Got my 2055s today, can't wait to get them on this week hopefully.

Down to business. What amount of power if any do headers actually add? I know they flow better but would it make a noticable difference on my car? How much on a dyno? My Iroc is an 89 LB9 M5 with 3.08s. Lets "pretend" it has 210 hp now. With all my exhaust done would i be looking at 220+ hp?

Heres how it stands (as soon as my headers are on lol).

Hooker 2055s with the collector opened up.---3" QTP cutout---3" magnaflow

 

They dont add power, they free up power lol. Definantly a noticable different with headers. Once you take off the stock manifolds and look at them youll see why.

 

If they're replacing stock manifolds, yes, it will definitely be a noticeable difference. You'll probably gain more than 10 hp.

 

I gained 2mph in the 1/4 mile after my hooker 2055's.

 

Just some general info that you may find interesting:

I purchased the 350 HO Deluxe based on a review/build up and dyno test in CarCraft (Feb. 04). With iron exhaust manifolds, 2 1/4" exhaust pipes and a pair of turbo mufflers, the HO Deluxe managed 354 lb-ft of torque and 320 hp (which apparently wasn't the way that GM tested). Throwing on Hedman 1 5/8" long tubes, with no other changes, added 23 lb-ft of torque and 17 hp.

JamesC

 

I have pretty much the same car, replaced stock stuff with 2055's, 3" Cat and 3" exhaust... Actual dyno numbers would be cool... I'm assuming some where between 10 and 20 HP for a complete exhaust, Headers / Cat & Cat Back...

Rafael

 

There are a LOT of factors involved to determine how much gain you will see. I have seen as little as 10HP gain up to 32HP gain on a chassis dyno with different combinations.

Here is a SWAG at what you will see depending on what all you do and how much you are changing.

Just headers and stock exhaust = 7 to 10HP
Headers with bolt on exhaust system and cats = 12-20HP
Long tube headers with a calculated size exhaust for your application and a GOOD free flowing (no turbulance) exhaust without cats = 20+ HP

Keep in mind the condition of the exhaust you have now makes a BIG difference in gains you will see. If you have cats now that are old and you remove them you will see a larger improvement. If your mufler is a stock setup and you go to a good flowing muffler you will see more gains.

As mentioned earlier, you are not building HP in the car, you are freeing up what was being restricted by the exhaust system you are replacing. The 32HP gain I was able to get was on a LS1 Camaro with LG headers, 4" single mandrel bent tubes through a high flow cat and single chamber race series flowmaster. It was not a "pretty" exhaust BUT made good power and had a good sound.

 

Getting mine soon, woot woot.

 

i freed up lots with my 2055s as you know... got my magnaflow cat back today. going on thursday. hopoe that test pipe works out for ya!!!