Car's a H/C forged 347 with 90/90; MAC mid's & ORY ... making the numbers in sig.

What will I pick up powerwise with the American Racing headers (1 7/8" primaries because of future FI plans) with CAT'd Y pipe.

 

Anybody made a similar swap?

 

I'm swaping from Mac mids to QTP LTs this winter. I doubtI'll pick up more than 10-15hp

By the way, Unless your going way north of 500 RWHP. 1 7/8 primaries are too big for your motor, especially if it's stock cube, stick with 1 3/4.

Re'

 

I was sorta' figuring about that much. As stated above, future plans for FI ... gonna' be a cog-driven D1SC with 8-rib, kit. So, yes, it will be well north of 500RWHP. That's why I went with a 90mm SLP MAF when I did my 90/90 setup. that's what my motor was bulit for ... minus the AFR's ... will be changing heads, but, will make money for a change.

Thanks for weighing in!

 

I went from Macs to XS long tubes. I'd have to go upstairs and dig out the graphs but pretty sure it gained less than 10hp.

 

Hoping not so much for power on the dyno, just overall performance on my ET and trap speed.

yeah, I believe the general consensus is that it won't show much of a difference on the dynojet. The main thing I'm looking at is to gain more up top and pick up my MPH. When I race the car, it's quick off the line, however, at the top of third (A4), it seems like I get 3/4 of the way down the track and I hardly pickup any MPH. The cam makes power on the dyno up to about 5800 rpm and levels out thru about 6500 rpm. Here's what I hope the LT's change and hopefully it will throw the torque curve higher in the rpm range:

****NOTE: Had a wheel a little out-of-round, so the lines in the graph are somewhat wobbly.

 

ttt ... anybody else owned MAC's and moved to LT's like American Racing Headers?

 

i had Macs and went to Pacesetters. power difference I cant really tell. but sound wise it was worth it!

 

Although not a great comparison, I gained between 10-15 RWHP from MACs to QTP standard collectors. I will admit that the MAC tune was a canned tune that wasn't too great. I'm sure you'd gain a lot more based off of your current mods' and especially future plans.

 

Thanks fellows ... appreciate the responses. Anybody got a dyno comparison of your old MAC's vs LT's?

 

nobody?

 

I honestly think your comparing apples to oranges, regardless of brand. I never, ever liked mids due to accessability and power gain, regardless of what brand of LT header you pic, the LT in my own opinion is superior for the aftformentioned reason compared to a shorty or mid tube style header.

Ground clearance does improve a little but ill take sound and power over that any day. I delt with both on my LT1 and I refused to go back on my current LS1.

As for brand, ARH, Kooks, QTP, Dynatech, all great headers, will not dissapoint, the Dynatech though does sell a COMPLETE kit in the SuperMaxx system, thats why I pic that.