I am really interested in the results here. Sub'd!

 

My guess with you cam and it wanting to breathe even more you will see closer to 30rwhp peak and 15-20 throughout the curve.

 

I'm curious as to the gains. I have a new set of headers and X pipe sitting here and can't decide whether to install or not. I'd be surprised if you didn't pick up at least 20 rwhp but I'm assuming that you'd have the tune adjusted for them. Without the tune I doubt you'll see much.

 

Putting on headers without a tune is about as bad as installing a pulley without tuning, a big no no.

 

I'm doing something similar today/the next couple days... Basic mods with borla mid section and I put down 570 rwhp. I'm Switching to kooks 1 7/8 headers and green catted mid section with cutouts/ and stock muffs. I doubt I'll see 600, but fuck me if it's somewhere between 590-600.

 

I doubt I'll see 600, but fuck me if it's somewhere between 590-600.

Seems like an odd request.

 

Cant wait to see your results Random! I have searched this multiple times and have never found any factual data. I'm betting there will be a decent gain.

 

Glad these are finally on the way to you! Thanks again for your business Jesse, and let me know if there is anything else i can do for you.

I would love to see the results you are going to gain with your setup.. Sub'd!

 

Curious to see the results as well.

I know Matt keeps cam specs close, but is this more of a stage 1, 2, 2.5 cam? Even Matt's stage 1 cam's are pretty stout based on mine, so this thing is probably wanting to breathe well. I always struggle a bit with exhaust because it's not as clear cut the effects of backpressure, scavenging, etc on power. The further you get down the tube the lower the impacts of certain types of pulses and wave pressures. So it seems the largest effects will be dictated by the pipe shape and configuration closest to the heads/exhaust ports.

What I am interested to see is if there is any change in boost pressure and what, if any, correlation that has with power output. What if your headers allow better flow, with a corresponding drop in boost pressure? Since there are technically no other changes, you may not gain as much power because you aren't re-upping the boost back to the previous 15psi levels.

What if boost does NOT change but the car DOES add power? Does that tell you that you are pushing more boost that the heads and cam can make use of? Should you turn it down to save on heat created? Or does that mean you need to go bigger on the cam's intake lobe only, or do you need to increase intake AND exhaust duration/lift? This is where it can get kinda tricky!...

Then what if boost goes down AND power goes down or even stays the same? Will you blame the dyno? The weather? The other party in your little wager? I dunno. Eagerly awaiting results!

 

You just made my fucking head explode! LOL

 

Definitely paying attention to this

 

Although the header horse has been beaten to death, one advantage to coated headers is the lower under hood temps. Good luck!

 

Jesse, hurry the fuck up! Need results.

 

Sub'd

 

Also curious what the results will be. FWIW, I picked up 24 rwhp when I did headers (although a new blower, ZL1 lid, and heat exchanger were also done). Same dyno, but different days. Tuned before and after. That's all on stock pulleys.

 

Stock pulleys, you can see the other mods below. It did SAE 526rwhp/508rwtq on a 91oct tune.

 

very interested in seeing the results. you always hear about power gains from just adding headers it will be interesting to see what this change will entail.

 

Would be good to log all temps and boost pressures before and after. And of course power gains. May decide to go with headers on mine if they are worth more than 20 hp.

 

In for results. I have headers already. Make me feel better about the price tag since I'm not convinced.

 

I've installed the headers and catted mids a couple of weeks ago along with new plugs and the cai. Tomorrow is dyno day with some road calibration thrown in. Any idea on what this will put down? I will post results tomorrow later in the day.

 

Interesting...

 

Sub'd.. I did BB test pipes and made no peak gain.. My peak power did hang on for another 500 rpm tho.. So avg power was up. Diff day same dyno. Yes tuned before/after.

 

I'm glad you posted that, in another thread someone was positive all the gains from headers were from deleting the cats which I know is silly.

 

Doesn't sound like he wants $s

 

When you say "no other changes," do you mean no tuning changes either? You've got to keep the AFR in the same range and try to add timing to test the knock threshold to get a meaningful comparison between the two hardware setups. If your headers shed combustion heat more efficiently, you should run leaner and also be able to take more timing, so add fuel and advance timing. If you don't, then you aren't getting the full benefit of the upgrade.

 

I'm almost positive he meant no other changes as in no other modifications other than headers. I doubt a shop will add headers and beat on the car without loading a base tune for the header change first and then adjust from there with what the car likes.

 

Tri, I agree with you completely on the choke point. The same can be said for any orifice in the airflow path of the motor and that choke point will move around. It's the same reason why some people see massive gains with a larger intake and throttle body while others do not.

Personally when I did my stage 1 build the data that I had seen for 1 7/8 headers on cars running only an upper pulley (<600rwhp) suggested that the headers did not get you much bang for the buck. Maybe 15-20 rwhp. However, as many have posted on here you are running the risk of blowing out / melting the stock cats as you start approaching that 600 rwhp mark. Some have been fine at those levels with stock cats and some have melted them after some spirited driving. If the cats are flowing correctly that I would guess that the hp difference between test pipes and cats is minimal (again below that choke point theory). If you melt them then you are screwed and of course you will see a power difference.

It does appear from several builds on here in the range of 650rwhp+ that headers begin to net you more than 15-20 rwhp suggesting that stock manifolds start to become a choke point at those airflow values. It really just depends on the other aspects of your build.

It would be cool to see two different cars do a comparison of stock exhaust / test pipes / longtubes where one car was a ~550rwhp car and one was ~650rwhp to see the difference.

 

Properly sized high flow cats do not cost you much power. The problem is that in higher boost applications the heat kills them and as they deteriorate they start to cost major power and even cause engine damage.

The easier solution is to remove them if they are damaged rather then keep replacing them with new ones.

For some they will never have an issue because the car is not driven hard regularly. Others will have issues because the car is used at track events, mile events etc... My personal opinion is cats will become an issue not much past 600whp, ymmv

 

Did this happen yet?

 

I think you should charge a fee for the results to help reimburse your costs.

 

Good call!

I'm going to sit on the results until a case of Ruination IPA is shipped to me at no cost. You guys can take up a collection among yourselves - but I will accept $20 via paypal as a suitable substitute.