Engine/Transmission (1994 - 1998) Top Speed

[Tomahawk]

Thanks Kyle B



I'll have to get the truck out this weekend and see what kind of RPM I'm pushing when she's topped out. Governor springs might be next on the list.

 

[BDeArmon]

So I take it 95 - 100mph is roughly where a stock 12v will top out? I'm lucky to get 80mph... ... the engine doesn't make it past ~2200rpm (stock 12v, stock auto, stock tires and 3. 54's)..... I knew this truck was a dog, but damn... . it's worse than I thought. We won't even talk about the 12. 3mpg I got while towing 6K worth of jeep and trailer yesterday (can someone say 40mph on a 7% grade?) :{

 

[WDixon27]

hmmm i guess my 96 with 4. 10s and a 5 speed aint that slow after all, things still pulling like a train at 85 when i get out of it, i aint that wild at going that fast with those tires and that much weight, now if i am in one of my bimmers that's another question

So I take it 95 - 100mph is roughly where a stock 12v will top out? I'm lucky to get 80mph... ... the engine doesn't make it past ~2200rpm (stock 12v, stock auto, stock tires and 3. 54's)..... I knew this truck was a dog, but damn... . it's worse than I thought. We won't even talk about the 12. 3mpg I got while towing 6K worth of jeep and trailer yesterday (can someone say 40mph on a 7% grade?) :{

 

[hsmith]

So I take it 95 - 100mph is roughly where a stock 12v will top out? I'm lucky to get 80mph... ... the engine doesn't make it past ~2200rpm (stock 12v, stock auto, stock tires and 3. 54's)..... I knew this truck was a dog, but damn... . it's worse than I thought. We won't even talk about the 12. 3mpg I got while towing 6K worth of jeep and trailer yesterday (can someone say 40mph on a 7% grade?) :{

Time to spend some $'s for fuel and rpm upgrades. Check the timing also.

 

[BDeArmon]

Time to spend some $'s for fuel and rpm upgrades. Check the timing also.

Yea, as soon as I find the $$$ for the transmission.

 

[Bob4x4]

Yea, as soon as I find the $$$ for the transmission.

The Gov springs are easier on the transmission than stock. No lugging in a higher gear Let'er rev



Bob

 

[pwerwagn]

My 1998 12V 5-speed with 3. 55's, and 305-70-16's will run 106. 4 on the GPS. No gov springs. and I can keep it to the floor for as long as I want, 106. 4 is all it gots. Until the gov springs go in.

--Jeff

 

[BDeArmon]

The Gov springs are easier on the transmission than stock. No lugging in a higher gear Let'er rev



Bob

So what is the downside of a GSK? There has to be a downside... as everything is a trade off.



BTW, I can only get 2500rpm out of the engine, transmission in park, foot on the floor... . as I understand it, it should turn ~3100?

 

[Bob4x4]

So what is the downside of a GSK? There has to be a downside... as everything is a trade off.



BTW, I can only get 2500rpm out of the engine, transmission in park, foot on the floor... . as I understand it, it should turn ~3100?

No down side I have seen yet unless you don't like a wider power band



Bob

 

[biggy238]

Only downside i've heard is some truck-specific egt problems. That and desideing between 3k's and 4k's (4k's being more intensive).

Towing shouldn't be a problem after a gov spring kit. Hit 3rd lockup and tach it to high heaven (3k). . the cummins will love it.



Oh yeah. . I blew my intercooler boot off at 105 and 25psi boost the other night. . scared the hell out of me. The truck will do 115 though. . I just wanted to double check.

 

[TPCDrafting]

It's hard to hold the camera, hold 3k, stay on the road and do it at edzachary 100k on the odo, well I came close

This was before the gsk, 11 plate, timing advance, switching to 235/85's and other mods. I get 22 mpg at 65 so I don't go much past that anymore.



#ad

 

[JZboril]

I have a 2001 24v. Mine slows down at around 90 like it is out of fuel. Sounds like the same situation as yours. I've read a few talking about governor springs and fuel plates. Can anyone give any specific recommendations?

 

[Mhannink]

Still running the stock 245/75R16 tires. It pulls real hard until it gets to 96 mph and it's like the fuel shuts down to slow it down. I know most production cars have a computer that limits top speed, is there something in the ECM that might limit speed on these trucks?

yeah its called a governer spring kit its mechanical like the rest of the motor no ecm just put a 3k or 4k gsk and it will fuel to that rpm i have a buddy that has a 4500 gsk i belive

 

[biggy238]

I'm pretty sure a 4kgsk will rev that high anyway (4500) as the 3k will turn up to 3600 in some cases.



A 24V is computer governored by the pump. You will need a box to disable it. I don't get into them much but I think the Redline boxes are still around.

 

[Bob4x4]

I'm pretty sure a 4kgsk will rev that high anyway (4500) as the 3k will turn up to 3600 in some cases.



A 24V is computer governored by the pump. You will need a box to disable it. I don't get into them much but I think the Redline boxes are still around.

It depends on what pump and how it is set-up how much rpm you can see even with the 4k kit.



Bob