Moving the Top Speed Limiter

[TXGREEK]

And back to our regularly scheduled show...120 with new driveshaft [emoji16]

My wife just asked me what’s so funny, why I’m laughing so much[emoji23]


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[dieselfan1]

1 hour ago, Imcrazy said:

If you drive that fast on public roads, your an @ss hole. The speed limiter is there for people who lack the level of personal responsibility required to make good decisions on the road.. If you're going that fast you need to be on a private road or a race track... This country needs to start enacting 5 year license suspensions and $10k fines for people who drive that fast on public roads and put others lives in danger... Grow up...

 

Im pretty sure I didn't endanger anyone when I wound her up to 97 the other day. I'd be more worried about the dumb shits that are texting and driving if I were you. 

Let's get back to talkin trucks here not morals. Jesus.

[TXGREEK]

I was also going to look into the cop brakes and shocks.

Depending on the height you’re going to keep your truck I’d seriously look into coilovers too.


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[dieselfan1]

6 minutes ago, TXGREEK said:

 

I’ve got my popcorn going


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I just made some too.?

[ftwhite]

My .02: consider you are driving a truck from a company that went bankrupt. If an accountant hasn't told the engineers to cut costs where ever possible (parts only need to last until the warentee expires, or speeds set by limiter) they are not doing their job or being accountable to shareholders or the tax payers who bailed them out. I would assume the limiter is not there for purely engineering reasons, but rather because it also limits liability and reduces costs. If there was a good cost saving reason to swap/build/spec a 110MPH capable drive shaft for a 180MPH drive shaft, it might have been done. But there are thousands of parts on a truck that this same engineering/legal/accounting decision was possibly made for. Tracking them all down so you can feel safe driving above the limiter is a difficult challenge. Focus on the driveshaft is just a start. Ford Exploders use to blow up at speed because of mismatched tires and wheels. I'd consider anything that rotates at speed to be a weak link, and get everything balanced if I wanted to spend time above 120. Given the limiter on my 6.2 was ~100 IIRC, I feel comfortable there is a 20% buffer built in by the lawyers.  Finding the top speed based of trail and error of factory parts, or paper calculations is a game of Russian roulette. 

[Husker_1911]

1 hour ago, SS502 said:

The limiter is there for various reasons...keeping people from doing stupid things isn’t it’s main purpose. Damn man you can kill a human or animal doing 10 mph if you’re a dip$hit. I agree wholeheartedly on the suspensions and fines...100%

Before legislating obedience, I’d rather see parents and elder siblings teach the young ones in the family the following:

-personal responsibility

-discretion

-situational awareness

-assertive driving (I don’t like the term defensive driving...  it sounds like you’re driving the car to not get hit and get where you’re going rather than get where you need to go without hitting anything...  I learned about this concept from a dude in 3rd Group)

-car control and braking

-how to use the gears effectively...  and drive a manual trans if you have one handy.

 

It would also help if parents would make getting grounded suck again when the kids screw up.

[Husker_1911]

15 minutes ago, TXGREEK said:

 

Depending on the height you’re going to keep your truck I’d seriously look into coilovers too.


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Roughly the factory height...  maybe a hair lower.  I know the Tahoe PPV has different springs than the standard Tahoe and I love the stance those have, but the coils in the back won’t work...  I am planning on Bilstien shocks all around before too long.  I had great results with my Dakota RT and my 1st Silverado using them.

[Husker_1911]

23 minutes ago, dieselfan1 said:

 

Im pretty sure I didn't endanger anyone when I wound her up to 97 the other day. I'd be more worried about the dumb shits that are texting and driving if I were you. 

Let's get back to talkin trucks here not morals. Jesus.

I’m definitely more concerned with the drunks and the texters than I am the Hoonigans...

[6_2LTZ]

I don't think the PPV Tahoe has a special drive shaft compared to a regular Tahoe or Silverado. It's just shorter overall and can handle higher speed. If you look at a 3500hd Crew Cab Long Box it has a 2 piece shaft thats 116" long. If you want to go faster you will need to change your drive shaft. Since it already has a 5" diameter shaft, a larger diameter shaft may not clear. I'd suggest checking with a driveshaft shop to see what they could do. 

[Husker_1911]

1 hour ago, 6_2LTZ said:

I don't think the PPV Tahoe has a special drive shaft compared to a regular Tahoe or Silverado. It's just shorter overall and can handle higher speed. If you look at a 3500hd Crew Cab Long Box it has a 2 piece shaft thats 116" long. If you want to go faster you will need to change your drive shaft. Since it already has a 5" diameter shaft, a larger diameter shaft may not clear. I'd suggest checking with a driveshaft shop to see what they could do. 

The data I found on the GM Police site just says it's a "4 in. aluminum" drive shaft...  That said...  There is a link in this thread for a google search for 2-piece K2XX driveshafts.  I saw one that's chrome-moly and supports 800 HP...  I like it.

[AtlasFBG2]

I raised my Silverado speed limiter to 112mph but rethinking it now after reading this thread. 

 

I have had a driveshaft let go once. Don't want to experience that again.

 

It was in a 81 Monte Carlo that had a built 406 sbc 4500 stall converter and 4:56 gears. 

 

Ripped a hole in the floorboard and cracked the tranny bellhousing. 

[Salciido_z71]

I’ve hit 130 in my 15 SLT on 305/55/20 MT 10ply tires? 

[Paintor]

In the 1960’s a nuclear missile caught on fire in its silo on Fort Dix, New Jersey.

 

The US Army I am told jumped in their cars and headed West thinking it was bye bye East Coast.

The burned up missile is still in the silo buried in concrete in New Jersey.

 

I’ve got my speed limiter set to 168 think it is with the Hypertech programmer. You boys keep your speed limiters set to under a hundred. Gonna need to pass you if something bad like a nuclear war errupts.

[swathdiver]

Husker, last time I looked, the K2 2WD PPVs were speed limited to 139 mph.  Every driveshaft has a critical speed that is determined by tube length and wall thickness and of course material.  It's a math problem to be solved.

 

My truck's top speed would be about 124 mph as that is the driveshaft's critical speed at that mph, about 4500 rpms.  If memory serves, the driveshaft tube is 53-1/2" long with .083" tube thickness and is steel.

 

In the early 1990s when aluminum driveshafts were all the rage in racing, I cautioned my customers and friends against using them but someone said they made their cars faster so they put them in.  One by one they twisted them in half and tank goodness for driveshaft loops!  

[truckguy82]

40 minutes ago, swathdiver said:

Husker, last time I looked, the K2 2WD PPVs were speed limited to 139 mph.  Every driveshaft has a critical speed that is determined by tube length and wall thickness and of course material.  It's a math problem to be solved.

 

My truck's top speed would be about 124 mph as that is the driveshaft's critical speed at that mph, about 4500 rpms.  If memory serves, the driveshaft tube is 53-1/2" long with .083" tube thickness and is steel.

 

In the early 1990s when aluminum driveshafts were all the rage in racing, I cautioned my customers and friends against using them but someone said they made their cars faster so they put them in.  One by one they twisted them in half and tank goodness for driveshaft loops!  

I’m pretty certain the limitation with driveshaft speed is all about the factory balance. I’m sure they have sloppy balance specs evident by so many people having shaking issues. If you driveshaft is on the upper limit of that spec and is out of balance your top speed will be lower. If it’s near perfect by coincidence, you should have driveshaft speed limitation of well over 300mph.

 

A perfectly balanced spinning steel tube could probably handle 100,000 rpm before the rotational g forces rip it apart.