ehall

ST, How about explaining to the class why it is so important to have equal length runners in the headers. That might better qualify your first post in this thread.

streckfu's

Would it be to balance the pressure waves formed by the exhaust gases with the exhaust valves?

Tms951

Thanks for the info guys. I had already read the European car article but not a few parts earlier about the B&B headers and how they increased down low torque and lowered spool up time sounded good. The loss up top sounded bad though. I do how ever like the idea of the SFR stage one headers. I would like to lower spool up time as much as I can, do you think I will lose top end power on my 2.8L, lindsey super 75-T4 turbo engine compared to stock headers?

special tool

No. You will gain a small amount of top end with the stage 1.

RolexNJ

As ST said, I'm sure youll gain some top end. But I would call Tim @ SFR and talk to him. Unfortunately, the "core" of dealing with your spool up isn't your header choice, but rather your turbo configuration. I can speak from "personal" experience. That's not to say that the LR turbo isn't a good turbo, for it is and pulls very hard to redline. But by comparison to another vendor, well, let's just say it's night and day difference!!! One word comes to my mind ---> www.vitesseracing.com

Rick

OK...so if the father & mother get divorced are they still brother & sister?..

Sorry my bad...got confused as to what state we were talking about here...

Tms951

ya, I'm thinking of getting a turbo from innovative with dual BB and stage 5 turbine wheel see what else they sugest to get it to spool quicker, First I have to see what my present turbo is like on my set up. But I thought the stage 1 headers would be a good combo with a slightly smaller innovative turbo.

RolexNJ

Trust me, or learn the hardway like I did. I was forewarned at one point in time too by several people. You will need John The Man when it comes to EMS stuff - custom MAF chips, MAF, an "optimal" turbo for your car, and other go-fast goodies, he is bar none the best in the market. Take my word for it, forget the dual BB talk to him first! Anybody who's a regular on here knows the things I went thru with my car, and you dont want to make some of the same mistakes I did. Ok, I said my peace more than enough in this thread and tried to help. I'm out, good luck and peace...

jimbo1111

I believe that equal length headers send a steady rhythm of exhaust gases to the turbine. When the header lengths are mismatched exhaust gases crash into each other causing some backpressure. One could go with a smaller turbine to recapture some spoolup and still benefit by having a better flowing topend exhaust with less backpressure.

Skunk Workz

Reason for the SFR St2 headers being so good is that they retain exhaust velocity far better than the stock ones... in other words,their "high-rpm inertia scavenging" is better. That's why Tool sees a bigger improvement the higher hp he gets...

streckfu's

Doesn't this:
Lead to this:

Skunk Workz

Nope...it's easy to have equal length headers which are way too big in diameter to retain the velocity...if the diameter is too big,the gases slow down,and then you ( effectively) get higher pressure in the primaries...which block the next "shot". Pulse "wave" tuning by lenght is all and well,but if you don't have "forward motion" in the gases,you don't get much effect from the pulses.

streckfu's

Thanks.

Porsche-O-Phile

Wow.

jimbo1111

The diameter of the tubes determines the velocity of the gases. The lenght of the tubes before the collector determines the rhythms. Two different subjects. Both are needed for the overall design. The collector is also involved in processing the gasses. The overall lenght is critical in heat dissipation. Tim design seems to be the best overall but one thing that both systems lack is thermal insulation to keep heat from dissipating. Porsches original design had a dual chamber with a ceramic insulator to retain heat. I dought coating are as good. That said i still think the benefit of 4 into 1 outweighs the thermal protecting losses. I'm sure there is still some improvement to be made in that area.