Torkman15

iTrader: (2)

I had the macs on my 2000 Camaro with a Flomaster catback when I had it dyno tuned. It went 12.80 109 1.84 60ft a couple days later. I waited for my BMR K member to install the SLP LTs and now can't get back out of the 13s. Still have 1.80 60 ft times and same MPH (108-109) Whats up???? I have'nt even touched the Diablo programmer yet cause it was running so good with the dyno tune in place.

Kenny D

Mid's are crap. If you plan on getting a cam or heads later on just soon get LT's. You will lose power.

BuffJoeyD

iTrader: (2)

Id think that you would need a different tune for the LTs- And Id imagine that - if you were running using the flowmaster with the LTs it would hinder your perfromace by a lot more than with the macs. What are your other mods? And are you noticing any kinda traction difference - Id think that with the lower end power from the LTs u might be skipping ur way to the same 60 but maybe ur breaking loose a little after the 60?

LS1LT1

iTrader: (16)

That doesn't surprise me in the least, it's happened numerous times before.
Macs are great headers, SLPs (pardon my French) suck most of the time.
If I already had Macs I would NEVER get SLP LTs to replace them, I would only consider a proven LT that makes power, maybe.
Sorry dude.

WILWAXU

iTrader: (6)

My 10 second N/A car runs mid length headers...

Are you thinking about shorties?

Torkman15

iTrader: (2)

No shorties but I might just have the old Macs coated and put them back on. They fit like a glove anyway. Also 10s sound better than 13s anyday. Why am I only having fun going faster and when I slow down I hurl ??? I shoulda known shiny doesn't = torque or horsepower.

lilstephsls1

iTrader: (5)

I've talked to an LS1 specialty shop about putting SLP LT in my T/A. The man I talked to said when installing those headers before, most of the time the car either lost hp or only gained no more than 4 hp. I guess that means they suck

Bad30th

iTrader: (13)

Folks please don't spread misinformation (and thank you to those who know enough to know midlength headers aren't "crap and will lose power and suck vs. LT's").

Look in the exhaust FAQ please, scroll down a little - I'll give you the cliff notes :



Red curve = Mac midlengths, blue curves = Grotts

LTs gained 6rwhp/6rwtq over the Mac midlengths in that dyno, though there are "under the curve" gains of ~10rwhp/10rwtq around 5000-6000rpm, dropping back to roughly equal.

FWIW, I made 410rwhp/415rwtq through Mac midlengths (which I recently had JetHot coated). That was N/A through an LS1 intake, Mac Y with 3" carsound cats.

Mac headers are a good value for the money, especially for convertibles with fitment issues and lowered cars that don't want to deal with scraping everywhere.

Granted, it's pretty clear that LTs offer a (small) performance gain - the car in the dyno picked up .2 at the track - but that could've also been influenced by driver or other conditions. I just hate it when I see these posts about how midlengths suck...

Bad30th

PREDATOR-Z

Gained 21rwhp and 14tq with MAC's and ORY with no tune over 01 stock manifolds. Can't complain, responsiveness has dramaticaly increased throughout the rpms. No fitting issues, no banging, no SES light nothing.
I like my midlength.

Torkman15

iTrader: (2)

I have to agree I like my mids also. as soon as they are coated they are going back under my car.

AINT SKEERED

iTrader: (2)

Very possible that the power gained was from switching to the 3 inch y-pipe also. Macs are great, I have been running them for 2 years and the coating that was put on at speed inc. when I bought them is still holding strong.
Car runs great #'s at the track with minimal heads and cam package and all through MAC HEADERS!!!

dug

iTrader: (10)

Theres no arguing with the graph. The rpm range the engine sees during racing is where the most gains are. I agree some the gains could be from the custom 3" ypipe. Also, I wonder if the macs had the primaries ported. If they werent, porting them could lower the hp gap between them. I got macs and am always wondering how much hp if any theyre leaving on the table and if it worth the added expense of better headers.

PREDATOR-Z

Better header would be like stainless QTP w/ HPV collector and Stainless Works.
Anything else, I wouldn't bother.

But does your setup warrant the swap and the 1500>1700 expense??? (Headers+ Y-pipe/duals etc..)

DD966

iTrader: (3)

My stock #'s 313hp 327tq
After Slp flowpac, SLP LTs w/hi-flo cats, and Hooker catback 350hp 372tq
All #'s SAE corrected. All-in-all, I'd say SLP does not suck too bad.

SSactionLs1

slp are the worst LT out there...My 230$pacesetters outperform them...BTW i had macs before, and my SOTP from the LT is impressive.