Iron Vs. Aluminum, the Final say!

[Superdave]

Just for kicks...



It's fairly close on the RPM measurements, not sure why his shop's software doesn't evenly divide RPM on the graph. He started his pull at quite a bit lower of an RPM than i did too.

Pretty impressive torque out of his though, would be a great engine for a S10.

[Guest]

Pretty impressive torque out of his though, would be a great engine for a S10.

Small, long runner intake manifold, combined with small port heads, combined with a cam designed for low end torque. Even so at about 3k rpm he still only has about 25lb ft of torque more than yours. BIG WHOOP. You would whoop him past 4500 rpm. he is crazy if he thinks he is going to make 80 more whp with just his custom intake swap.

guarantee he will lose that low end tq too with that new custom intake too.

[Superdave]

[ATTACH=CONFIG]7355[/ATTACH][ATTACH=CONFIG]7356[/ATTACH]

Pretty similar WHP numbers we've gotten with Jbody 5 speed swaps, more impressive torque though. nice work!

Small, long runner intake manifold, combined with small port heads, combined with a cam designed for low end torque. Even so at about 3k rpm he still only has about 25lb ft of torque more than yours. BIG WHOOP. You would whoop him past 4500 rpm. he is crazy if he thinks he is going to make 80 more whp with just his custom intake swap.

guarantee he will lose that low end tq too with that new custom intake too.

Yep, I was thinking the same thing.


Somewhere i have a few dyno graphs from stock 3400 5 speed cars, and i think i have one from Moonwell's car. When i get some time i'll look around for those.

[caffeine]

As you can see my AFRs start to get lean at high rpms. I haven't tuned this with a wideband but I will be. Is it normal for power to disappear at 5200 rpm?

Edit: I've never had any high-rpm knock issues with this though according to my datalogs.

[Superdave]

if it's bone stock, yes. That's about when i usually see them start to drop off.


Here are some from our adventures.. all on the same dyno.

Damon's Sunbird with the stock 3400, had around 90K on it. http://www.sdsgarage.com/60degree/Da...3rd%20runa.JPG

Here was one of Moonwell's, i think this was before we put the longtubes on it. (3400, MMS Stage 2 cam, mild porting, good tune) http://www.sdsgarage.com/60degree/Mo...07.09.21-4.jpg

Here was Brads (overlay from previous year).. iirc it's a stock 3400 with a 3500 UIM, 65mm TB and i think it had a UDP. http://www.sdsgarage.com/60degree/Br...%20compair.jpg

[Alxsmt]

am I the only one that noticed the hp/tq crossing on his graph is wrong? lol

I was told by a guy that ran an engine dyno for 30 years, 5250 is where they cross. its simply how its calculated. if it doesnt cross at that rpm they dyno was not being operated correctly. maybe chassis dyno is different but from the sheets I have seen it stands correct. correct me if im wrong :-)

[robertisaar]

if you're measuning imperial units (HP and lb-ft), then they will always cross at 5252 RPM.... assuming they're on the same scale. a lot of SAE stuff has the HP and TQ set for different scales, so you'll see it there as well.

[Superdave]

am I the only one that noticed the hp/tq crossing on his graph is wrong? lol

I was told by a guy that ran an engine dyno for 30 years, 5250 is where they cross. its simply how its calculated. if it doesnt cross at that rpm they dyno was not being operated correctly. maybe chassis dyno is different but from the sheets I have seen it stands correct. correct me if im wrong :-)

He's got iron heads, he can't rev to 5252.

[3400-95-Modified]

Shift_4700....

[Alxsmt]

gotcha. that makes sense. but his hp isnt calculated the same as everybody elses dyno runs then. meaning you cant even compare it. you really cant compare dyno to dyno anyways, they all do read different to an extent.

[3400-95-Modified]

A dyno is best used to measure changes that you make to the car at that moment, get a baseline and tune or change a part and see what it does... Any other way of comparison there are just too many variables.