3800 spring question

sweetdreamz

sweetdreamz

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Mar 9, 2013
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19
Installing 3800 spring next week. Is a valve spring upgrade necessary? See sig for truck specs.
 
Not seeing your sig, no. However i would caution going more than 3500. Mt truck could hit +4k but had a hard time getting there. I didn't have a good enough lift pump.
 
I have an hx35, fuel pin, exhaust, intake, pump turned up. Just want better driveability at highway speeds, hard getting pass 70mph.
 
A 3200 spring and removing the high idle screw helped me be able to cruise the freeway pretty easy. We have some 75mph sections on the interstate, and I have no problem holding at 80 on them. After the spring and idle screw I could hit 100mph if I want.
 
That 3800 spring is a touchy one! I get a lot of "surging" while driving over small bumps in the road. It doesn't take much movement of the pedal. I tend to give it more throttle to prevent it from doing that but it gets rather annoying sometimes. Maybe if the truck rode a little smoother...
 
Guess i'll do a little fine tuning. Supposedly governor springs give a smoother fuel curve and better driveability. We'll see.
 
Not sure about driveability for a DD. I had Giles put it in just to have room to grow. I initially wanted the 3200 spring but he told me that once the spring stretches beyond the limit, you can't un-stretch it. Nor is it a good idea to do so. Granted, it's only just a spring but I'll take his advice. After hearing that, I just didn't want any hassle. Besides, the VE's don't fuel any harder over about 3300RPM from what others have found. I'm tempted to swap out the 3800 for a 3200 spring with a coil clipped when the motor comes out.
 
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You haven't said what you're doing with your truck. Any racing?

The 60# springs aren't really an improvement over stock in an engine that's gonna be revved-up higher than 3200rpm (or so) combined with high boost and/or back-pressure.

Running the 60# springs in the past, I've floated my mess at about 3800 just free-revving it with no load.

Do a search of Zach Hamilton's (Texashighways) posts regarding the 60# springs for some good info. ;)

jimbo486 said:
Besides, the VE's don't fuel any harder over about 3300RPM from what others have found.
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Maybe . . . . I've put down over 400hp to the ground at over 4000rpm in the past. For what the VE is, it does alright.
 
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Impressive as always David! What did the graph show at the 3300RPM range?
 
447Dyno.jpg
 
BC847 said:
You haven't said what you're doing with your truck. Any racing?
Click to expand...

Not racing. De-fueling so early cuts my highway speed, it takes a lot of effort to get over 65-70. Pretty much the only reason I'm installing the spring, don't plan on revving too high.
 
Just listen to the little devil bastard on your shoulder known as me and PPump it.
You know you want to.
 
I don't know why this didn't come to mind earlier but have you tried backing out the high idle screw on the pump? Even with a factory 2500RPM spring, that can get you a few more R's.
 
Nearest I can tell my new converter helped running down the road more than anything else, so so much better.
 
Knoberman said:
Nearest I can tell my new converter helped running down the road more than anything else, so so much better.
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Between the 366gsk and aftermarket converter, I honestly don't know which one was the best bang for my buck. The spring helped the top end big time, while the converter was a improvement everywhere.
 
They both should be high on the list. Most don't want to pull trans, but so worth it.
 
Actually my truck is at transmission shop as we speak. New converter is on my list.
 
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