# spring, but lower your rev limiter to whatever rpm your injector duty cycle allows. This will still allow for some fun street driving until you finish the fuel upgrades.

Texas_WS6

iTrader: (9)

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.