cjv,
I realize that heat is energy of course. But I am unclear why heat loss through a thin walled header will affect the airflow to the turbos. Can you explain?
I certainly understand the exhaust velocity trade-off.

Smaller diameter=faster velocity=higher backpressure

Larger diameter=slower velocity=lower backpressure

There must be a happy medium and that would have to vary depeninding on type of mods. It sounds like Porsche got this right with their design given the stock setup??

That said, I would tend to think a header's effectiveness at spinning the turbos strictly relates to exhaust gas velocity (due to diameter of header pipes) and backpressure effects on engine's functions.

I patiently await enlightenment.

 

Dang.. I love carnage.

 

kpv, the hotter you can keep the air the less dense and therefore it can move through the exhaust faster. of course there comes a point where there starts to be a negative relationship here too. does that answer your question?

-Steve

 

Ken,

Heat is energy. If your headers are glowing red, the heat is disapating through the header walls, not the impellers. I discovered this after Stephen did his test with the S Car Go headers on Ryans car. There were some other problems, but we discovered a dramatic difference in turbo response when we wrapped. On my car we also tested the 1-5/8" and 1-3/4" headers. I stayed with the 1-3/4" tube size because the two were equal in the mid rpm range and the 1-3/4" size was superior in the upper rpm range. Think about it. One reason the stock headers perform well is because they a well insulated with the thick cast iron.

 

LOL, I am only a dyno queen on the front. It is the safest way to descibe what I do with my car

 

Yes, everything has a cost. Are you saying the Stage IV (which this thread is taking about) is made for little old ladies? I would be very surprised if the Stage IV lived for more than 70,000 miles. It may be in the range of 50,000 depending on who drives it.

I believe with my multiple ranges. I will see the above mileages. Again, I am running much more power and torque. Oh yes, that N2O. I don't want to get you going over that one again.

 

Chad,
The headers that were on Ryan's car were over twice the length of the factory header and 1 3/4. Here we go again. Velocity. You don't have them on your car anymore....They were fine from our redline on. Not practical for street application unless the autobahn is on your way home.

 

Then why did they work on my car when at the time it was only producing 516 rwhp? Could it be they were tuned?

 

The AFR was leaner with the long headers than stock. They should have made more powe. If they are so good why aren't you running them? The last set of numbes you posted showed your max power at 6900RPM.

 

This feels like a deja vu!!

 

LOL, you are telling me!!!

 

Stephen,

If you install the headers and they run lean....good news. Add more fuel. Fuel makes power and now you are not lean. I believe this is what tuning is somewhat about.

Why am I not using the S Car Go 1-3/4" long headers? Good question and it needs a response. It is called technology marching on. The short headers proved to be an improvement. Since that time I have actually tested two different S Car Go design's. I am currently using the 1-3/4" tube size short header.

Please remember the 1-3/4" S Car Go long header was installed about 1-1/2 years ago. We were making 516 rwhp at the time. I don't believe the Stage IV existed at that time and it hasn't been until the recently released Stage IV GT that this old bench mark was surpassed. Again technology marches on.

 

.3 points ???
Granted, I will give you that if they were near 13, but we are talking 3 10ths. As I said before that the application is not practical. 6900RPM is not a range most want peak HP. In that regards the TQ it took you until a few months ago to catch us. We tuned those headers as I explained before and they made nothing...Why? because we don't run our cars to 7400RPM. This is a documented fact by many, not just me.

 

I also agree that the header issue is looney. I would be the first person to buy them from SCARGO if they had a header/ecu package that guaranteed horsepower.

I would be willing to supply my car as a test mule to settle this once and for all and then buy the stuff if it works. Would SCARGO be interested in coming up with way of doing this? I live 4 miles from Perfect Power, who is one of their dealers, and they have all the stuff in stock. I will pay for dyno time and have independent results reported. I also have a brother who has a car that is identical in speed to my car and will be happy to post pre and post modification videos. This will really represent the real world CJV as most of us cannot ship our car to SCARGO.

Let me know what you think of my idea Chad.

David

 

LOL you probably have more Dyno mileage than I do drag racing?