Header Recommendation – Street Application
 

UPDATE: I went with RarlylL8 Equal Leangth Slip fit headers. See picture in Post #3

Original Post:

I have searched the forums here and other sites as well, but am interested in current opinions.

Currently I am running Thick Flange SSI’s and backdated oil lines and heat into an M&K 2 in 2 out.

I will be keeping the M&K.

I do not want heat.

I have not dyno’d my engine yet but will.

I want, 1 ¾” with 42mm ID.

I have a 3.2 Liter SS, built from a 78 3.0L with Larger Port Heads. I have 9.5:1 CR J&E pistons, Daugherty Racing Cams GT 108-2 (GE 60’s), PMO 46 Carburetors.

The options seem to be standard equal length headers, or short racing headers with street extensions into the M&K.

I would like to primarily go with the equal length short racing headers into street adaptors. I have looked at cost and the cheapest option is of course OBX $350, and they come in 304 stainless.

The best quality for the cheapest price seems to be European Racing Headers $700+ (w/ street adaptors), but they are mild steel and should be jet coated which adds another $200.

Everything else stainless is in the $1500 – &2000+ range.

I know that there is no free lunch, and you get what you pay for. But I am inclined to give OBX a try.

Please let me know other comaparative options if they exist.

Thanks, Shane

You have spent a lot of money on a nice build. Don't hobble it with cheap low performance headers. If your going to do that just keep your SSI's.

Thanks Brian
 

Great advice, I mounted some RarlyL8 Headers up last weekend and have 50 miles on them. Great performance, I think I lost a little in the bottom end, but no doubt it has more top end. And the sound is deeper, and probably louder. I have a little drone but not too bad.


http://forums.pelicanparts.com/uploa...1298272438.jpg

Shane

Do check out RarlyL8's headers. The best stainless steel, TIG welded by craftsmen, heating shielding can be added later if you sell it, dynoed for true performance. NON of these things are on the OBX headers. He can custom build them for you and, you don't need to replace the oil tubes (but you did). They fit on the M&K you have. Look great! Sound great, MADE IN THE USA, guaranteed forever, hand tools is all you need to install. You can sell the SSI's and the oil hoses for about 3/4 of the cost. It's a no brainer!!!!

For Street, OBX is not a bad choice. I was only able to get about a year on one side before a weld went bad... keep in mind though, primary use was for TRACK! Furthermore, I sent the bad unit back to the seller, and had a new piece within 2 weeks, no questions asked.

I run George's Euro now, and they are better build quality for sure. Performance wise? Exactly the same numbers were reached on the dyno.

I'm running 1 5/8 Bursh on my 3.0 and they work well. Not Buckley Racing but I;ll bet I'm within 10 hp or so of them. $500 compared to $2500.http://forums.pelicanparts.com/uploa...1298299217.jpg
Lindy

+1

James,

I did use the RarelyL8's! That is what is shown in my picture in the second post above. Thanks!
Here is another angle;

http://forums.pelicanparts.com/uploa...1298313254.jpg

Shane

You didn't mention what RPM range you are running. For just about anything except extreme (extreme!) high RPM running, 1-3/4" is going to be too big. All other things being equal the 1-3/4 will produce more HP at peak but you will pay in the midrange where you spend most of the time and the low end will lose even more.

1-5/8 is about the best choice for a really hard driven car with a 3.2 in it. If you are mostly doing a spirited driven street car then the 1-1/2" SSIs are already the best choice.

The headers shown are 1 5/8. You are right about loosing the low end, I haven't dyno'd yet but the sweet spot was around 4k with the SSI's now it is up around 5k with these headers, it spins up easy.

I like them Shane! looks great. I also like the face that changing them is only a 1/2 hour project. (after you get the old ones off).

Thanks James, The old ones did'nt have long enough to sieze up. I did change the studs again because these are thin flange.

It probably would have taken about 30 mins but I decided to port out my exhaust ports to make the step for the gasket blow out sleeve. That was not a fun experience.

Lindy,

What muffler are you running, I think I remember you had a single out? Also what RPM range is best tourque? Mine is a little higher than it was with the SSI's. I am finding that it is a whole different engine with the 1-5/8 " headers. It really felt a lot snappier with the SSI's but it ran out of breath quicker.

Shane

I took all my heat out.

See my post at:

http://forums.pelicanparts.com/porsche-911-technical-forum/439041-best-exhaust-header-combo-4.html

Should be fine with your M&K.

For the price, Check out the OBX, and let us know!

Update: I found my low end torque again.

Spent a few hours tuning, tweaking my carbs and dialing in timing and adjusting plug gaps.

The muffler and exhaust have mated nicely and it seems a bit smoother than it was upon initial installation.

All is very good, the power comes on at 4k and continues on up through 6k. Very nice...very, very nice!

This combination is very streetable and the car pulls of the line nicely, lots of pedal in every gear, third gear is awsome in the twisties, just a couple of quick stabs at the brakes here and there and the rest is all peddle.

Stay tuned, video coming soon.SmileWavy

Shane

Shane getting sneaky with the mods........................:D

Ha! You caught me. SmileWavy I have to get down there and see your progress, I have been peeking in on your thread.

I need to get to a dyno, I think I am done playing with this motor now.

I can't imagine it sounds better that it did the last time I rode in it.....It must scream now:eek:

Video Sound Preview
 

I posted this in 911 tech as well.

Quote:

Originally Posted by snbush67 (Post 5900275) <EMBED src=http://www.youtube.com/v/fgSFldVTxT8?fs=1&hl=en_US width=560 height=349 type=application/x-shockwave-flash allowscriptaccess="always" allowfullscreen="true"></EMBED>

Shane

Sounds awesome! I love my M&K also.