[Tommy R]

Hey you all,

I'm looking for information on 4th Gen F-bodies. Specifically, I'm interested in the diff options, gearing differences (rear end and tranny), 1LE vs. base model specs, and any other differences from model year to model year.

For example, I know the '93s are speed density, not mass air. Are there any differences there from a performance or maintenance standpoint? The '93s also had a slightly different T-56 tranny, as I understand it. Were '93 and '94 models not available with 3.42 rear gears? Would a 150 mph speedo indicate that the car has 3.42's? No governor? I remember my old roommate's '94 T/A didn't have the "GT" package and as a result had the 115mph speedo, governor, and maybe even 3.23 gears (instead of 3.42s).

I know in '96 they went OBD-II with dual cats. They're also rated at an insignificant 10 hp more than the '93-'95 models. Of course, in '98 the LS1 came out with much more power. However, the LT1s are obviously still very compeitive in F-Stock, despite the power deficit, iron block, and smaller front brakes. Any particular reason for this? Or are the right people just not running LS1's? (IMG:http://www.frrax.com/rrforum/style_emoticons/default/unsure.gif)

So, needless to say, I'm intersted in LT1 vs. LS1 differences, too. But, I'll likely stay with the cheaper candidate, i.e. the LT1.

I should point out that I'd mainly be interested in F-Stock, so update/backdate concerns are of less importance. I'm not sure if/when I'd move to ESP.

Thanks in advance,
Tommy

[LT4Firehawk]

What I was trying to say is that LT1's feel like they have more low end grunt to me and yet, I make more torque at 2500 than most of them seem to. Meaning, the LS1 isn't lacking low end grunt, but it feels like it is (compared to the LT1). I was trying to explain that the numbers say the LT1 does not have more grunt on the bottom (on paper), but they sure feel like they do. I'm open to explanations/suggestions as to why that is.

Depends on the LS1 I guess. My bone stock 2000 TA (M6) has the following dyno:
(IMG:http://www.lt1.net/images/evandynostock.gif)

As you can see, it doesn't hit 275 lb-ft of torque until 3300rpm and doesn't hit peak torque (304) until 4000rpm. I repeat, this was a completely bone stock 2000 TA that had 1750 miles on it. By comparison, my bone stock 95 Formula (M6) made 289lb-ft (table top flat curve) to almost 4000rpm. Also, the LT1 in my 92 Vette made 300lb-ft from 2000-4000rpm bone stock, again with that table top smooth curve.

FYI, the LS6 in the Z06 has a similar tq curve to the LS1, but with a more gradual rise from 300 lb-ft @2500rpm to 340lb -ft @4500rpm. The LT4, has the same characteristics as the LT1, just a higher level of torque (328lb-ft from 2000-4500rpm).

I've always said the LSx engine are stronger on the top end than an LT1, but that they lack the low end grunt. These figures back it up. The best is the LT4, torque of an LT1 and HP of an LS1, but of course you'd have to be ESP to run one of those, plus they aren't nearly as cheap as the LT1 (or even LS1) cars.

Anyway, back to the primary question, for FS I'd favor the LT1 for several reasons:
cheaper
no brake hop issues
better low end torque

For ESP or roadcourse use, I'd recommend the LT4.