New equal length headers

[Larry_Ratcliff]

It seems to me that a reasonable trade off was made. If the primary's were any longer then you would have to go with a muffler similar to the B&B. To me the fact that I can keep the muffler that I have is what makes them attractive to me. I am curious to see the dyno results with these vs others but I suspect on my 3.6 they will have to be better than the SSI's I have now. If you consider the length of the primaries on the SSI's these are surely no worse than that and benefit from what looks like a well designed collector and larger pipes. I am more than willing to leave a little mid range on the table to not have to redo my back bumper ....

I have found many times that the 'best' is often 2x (or more) as much and really does not deliver such measurable differences. I really doubt this system is leaving all that much on the table. Also, available with heat is a very nice feature.

I guess if you are a racer in a class trying to optimize the hp within the constraints of the class you run in then your goals are much different than a street performance car. I for instance would not spend 10K plus on head work on my car. However, a friend of mine trying to be competitive with his 356 spent over 10 K so he could have custom valve guides lightened valves perfect ports reshaped combustion chambers on and on... However, the $ spent vs just a port and polish from a shop like Ollies was a 5 x difference... I suspect the net difference in hp was about 5 to 10. I hope the comparison here makes sense.

I cant wait to see the heat exchanger version.

[911st]

There has been kind of a hole in the market for a good header with heat at a reasonable price. SSI 1.5" headers leave a good 10 HP on the table for stock block 3.2's over SSI's or stock HE's with a cat bypass & sport muffler.

Larger tube B&B's are about the only other option and are expensive and many do not care for there mufflers ability to hold up and it dose not fit off the shelf Porsche Mufflers.

I suspect primary length is more important with carb style cams that have overlap where savaging can be a benefit.

With mild SC, Carrera, C2 cams the primary length dose not seem to be so important as there is not much savaging potential.

It is more about getting the exhaust out without the events colliding which is what equal length headers are about.

Per SW of 911chips.com a tuned 3.2 with 1.5" tubes and Phase 9 race mufflers and chip pulled 249fwhp. Larger headers with full race exhaust made 10hp more.

I suspect the key to success here is the quality, equal length, ability to use a stock style muffler, fair price, but most importantly effective heat exchangers.

[RWebb]

are you saying that a stock 3.2L motor with SSIs can have 10 HP more if using something else?

I am having a little trouble parsing your sentence structure above, but that is counter to what I've heard from people who have dyno'd thousands of motors.

[911st]

Sorry, I just got off a 9 hr jet ride.

There is a great comparison around here some where that SW did from many dyno runs.

[911st]

Here it is:

Originally Posted by Steve W

I've compiled a spreadsheet of expected power output values based on a internally stock 3.2 Carrera motor based on dyno tuning data that I've accumulated from many cars over the years. The output values are given in engine flywheel hp assuming a Superflow engine dyno such as at Jerry Woods. You results may vary, based on the flow quality of your muffler, but for a healthy 3.2 motor, I estimate these values to be accurate to within 2-3 hp of each other.

Also, there are a lot of dyno charts on 911chips.com

[TimT]

UPS left a set of headers on my steps yesterday..

The build quality of these is impressive. The slip joints will really help with ease of mounting.

I have to cut the stubs off my set since my engine has 38mm exhaust ports (small disp/NA) , and the o.d. of the pipe is 38.07mm or so..Got my old headers off in about 30 minutes.. So in reality you could get these installed in around 1-1/2 hours.. (if you have co-operative exhaust hardware, my engine gets torn down once a year so the exhaust nuts are easy peasy to remove)

Pictures comparing M&K headers with Narbel (on my newly refinished vertical grain Fir floors)







I had O2 bungs and v-bands welded on..

[911st]

Nice!

Any chance you can measure the length of the primary tube on each set?

Those shorties are just begging to go straight and have a turbo stuck on each one.

[Larry_Ratcliff]

Originally Posted by TimT

UPS left a set of headers on my steps yesterday..

The build quality of these is impressive. The slip joints will really help with ease of mounting.

I have to cut the stubs off my set since my engine has 38mm exhaust ports (small disp/NA) , and the o.d. of the pipe is 38.07mm or so..Got my old headers off in about 30 minutes.. So in reality you could get these installed in around 1-1/2 hours.. (if you have co-operative exhaust hardware, my engine gets torn down once a year so the exhaust nuts are easy peasy to remove)

Pictures comparing M&K headers with Narbel (on my newly refinished vertical grain Fir floors)







I had O2 bungs and v-bands welded on..

those look sweet! I cant wait to see the heat exchangers.

[mnmasotto]

If someone ordered a set in 1.625" today what would the turnaround time be?
Thanks Mark

[TimT]

This is a very good article on exhaust design....

http://www.n2performance.com/performance/exhaust-systems/index.htm

I ran the numbers on these headers... yeap with short primaries I give up bottom end..

ok... what 2.2 or 2.4 Porsche 6 has any grunt .. to begin with... btw I'm using these on a full race 2.4

[TimT]

Found a picture of the headers that were on our GT3RS at LeMans

shorties... the whole torque curve shifts right..

oops posted wrong picture

[TimT]

Porsche Motorsports headers..

[911st]

Originally Posted by 911st

Nice!

Any chance you can measure the length of the primary tube on each set?

Those shorties are just begging to go straight and have a turbo stuck on each one.

[RarlyL8]

1.625" are in production right now. Each production run lasts a couple of weeks. There are 3 sizes available; 1.5", 1.625" and 1.75" for both 911 and 930.
Primaries are 17.5" +/- 0.25".
We are making a set for a twin turbo application as well. One aspect of the design is that it will accommodate other applications with a simple secondary pipe change.

[1979911sc]

Didn't see any of these headers available for a n.a. 911 on host's website... Are you still making them?

[Pierre911SC]

I just bought & received a set of 1 5/8 in. headers from him.
rarlyl8.com

[RarlyL8]

Yes we are still manufacturing these headers. Our host has not picked them up yet but probably will at some point. Power is enhanced in the midrange and top end without taking away from the bottom on 3.0L+ modified engines.

[paulgtr]

only as headers, or is their a similar set up as heat exchangers? running SSI's now and wonder if I am giving away top end. doing more track time now so running near redline is common.

[RarlyL8]

No heat exchangers for the 1.625" headers right now but we are working on it. The 1.5" and 930 headers now have revised exchangers that bolt-on.

[paulgtr]

I should hold off on any changes until the bigger headers have the option for H.E. otherwise the 1.5" are too close to what I have already, yes?