I have a basically stock LT1, I think I'm finally about to get around to doing some performance mods to it..

I met a guy kind of local to me with a 383 LT1 with heads and cam full bolt ons and all. I didn't really get a lot of specifics on the car, but I found out later that he only dyno'd at 391HP and something a lot lower in TQ..

Surely there's something wrong with his setup, right? He did say him and his dad built the motor themselves..

 

meh it could just be a miled build or a bad tune or even a bad dyno.not all 383's make 450 + hp

 

x2 ^^^^ Not all of them are built to be really nasty. He could have home-ported the heads, and is possibly running a milder cam (for a 383). 391hp at the wheels is still around 440-450 at the flywheel which is not bad.

 

i dont see anything wrong with those numbers...like they said above maybe its not a crazy build and might even be an auto.

 

Dyno #'s isn't everything. I know of a few LT1's that have lower #'s than that, and still run mid 11's all day long. Next time you talk to that guy, see what it run's at the track. You might be surprised

 

it all depends on the dyno. i have a 383 stroker lt-1 in my camaro and i dynoed at 394 plus mine was running rich his could of been too

 

"heads" can mean anything from a slight mill and a valve job to full CNC porting
Depends on who does any porting if present.
Depends largely on the cam.
Depends on the tuner.
Depends on the dyno.

Only if we had a full, detailed mod list, could we comment on the numbers.

 

Maybe it was a Mustang dyno. Those typically result in considerably lower numbers.

Regardless, like already stated, dyno numbers mean almost nothing. It's all in how it runs and drives.

 

One of the biggest problems with people spouting off HP/Torque numbers on here is that they do NOT tell teh full story of power 'under the curve', ie, xxxhp and xxx/tq at xxx RPM... Gaphs are much better, but even that doesn't mean jack because not all dynos are loaded the same and those 'interpreted numbers' don't mean much except a nice comparison of before/after on THAT DYNO...

I mean a lot of theese 500hp LT1s have abysmal street manners due to no torque below 3000rpm, and if you are talking a M6 buildup that means **** driveability... Even with an auto you are talking high stall and giving up 'manners' for twitchiness and high-revs all the time...

Personally, a 383 should MEAN that you have great torque throughout the powerband... Peak HP is all great for spouting a number and *possibly* running a fast ET given the rest of the car is setup for it... I would personally take 400rwhp@6000rpm and 400rwtq from 1500rpm+ vs a motor that makes 510rwhp @ 7000rpm and 220rwtq@1500rpm and a max of 400rwtq@4000rpm... The former would be a better driving, more enjoyable all-around car... The latter would pull better numbers at the strip...

Gotta figure out what you want to do with the car before you go after a goal... I know plenty of the 'racer'-type that just want high-hp and only car about the dragstrip... Then there is everyone else that wants to be able to actually enjoy thier car at any time on the street...