Plus sized SSIs

[Jonny042]

These showed up the other day:

[Hulley]

The SSis look so good!

[Jonny042]

They are pretty nice!!!

[Jonny042]

Eagle eyed readers may note the DHL shipping label with the origin "BRU".

According to Dansk these aren't available in North America at this time which completely mystifies me. They are being built in limited quantities so that might be the reason, I got in on the second batch after missing out on the first.

I would prefer the 1mm bigger 42mm Eisenmann's which are every bit as nice, but the pricing on them has gone through the roof. Although to be fair the 41mm SSI's are close to %50 more than the 38mm version.

[Duc Hunter]

Stunning looking. My question.....the "larger" 41mm SSI's.....are for up to what horsepower engine? Or maybe what capacity (3.0, 3.2, 3.4, 3.6, etc)??

[theiceman]

i got mine of craigslist many years ago. now i want to go measure them as i have no idea what i have on my car .. but they sound nice

[Bill Verburg]

Originally Posted by Duc Hunter

Stunning looking. My question.....the "larger" 41mm SSI's.....are for up to what horsepower engine? Or maybe what capacity (3.0, 3.2, 3.4, 3.6, etc)??

Here's the theoretical flow into each pipe for 2.7 thru 3.8


the original SSI's that I had back in the day were 35mm ID w/ 47.6mm collectors, I've used them on 3.0 thru 3.6, they were fine for the 3.0 Carrera 3.0 and a nice improvement over stock

on a 964 3.6 they were fine around town at lower rpm but lost ~20hp at 6500 on the dyno

So it depends on use, displacement and the rest of the engines design, generally for stockish 3.2 and up 39mm ID(42mm OD) is much preferred

stock 964 use 41.275" ID and stock 993 uses 39mm ID but w/ a more efficient design than 964
factory race 3.0(SC/RS & RSR) used 42mm ID, 993 race used 42mm ID

I've used stock 993 and custom 42mm ID on 3.6 and 3.8 RS and don't se a difference on a dyno or seat of the pants

[snbush67]

Very nice!

[brighton911]

Thanks for the very helpful empiricle data Bill.

[Jonny042]

Originally Posted by theiceman

i got mine of craigslist many years ago. now i want to go measure them as i have no idea what i have on my car .. but they sound nice

They will be 38mm OD. These bigger ones are only recently available.

[Jonny042]

Originally Posted by Duc Hunter

Stunning looking. My question.....the "larger" 41mm SSI's.....are for up to what horsepower engine? Or maybe what capacity (3.0, 3.2, 3.4, 3.6, etc)??

Like Bill says..... it depends. But in general these should be a benefit over the 38mm version to 3.2L and up and maybe even a highly tuned 3.0.

The choice of 1-1/2", 1-5/8", and 1-3/4" primary diameter has been debated and covered many times. Headers in these sizes have been readily available for some time, if you're willing to go without heat. Of course there are a few aftermarket heat choices but IMO none quite as elegant as a factory style heat exchanger like the Eisenmann or SSI.

[Duc Hunter]

Originally Posted by Jonny042

Like Bill says..... it depends. But in general these should be a benefit over the 38mm version to 3.2L and up and maybe even a highly tuned 3.0.

The choice of 1-1/2", 1-5/8", and 1-3/4" primary diameter has been debated and covered many times. Headers in these sizes have been readily available for some time, if you're willing to go without heat. Of course there are a few aftermarket heat choices but IMO none quite as elegant as a factory style heat exchanger like the Eisenmann or SSI.

Thank you Bill and Jonny. I agree 100% with both of you in that "it depends" on many factors, on one hand.

On the other...Bill said it best. "On the 964 3.6 they were fine around town at lower rpm but lost ~20hp at 6500 on the dyno." That's not a light switch, that at 6,400RPM they lost no HP vs better solutions, and at 6,500 they suddenly lost 20. I am not even sure if they lost 20 to the stock setup, or something better like B&B headers and a good muffler either. Regardless it's a sliding scale that probably started back at around 5,000RPM, and probably really kicked in at 5,500 when the intake flap opens. My particular car is my 1975 rat rod, so its light and SSI's would fit the look/feel of the car aesthetically. The car doesn't need any more power than it already either, its plenty quick. That said it's all personal, and for me I would not want to put headers on my street car that "cost me" power, and certainly not 20HP near redline.

I just keep hoping for the unobtainium of SSI's that are sized properly for a mild 3.6. I also think its just about impossible to do because the packaging required for SSI's shape etc vs the tubing size required for proper flow for a 3.6 don't mix. But hope springs eternal!

And again beautiful headers! Should be an amazing setup for the OP.

[Jonny042]

Originally Posted by Duc Hunter

I just keep hoping for the unobtainium of SSI's that are sized properly for a mild 3.6. I also think its just about impossible to do because the packaging required for SSI's shape etc vs the tubing size required for proper flow for a 3.6 don't mix. But hope springs eternal!

And again beautiful headers! Should be an amazing setup for the OP.

Well, I'm putting then on a 3.4, albeit a 10.5:1 twin plug with ITB's and relatively aggressive cams. Horsepower will probably be similar to a mild 3.6.

These would probably work well for you. Any bigger and you're getting into pretty rarified territory, mostly reserved for race cars where low RPM driveability isn't a concern.

[Jonny042]

Just checking, you know that Bill was referring to the smaller sized SSIs, right? The 41mm version hot off the presses in Denmark have considerable more flow capacity.

[GG Allin]

I've been waiting for something like this for my relatively high hp 3.6. Sure would like to have heat.

[pampadori]

Never expected to see GG Allin on a Porsche forum talking about headers

[theiceman]

Originally Posted by Jonny042

They will be 38mm OD. These bigger ones are only recently available.

ah thanks

[Jonny042]

For you guys with bigger motors and deep pockets who decide you absolutely need that 1 extra mm of flow in the primaries (it DOES calculate to be 5% more pipe area) the Eisenmann 42mm HE's are pretty nice.

Originally Posted by Jonny042

[Cairo94507]

Those are beautiful.

[theiceman]

there's absolutely nothing wrong with a nice set of 38s .....

someone want to remind me what we were talking about again ???

oh yeah ...