An annoyance at high speed

Post by **Walt** » Tue Dec 26, 2006 9:11 pm

This is somewhat related to the post I just made in the N.O.S. forum about our ordeal today with one of my little girls.

On my way to the hospital, which is about six miles away, I pretty well kept my foot on the floor, but my truck never went above 95 mph, which was pretty frustrating. I didn't notice it at the time, but now that I think about it, I think the torque converter is engaging (or is it disengaging) at 90-95 mph, as my truck will accelerate quickly to 90 mph, but after that, the engine seems to slow down a bit, and getting to 95 mph takes forever, and 100 mph is out of the question. I don't regularly drive at these speeds, and I know that this is a minor annoyance, but it's an annoyance just the same. I may have to bite the bullet and do Brule's torque converter switch mod. Would that be the solution, or should I try something else?

BADs Crew · Post by **BADs Crew** » Wed Dec 27, 2006 1:26 am

Glad to hear your girl is ok. If it was me I don't think I would worry to much about going 95 mph a S-Crew. I think your family needs you more than that....
Just my opinion.

Post by **HenryJ** » Wed Dec 27, 2006 4:11 am

What is your rev limiter set at? What is your speed limiter set at?

Both settings can be adjusted with the HPPIII.

Does the converter lock at WOT?

WVHogRider · Post by **WVHogRider** » Wed Dec 27, 2006 4:48 am

BADs Crew wrote:Glad to hear your girl is ok. If it was me I don't think I would worry to much about going 95 mph in an S-Crew. I think your family needs you more than that....
Just my opinion.

I agree, especially in cases like rushing to the hospital, one is usually preoccupied with the thoughts about the loved one, and not on the task at hand, as in driving. What would the extra 5 to 10 MPH save you in a six mile drive? Like 20 seconds!!! Not worth the risk to me. However, I understand your where you are coming from.

Post by **Walt** » Wed Dec 27, 2006 6:05 am

Yes, the HPP3 is set to 110 mph. Rev limiter is set to 5600rpms, and I'm at WOT, still in 3rd gear. Even if I manually keep it in 3rd, it still does it. But it never shifts into overdrive.

2kwik4u · Post by **2kwik4u** » Wed Dec 27, 2006 6:20 am

Stock shift tables will never let it shift into OD at WOT......Just like Torque Management, it's a tranny "saving" feature.

Likewise the TC should be unlocked at WOT, although that might be tickling a lockup point, and slightly bogging the motor making you lose the power required to maintain that speed (with your tire/gear/mod combo that I'm not 100% clear on).

Just some thoughts.

Post by **HenryJ** » Wed Dec 27, 2006 6:26 am

Walt wrote:Yes, the HPP3 is set to 110 mph. Rev limiter is set to 5600rpms, and I'm at WOT...

Time for a tune-up? Check the ignition system (cap-rotor-plugs-wires) How is the fuel pump and fuel filter?

Post by **Walt** » Wed Dec 27, 2006 4:35 pm

Fuel pump and filter are brand new. Plugs and wires are only a few months old as well. Haven't checked cap and rotor. That'll be on my list of things to do next.

The drop off of power isn't gradual, it happens at just above 90 mph, with the same effect as when the TC does it's thing in OD, the RPMs drop a bit, as does power.

F9K9 · Post by **F9K9** » Wed Dec 27, 2006 5:27 pm

Do you have a HPP III? If. not when the max speed is reached, it just shuts down. Even the police packaged Tahoes did at 99-100mph. My 97 zr2 shut down at 90. Scare the H out of you until you realize what is happening.

Post by **HenryJ** » Wed Dec 27, 2006 5:43 pm

f9k9 wrote:Do you have a HPP III? If. not when the max speed is reached, it just shuts down. Even the police packaged Tahoes did at 99-100mph. My 97 zr2 shut down at 90. Scare the H out of you until you realize what is happening.

Walt wrote:Yes, the HPP3 is set to 110 mph. Rev limiter is set to 5600rpms...

He does.

F9K9 · Post by **F9K9** » Wed Dec 27, 2006 6:37 pm

HenryJ wrote:......He does.

Sorry, I missed that.

Well, I guess that is all I can say about that

Post by **Walt** » Thu Dec 28, 2006 4:56 am

f9k9 wrote:
HenryJ wrote:......He does.
Sorry, I missed that.

Well, I guess that is all I can say about that

Your effort is appreciated nonetheless.

daevans315 · Post by **daevans315** » Thu Dec 28, 2006 2:48 pm

My 97 S-10 with the Hypertech will not shift into OD over 98 mph either. The way its setup now it will run out of HP at about 115 and 5,500 RPM's in 3rd. If I let off the gass it will decelerate hard till 98 when it pops into OD. Although I did take the crew to the fuel shut off at 98 once it was definitely working harder to get there and much less stable at speed. I would guess into a head wind, up hill, with 3.42 gears, or needing a tune up it might not even make it to 100.

I second the statments above about running the crew over about 80. Its an SUV...

Post by **Walt** » Thu Dec 28, 2006 3:49 pm

Mine accelerates strongly until I get between 90-95mph, and it starts to taper off, and barely makes it to 95mph with enough room. Before the HPP3, it would shift into OD at 90mph or so, but I still had the power loss between 90-95mph.

Post by **Walt** » Sat Jan 06, 2007 8:56 am

Ok, another update. At roughly 90-05mph, the engine speed drops by just over 100 RPMs suddenly. This isn't noticeable except for a gradual loss in power/acceleration.

Post by **HenryJ** » Sat Jan 06, 2007 9:01 am

How is the condition of your cap, rotor and fuel regulator?

Post by **Walt** » Sat Jan 06, 2007 9:35 am

Still need to check those. We're in the process of moving, and I'm still working full time, atleast until next Friday

, so I've been busy. I'll try to take a look ASAP.