torque gains

[Kevin]

I was looking at marc's site the other day to get a price on a 415 package, not that I'm considering it, i was looking it for an email on the list serv. and I saw that he has listed hp gains for porting, headers, exhaust, ect but not torque gains. does anyone have any ideas for what the torque gains are?

[tomtom72]

I would think that you could get a feel for the T/Q gains from all the dyno sheets posted by the guys that have had various types of work done. Dominic comes to mind instantly as he posts some very interesting charts.

Generally I would offer this thought. The bigger the explosion, the more T/Q one would see to a limit. So a P&P job would be going in that general direction. However, T/Q is also influenced by how big the piston is, so bigger = more T/Q. Also along the same thought pattern, the longer the con rod the more the T/Q as it's a longer lever with which to do work. Those are my thoughts, JMHO.:o

:cheers:
Tom

[Kevin]

I would think that you could get a feel for the T/Q gains from all the dyno sheets posted by the guys that have had various types of work done. Dominic comes to mind instantly as he posts some very interesting charts.

Generally I would offer this thought. The bigger the explosion, the more T/Q one would see to a limit. So a P&P job would be going in that general direction. However, T/Q is also influenced by how big the piston is, so bigger = more T/Q. Also along the same thought pattern, the longer the con rod the more the T/Q as it's a longer lever with which to do work. Those are my thoughts, JMHO.:o

:cheers:
Tom

more coffee is needed before I can even begin to figure out this post.:coffee:

[1990 quasar blue]

See Kevin......... nothing to it...............right?:mrgreen:

[Kevin]

i'm going to go cry in the corner now

[tf95ZR1]

Easy:

Torque (& HP) =


$$$

[Paul Workman]

The lines are kinda faint, but if you can make them out, here are some graphs to compare one of Marc's 415s to a "500" packaged 350 and a stock 90.

Compare one of Marc's 415s to a stock 350 with and without a "500" package 350:

The 415-

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/Joes600hp415byHaibeckAutomotiveTech.jpg

The "500" build-

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/DynoLT510-19-10.jpg

The stock (90) w/ a Borla cat-back.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/Basecase-DynoZR-19-20-08Large.jpg

No replacement for displacement, as the saying goes! the 415 makes approx 27% more torque at 5000 and generally across the rpm range over a "500" package 350, and something like 46% more over a stock (90) at 5k rpm.

Hope this helps.

[XfireZ51]

Pretty lousy fuel curve on the stock motor!

[Kevin]

paul,
thanks for the graphs but it's not really what I was looking for. as I said, on marcs site he has a break down of porting adds x hp, headers add y hp, flywheel adds z hp, I was wondering if there was a corresponding break down for torque gains

[XfireZ51]

Kevin,

If you look at some of the sigs on the forum, you'll see as an example
3 5.7L motors in various stages of modification.

Pete 474hp/400tq Ported top end, heads and 242 cams + exhaust
Paul 432hp/377tq Ported top end and heads, + exhaust, stk cams
Dominic 430hp/385tq Ported top end and GVD heads,+exhaust,236 cams
Dominic 399hp/359tq Ported top end + exhaust, stk cams

Recently, Marc H had a 5.7L, stock cam/ported motor at 348hp.

Sure looks like the stock motor was "choked" coming from the factory. Imagine the furor a 5.7L putting out over 500chp
would have caused back in 1990!
All power and tq is quoted as rw here.

[tomtom72]

paul,
thanks for the graphs but it's not really what I was looking for. as I said, on marcs site he has a break down of porting adds x hp, headers add y hp, flywheel adds z hp, I was wondering if there was a corresponding break down for torque gains

Kevin, Marc displays the results in a way that most people can relate to. So HP is the often quoted number. It's the "headline" of the story because most of us what to know "how much more HP do I get for my coin?"

That said, along with the HP gains there is a concomitant increase in T/Q output because T/Q output can be translated into HP output and vice versa using a formula. The reason that HP increase figures are always given is because the T/Q gains are a smaller number than the HP gain number, and to quote HP gains gives us a bigger number. It's a better "headline". ;)

:cheers:
Tom

[Corbusa]

Is the 415 a stroker kit? different crank etc?

[Kevin]

Is the 415 a stroker kit? different crank etc?
different crank, rods, pistons, liners, ect

[Paul Workman]

Pretty lousy fuel curve on the stock motor!

No chit!! That's why the rpm was limited to 6k.

P.

[Kevin]

No chit!! That's why the rpm was limited to 6k.

P.

could that be due to the restrictive borla on there?

[XfireZ51]

No chit!! That's why the rpm was limited to 6k.

P.

I was really commenting on the mid rpm curve.
Terribly rich and badly controlled overall. Unlikely exhaust is the culprit here.

[Paul Workman]

I was really commenting on the mid rpm curve.
Terribly rich and badly controlled overall.

Oh. Well, it was when it crept over the 14.0 value (on the lean end) that we got concerned. In any case, it was making pretty good power. It was stock except for a Borla exhaust.

Changing the subject, looking at torque (speaking of torque) the stock vs. my "500" package results - as well as yours and all of the FBI tunes, for that matter, show NO reduction of torque in the low/mid range, compared to stock. In fact, they show increases. So much for that tired old saw, "Increasing port runner size will hurt low/mid range torque..." :blahblah::blahblah: Doesn't seem to hold true - at least as far as the stock LT5 goes, huh?

P.