will a 3200 spring and slight timing bump give more boost?

[Rbracey]

hi all,

working on the truck in my sig, have the transmission out for a rebuild and while its out i put in a 3200 gov spring and turned the pump 1/8th an inch at most, maybe a hair less.

the truck spikes 45-46psi as it is and has 113,xxx miles on it and im worried that it will push too much boost(dosent sound right saying "too much" boost) for the stock head bolts, i figured i will re torque them while im waiting for the trans, but with all my money currently invested in that i cant afford head studs just yet.

trying to get it all together for Fall brawl 2012, a dyno day at Dave Guy Racing in Dillsburg Pa

also would anyone with a similar setup have any idea of a hp/tq estimate to expect

im also going with performance clutches in the trans/ shift kit, and a bd diesel converter

[Rbracey]

The dyno day is the 27th if anyones interested in going

[cmann250]

Is your truck factory intercooled?

[Rbracey]

Is your truck factory intercooled?

it is not

[Rbracey]

evening bump

[RCCUMMINS89]

Yes, you are pushing too much boost for stock head bolts.

The 3200 gov should give you a higher boost number. Becuase you are more available fuel at a higher rpm equals more exhaust velocity through the turbo.

A timing jump however will decrease your boost a little, even though an 1/8th might not be enough to change it. Reason is you are holding more heat in the cylinders which doesn't spool the turbo as much.

[Rbracey]

Yes, you are pushing too much boost for stock head bolts.

The 3200 gov should give you a higher boost number. Becuase you are more available fuel at a higher rpm equals more exhaust velocity through the turbo.

A timing jump however will decrease your boost a little, even though an 1/8th might not be enough to change it. Reason is you are holding more heat in the cylinders which doesn't spool the turbo as much.

So over all i should see a small increase in boost? and i plan on going with studs when i can afford it, as the truck is it dosent see full boost too often, and actually floats the valves a little at full boost, i just hope it holds together just to drive everyday for a little while haha

i plan on doing the valve springs while i do the studs, does the head need to come off to do the studs? and replace the head gasket? i would assume thats the best way?

[RCCUMMINS89]

Most people do studs without doing the gasket and don't take the head off. But, I think the best way is to do it all.

[cmann250]

The need for studs all depends on your driving style. Plenty of people have made 500 hp without studs (not necessarily with a VE) and plenty more have blown a headgasket with a nearly stock truck because they like to drive fast and not warm it up.

The head does need to come off for studs because you need to bottom tap the block. Replacing the head gasket is wise too. Ask the manufacturer if any other modifications need to be made because some studs need to have the rocker pedistals milled down a bit

Edit: RC, that may be the quick and dirty way but I've never heard of doing studs with the head on. Not bottom tapping the block kind of defeats the purpose of studs, correct?

[RCCUMMINS89]

You don't need to bottom tap your block unless you use Haisely's studs. ARP's don't require it.

I know probably a hundred people who never took the head off. I however, take the head off.

Driving style has a tremendous amount to do with if you need studs.... HOWEVER, just as important is one's drive pressure with a given turbo, timing, and all things that correlate into overall CYLINDER PRESSURE.

[cmann250]

Interesting. I've never done studs and I'd prefer to keep it that way I suppose that in every example that I can think of, the hed gasket was already blown and studs were installed afterwords

[RCCUMMINS89]

LOL, I have to agree that's why I did mine....... twice.

both times on my truck was due to drive pressure and timing combo. I let my truck warm up lots before I even think about getting on it. My cylinder pressures are so high at times that I lifted my head with studs.

[Tacoclaw]

Horsepower estimate would be around 230-250 if it's an auto. A bit higher if it's a stick, but I'm assuming it's not since you're rebuilding it. Your torque number will be higher with an auto, but my dyno run didn't read it anyways so it won't be a worry to you if you can't see it.

There's also a chance you'll end up on one of those dynos that will give you a 300+ number, but I wouldn't put too much heart into it. My truck, with a stick and an S362 did 268 horse. Stock injectors, fuel pin, LPLP, and 4" exhaust.

Do you have an upgraded LP?

[Rbracey]

Horsepower estimate would be around 230-250 if it's an auto. A bit higher if it's a stick, but I'm assuming it's not since you're rebuilding it. Your torque number will be higher with an auto, but my dyno run didn't read it anyways so it won't be a worry to you if you can't see it.

There's also a chance you'll end up on one of those dynos that will give you a 300+ number, but I wouldn't put too much heart into it. My truck, with a stick and an S362 did 268 horse. Stock injectors, fuel pin, LPLP, and 4" exhaust.

Do you have an upgraded LP?

oh, thats lower than what i was expecting. what type of mods would i need to break 300/350ish? i know the stock injection pumps arent known to do much more than 400

and it is an auto, going with a BD diesel converter when it goes back together

[Tacoclaw]

A bigger set of injectors and a good intercooler would probably do it. I would think your turbo could push you to 300, though with the injectors it you'll have to watch the pyro if you work it.

Maybe a different air filter setup if you feel like fabbing one up. And you will need to upgrade your lift pump as well. Tyler Ward's D250 with DDP4's, maxed IP, stock cone, stock auto and converter, HX35 cold side stuck into his 18cm turbine, Cooler Tubz, and 1stgen IC added on dynoed at 270hp. His truck was starving for fuel with the factory LP and either started missing or completely died on the last run.