Why do LT1's have more low end torque. I'm planning on swapping my LT1 for a LS1 and i want my Ls1 to have the same low end torque. How could i do that???

I want a cam for sure and maybe ported Heads. Let me know guys!

 

they might have a longer connecting rod. but i might be wrong

 

i believe it has to do with the design of the heads. lt1s are old school, and ls1s are new school.

lt1 = square port
ls1 = rectangle/cathedral style

also the cams have some bearing on the powerband.

you won't get the low end tq. of an lt1 in an ls1.

 

Thats sad but i know Ls1's scream at RPM's. Atleast i'll make up for it. Hahaha.

 

You'll learn to love the LS1's powerband. Just put in some gears to make up for the low end torque.

 

like what size gears....i think 4.10's would be a little too much. I do alot of highway driving. Daily driving. I rarely go to the track. I think 3.73's would be fine. I think i have 3.42's on my 96' and i like it. It does 80mph at like 2krpms

 

dude, the ls1 engine is far superior to the lt1. if low end tq. is your goal, just get an old bbc.

old school bbc = torque king

 

3.73's were one of my 1st mods. I've driven a few LT1's and amost bought one, before buying my LS1. My 1st feeling after swapping the stock gears for 3.73's, was that it felt almost like I was driving an LT1. For a DD with some freeway driving, the 3.73's would be a great upgrade.

 

Well then i would probably go for the 3.73's. That would make me feel close the feeling of my LT1. Hahah. Thanks for the help guys. How much does a used 3.73 gears run or even a new set roughly?

 

Look at a dyno sheet, the LS1 has it all over the LT1 through out the whole rpm range. GMHTP magazine had an article with the 2 dyno #'s over each other.

 

If you really want that low end torque feeling get an auto and throw a 3500 or larger stll on there, that'll be more torque than you'll need.

 

I'm not an automatic man. I' m sticking with the automatic!

 

I was always told that the LT1 low end compared to an LS1 was just a myth. That it was the fact that the LT1 had no top end at all compared to the LS1 so it made it seem like it had more low end.

 

And it is a big myth.
Guys you can prep an LS1 stock cubes to make soo much trq down low, you'll need to grab your stomach in the back seat (if you didn't remove it) .
It is a matter of putting together a combo for a specific range of power.
You can't have both world, tons of trq low in rpms + high peak hp at 6300+, but there are good compromises.

Or there are strockers

 

that is what I have always assumed.

 

I'm glad were finally getting some opinions from the big posters!!

 

I think it is a myth as well. The LT1 just feels that way. The LS1 car has a better average curve. I make 325 rwtq at 2450 rpms, 350 rwtq by just over 3000 rpms, it peaks at 373 rwtq at 5000 rpms, and is still at 350 rwtq at 5750 rpms.

 

Don't worry about it and don't pay any attention to most of the early posts in this thread.

LS1's make WAY more torque and power than an LT1 at ANY rpm range.

An Lt makes it's PEAK torque of 325lb ft @ ~2500rpm (if memory serves). So it has a lot of grunt down low, but rapidly tails off as rpms increase beyond PEAK torque.

An LS1 may make it's PEAK torque at ~4400rpm, so many people incorrectly assume it must make less than the LT1 in low rpms. This is WRONG.

In fact a STOCK LS1 makes nearly 90% of it's peak torque by only 1500rpm or so, the big bonus is it can sustain it until much higher rpms, giving a broader spread of power, rather than an early peak like an LT1. So the sensation of driving one will be different. But the LS1 is superior.

Here's a dyno chart for the LS1:


NOTE: the scale for torque (on the left) makes it look like a steep curve, where in fact from 1500rpm to 4500rpm the torque only varies by 50lb ft or so. So it is actually a very 'flat' torque curve.

Essentially a LS1 makes more torque at 1500rpm than an LT1 makes at all!

To me that's impressive.

If you go with a bigger cam, you'll make more power and torque but it will essentially move it up the rpm range.

 

LOL, looking at that graph just proves what well have all known all along LOL. LS1 was way underrated by GM. I know that has nothing meaningful to add to the thread, I just thought it was funny.

 

I've been daily driving 4.10's for many years now. your only hurting yourself if you don't get them. I've had 3.73's and 4.10's, needless to say, I'm going with 4.30's on this project.