Chevy SSR Forum banner

1 - 12 of 12 Posts

·
Senior Privileged Member
Joined
·
4,100 Posts
Discussion Starter #1
Comments made by some who have seen it make me suspect that many observers do not understand how clever a solution Reese Cox at MTI Racing in Atlanta developed for use as part of my "MTI True Dual Shotgun exhaust" system.

To be fully effective, a true dual exhaust needs a "crossover" section in which the two exhaust streams from the left and right engine banks briefly merge and then diverge. I don't pretend to understand the mathematics of this crossover, but Reese clearly does.

The solution he developed has several huge advantages:

- It is simple and inexpensive

- It provides the required crossover

- It maintains the "factory flange" between the header / cat subsytem and the dual exhaust system, facilitating disassembly for modifications and / or repairs to the engine or transmission.

Examine closely the atatched photo of the solution that Reese develped for use on my SSR. The diameter of the merged section right behind the factory flange is large enough to not represent an exhaust restriction, because its diameter is about 33% larger than that of the individual exhaust pipes behind it. Since the cross-sectional area of a pipe is proportional to the square of the diameter, this merged piping has about 180% of the flow capability of each individual exhaust pipe behind it!

Those of you who have seen my 03 SSR's dyno charts previosuly published both here on the forum and also in my book, know how wildly effective this exhaust system is (mid range gains of 30 to 40 ft lb of torque before swappig cams, and increasing the effectiveness of the Z06 cam from about 33 rwhp normally gained to about 78 rwhp with this exhaust!).

This is a really good example of subtle but smart engineering by Reese. (Yes, he does have an engineeering degree)

Jim G
 

Attachments

·
Supporting SSR Hobbyist
Joined
·
10,127 Posts
What the heck are those?

Jim,

What are those two little lumps in the pipe, about 15 inches downstream of where they split?:skep

Are those some sort of miniature resonators?:eek

They surely aren't the mufflers, are they?:jester

All kidding aside, it looks like an excellent solution to the system restrictions. Congrats to Reese.

Mike
 

·
Senior Privileged Member
Joined
·
4,100 Posts
Discussion Starter #3
Yes, I blush to admit that those ARE the "mufflers". Dynatech "Split Flow Race mufflers", they are called . . .

Under $100 each.

You can look through them . . .:)

Believe it or not, they are remarkably civilized at low and moderate throttle openings. Somewhat "intense" at WOT.

Jim G
 

·
Registered
Joined
·
421 Posts
?

How is that a true duel exahust if, even for a short span, both sides go thru a single pipe? I thought that true duel exhaust was the left side and the right side never meet?
 

·
Chevrolet Nut
Joined
·
1,420 Posts
True duals

I ahve true dual exhaust run on my 04. I ahve a freind that owns a exhaust/fabrication shop. He had the exhaust pipes cut just after the cats. and had the passenger side 02 sensor relocated in the new pipes and run the pipes into a dual inlet and dual outlet polished Dyno Max muffler. after the muffler the pipes were bent over the rear end and reconnected to the stock exhaust tips. The whole system cost me under 350$ and didn't void any of my waranty.
 

·
Senior Privileged Member
Joined
·
4,100 Posts
Discussion Starter #6 (Edited)
Matjow: By your definition of a dual exhaust, NO properly crossovered exhaust would be "dual". You NEED that crossover / merge. Reese just did it in an unusual way. You like many others, can't see that.:)

They key is that nowhere is the entire gas stream subjected to one pipe that is only the same size as the individual pipes, and nowhere do the two xhaust streams share one muffler.

Note that some mufflers are available that contain two individual (never share internal space) chambers, but naturally the overall size of such a muffler must be large enough to accommodate two such channels, neither of which would be more restrictive than individual mufflers.

Exhaust system advertising is among the most slimy in aftermarket advertising. You have to look at proven results on vehicles comparable to YOURS, not on vehicles that have been so modified that the exhaust is a major "plug" and where ANY exhaust better than factory would make big improvement numbers. This is where you get those "increase your hp by 50 hp" ads for catback systems. That 50hp gain would only happen on a nitrous and blown engine trying to breath through a stock single, small diameter exhaust! ANY better system, no matter how comparatively poor, would give you better results in that contrived situation! Yet, this is how many of those ads are written. Buyer beware.

Jim G
 

·
Senior Privileged Member
Joined
·
4,100 Posts
Discussion Starter #8
hdflstf: I don't know if MTI ever went into "production" with it. Last I heard they needed a higher sales volume on it to justify engineering a "mail order kit". They are happy to provide and install it if you visit them, I think.

Jim G
 

·
Resident Rocket Scientist
Joined
·
11,997 Posts
JimGnitecki said:
hdflstf: I don't know if MTI ever went into "production" with it. Last I heard they needed a higher sales volume on it to justify engineering a "mail order kit". They are happy to provide and install it if you visit them, I think.

Jim G
Nice thought, but the drive is a bit on the far side.
 

·
Senior Privileged Member
Joined
·
4,100 Posts
Discussion Starter #10
Here is some "proof" that Reese really knows what he is doing.

Look VERY closely at the photo atatched and you will see that there is blistering of the exhaust system hi-temp paint at TWO points - right after the factory flange at the bbeginning of the merge, and just before the end of the merge where it again becomes two pipes.

One theory behnd WHERE to place a merge / crossover is that you want it where the exhaust is HOTTEST, as that is where it will have the best impact.

Randy and I measured the distance between those two blistered areas. That distance is IDENTICAL to the difference in length of the right hand and left hand cylinder bank exhaust piping BEFORE the merge /crossover. In other words, Reese positioned that merge / crossover as perfectly as it can possibly be positioned.

Maybe this is why this speicifc exhaust system is SO effective.

Jim G
 

Attachments

·
Registered
Joined
·
269 Posts
Could it be...

where the left and right header merge into one pipe (bottle neck) it takes the exhaust longer to move through this section of pipe therefore heating it up and causing the blistering. Then when it reaches the (Y) pipe where the single pipe is converted into two pipes the restriction is less and the gasses split thereby reducing the heat and thus no blistering.

I would think that the exhaust is it's hottest where it actually leaves the exhaust port and makes the first turn in the header.


Just food for thought on a rainy day....:)

I hope the install is going good. At this point I'm guessing you have bolted uo the S/C. Your gonna love it.

Scott
 

·
Senior Privileged Member
Joined
·
4,100 Posts
Discussion Starter #12
If you check the pipes even on completely separated dual exhausts, you will find one point on each where the paint blisters!

Jim G
 
1 - 12 of 12 Posts
Top