Anyone using this exhaust?

[petevb]

Originally Posted by 911st

He noted needing more fuel to correct the AF's with the change to straight pipes but that the muffler made more HP.

That certainly does sound not quite right...

[Blackie911]

Getting back to the original post- it is really poor form to be posting competitors products on this Pelican site. We should show our host more respect and diplomacy, and support Wayne and his company.

[911pcars]

Originally Posted by petevb

I was going to mention that it is still a matter of debate if a crossover works on a flat 6 or not, and if so under what conditions.

This dyno (stolen from dfink, posted here last week) was interesting:

"Red is with the dynomax exhaust the blue is re-tuned with the straight pipes."

I was surprised that the muffler (with gases mixing/ crossing over) beat the straight pipes, but then the old questions (conditions, correction) muddy the waters. It's still an interesting result...

I hope to dyno my setup in the next couple months with and without a crossover- it will be on a wheels dyno, but at least we'll get another data point.

For the purpose of comparison, I think these two setups are essentially the same. Any minor differences could be compensated by changing/optimizing another setting (e.g. timing, A/F ratio, etc.) or running the test another part of the day.

Sherwood

[911st]

Originally Posted by Paul Thomas

It's called a Stinger exhaust by Weltmeister. It is stainless and rediculously priced at $989 in a catalog parts seller we all know. I have never seen it in Pelican's catalog although i'm sure he could get it. It has a nifty mounting bracket but otherwise could be duplicated much cheaper in stainless and much, much cheaper in mild steel.

I am wondering how it flows and if having the exhaust merge at the end serves the same purpose as having a crossover. I thought i remembered seeing someones car here with one like it.

Paul

I am not an expert but the secondary tubes seem long to work well. With all the air flowing around them I suspect the long secondary tubes will let the exhaust gasses cool and slow down and create some unnecessary back pressure.

I read somewhere that an ideal secondary tube length is about 18". Looking at the Cox stepped headers and assuming they used the very best modeling to develop them, this may be close.

I am starting to think the George headers exiting with a nice smooth bend into a Flowmaster is a near best practices track muffler set up for HP.

[jpahemi]

I tried a set of Ben's shorties on my DME 3.2 and there was a drop in low end torque when compared to running the dual inlet muffler.

jp

[911st]

Sorry, the picture helps.

Originally Posted by Paul Thomas

I am not an expert but the secondary tubes seem long to work well. With all the air flowing around them I suspect the long secondary tubes will let the exhaust gasses cool and slow down and create some unnecessary back pressure.

I read somewhere that an ideal secondary tube length is about 18". Looking at the Cox stepped headers and assuming they used the very best modeling to develop them, this may be close.

I am starting to think the George headers exiting with a nice smooth bend into a Flowmaster is a near best practices track muffler set up for HP.

[petevb]

Originally Posted by 911st

Sorry, the picture helps.
I read somewhere that an ideal secondary tube length is about 18". Looking at the Cox stepped headers and assuming they used the very best modeling to develop them, this may be close.

The 18" might be ideal for one motor, but totally wrong for another. The RPM you're looking to make power at and cam timing both have big rolls in ideal primary length, and there are lots of smaller players as well. There is no one correct answer for header length.

[911st]

I understand there are a lot of variables like Primary ID and length, Secondary ID and length, collector design, anti revisionary strategy's, with or without a cross over, megaphone, chambered muffler, straight through muffler etc.

Then, as you point out we have to work around the effective rpm range and capacity of the motor. Then the physical limitations they have to accommodate.

Still, primary and secondary make up seem to be what is most important. Then after that, playing off low back pressure against any muffling requirements.

Just thinking of reference points we can use. The 18' from my memory is not a good one. The Cox secondary length and the secondary length of the 73 factory exhaust (SSI) may be good points of reference. Also worth noting is where the collectors were put to accommodate the secondary lengths they wanted.

The pipes we were asked about look at approach up to 4' each in length. I guess what I am saying is working with the components we have easily available, I bet about a 18" secondary after the Georges running into a Flowmaster may make a better starting point and possibly more HP than the long single pipes going through two turns and meeting at the center. That system has modest length primaries that would be good for mid range HP and long secondaries that mightt be good for very low rpm. I would at least wrap the pipes up to the tail pipe area.

I also recall in Bruce Anderson's Performance Handbook that he got more HP from Flowmaster's on a tuned race motor than from a full race megaphone exhaust.

It might be if one went to a header design that put the collector closer to the rear (B&B?) so the secondaries can be shortened, it mightt help.

I guess this is all opinion and only the dyno can tell. I would not run that system without good dyno info to back it up or seeing the class leaders running it successfully.

[flatsixnut]

Originally Posted by Blackie911

Getting back to the original post- it is really poor form to be posting competitors products on this Pelican site. We should show our host more respect and diplomacy, and support Wayne and his company.

Last time I checked, this forum was about Porsches. If there is something out there other than what Wayne sells, and its good for our cars...then i am sure most of us appreciate the tips. Plus this is a very interesting topic.

[KTL]

Originally Posted by KTL

It's January. Are they available yet?

It's almost January, again. Anybody seen this bargain exhaust system yet?

[vmax]

Originally Posted by KTL

It's almost January, again. Anybody seen this bargain exhaust system yet?

MSDS - Exhaust Systems

[Roc Doc]

Originally Posted by 911st

I am starting to think the George headers exiting with a nice smooth bend into a Flowmaster is a near best practices track muffler set up for HP.

I stopped by George's shop this morning, and spoke to him at some length about the options, and what they mean for performance and/or noise. He builds an exhaust system similar to the picture, but with SS wool packed silencers, and he said that is the best system for HP he's been able to come up with, but it's about 100db, (vs. 108db for Megaphones), so it'd be too loud for most folks and some tracks. I'd love to run that on my street car, but I'd be worried about bashing the tail pipes coming out of drivways, etc.

I'm going to get a set of his headers and go into a Dansk or M&K 2/2 muffler.

[Bmxrams80sc]

So how about a a dual in, dual out flowmaster or any welded muffler? Gasses considered to be mixing? Are straight pipes best for horsepower as opposed to torque? Mufflers confuse me. lol but mine sounds good

[Slow911]

So who has one of these of their cars ? and how loud are they ?

[xReddogx]

Originally Posted by Bmxrams80sc

So how about a a dual in, dual out flowmaster or any welded muffler? Gasses considered to be mixing? Are straight pipes best for horsepower as opposed to torque? Mufflers confuse me. lol but mine sounds good

I'm having something like this on Friday. My car appears that the PO installed a Bursch but though the pipes are perfectly fine...the muffler has a hole in it the size of a coffee can. So...I thought for $100 it was worth a try to use the existing pipe and put a 14" Flowmaster in its place.


Not sure how it will turn out but would be more than happy to post some results if you would like when I get done Bmxrams80sc.

[sithot]

Any sort of active pulse control allowing one cylinder to aid in pulling the gases from anotherr is a tremendous benefit. Motorcycles have used this for years to get the most horsepower. A 4-2-1 or 4-1 or 2-1. All preferred over idividual runners. Even Harley Davidson's use a Siamese setup. FWIW.

Here is the "Italian's Finest". (fantastic tube benders they are!)
A photo of a "Spaghetti" exhaust from the early mid-90's for a Ducati. Termignoni/Fast By Ferraci referred to it as the Franco Farne Exhaust.

And how loud is the Porsche Siamese setup? You're kidding, of course? It's an O P E N exhaust!!!

Tom