Equal length headers

[Boost231]

WOW! that's hot! i love the v-band clamps are those custom single slip collectors? or did you get them from burns' stainless? you've handled thermal stress very well.

the longer the headers, the more it enhances torque, but also within a smaller rpm band.

the pictures he posted dont do the car justis

 

[wbrophy]

Equal length tubes does not mean that the tubes will flow the same unless all the tubes have the same bends. Bends cause resistance to flow, so to get a true "equal flowing" set of headers the tubes need to be made different length.

 

[Alky V6]

WOW! that's hot! i love the v-band clamps are those custom single slip collectors? or did you get them from burns' stainless? you've handled thermal stress very well.

the longer the headers, the more it enhances torque, but also within a smaller rpm band.

Thanks man. They're Burns Stainless Turbo double slip collectors.

The length and diameters (single step 1.625 to 1.75), along with the rest of the package (cam, intake design) target a hp peak at 6750 rpm. The torque range is rather large really. Peaking at 5200 and lightly ramping down to 7200 rpm where the drop off begins to steepen. On one run at Vegas I short shifted 3rd by accident. Nerves. Big rpm drop from 1st to 3rd. I only lost 2 tenths on the run. The engine pulled it rather well.

 

[Alky V6]

Equal length tubes does not mean that the tubes will flow the same unless all the tubes have the same bends. Bends cause resistance to flow, so to get a true "equal flowing" set of headers the tubes need to be made different length.

That's correct. Simple fluid dynamics for some. Still, the attempt was made. I believe sonic waves aren't affected as much by the bends though.

 

[SAMBALLS1]

I'm not sure how true this statement is, but from what I understood it's always good to try and keeps the tubes equal length and to try to keep the crossover as short as possible. The idea behind it, is that you want to keep the exhaust temperatures at high as possible... Logically, hotter air has a faster velocity and as the length is kept short not much heat is lost.. (Gives for fast spooling and and squeezing all the power out of your car.)

Just verify some information given to me?

 

[Alky V6]

I'm not sure how true this statement is, but from what I understood it's always good to try and keeps the tubes equal length and to try to keep the crossover as short as possible. The idea behind it, is that you want to keep the exhaust temperatures at high as possible... Logically, hotter air has a faster velocity and as the length is kept short not much heat is lost.. (Gives for fast spooling and and squeezing all the power out of your car.)

Just verify some information given to me?

There are a few schools of thought on header design for a turbocharged engine. The problem is, they all have merit. There is the plus side and the negative side to each.

It is very important to first consider the ultimate configuration and usage of the engine.

Take my case for instance. From the very start I knew this would be a race car only. No street use. I was interested in obtaining the maximum output that I could for the heads that I chose to use (M&As) with a reasonable boost level (around 30 psi), torque and horsepower wise. As far as the choice of short tube, untuned versus long tube, tuned exhaust, since my main goal was maximum output and not the quickest spoolup possible, I chose tuned exhaust. There is just no comparison in that arena. Again, from the very start I also knew that long tuned primaries would mean a longer spoolup time. This is true. It takes a god awful long time to spool. But,... the use of nitrous oxide injection to spool the turbo was also in the plan from the start. So now I have ended up with the best of both worlds. Tuned exhaust to maximize power AND a quicker spoolup than any header design and/or tuning stradegy (ALS) on earth could ever provide.

 

[Alky V6]

I don't have any real data to back up my opinion but I think the gains from an equal length header would be minimal. The reason I believe this is because a well disgned turbo system would have 1.5 psi of exhaust pressure per psi of boost which would mean 40+psi of pressure in the headers which means the exhaust has to force its way into the headers as opposed to a N/A type of application where exhaust can flow thru the header. On other boards this gets argued all the time. People always claim that equal length primaries are better than log style manifolds but no one can prove that the log style mainfold set ups are down on power compared to the full equal length set ups. There are a ton of fast LSX cars using 6.0 truck mainfolds. There are just too many cars going fast with log style mainfolds to believe the full length headers would be a big improvement and worth the costs and hassle. Just my opinion.

I had a discussion at length about equal length versus short or log manifolds on my thread in the time slip section. Look for the thread titled 9.28 @ 147. Should be on the 3rd page.

 

[cstavro]

those burns collectors are a big part of getting headers to work well. they're not cheap. don's setup is ideal, and won't crack from expansion.

TurboCollectors

 

[JayC]

those burns collectors are a big part of getting headers to work well. they're not cheap. don's setup is ideal, and won't crack from expansion.

TurboCollectors

And people wonder why you cant build a set of headers for $300 in the US. Both of the sets of prototype headers I had built have Burn's collectors on them. $700 tied up in just collectors.

 

[Alky V6]

Wow. That is so true, it's not even funny. If I had to do a set like those again for someone, I'd probably charge 3,000 and I'd still be losing money.