Guys with 347ci..how's your low end/tq curve compared to a 302?

[Pokageek]

Just like tittle says. Is it serious noticeably more TQ ? Thx.

 

[Pops Fun]

Hi
Here is my car page with dyno sheets for the mods I have gone through. Hope it helps.


http://popsfun.com/mustang/stangdyno.html

 

[WhiteDevil]

Here is a back to back of my old H/C/I 302 vs my 347. Both engines have the exact same heads and same intake manifold exept with the 347 it was ported and same exhaust set up . This side by side was made up couresy of the Magic man Grady! Thanks again.

 

[Grn92LX]

Mine seems similar to my 302 down low. But now with 4.30's its defiantly better. I did not build this combo for low end power. My main concern was what happens from the 3500-6800 range. From a 2nd gear roll on the street when it hooks from a 4000 rpm roll the car is WICKED deadly Now that its winter I can't get on it til 3rd gear. Drag radials suck in the cold. I need et streets.

I never dynoed it and probably won't anytime soon. I would like to dyno it only to see where it peaks and to see where to shift, I could care less about a hp or tq number. The car needs 3 things" Weight reduction (it WAY too heavy at 3,200 with me) suspension and et streets and a 3" exhaust.

 

[Pokageek]

Here is a back to back of my old H/C/I 302 vs my 347. Both engines have the exact same heads and same intake manifold exept with the 347 it was ported and same exhaust set up . This side by side was made up couresy of the Magic man Grady! Thanks again.

This is just what I was looking for. Thanks! I bet long tubes on that engine would be even better low end (street)!

 

[5spd GT]

Nice graph...I like that!

I gained nothing with longtubes on my 302. I was told my numerous people that it would. Nope It didn't show anything at the track.

 

[Pokageek]

5 spd, you are the only person I have ever heard that gained nothing from long tubes. The gain from long tubes wil l be in low end to mid range though. It will not show up in track e.t.'s. Are you saying you got no seat of pants or torque gain? Grady's dyno chart show significant low-mid grunt improvement and at least 10 rwtq over most non-long tube dynos that I have seen. This equates to much better street driveability and enjoyment. I have learned that peak HP and TQ and track times have nothing to do with fun and driveability around town. I never go to the track so that is where my goals are now.

For example, I want more low end tq so when I hit the gas in any gear, it goes. Not just upper RPMS. I hate redlining my car anyway and would definitely not be a candidate for a 7000rpm stang.

 

[Pops Fun]

Hi
I recall an article in 5.0 that showed not mush gain between shorties and long tubes... I'll look.

Edit: Found it The long tubes did a little better til about 3K

http://www.mustang50magazine.com/techarticles/29618/photo_14.html

Pops

 

[Pokageek]

Thanks for the post pops. Yes, that stang also looks close to stock. h/c/i with lt's is what I was thinking. Sorry I didnt clarif ythat.

 

[VibrantRedGT]

The low end TQ on mine is very noticeable. It holds you in the seat wide open too. I need to get to a dyno for proof though.

 

[5spd GT]

5 spd, you are the only person I have ever heard that gained nothing from long tubes. The gain from long tubes wil l be in low end to mid range though. It will not show up in track e.t.'s. Are you saying you got no seat of pants or torque gain? Grady's dyno chart show significant low-mid grunt improvement and at least 10 rwtq over most non-long tube dynos that I have seen. This equates to much better street driveability and enjoyment. I have learned that peak HP and TQ and track times have nothing to do with fun and driveability around town. I never go to the track so that is where my goals are now.

For example, I want more low end tq so when I hit the gas in any gear, it goes. Not just upper RPMS. I hate redlining my car anyway and would definitely not be a candidate for a 7000rpm stang.

If you look around you will see similar results. Some on the corral have posted this as well as other sites.

I think there are cases where gains will be seen, no doubt. Unfortunately in most cases the hp/per dollar isn't to good, especially with some of the cons it has by having longtubes.

I do like the sound better though, but I think many get fooled by it and think they gained something significant...and some actually gain something. On a h/c/i car, any quality 1 5/8 inch header will do, shortie or longtube in my opinion.

The 1 5/8 inch opening is bigger than your exhaust valve on the head which is even restricted more with the actual valve and sealing lip on the head. So the headers will flow plenty...

 

[Black95GTS]

If you look around you will see similar results. Some on the corral have posted this as well as other sites.

I think there are cases where gains will be seen, no doubt. Unfortunately in most cases the hp/per dollar isn't to good, especially with some of the cons it has by having longtubes.

I do like the sound better though, but I think many get fooled by it and think they gained something significant...and some actually gain something. On a h/c/i car, any quality 1 5/8 inch header will do, shortie or longtube in my opinion.

The 1 5/8 inch opening is bigger than your exhaust valve on the head which is even restricted more with the actual valve and sealing lip on the head. So the headers will flow plenty...

I think this is the first time I've ever agreed 100 percent with you!

The common 302 based 6000 rpm windsor does not move enough air to reap the benefits of long tubes. A 10 rwtrq gain in 320 rwtrq car is about 3 percent... you're not gonna feel that! And is it worth shelling out the loot for new headers and mid pipe? I don't think so.

If you want to feel "low end grunt" then build the motor for horse power then gear it up appropriately. You'll feel it plenty then.

Adam

 

[Pokageek]

I think this is the first time I've ever agreed 100 percent with you!

The common 302 based 6000 rpm windsor does not move enough air to reap the benefits of long tubes. A 10 rwtrq gain in 320 rwtrq car is about 3 percent... you're not gonna feel that! And is it worth shelling out the loot for new headers and mid pipe? I don't think so.

If you want to feel "low end grunt" then build the motor for horse power then gear it up appropriately. You'll feel it plenty then.

Adam

Thanks man..guys! You may have just saved me some buck$. :SNSign: