I just read here somewhere that the 3200 rpm spring will make a 700 rpm difference,,,,,
Please tell me why? I has under the impression that the stock spring allowed about 3 k, and the 3200 spring allowed just that,
I dont have a tach, but if it helps, 354 rear 235/85/16 tires allowed me 90 mph in 5th
65-70 4 th
45-50 3rd, that was with the stock configuration
I just did the 3200 spring, and i havent been out on the interstate yet,
My registration was lost by penndot, so my new to me truck is off the road till pendot bucks up,,,, I am quite annoyed that i did the spring, and pump mods, now with bad registration till??????????????
MMMMMMMMMMM
Well someone please tell me abouot the rpm diff. with the new spring compared to a good stock set up!
Thank you all, you have been great!
Peter.

 

I believe stock governed speed is 2400, or thereabouts. I noticed a HUGE difference in driveability of the truck with the 5sp. Winding up a little more between gears made it much more pleasant to drive. Doesn't feel like it is struggling to get up to speed anymore. With the 4.10 gears in mine it was literally running out of gas between gears almost as fast as I could shift them.

 

Will i have any valve spring issues with the new 3200 spring?
It is hard to believe that it went so well with such a low stock rpm!
Peter.

 

No, we wouldn't see valve float until well above 3200. Not sure exactly where, but well above 3200. I believe the heavier springs are only needed to avoid problems with exhaust brakes and high-end mods.

 

I dont have a tach in my rig......

Is the top RPM really 2400??? No way !

 

Try to keep the RPM under 3400.

The 3200 RPM spring will give you about 700 RPM of useable power above where the stock spring made the truck defuel. The stock spring will let you free-rev over 3000 RPM, but the engine will fall on its face around 2500 RPM under load. With the 3200 RPM spring, the truck will pull hard to over 3000 RPM. You can free-rev the engine over 4000 RPM if you feel brave.

 

After the install of my 3200 gsk I see slightly different performance numbers on the dyno. Torque peaks at about 2400 RPM. RWHP peaks at 2600 RPM but holds relatively the same from 2400 to 3000 RPM. The GSK allows the injection pump to continue to provide fuel at higher RPMs. With the stock spring my dyno sheets would peak at about 2450 then drop off sharply as the injection pump started to defuel. Throttle responce has improved dramatically.

Since I've built my truck for towing this is what I want to see. Torque gets the load moving and HP keeps it moving.

I've got the 60lb springs on my exhaust valves and do run an exhaust brake - which I use all the time. The best plus with the e-brake has been brake life. I just had the rears done with 100,000 miles on them. The fronts are at 60,000 miles and are still good.

Bob

 

Where do most buy there spring from? Is it a kit?

 

Any Bosch pump shop can get you the spring if you give them the part number (which is in the FAQ).

 

With the stock spring I have revved my engine to 3600 in the driveway. The RPM value is where its limiting starts.

If you've ever messed with a lawn mower govenor, the VE govenor works exactly the same way. The throttle lever pull a spring which pulls the throttle thingy back. The centrifical govenor pushes the throttle thingy down against the spring. A tighter spring results in more RPMS.

Edwin

My appologies for the "thingy" reference but I'm to lazy to go look it up.