Think of an organ pipe... A specific volume of air will tune to a specific frequency.. This is your header collector.. So, by tuning the collector volume you can tune the RPM range at which the header will 'resonate', or scavenge with the highest efficiency. Depending on what cam, and what heads you have this will make quite a difference on power output. The primary tube is sized for the flow of the motor, and is length tuned to get the pulses arriving at the collector at the right time. This all enhances the power output when properly tuned to the RPM range it will be most useful.

In simple generic comparison terms, a longer/larger column of air will tune to a lower RPM. A shorter/smaller column of air will tune to a higher RPM. So, a long tube design header with a proper collector will build significantly higher torque than a short or mid length header design.

The reason our cars tend to build more torque with catalysts installed is the terminating effect they have on the system. Without catalysts, the collector volume INCLUDES the Y-pipe and to some part the intermediate pipe. The cat will act as a 'terminator box', since the exhaust pulses diffuse as they expand and slow down passing through the core of the converter. To the motor this looks like open atmosphere for the most part, and looks like the end of your collector. The trade off is flow - at higher RPM's and higher flow rates, the core can only pass a finite amount of air, and in the upper flow rates it isn't as efficient. Then things start to stack up and your power begins to fall off.

If you search the 'net long enough, you can find formulas to calculate the proper header primary tube diameter and length. The collector volume is generally best found either on the dyno or (preferrably) the track.

 

thank you very much for your reply's....i only have one more question...i am planning on getting the cam and heads that john roughhammer's campbells car has.....the stage 2's and hammer cam...so what would go best with that....a set of hooker long tubes or good ol macs that everyone else has???

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DaddySS:
<strong>Anyone have comments/ experience with TTS?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I helped a friend install TTS headers. Install was simple, they look great, and no problems at all.

 

yes friend stick with the FLP's and you wont go wrong i have them and thay rock man i love the way thay sound and i never had any problem with. the 2 day when i got my car back from thunder raceing i took the cat's off took me about 35 min's to take both of them off. and thay sounded great <img border="0" alt="[Firebird]" title="" src="graemlins/formula.gif" /> try it you wont go wrong. i would not try any other header out there i can tell you that and i been dealing with header's for a long time. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> thay go in easy fit good No problem's with the gasket. just your computer need's to learn the new header and getting usted of the new mode is all.. for the O2 <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

well, i dont know why nobody has really mentioned the slp's. i really like my set, and unlike ALL of the other headers out there, i will never have to worry about the slp's rusting (stainless). i have seen a set of mac's, and a set of flp's that were pretty rusted up. the slp install sucks, but the return is awsome, and low'end torque isn't even comparable to what it was!

 

what would happen if you have a supercharger (4psi procharger)and you kept stock manifolds but cut off cats, and got o2simms? wouldn't that create some good flow? please reply <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />

 

The hookers are cheaper than the MAC's because the hooker price probably didn't include a Y-pipe. I have macs on my daily driver for about a year now, uncoated, and have just a little surface rust on a few spots. I made 392hp with MACs and stock 98 tuning on my heads/cam car, so they make good horsepower. They were a BI*ch to install though....good God!!! Go with Hookers for the money with their Y-pipe, weld in a flowmaster Y-pipe collector, and you'll have an awesome set of headers.

GregM

 

Long tubes increase it a lot in the lower rpm range (3000ish). Top end you see some gains as well but may not be enough to justify getting long tubes.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by restoman45:
<strong>well, i dont know why nobody has really mentioned the slp's. i really like my set, and unlike ALL of the other headers out there, i will never have to worry about the slp's rusting (stainless). i have seen a set of mac's, and a set of flp's that were pretty rusted up. the slp install sucks, but the return is awsome, and low'end torque isn't even comparable to what it was!</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sorry to be the bearer of bad news, but your SLP headers will rust. They technically are stainless steel , but are 409 grade. 409 has a high chrome content which is wonderful for high temp use. When you think of stainless steel usually think of 304 or 316 which has a high nickel content and does not rust. 409 does not have this. So if you scrape your coating off, your headers will rust- just like the mild steel ones.
I think SLP uses the stainless thing as more of a gimmick to sell headers by making people think that they are the 3 series pretty stainless. Just like in the advertisement they say 44RWHP from installing headers. Yeah maybe on a stroker motor or H/C car.

 

They gain the 44rwhp in the 3000 rpm range area, not at peak. It is a misleading ad.

 

From what I understand (and I'm new, so I don't understand much <img border="0" title="" alt="[Embarrassed]" src="gr_emb.gif" /> ), long-tubes will not produce more horsepower on a stock (heads/cam) car than mid-lengths. Is this correct?

With that in mind, anyone have any experience w/ the Bassani mid-lengths? I will be in the market for headers soon and don't want to deal w/ all the banging b.s if the long tubes don't make any more power than a mid length.

 

yea, i know they arent the best 316 or even 304, but 409 is better than nothing. and for what its worth, long tubes will always be better than midlengths...do u ever see any old school 60's ss's having mid-lengths? u only see a bunch of 5.0 guys running the shorties/midlengths...they are a good dollar/hp deal, but if u want the best, lt's are the way to go. they are really pricey though. its all about scavenging the exhaust in the most efficient manner, and long tubes are far superior. my .02

 

409 stainless steel will NOT rust like regular mild steel. It may discolour with a bit of surface rust without the coating, but it won't rust all the way thru like mild steel.