MAC Shorties vs. Stock Tubular

dubbsix · Dec 19, 2006

Hey guys

How much power can be realized by going with after market headers (like macs) vs the stock tubular manifolds?

ninety15.0 · Dec 19, 2006

not much...if i were you i would just save up for a nicer set of long tubes. Not only will peak HP be increased but the area under the torque curve will be the biggest improvement...right where you want it! BBK's can be had for ~$250 and there are other reasonably priced LT's out there. good luck man

dubbsix · Dec 19, 2006

No LT's for me

Really? So youre saying that switching from those crappy looking headers to an aftermarket set wont yield much? I guess looks can be misleading.

I live in Smog Hell aka California so long tubes arent an option (legally)

1SLO306 · Dec 19, 2006

so LT's are ugly to you??

i would say LT's also cause they do give more power down low where the 5.0 likes it but a nice set of equal length header would do good also.

ninety15.0 · Dec 19, 2006

i guess if you live in cali you should opt for a nice set of equal length shorty headers like 1slo306 said. They are the best of both worlds i guess...they are legal and they flow better than un-equal length shorties. Apparently the stock manifolds are not all that restrictive until you are making quite a bit more power than stock! good luck

dubbsix · Dec 19, 2006

Thanks guys,

I guess i was hoping my 5.0 was like my z28. I changed exhaust and intake and picked up 25hp... THOSE were the days!

Roland69 · Dec 19, 2006

the stock headers are good till around 300 HP.....if your stock they are almost a waste of money. The stock ones do the job good on a basic stock 5.0

jtfairlane · Dec 20, 2006

I have a dyno sheet in front of me here, for someone's '89 LX 5.0 and T-5 combo. With an otherwise stock motor with the following minor mods : K&N Filter, March Underdive Pulleys, Paxton Fuel Pressure Regulator, Mac 2-1/2" cat-back, and a Mac 2-1/2" catalytic H-pipe....that combo made 210.0 hp and 276.6 lb/ft of torque at the rear wheels.

By adding Mac's standard un-equal length shorty 1-5/8" HTS coated headers, there was a peak total increase of 5.2hp and 8.3 lb/ft of torque, for a new max of 215.2hp and 284.9 lb/ft of torque.

FWIW...

1SLO306 · Dec 20, 2006

jtfairlane said:
I have a dyno sheet in front of me here, for someone's '89 LX 5.0 and T-5 combo. With an otherwise stock motor with the following minor mods : K&N Filter, March Underdive Pulleys, Paxton Fuel Pressure Regulator, Mac 2-1/2" cat-back, and a Mac 2-1/2" catalytic H-pipe....that combo made 210.0 hp and 276.6 lb/ft of torque at the rear wheels.

By adding Mac's standard un-equal length shorty 1-5/8" HTS coated headers, there was a peak total increase of 5.2hp and 8.3 lb/ft of torque, for a new max of 215.2hp and 284.9 lb/ft of torque.

FWIW...

not to be an ass but i would like to see the sheet. i wouldnt think a auto 5.0 with them mods would lay that down to the wheel cause the lose roughly 5% more then the 5spds

Maryland Stang · Dec 20, 2006

1SLO306 said:
not to be an ass but i would like to see the sheet. i wouldnt think a auto 5.0 with them mods would lay that down to the wheel cause the lose roughly 5% more then the 5spds

It says T-5 combo.

Maryland Stang · Dec 20, 2006

dubbsix said:
Thanks guys,

I guess i was hoping my 5.0 was like my z28. I changed exhaust and intake and picked up 25hp... THOSE were the days!

Change the exhaust and the intake and you may very well pick up 25 hp. The stock intake on a 5.0 is pretty bad especially on cyl. 1 & 5.

Sicarius428 · Dec 20, 2006

You will probably pick up more power getting a high flow X or H pipe. Those 4 cat designs are pretty restrictive.
Kevin

donsbad68 · Dec 20, 2006

5-7hp

jtfairlane · Dec 20, 2006

1SLO306 said:
not to be an ass but i would like to see the sheet. i wouldnt think a auto 5.0 with them mods would lay that down to the wheel cause the lose roughly 5% more then the 5spds

As maryland stang pointed out, and as I said in my original reply, this was for a T-5 car not an auto.

If you want to check it out for yourself, knock yourself out. You can see the dyno sheet and step by step results in an old Hot Rod Magazine article titled "Bolt-On Dyno Thrash, Shooting for 300 Naturally Aspirated Rear-Wheel Horsepower" by James Lawrence.

I'm sure you could get a hold of the same article/dyno sheet if you contacted Hot Rod Magazine or did a search online. The copy I have is in Volume 6 of "The Best of Hot Rod Magazine" book series on High Performance Small Block Ford Engines.

TENGRAM · Dec 20, 2006

jtfairlane said:
As maryland stang pointed out, and as I said in my original reply, this was for a T-5 car not an auto.

If you want to check it out for yourself, knock yourself out. You can see the dyno sheet and step by step results in an old Hot Rod Magazine article titled "Bolt-On Dyno Thrash, Shooting for 300 Naturally Aspirated Rear-Wheel Horsepower" by James Lawrence.

I'm sure you could get a hold of the same article/dyno sheet if you contacted Hot Rod Magazine or did a search online. The copy I have is in Volume 6 of "The Best of Hot Rod Magazine" book series on High Performance Small Block Ford Engines.

i think i've seen that same article (reprinted apparently) in a 5.0 mag

GTOreturns · Dec 20, 2006

The stock headers are the best for performance. They are good till 250-270HP then you wanna change em. Till then I'd keep em on. They retain that low end torque. An intake plus a catted x pipe and cat back exhaust along with gears will net you the best results without digging into new heads and cam.Also a 65mm TB and power pipe would compliment the above mentioned mods.

90_Red_LX · Dec 20, 2006

I put mac 1 5/8" shortys on myn and picked up .1 in the 1/8th mile. Cost effective no, but I got a deal on em and put em on. Didn't make the car much louder like I expected though. All in all I was happy I put em on because it certainly didn't hurt. That was before my intake, so my only major mod was 3.73s, along with midpipe and cat-back.

kpack5982 · Dec 21, 2006

I love the mac unequal shorties I put on mine just a couple weeks ago. Definitely not a good horsepower gain, but it totally changed the tone and helped lessen the drone of the flowmasters. Plus wot it sounds outstanding!!! Would recommend, but only if other options like the rest of the exhaust and or intake are upgraded.

Roland69 · Dec 21, 2006

GTOReturns said:
The stock headers are the best for performance. They are good till 250-270HP then you wanna change em. Till then I'd keep em on. They retain that low end torque. An intake plus a catted x pipe and cat back exhaust along with gears will net you the best results without digging into new heads and cam.Also a 65mm TB and power pipe would compliment the above mentioned mods.

dubbsix · Dec 22, 2006

No headers right now then..

Sounds good guys. I'll hold off on the header swap until i have more supporting mods.

MAC Shorties vs. Stock Tubular

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