Planning on getting my aftermarket header finally. I did notice a few companies selling a 2" inlet at the exhaust port on the header (not talking outbout the collector), and most of the other companies are at 1.75" inlet.
Is there a major advantage over the inlet size being a quarter inch bigger? I would think it could help with scavenging, but it may be a bit overkill for a stock LS/V motor and will get a tune. The only thing different is my compression around 11.3 Static compression because GSR crank and ITR pistons, and I guess a true cold air intake and 2.5" SP2 exhaust.
I would focus more on the overall package and not one thing like primary size. There may be a header which has a better primary size but overall the design is worse than something with a less than ideal primary size.
What particular headers are you looking at? Have you read through all of the available head to head dyno comparison threads?
Two other comments:
As far as I know there is no 3" cold air intake available for the DA. I don’t know if a 2.75" CAI or a 3" short ram will perform better, and obviously different motors will respond differently to different intake lengths and diameters. From my conversation with Sean Church, it seems there’s definitely a benefit to having a full 3" cold air.
The SP2 is NOT a 2.5" exhaust. Pretty sure it’s a 60mm like most of the other exhausts for the DA. 60mm is basically right between 2.25" and 2.5" and is a good all around size for a B series motor. You could probably benefit from a 2.5" exhaust but there aren’t any available for the DA and I’d choose a nice 60mm opposed to a muffler shop 2.5" since that’d be crush bent. Or you could opt for a custom setup from someplace like KTeller so that you can get a true 2.5".
[QUOTE=Colin;2299743]I would focus more on the overall package and not one thing like primary size. There may be a header which has a better primary size but overall the design is worse than something with a less than ideal primary size.
What particular headers are you looking at? Have you read through all of the available head to head dyno comparison threads?
Two other comments:
As far as I know there is no 3" cold air intake available for the DA. I don’t know if a 2.75" CAI or a 3" short ram will perform better, and obviously different motors will respond differently to different intake lengths and diameters. From my conversation with Sean Church, it seems there’s definitely a benefit to having a full 3" cold air.
The SP2 is NOT a 2.5" exhaust. Pretty sure it’s a 60mm like most of the other exhausts for the DA. 60mm is basically right between 2.25" and 2.5" and is a good all around size for a B series motor. You could probably benefit from a 2.5" exhaust but there aren’t any available for the DA and I’d choose a nice 60mm opposed to a muffler shop 2.5" since that’d be crush bent. Or you could opt for a custom setup from someplace like KTeller so that you can get a true 2.5".[/QUOTE]
That’s what i was assuming. It didn’t seem that it would make such a drastic difference to be noted.
I’m looking at a specific ebay brand, as I cannot afford a PLM replica or anything big name, and I’m heading to the dyno in a few weeks to tune my ls/v basemap. So I figured i might as well complete the last bolt on. My buddy recommended them to be and he says hes used them on multiple engine dynos and made good power. Supposedly the clearance is pretty good too. I’ve looked at dyno comparisons between tri-y and 4-2-1 and a few flow charts but I’m not expecting anything wild out of a ebay replica. Just need something to get rid of the bottleneck and didn’t want to do a 2" DA specific header.
And thank you for the correction, I’ve been used to domestics all my life so I always just claim the 60MM to be a 2.5. Ye olde Metric vs. Standard haha.
Also, if you posted the CAI fact for curiousity, mine was only a 2.5". I don’t think there is a benefit of an intake tube bigger than your TB because your TB is only going to take the amount it can. I believe the TB is close to 2.5", correct? Plus, it was only 60 bucks brand new
Oddly enough, I searched the same part number on google shopping and there are quite a few of them. Some even at 75 bucks. Which I don’t think I would trust lol.
