ok so I was told that I should not consider using a set of T/A performance or any other shorties cause there would be no benefit or not significant enough power increase over stock manifolds. fact or fiction?
I hope someone has an answer because I need to know also before I sell my full length headers to get those shorties.
Shorty headers don't perform as well as full length. This is more obvious when running open headers. Shorty headers are better than stock exhaust manifolds I'm sure. Maybe someone else will jump in here. I have shorty's on my 53 and it hauls. I have no choice though there are no stock manifolds for Stg2 heads. Bob H.
My guess would be that the shortys would be about a 5-10 HP gain, due to being slightly less rstrictive then manifolds. So to answer your question, yes, there will be a slight power gain, but maybe not enough to justify the price depending on your build.
"Exhaust headers with equal length tubes have been shown to develop slightly more power in an open system, but not when hooked up to a street system with mufflers. Fact is, most street motors with shorty headers will produce the same power as they would with>>>>>>>>>" http://www.sandersonheaders.com/tech_get_technical.php For street engines using full exhaust, shorties and full length headers perform the same. The gain will vary with the application but it is around 20 hp.
I'd go for the headers...you'll be glad you did if you choose to upgrade cam & induction later. Nothing worse than a healthy aftermarket cam & intake/carb with a cork in the exhaust pipe. Been there, done that. Devon
I will say that you will absolutely notice a seat-of-the-pants difference with shorty headers. They are not as great as full-length, but I run shorties and wouldn't even consider manifolds again. I used to run full-length, the main reason why I went to shorties was because they take up less real estate (easier to pull transmissions, starter motors, etc.). -Bob C.
One difference that will be noticed with jet hotted shorties is your underhood temp. I measured a huge drop in termperature when I put my HVAC gauge under there while driving
My experience was with my stock manifolds to the shorties. I got a hundred degree drop on the primaries with my infrared gauge.
thanks for all the info...I'll start saving! ALSO NICE TO HEAR FROM YOU JIM. YOU WERE A GREAT HELP WHEN I BUILT THE 455 BACK IN 05' THANKS!
71 RIV GS, I am shure you will feel an increase in preformance as long as you tune as needed i.e. jetting & timing .... hate to bring this up but in your engine photo ,is that a FRAM filter ? I hope not ... get a good WIX filter on that BBB ! Good Luck , ick
When we first came out with our shorty headers years ago we sent a set to Pee Gee Performance to have them tested against stock iron manifolds. The test did not give us the exact results we were looking to get because the only set of stock manifolds Scott had was a set of Gessler fully ported ones. What I remember was the shorty headers made 30HP more. Long tube headers made about 20 more. Also know that results can vary a lot depending on your engine build. So as you can see if we new what the Gessler manifolds did over stock we would of had the number, but we didn't. We tell people that they can make 30hp over stock. On the nailhead we have customers tell us that the shorty headers were the biggest HP gain for a single item they have installed. Seat of the pants increase. Hope this helps in some way.
