Putting a 2.7 -6 in my white car, looking at headers it seem they come in three diameter sizes.
So what size would work best for a 2.7?

TIA,

Jeff

Street car?

I'd use the 1-5/8" tubes if it's a stock engine either CIS or carb'd. That's what I ran on mine when it was a carb'd 2.7. That was true the Porsche sport muffler all the way to SuperTrapp's and megaphones. I like the SuperTrapp's for their "tuneability" (... is that a word?) which is useful if you have a dyno nearby.

If you go with larger your low-end torque will suffer as will your ability to get proper jetting at low RPM. The 1-3/4" tubing, (in a huge generality) is good for ~300hp and above, but even then at higher RPM's. For a street car the tuning on the carbs gets harder as well with either too-large carbs and/or exhaust. They have to work together.

Unless I'm building a fire-breather of a 3.4 or above, or a cammed up 3.0 - 3.4L engine I wouldn't consider large tubes because you're still gonna need some torque driving around town.

Of course there might be someone here who has setup a specific exhaust/intake balance and can chime in on their configs.

Good luck!

Thanks for the reply, sorry here's more info.
Street car, stock 2.7 with CIS , haven't thought about muffler yet, any recommendations welcome.

Thanks again,

Jeff

To me a "sport muffler" made from the stock Porsche (Helmholtz resonator) banana muffler sounds just right, but it might be a bit loud for some. But then I don't need quiet to make myself happy. Phase 9's (Jerry Woods or Smart Racing... I can't remember) used to be good but I haven't thought about them in a long time and they might not still be around.

The stock 2.7L muffler is right for your CIS and it's not that tolerant of huge differences in backpressure. Any of the above will bolt onto the headers just fine. Regardless of which you choose, I'm fond of SS these days... just less trouble in the long run.

2.7, 1-1/2" would do, I like the quality of MSDS.

Correct on the tube size 1 5/8" for the 2.7L street\ some track use 9146.
Remember that headers are built + sold with their tube sizes spec'd in outer diameter (od).
So the od minus the gauge thickness of tubing, ours(MSDS) =16 ga. will equal the inner diameter (id). So the 1 5/8" headers will have an inner diameter of 1 1/2", which works perfect on the 2.7.
Thank you Mark for using our upgrades
914 world members always get the forum discount, pm me if you need a set !
Marty

I haven't run any exhaust through mine yet, but I can see they are very good quality and the price was very right. I just referred Doug Gale of Trackmasters Racing who was about to spend almost double for some B&B headers for a conversion he is doing for his octogenarian mother who daily drives her 914. He's going to have McMark fashion heater boxes for them as well.

Bottom line, MSDS!

I got a Dansk sport dual in/single out with MSDS headers on a 3.2. Outside the car at idle it doesn't sound like a 911 anymore, although inside it did. It's definitely louder than stock, but not painfully so. Also, no drone. Cruising in the low 2k rpm produced a glorious stocatto. For comparison, I once had a dual monza on a -4. That thing was so loud I could only tolerate it a few weeks before taking it off and ultimately throwing it away. I'm not a track guy so can't comment on performance of the msds/dansk combo.

Thanks everyone for all the great info, did some more research and decided on my exhuast. Marty offered me a deal I couldn't refuse......a discount.

So its going to be MSDS 1 5/8" headers ceramic coated, and the sport dansk muffler from patrick motorsports.

Click to view attachment

Thanks again everyone, talk soon Marty,
Jeff

Hey Jeff, you could have Marty put a bung for an O2 sensor in one or both exhausts. Can plug when not used.

Beware the sport mufflers are pretty loud. You will notice quite a few used ones on Pelican. I tried one and did not like the looks on my neighbors faces so I switched back to a quiet bursch muffler.

Agreed. I understand a dual out will be loud. I live in a tract and will likely switch to a stock Dansk in the future in order to keep the peace.

Thanks for the info, sooooo, may have to think more on the muffler.

Jeff

I found a stock 914-6 muffler NOS on eBay. I'm going to start with that and see if it is too restrictive.

Hey Jeff, I'm using 1-5/8 headers and a Dansk two in and two out not too loud and nice sounding when giving the gas. John

We need to get together, love to check out the new ride and hear it too.
Glad you got it going John.

Jeff

I have the sport muffler on Huey and never thought it was loud at all. Louder than stock? sure, but it has that 'early 911' sound vs sounding like a VW (unless you're into the VW sound). Personally, I love it and so does everyone that hears it.

Thanks, I don't mind louder than stock, as long as its not annoying, sounds like you and John have the same muffler I was thinking of, guess I'll have to hear Johns, then go from there.

If Rob would ever get his going I could hear his too.

I do like that 911 sound, it's the only reason I used to drive the boxster....just to hammer the throttle and listen to the sound, other than that didn't really care for the car.

I've got time, the car is still on the "list" waiting to get into McMarks shop for the engine mount, and other conversion goodies.

Jeff

Rob's will be done later this month or early next month.
Kelly's (echocanyon) is here too and has a Triad, which I like and is half the price.

In the midst of this decision right now, and looking at three finalists:

-M&K 2-in, 2-out or possibly something a bit custom
-Patrick Motorsports sport muffler as pictured here
-Monty 2-in, 2-out

Curious to hear back from others who have any of the above...

I guess I need to go visit Sonoma, I've been wanting to hear a triad.

Jeff