Tom400CFI

The TPI does feel like a "TQ monstah!".

That is due to the shape of the tq curve; peaky. Other cars with similar tq curve also feel tough; the VAG 1.8T -nothing below 2k RPM....nothing above 4.5k. You feel that "hit", from 2-4...you get that "push" relative to what's above and below...and it feels great.

The following is copied from another forum post:
it is documented in a technical paper, SAE 920673, that Chevrolet published in 1992 that described the technical details of the LT1. So, if you don't believe me, spend $12 for yourself download the paper and read the facts...

In the paper, they compared torque and hp curves for the 92 LT1 (and the 93 was even better with the slight cam change) that showed the LT1 had MORE torque (almost 10 ftlbs) between 1,000 and 2600 rpm. So the real low speed torque is actually better in an LT1.

There is a bump in the L98 torque curve in the MIDRANGE, just before it falls off the cliff, so from 2600 to 3300 rpm there is a little more torque in the L98 (imagine a bulge that goes from zero at 2600 to 10 lbs at 3000 and back down to zero by 3300). At 3300 the curves cross again, and the L98 is headed for the sewer, while the LT1 is still climbing to over 4200 and then it starts to taper off... The L98 is done at 4500 rpm and need to shift an L98, no matter what the engine is readlined at.

Joe C

interesting chart. granted, the LT1 has more torque than the L98, however, the L98 builds torque, at a faster rate, in a narrower band. if I'm reading the chart right, the L98 builds 65# within a 2200 RPM band (1000-3200 RPM), whereas the (92) LT1 only builds 35# in a 2750 RPM band (1000-3750). a flatter curve is actually the better curve. one question - are all torque curves for L98's from 1985 thru 1991 similar? overall, the 1993 curve does look good. as far as my 85, there's not a lot I can do about it - it is, what it is....

Tom400CFI

Yes. They're all pretty darn similar, except that the later ones go about 10 lb higher. The runner length fairly well defines the shape of the curve.

I agree that it is interesting. I was surprised, the first time I saw a graph that depicted that comparison.

VikingTrad3r

this graph is why i drive around in second all day long!!

Purple92

The beauty of the large displacement V-8's is that they make low RPM torque. Engines like the LT1 and the LT4 also have a very broad torque curves, and if you think of the area under the torque curve - it tends to help explain why they are so much fun to drive.

Cars with smaller displacement NA engines can make more HP - but it's almost always at pretty high RPM, so to use that power you have to keep the engine RPM up. That's fine when you're on the track - but it isn't how most of us drive on the street.

If the L98 Vette motor and the 4.6L BMW were both installed in 3,300 Lb cars with manual trannys, and both were in top gear and the drivers accelerated at 70 MPH -chances are the L98 would walk away from the BMW. The BMW engine just doesn't make torque at lower RPM's - but odds are the BMW is an automatic, and will downshift a few gears to let the engine rev... Of course - if we change the L98 to a more modern LS7 motor in the car - and it got to rev up as well - things could get downright interesting.....