My new project truck: '99 K2500 Suburban

[stutaeng]

I thought the HD got the full floater? Don't quote me. I'm told a 2500 non-HD did not get a floater but a 2500HD did.

Yes, that's correct.

 

[Dravec]

All I know is, that 1500HD does have a ff rear. Don't know if it was special ordered or what. My grandparents picked it up as a lease return in Autumn of '03 with somewhere between 18k-25k on the clock. Don't quite remember, as I was only 13 at the time. My grandad really wanted a 2500HD 4x4 with the Duramax and Allison, but my grandma refused to have a diesel. So they got the 1500HD 2wd instead.
But goodness, it has no bottom end. Completely gutless below 2100 rpm with any load. But once you hit that magical number though, she pulls fairly well. And unloaded? She runs crazy hard. Truck has never had a programmer or any performance anything put on, and she pulls to every bit of 6000 at wot. She was actually faster than a few of the late '90's early '00's sports cars where I grew up.
(I got to drive her to bring back take out a few times as a teenager, and wouldn't you know it? I did stupid teenager stuff. )
I completely stuffed an '01 Mustang GT to 50 once, and another time just barely pulled a '98 Camaro Z28 on the highway from 30 to 80. Both kids I went to school with.

 

[stutaeng]

I wouldn't trust the wikipedia for those numbers....

"But why do GM rate the lq4 in the suburbans to 335hp then?

...Now here comes the tricky part. Your Silverado 2500 is considered a heavy-duty truck due to vehicle weight and therefore falls under certain federal regulations, one of them being the Transportation Equipment Noise Emission Controls. There was a problem with the Chevy and GMC 3/4- and 1-ton trucks equipped with the 6.0L V-8 engine producing excessive noise. Your truck's LQ4 engine actually had its potential horsepower downgraded. It now peaks at 300 hp at 4400 rpm because it was too noisy and would have failed the test pushing more horsepower at a higher rpm...

...and the downgrade was accomplished through various means including the programming of the powertrain control module"

Post #6: https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/6-0l-lq4-358226/

Downgraded?

So you are correct, LQ4 = LQ4, but different PCM tune, as I assumed.

If you go over to the Ford forums, you realize that the same exact engines on the F450+ are derated compared to the F250/F350, and it has to do with GVWR and probably other regulations I don't know about. Rams & Silverado 4500/5500 vs 3500/2500 as well.

Sorry OP, did not mean to derail your thread...

 

[OutlawDrifter]

Last post on the derail...

stutaeng and I finished our discussion outside of the thread, haha. I think what wikipedia fails to mention is the change in camshaft when they went to aluminum heads. Different cam and heads will definitely explain 35hp, and with the iron heads, I'm sure there were tuning differences in the timing maps to thwart any pinging.

LQ4
99-00 12560967 191/190 .457/.466 114
01-04 12561721 196/207 .467/.479 116
01-04 LQ4 cam is same as Camaro, Corvette LS1 and LQ9 cam

 

[Dravec]

Last post on the derail...

stutaeng and I finished our discussion outside of the thread, haha. I think what wikipedia fails to mention is the change in camshaft when they went to aluminum heads. Different cam and heads will definitely explain 35hp, and with the iron heads, I'm sure there were tuning differences in the timing maps to thwart any pinging.

LQ4
99-00 12560967 191/190 .457/.466 114
01-04 12561721 196/207 .467/.479 116
01-04 LQ4 cam is same as Camaro, Corvette LS1 and LQ9 cam

No problem. I love learning new information. And to be fair, I helped to derail my own thread.

 

[Supercharged111]

Last post on the derail...

stutaeng and I finished our discussion outside of the thread, haha. I think what wikipedia fails to mention is the change in camshaft when they went to aluminum heads. Different cam and heads will definitely explain 35hp, and with the iron heads, I'm sure there were tuning differences in the timing maps to thwart any pinging.

LQ4
99-00 12560967 191/190 .457/.466 114
01-04 12561721 196/207 .467/.479 116
01-04 LQ4 cam is same as Camaro, Corvette LS1 and LQ9 cam

The early LS1 had a less torquey cam and the 2000 Corvette had a 1 year cam that may have been the best of all if you really want to split hairs. The Camaro never got this cam to my knowledge. I'm only posting this to add context.

 

[stutaeng]

Yep, LOVE this forum. Always learning something new!

OP, are you going to add a tranny temperature guage? I've thought about adding one to my '00 K3500 4L80e, but don't really know what's the best way. Did these trannys already have the temperature sensor in them? It's always nice to know you are not cooking your tranny when doing heavy towing, no?

 

[Supercharged111]

Yep, LOVE this forum. Always learning something new!

OP, are you going to add a tranny temperature guage? I've thought about adding one to my '00 K3500 4L80e, but don't really know what's the best way. Did these trannys already have the temperature sensor in them? It's always nice to know you are not cooking your tranny when doing heavy towing, no?

The Vortec trucks have stock trans temp sensors, not sure about the TBI trucks. If you keep the converter locked, the trans won't overheat. The only time the trans in my 1500 gets warm is stop and go in town. Once I'm on the highway with the trailer, the trans runs 160-180. I was on a crosswind once with the trailer and the truck was chugging along in 4th but unlocked. The trans went over 200 in minutes. I was kind of zoning out not really paying attention. Once I pulled it back to 3rd and let it lock, it dropped back down.

 

[Dravec]

Yep, LOVE this forum. Always learning something new!

OP, are you going to add a tranny temperature guage? I've thought about adding one to my '00 K3500 4L80e, but don't really know what's the best way. Did these trannys already have the temperature sensor in them? It's always nice to know you are not cooking your tranny when doing heavy towing, no?

Yup. Plan is definitely to add a temp gauge. I'm insure if the non-LS 80Es got a trans temp sensor or not. I was planning to get a TCI deep pan for a few extra quarts, and it has a bung for a temp sensor. So that's how I plan to gain that extra level of security.

 

[Dravec]

Welp, thanks to @1ton-o-fun for giving me the link to get my RPO codes decoded!

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I knew she was loaded, but wow.