Pelican Parts Forums - Which Muffler? Dynomax, Magnaflow, M&K

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We're getting closer. Again, cat arraignment is for access during competition tech inspection. Will have non-cat pipe also for other use.

http://forums.pelicanparts.com/uploa...1657416530.jpg
http://forums.pelicanparts.com/uploa...1657416530.jpg

Looks great.
Can't wait to hear it with, and without, that cat.

Wow, now I understand why it's taking a couple of weeks. Looks beautiful.

That is a really great looking install! I can't comment on the actual quality of the welding (not an expert and can't tell if they "backpurged" or whatever) but the fabrication design looks fantastic!

Waiting patiently to hear what you think of the end result.

Quote:

Originally Posted by pampadori (Post 11741381)

The pictured welds are extra beautiful because they're absent.
That whole exhaust is just tacked together.
What we're waiting for now is final welding and re-fitting to the car.

How long are the primaries? and what diameter ID is the primary?

Quote:

Originally Posted by 3literpwr (Post 11739999)

A couple more images. Should be welded and have heat added today.

http://forums.pelicanparts.com/uploa...1657550464.jpg

http://forums.pelicanparts.com/uploa...1657550464.jpg

http://forums.pelicanparts.com/uploa...1657550464.jpg

These look a little long to me.I have built step headers for 37 years.Just curious.Fred

They are 1 5/8 OD and mate with my 38mm ports. 24” primaries and spring mounted collectors. If they are too long, it’s an easy mod. Also, rally car with a focus on mid range.

First, the workmanship on these headers looks really good! Nice job on fabrication.

The 3.0L SC Engine with stock intake plenum generates peak torque at around 5000RPMs.

The 3.2L Carrera Engine with stock intake plenum hits peak torque around 5800RPMs.

The plenums in both these engines have tuned runner lengths for those sweet spots.

Magic will happen if you know what the exhaust runner length needs to be to match the intake sweet spot.

The 3.2L needs/requires long tube headers at 1 5/8" OD and 30" long runners, this is the correct calculated exhaust runner length for the 3.2L

And my educated estimate for the 3.0L puts the runner length at 32-34" for optimal headers.

A 24" header runner length is designed for above 7000RPMs it's to short.

Now you could build the headers at 1/2 wave tune point, so a 30" runner could be shorten to 15" but this is not desirable.

Trust me on the 3.2L I have the dyno proof that says 30" is the correct runner length for the 3.2L you can see some fascinating results on this engine I helped design and tune.

http://forums.pelicanparts.com/porsche-911-technical-forum/1077817-84-89-3-2l-upgraded-3-5l-267-wheel-hp.html

And this single plug 3.2 followed my same recipe with stellar results! look closely at the header design:

http://forums.pelicanparts.com/porsche-911-technical-forum/962997-1984-911-3-4-sleeper-hotrod-end.html

Both those Engines have 30" long tube headers.

Quote:

Originally Posted by 3literpwr (Post 11741648)

They are 1 5/8 OD and mate with my 38mm ports. 24” primaries and spring mounted collectors. If they are too long, it’s an easy mod. Also, rally car with a focus on mid range.

FYI - This is a 46mm carb'd, 10.6:1, 3.0 with DC60 cams and twin plug heads. Also, SCRS gearing. The headers are about 30" at the merge collector where it finally meets.

Sal , This car is a ripper, 0-100 in 12.5 seconds at 5,000 feet of elevation
That is fantastic out of a 3.0
on 46 PMO as well
This car gets my vote
Ian

The car is done and ready to rip. Sound is very quiet! It’s like a stock “sport” muffler. Very chill, which I wanted, especially with all the induction noise. Headers are 30” to merge point, so it’s good. Will post a clip tomorrow.

http://forums.pelicanparts.com/uploa...1657940546.jpg

Quote:

Originally Posted by 3literpwr (Post 11744479)

looks fantastic.

That exhaust is art.
If it sounds half as good as it looks, your exhaust/fab guy has really outdone their self.

Can’t wait to hear it.

Need video!

Any drone 2000-3000rpm?

Zero drone. Mild at idle and won’t wake the neighbors. Nice tone with some burble and a pop or two. Less sound and noise then my 1 in 1 out (magnaflow) that’s on my 87 3.4 with stock manifolds. Strong pull to 7200 where I had my redline set. Need to increase as it didn’t feel like it was falling off.