Well I oredered a new gov spring last Monday from a local dealer here in Calgary. I gave him the Bosch number listed in the instructions here on the web site and told him what it was for. He did not have one in stock but said he would try to get one in.

I picked it up today and it was $40CDN, $17 for the spring and $17 or so for shipping(came from out east overnight) and then tax. He said that he could not get the one I asked for so he ordered in the one that his catalouge had listed as a perfromance gov spring. The part numbers are very identical. Instead of ending in 366 its 386. Anyone know what the difference is? Perhaps a lower RPM rating?

 

cLAYH;
I found this number in the 1st gen FAQ section by Monty, 3200 RPM Gov Spring
1-464-650-366 for 89-93'. I've got one that's been laying around for a couple of months, just have to muster up the energy to change it. Not a fun task in my opinion but worth while I'm sure. Good luck!

ramguy

 

Yes I know what part number everyone else is using, the problem is since the shop I ordered could not get the 366 spring they got me a different one. Same part number but ending in 386 instead of 366.

So the qusetion still stands does anyone know what the difference is? The shop I purchased this one from has it listed as the performance gov spring to be used on our trucks. I'll probably put in on tommorrow unless someone tells me not to.

 

I have the 366 number written down in my notes as being the 3000 rpm spring. I think I got the number from the TDR.

 

Hmmm, I wonder then if the 386 spring is teh 3200 RPM spring?

 

Most Bosch parts will start out with the 1-464 and all the springs will be designated with a 650, the model number of the spring is its last three like you mentioned. I cant remember what the stock spring number was on my truck, but I believe it was a 388.

I see no reason not to try it if the shop says it is the performance spring for our trucks. However, if it isnt what you want, you will just have to tear the top end back off and install the 366.

BTW: if you do install the 386 watch your rpms closely and dont go over 3200 until you know what RPM this spring lets you operate within. Bosch makes springs for the VE that will turn over 5k, but are usually used for the 4cyl versions. But its better to be safe than sorry.

I will take a look at my stock spring tommorrow and make sure it was a 388.

The 366 is commonly referred to as the 3200 spring or the 3k by mistake. Anyone that owns one knows that it will take you quite a ways over the 3k mark.

 

Thanks for the info.
So what is the coresponding RPM for the stock spring? I know with mine that before I adjusted the high idle screw the most I could get was around 2800RPM, backing the screw out lets me hit 3000RPM. I know the spring controls the defueling point which I'm guesssing was 2600RPM stock, so with a 366spring the gov will not start defueling untill 3200RPM? Which I'm guessing most people probably will not normally exceed 3000RPM so it won't normally come into play. Which is basically the point I guess. Full power all the way up the band.

 

Okay...I did confirm that my stock spring that I took out was a 388. Here is part of a post from Bushy that gives a good explanation of RPM with the spring verses RPM with stock spring.


First the spring really seems to override both the RPM AND Load governor functions/systems.
On a stock spring, you have both. The RPM will begin your defueling prior to your high idle limit setting. I think that defuel ususally is about 300 RPM (+-) lower than high idle. If the RPM warrants defueling BUT the LOAD requires equal or more fuel then defuel does not happen till later on. Either the RPM fully overrides the Load effect, or the Load itself decreases, resulting in defueling.
By using your high idle system you can run the RPM up to what you think is the safe max (usually around 3400 or so reliably, with stock springs). In doing so, you have basically drawn your "defuel" up to about 3000-3100 RPM, assuming load merrits the fueling to that point. It could be even lower if you cannot load the engine enough.

So, the spring pretty much overrides both. It will run pretty much "full fueling" right up to the governed speed. By that I mean the "physically governed speed", as in the high idle screw. If you have that backed out alot, then hang on when you go WOT with no load.... I flared OVER 3800 before I could lift off... shocked the heck outta me...
You will still have both RPM and Load impact your fueling, but it is significantly reduced.
I have found that the gov spring has literally dragged the max fueling point to pretty much were ever I've set the gov screw.
That results in a much stronger "feel" when doing even normal driving styles...

 

Hmmmmmm.....a 4K spring you say..........

That darn jughead... see what he started.....were's my STICK !!??

Pastor Bob ..... covet not thy neighbours turbo for it shall not be so pleasing as the wanting.....hey!! not bad eh...

 

ok i kinda understand all this spring mumbo jumbo but the bottom line for me is, will it kill my gas milage? will it put my truck in any danger of anything? and will i see a power increase at all? and if i do buy itr what are we talkin to install this do hickey?

 

If you go into the tech facts at the top of the page it goes into details on the install. I bought Clays truck and on the highway I see about 25mpg. The spring allows you to rev higher

 

When I went for a new gov. spring I was told to get the 366 (3000-3200 rpm). I was warned not to put in the 3800/4000 rpm spring without new 60# valve springs to prevent valve float. Just thought I would pass that along.

 

Heck, the 366 spring will put you in valve float territory if you arent careful. I have caught meself in traffic turning 3500 and still pulling hard. I have no idea how high it will go. Didnt seem to make any difference in MPGs overall for me.

Daniel

 

i just switched mine out to a 366 and the stock number is 388 FWIW. I dont know if that was already established and I cant read but there you go anyways...

 

My power and mileage is better with the 3200 spring installed. The engine feels more lively, (doesn't start running out of ummph) like the stock spring would be pulling back the rpms earlier. You probably wont actually rev it up unless you try. I find I need to push down on the throttle less to get the same and better results before the new spring.