The L31 in your truck and the LT1 in your Vette may be similar in the fact that they are both 350 SBC motors and share a similar head design. From that point on there is no similarity. Camshafts, timing, fuel curves, rotating assembly mass all different. The L31 was designed and tuned to be a truck motor with HP and Torque curves to live in a truck environment. The LT motor was designed and tuned to be a sports car motor.

How many gears does your truck have? What is the final drive ratio? What RPM is the L31 doing while cruising up that hill as compared to the LT in the Vette that is laid over just above idle in it's double overdrive sixth gear? What do the torque curves of those motors say at those RPM? Which motor is in it's power band going up that hill in top gear?

This is like comparing a Dodge Ram V10 to a Dodge Viper V10. While they are the same motor in theory, they are light years apart in every way.

Come on Tom. I have seen enough posts from you that I think you know this already.

 

Guys. You're bringing up **** that don't matter in this discussion. "Throttle body design"?? Rotating inertia?? Tq curves?? Vipers (aluminum engine) and Rams (cast iron)? NO, NO, NO, people. Get with the program!

What is the meaningful difference in the crank shaft between and L31 and an LT1? Rods? Flywheel? Harmonic balancer? What is the total weight of the rotating assy of the LT1 crank and DM FW vs. the L31 and it's single mass FW?

I don't know...but I can tell you this....in the big picture, in the realm of what I'm talking about, IT DON'T MATTER. They're close enough, similar enough and damn near functionally the SAME. Just b/c ons has a "truck" label on it has nothing to do w/this conversation. TPI had a "sports car" label on it...was THAT a "sports car" motor?? No it was better suited for use in a truck. So let's please get past titles, and minute minutia and look at the symptoms here. Please.

How can the truck's fuel economy change indistinguishably from AC on to off, but the 'Vette, you can chop 3-4 mpg right off when you turn the AC on? Gear, tq curves, engine titles, throttle body designs...none of this matters here.

Just to feed the lunacy, truck has 3.73 rear, NV3500 (5 speed), turns 2400 RPM to the 'vettes 2000 RPM, but weighs 1800 lbs more. All...totally...irrelevant.

Guys, I mentioned the truck b/c the motors in the truck and 'Vette are so similar -the rotating assy is virtually identical. But other cars are also far less affected by the AC; our CTS-V, my old '83 Trans Am (with a carb!), an old 1.6L Integra I used to have. The LT1 'Vette stand out very clearly, as being most severely handicapped by AC use of any AC equipped car I've ever owned -look at all the posters who agree that it's profound in this thread and the other! -....even though it has more tq, more displacement, more rotating inertia than most cars.

.

 

[QUOTE=Tom400CFI;1589849074] LT1 'Vette stand out very clearly, as being most severely handicapped by AC use of any AC equipped car I've ever owned -look at all the posters who agree that it's profound in this thread and the other! -....even though it has more tq, more displacement, more rotating inertia than most cars.
.[/QUOTE
Exactly! So from the sounds of it my AC is working normally. It's a 6 speed by the way. I have only owned it for a year now and this is why I asked. From now on I wont "sweat" it and keep the AC on high. Lol.
]

 

It doesn't matter ... Not arguing anymore.

 

Apparently, it's pretty normal, and there is nothing that can be done about it. That's what I've learned from these two threads and from working on my own car. The nature of the beast....apparently. I've owned mine (also a 6 speed) for over 5 years, and the compressor hasn't seized up yet, so I guess it's...."normal".

If my compressor ever does take a dump, I' may try a different compressor and see if that helps.

 

Just got done doing some research for anyone interested.

First I went looking for a more efficient automotive compressor. Zilch vs what we have.
Older compressors do cause even more load but again there just isn't anything earth shattering that's newer. Before someone brings up the Cadillac SRX compressor used on the c6.r its actually just as bad as what we have now its just driven slower on the c6.r since its just used to cool the drivers seat basically but still technically have a/c to meet the requirements for the racing its designed for. Think of it as underdriving the current compressor. Yep that will save hp but wont cool worth a flip.


Next I went looking for an electric compressor solution. Yep there are ones out there. But they only do 1.5 tons of cooling at the current our cars can provide. I was thinking that 1.5 tons of cooling sounded pretty good till I read the ratings of a typical cars a/c system.

Try 6 tons. WOW.

So no luck folks.

 

Six tons !! I didn't expect that. Kind of explains the normal characteristics. Regardless, I found that the parasitic draw is pretty easy to live with once you verify that it is actually functioning properly.

 

Not quite!

the 92-96 vette came with a Denso 10PA [20]C Compressor. The [20] stands for BTU X 1000 = 20K BTU... or 1.6 Tonns. This is about 1/2 of the Cooling I use on an 1900 Sq ft House.

And for the Record; I don't feel a thing when my Compressor engage's.. So this pretty much "Negates" all of the earlier Comparison's between Axle's etc. Because; I'm running the same equipment as most of you,, Back to the Drawing Board!!

 

It feels like it's using up about 50 hp on my '85.

 

The compressor puts out the same as a 6 ton a/c unit for a house.

I didn't mean the net results in btu's.

But heres an idea of a typical American cars ac.

12000 btu/hr to 48000btu/hr
about 2hp per ton

The rating is rpm dependent of course where car a/c's change the rpms of the compressor and home units are fixed for the most part. Some home units can vary the compressor speed but not normally.