Hi guys. Can someone please explain to me what a 3k or 4k GSK upgrade exactly does? I'm under the impression it allows the motor to rev abit higher...I can see how this would work with a manual transmission but does it improve things with an automatic transmission? I would think that with a good TC & VB the stall speed of the converter won't let the motor rev up to use the higher reving ability? I think I'm missing something here...I have an automatic tranny with a #8 plate and in the process of installing a Goerend TC & VB. Would this 3k or 4k GSk upgrade be worth it and what exactly could I expect for performance increases??? (I believe I'm currently in the neighbourhood of 230hp/605 ft-lbs of torque). Thanks in advance for any replies!

 

Would it be worth it? My response is yes. I had a 3kGSK in my '98 and found that I was able to get up to highway speed much sooner when merging onto a highway towing my RV than before the GSK install. On stock engines, the govenor begins to defuel at about 22K RPM and by 26 or 27K you lose power. Holding onto the power up to or close to 3K gets you there quicker and allows you to be rolling with traffic before you hit overdrive and ease off. That was, for me, the primary benefit of the GSK.

Dan

 

You can reprogram the trans to shift later too.

 

My 1st to 2nd and 2nd to 3rd happen fine but I'd like it to go into OD sooner. Can you adjust for that on a 97?

 

are you referring to OD or the converter locking? you can lock it manually by installing a lockup switch. my reccommendation... do the tc and vb, install a tc lockup switch (you can lockup in drive as well) and install a 4kgsk. you will have what feels like a new truck.

 

So does it help any under 2200 rpm?

Ex: When my speedo is at 50 I'm at about 1900 in D. It takes very little throttle to get there. 55 speedo/2200 RPM takes about twice as much throttle to get to. It gets progressively worse after that to maintain higher speeds, i.e. a hell of a lot more throttle. I'm not out of power at 55 as I can floor it and easily get up to 60 but it just takes too much throttle to maintain speed above 55.

 

thats your stock govenor springs choking your fuel out so you dont over rev. they start wayy to early. the pull your truck has now from 1600-1900 rpms will continue all the way past 3000 with a gsk alone and more mid and top end with timing.

 

back to the original question of this thread.... what does a 3kgsk actually do?

what happens is as the engine turns faster, the govenor springs compress due to the centripital (it is not centrifugal) force of the rotating govenor weights in the injection pump. once they compress to a certain point, there is linear defueling as the rpms go up. the 3 or 4kgsk are simply tighter springs that are supposed to give you full fuel to 3k or 4k rpms. somply put, they dont reach the defueling point until higher rpms because to get the tighter springs to compress as far as the stock ones you need more force and since you are not changing the govenor weights, you need more speed and more speed in a circle is rpms. you can build more boost at higher rpms because there is more fuel and more rpms = more volume, faster turbine speed, more boost, more power... you get it. make sense? the directions for the gsk install confused me because it used all the technical names for the parts and i had no idea what they were at the time. i'd be glad to type up laymans term directions to help someone out. the gsk makes it a completely different machine. one more thing, get the 4kgsk if you order one. i garuntee if you get the 3kgsk, you will upgrade to the 4k kit down the road. my advice... do it once and do it right.

 

"Why I went with a GSK by Ronco95"

I had good power with a few mods. I went 309/751 rear wheel on a chassis dyno several years ago. My real complaint with the power was that it did not "feel satisfying" on full throttle. Let me explain.

When I took off under full throttle, I had a power surge at about 1800 RPM and the truck really launched, but, the power fell off quickly at 2200 RPM. I was well into the governor before my trans would upshift. It felt like a big rev limiter in a drag race car.

Now, when the trans would shift, the engine RPM would naturally reduce and the governor would allow full fuel and the truck would accellarate again.
This would last two seconds and the governor would defuel and you would find the seat belts keeping your face off the dash while waiting for the trans to upshift again.

There was always about a one second delay between the governor really pulling the fuel and the time the trans shifted and loaded the engine again.

Now, with a GSK I can fuel the engine and keep it loaded until the trans upshifts and maintain accellaration, until I choose to slow down (which happens quickly often).

This also allows me to use O/D off on the interstate to reduce EGT's if I am towing heavily. Without the GSK, I might run 65 MPH if I was unloaded or closer to 55 loaded simply because the governor pulled the fuel so quickly.

From what I have read, I do not make any more power with the GSK, I only make power longer which is a lot more satisfying than before.

I understand the 5 speeds have quite a gap between a couple of gears and, if loaded, you have to wind one gear out to meet the upshift and keep the engine in the power band. With a GSK you can accomplish this and not come close to making the engine work.

I hope this helps.

Ronnie

 

Does running the engine at 3000 or 4000 rpm hurt the engine at all? The tach on the truck shows the redline at 3000 rpm. When do you need to worry about rods coming through the hood or wearing out engine components with sustained high rpms? Another question, with a 4K GKS install I've read you should install new exhaust valve springs? Thanks you for the replies.

 

You can over-rev any engine.

On my old bike it was 14K on my new truck it is 3K.

Not sure why the 4K is being recommended when this seems to be a question for a stock truck, not a professionally balanced and blueprinted engine...

 

According to people Ive talked to like TST and PDR you WILL hurt a stock motor at with a 4gsk if you do not install heavy duty valve springs.

 

* Destructive torsional harmonic resonance occurs at 4100 RPM
* Crank and rods fail at 5400 RPM (if you make it through 4100 RPM)

http://diesel-world.com/?q=node/28

 

if you havn't noticed, these engines are rediculously de-tuned from the factory. the only thing you need to rev to 4k is HD valve springs and a gsk. go past 4k and you will need a fluiddampner (or however you spell it). just because you CAN rev to 4k doesnt mean you have to. ive had my 4k kit on my truck for over a year and have never taken it past 3200 but it pulls hard until i let off the pedal without defueling.

 

How far will a 3k and 4k actually let you rev to?
Wanting to get one myself.

KO