Turbo Boost

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Turbo Boost

Postby opofus » Fri Apr 25, 2008 7:45 am

Just got a ISSPro 60psi boost gauge installed, and I was disappointed to find that my boost pressure WOT is only 15psi.

Is this normal? Should the engine alway run under about 5-7 psi boost? Is there a way to adjust the boost?
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30psi Gauge Uses More Gauge

Postby Ace » Fri Apr 25, 2008 8:19 am

I got a 35psi gauge on mine. Seems like more when it's using most of the gauge and you see it jump way up. Woo-hoo!

But those numbers you're seeing sound about right for a stock I/C truck.
Last edited by Ace on Fri Apr 25, 2008 4:51 pm, edited 1 time in total.
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Postby Falcon » Fri Apr 25, 2008 2:01 pm

I got a 60 on mine WOT it hits 31lbs. Be nice to your head gasket it may leave on the side of the road some day.
Greg
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LAST REAL TRUCK!!!
93 ex cab 4x4, Hybred 35/40,4" exaust all the way,pump turned alittle,DDP Stage III's, 366 spring,DDP fuel pin,AFE first gen air intake,pyro and boost gauges
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Postby PToombs » Fri Apr 25, 2008 4:18 pm

Maaaaann, all you guys need more fuel! :lol: I can hit 42 pretty easy. :D

opofus, fuel is boost. More fuel, more boost. It won't have much boost running down the road steady. If you come to a hill, or step on it, it will come up. At 70 mph, I run about 3-5 psi. If I have the trailer on, the weight difference is noticable. 10-15 psi.
If you want more boost, turn the fuel screw in. 8)
pete

Just enough power to break everything behind the crankshaft.
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Boost

Postby opofus » Fri Apr 25, 2008 9:06 pm

What is need is a Pyro. I can't do anything until I scrape up the $150+ for that instrument. ISSPRO's are pricey...
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Postby Falcon » Sat Apr 26, 2008 7:24 am

PToombs wrote:Maaaaann, all you guys need more fuel! :lol: I can hit 42 pretty easy. :D

opofus, fuel is boost. More fuel, more boost. It won't have much boost running down the road steady. If you come to a hill, or step on it, it will come up. At 70 mph, I run about 3-5 psi. If I have the trailer on, the weight difference is noticable. 10-15 psi.
If you want more boost, turn the fuel screw in. 8)


My fuel screw is maxed out I can turn it in any more.
Greg
Graham, Washington
"FIRST REAL TRUCK ENGINE...
LAST REAL TRUCK!!!
93 ex cab 4x4, Hybred 35/40,4" exaust all the way,pump turned alittle,DDP Stage III's, 366 spring,DDP fuel pin,AFE first gen air intake,pyro and boost gauges
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Postby PToombs » Sat Apr 26, 2008 4:29 pm

Sounds like you need to pull it out and weld a little extra on the tip. ;-)
pete

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Postby c12h26 » Sat Apr 26, 2008 5:47 pm

My fuel screw is half a turn from a runaway and I am only building 27 psi of boost.
1991 D250 reg. cab 518
4" turbo back,pump turned up,bumped timing,intercooler,HX52,366 spring,ground AFC lever,piston lift pump,Goerend converter,M/T ET street radials,nitrous,lowered.
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Postby PToombs » Sat Apr 26, 2008 6:27 pm

There are many factors that affect this. Fuel supply pressure, fuel screw, (I know you are maxed c12h26) injectors size, air flow, timing. I could hit 36 or so with stock sticks and stock turbo, 16cm housing. All the trucks are different, and react different with the same adjustments.
c12h26 is making decent boost with a mostly stock truck. (according to his sig)
pete

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Postby c12h26 » Sat Apr 26, 2008 7:10 pm

PToombs I could hit 35 psi before the water to air intercooler was put on,3 weeks ago the truck made 298 hp on that setup still have the stock turbo,injectors and trans,not bad for a stock truck and $200 in mods
1991 D250 reg. cab 518
4" turbo back,pump turned up,bumped timing,intercooler,HX52,366 spring,ground AFC lever,piston lift pump,Goerend converter,M/T ET street radials,nitrous,lowered.
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Postby dvst8r » Sat Apr 26, 2008 9:51 pm

I hit 50psi stock sticks, non ic'd, hx35.12 I think it might have popped the HG. :oops:
1990 W250 non ic'd. Under the knife again.
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Postby PToombs » Sun Apr 27, 2008 5:29 pm

ch, that's pretty good. I always thought that the air to water coolers are restrictive, that kinda proves it huh?
I think mine was close to 300 before I put the big sticks and stage IV in. I didn't dyno, so I'll never know. I ain't going back now! ;) :lol:
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Postby boostedve » Sun Apr 27, 2008 6:39 pm

but when you lower the charge air temp. doesnt that lower your boost. so it would be nice to know what the boost press is on the inlet side of the i/c is. the turbo might be workin just as hard.. just my 2 cents.. :?
FOR SALE 1991 dodge d350 hx40 2nd gen intercooler, few pump mods, 366 spring, no afc, timing bump,pistion lift pump, 5" down pipe, bhaf, old smokey fuel pin, boost, pyro, tach gauges 14.10 @96mph 310hp, pm for pics and info..
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Air temp

Postby opofus » Sun Apr 27, 2008 8:33 pm

That would make sense, but in a naturally aspirated engine, isn't is all about expansion, therefore cooler, air means more expansion, and more HP. Isn't that the concept behind meth/water?
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Postby cummins king » Sun Apr 27, 2008 8:47 pm

when the air is ore dence then it equals more hp,
93 4X4 auto
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